EP0787856A1 - Oleophobic and hydrophobic fibrous substrate, and process for making the same - Google Patents

Abstract

A oleophobic and hydrophobic fibrous substrate comprises at least one cationic binder, at least one oleophobic and hydrophobic fluorinated acrylic copolymer and at least one glyoxal or compound containing a glyoxal. Also claimed are: (i) a process for the preparation of the claimed fibrous substrate; (ii) hydro- and oleophobic packaging; and (iii) a composition having hydro-and oleophobic properties.

Description

The invention relates to an oleophobic and hydrophobic fibrous substrate.

It also relates to the process for the manufacture of this substrate by the papermaking route as well as to a composition suitable in particular for the treatment of a fibrous substrate intended to make it oleophobic and hydrophobic.

We know so-called greaseproof papers which must be barriers to grease and water. These papers are used to make packaging for fatty foods such as kibble for animals.

In patent application FR-A-2679574, grease-resistant papers have been described, the composition conferring on them this quality comprises at least 0.03% of glyoxal, at least 0.01% of an alkyl ketene dimer as a bonding agent , at least 0.002% of a fluorinated salt chosen from the family of diethanolamine salts of perfluoroalkyl ethyl phosphates.

The fluorinated salts provide a barrier effect to fats, however it was necessary to add glyoxal and a bonding agent to have better resistance to water.

Fluorinated resins are now more effective than these salts. In European patent application EP-A-542598, fluorinated acrylic copolymers have been described which have excellent resistance to grease but also excellent resistance to water. These polymers are presented as not needing additives to give them hydrophobic or oleophobic properties.

However, it turns out that the oleophobicity and hydrophobicity characteristics of the substrates treated with these polymers do not develop immediately and that in some cases it is necessary to wait up to two months.

• le KIT TEST, méthode de la société 3M et définie selon la procédure TAPPI UM 557. Un substrat ayant une note d'au moins 10 est supposé présenter de bonnes propriétés d'ingraissabilité, le maximum de l'échelle étant 12. En fait ce test détermine la tension superficielle du substrat et n'est pas suffisant pour connaître véritablement l'effet barrière aux graisses des emballages de croquettes.
• la méthode COBB eau, définie selon la norme AFNOR NF Q 03-018 , on mesure le COBB eau, 1 minute, pour déterminer la résistance du substrat à la pénétration de l'eau. Le COBB eau, 1 minute, doit être inférieur ou égal à 21.

A person skilled in the art checks the characteristics of a greaseproof paper in general according to the following tests:

• the KIT TEST, method from the company 3M and defined according to the TAPPI UM 557 procedure. A substrate having a score of at least 10 is supposed to have good greasability properties, the maximum of the scale being 12. In fact this test determines the surface tension of the substrate and is not sufficient to really know the grease barrier effect of kibble packaging.
• the COBB water method, defined according to the AFNOR NF Q 03-018 standard, the COBB water is measured, 1 minute, to determine the resistance of the substrate to the penetration of water. The COBB water, 1 minute, must be less than or equal to 21.

This COBB test simply gives an idea of the hydrophobicity of the substrate.

These two tests are combined to judge the grease-proof nature of a substrate, however, good results can be obtained simultaneously with these two tests without having a substrate which is sufficiently greasable.

It is in fact essential to check the fibrous substrate according to the so-called "kibble test". This test is described at the end of this description, it gives the percentage of surface stained with grease; this percentage must be less than 10.

This test being carried out hot (60 ° C), under the pressure of a weight and for 3 days, it is more draconian than the previous ones as shown in Comparative Examples 1 to 4 described below. It is representative of the resistance to grease contained in kibble for animals.

One of the known means for accelerating the development of this grease-proofing effect is to overheat the substrate, for example in the case of a paper it can be over-dried at 160 ° C. in the dryer of the paper machine. However, this consumes energy and slows down the manufacturing process on the paper machine; moreover, a very dry and therefore brittle paper is obtained.

The object of the invention is therefore to provide a fibrous substrate which has a good level of oleophy and hydrophobicity, in particular according to the "kibble test", that is to say a level of less than 10%, this level must be reached immediately, at the end of the manufacture of the substrate without having to overheat said substrate.

The Applicant has found that this object is achieved if the fibrous substrate is treated with a composition of a synergetic mixture of a cationic binder, of an olephobic and hydrophobic fluorinated acrylic copolymer and of a compound comprising glyoxal.

The invention therefore provides an oleophobic and hydrophobic fibrous substrate, characterized in that it contains at least one cationic binder, at least one oleophobic and hydrophobic fluorinated acrylic copolymer and at least glyoxal or a compound comprising it.

• 1 à 5 % en poids sec d'au moins un liant cationique,
• 0,25 à 1,25 % en poids sec d'au moins un copolymère acrylique fluoré oléophobe et hydrophobe et
• 0,1 à 1,5 % en poids d'au moins du glyoxal ou un composé en comprenant.

In particular, the substrate is characterized by the fact that it contains:

• 1 to 5% by dry weight of at least one cationic binder,
• 0.25 to 1.25% by dry weight of at least one oleophobic and hydrophobic fluorinated acrylic copolymer and
• 0.1 to 1.5% by weight of at least glyoxal or a compound comprising it.

Preferably used as compound comprising glyoxal, compounds of glyoxal and urea.

Preferably the cationic binder is a starch, more particularly it is a quaternized starch having a degree of cationicity characterized by its nitrogen content on dry matter of at least 0.14%.

As fluorinated acrylic copolymer, any acrylic fluorinated copolymer of oleophobic and hydrophobic nature can be used.

Preferably the fluorinated acrylic copolymers are those claimed in European patent application EP-A-542598 introduced in its entirety by reference.

• (a) 92 à 50 %, de préférence 90 à 70 %, d'un ou plusieurs monomères polyfluorés de formule générale :
  
  dans laquelle :
  • Rf représente un radical perfluoré à chaîne droite ou ramifiée, contenant 2 à 20 atomes de carbone, de préférence 4 à 16 atomes de carbone ;
  • B représente un enchaînement bivalent lié à O par un atome de carbone et pouvant comporter un ou plusieurs atomes d'oxygène, de soufre et/ou d'azote, l'un des symboles R représentant un atome d'hydrogène et l'autre un atome d'hydrogène ou un radical alkyle contenant 1 à 4 atomes de carbone ;
• (b) 1 à 25 %, de préférence 8 à 18 %, d'un ou plusieurs monomères de formule générale :
  
  dans laquelle :
  • B' représente un radical alkylène linéaire ou ramifié, contenant 1 à 4 atomes de carbone,
  • R' représente un atome d'hydrogène ou un radical alkyle contenant 1 à 4 atomes de carbone ;
  • R₁ et R₂, identiques ou différents, représentent chacun un atome d'hydrogène ou un radical alkyle linéaire ou ramifié, contenant 1 à 18 atomes de carbone, hydroxyéthyle ou benzyle ou R₁ et R₂ ensemble avec l'atome d'azote auquel ils sont liés forment un radical morpholino, pipéridino ou pyrrolidinyle-1 ;
• (c) 1 à 25 %, de préférence de 2 à 10 %, d'un dérivé vinylique de formule générale :
  
          R"-CH=CH₂     (III)
  
  dans laquelle :
  R" peut être un groupement alkylcarboxylate ou alkyléther contenant de 1 à 18 atomes de carbone ;
• (d) 0 à 10 %, de préférence 0 à 8 %, d'un monomère quelconque autre que les monomères de formules I, II, III.

More precisely, they are fluorinated copolymers, optionally salified or quaternized, which comprise by weight:

• (a) 92 to 50%, preferably 90 to 70%, of one or more polyfluorinated monomers of general formula:
  
  in which :
  • Rf represents a perfluorinated radical with a straight or branched chain, containing 2 to 20 carbon atoms, preferably 4 to 16 carbon atoms;
  • B represents a divalent chain linked to O by a carbon atom and which may contain one or more oxygen, sulfur and / or nitrogen atoms, one of the symbols R representing a hydrogen atom and the other a hydrogen atom or an alkyl radical containing 1 to 4 carbon atoms;
• (b) 1 to 25%, preferably 8 to 18%, of one or more monomers of general formula:
  
  in which :
  • B 'represents a linear or branched alkylene radical containing 1 to 4 carbon atoms,
  • R 'represents a hydrogen atom or an alkyl radical containing 1 to 4 carbon atoms;
  • R ₁ and R ₂ , identical or different, each represent a hydrogen atom or a linear or branched alkyl radical, containing 1 to 18 carbon atoms, hydroxyethyl or benzyl or R ₁ and R ₂ together with the nitrogen atom to which they are linked form a morpholino, piperidino or pyrrolidinyl-1 radical;
• (c) 1 to 25%, preferably 2 to 10%, of a vinyl derivative of general formula:
  
  R "-CH = CH ₂ (III)
  
  in which :
  R "can be an alkylcarboxylate or alkyl ether group containing from 1 to 18 carbon atoms;
• (d) 0 to 10%, preferably 0 to 8%, of any monomer other than the monomers of formulas I, II, III.

Preferably, cationic copolymers, more particularly quaternized, are used.

As adjuvants necessary for the implementation of the composition, they may in particular be antifoams.

The substrate of the invention can be any substrate comprising fibers.

It is advantageously a substrate comprising fibers chosen from natural organic fibers including cellulose fibers, synthetic organic fibers.

According to a particular case of the invention, the substrate is a paper essentially comprising cellulose fibers and optionally adjuvants stationery classics that do not detract from the desired oleophobicity and hydrophobicity characteristics.

The fibrous substrate may in particular comprise a wet resistance agent.

Preferably, the substrate is not bonded.

It can also be a box.

It can also be a non-woven substrate, in particular based on polyester or polyolefin fibers, optionally obtained by the papermaking process.

It can also be a fabric.

The invention also relates to a process for obtaining a fibrous substrate with an oleophobic and hydrophobic character and, more particularly, to a process for preparing a fibrous substrate treated on the surface.

• on mélange, en milieu aqueux, les fibres et éventuellement des adjuvants,
• on envoie ce mélange sur la toile d'une machine à papier,
• on presse la feuille humide obtenue,
• on traite la feuille à l'aide d'une presse encolleuse ou d'une imprégnatrice avec une composition de traitement contenant au moins un liant cationique, au moins un copolymère acrylique fluoré oléophobe et hydrophobe et du glyoxal ou au moins un composé en comprenant,
• on sèche la feuille.

Preferably, such a papermaking process for manufacturing the fibrous substrate having oleophobic and hydrophobic properties is characterized in that:

• the fibers and optionally adjuvants are mixed in an aqueous medium,
• we send this mixture on the canvas of a paper machine,
• the wet sheet obtained is pressed,
• the sheet is treated using a size press or an impregnator with a treatment composition containing at least one cationic binder, at least one oleophobic and hydrophobic fluorinated acrylic copolymer and glyoxal or at least one compound comprising,
• the sheet is dried.

The drying is advantageously carried out between 80 and 120 °, preferably around 100 ° C.

Such a treatment is particularly applicable to materials based on cellulose fibers.

The substrate can be obtained by mass treatment, the treatment composition being added by mass to the fibers.

The invention also relates to oleophobic and hydrophobic packaging, in particular grease-resistant packaging, manufactured from the fibrous substrate of the invention, in particular packaging intended to contain food products and more particularly food of the kibble type for animals.

The invention also relates to a composition in particular intended for the bulk or surface treatment of a fibrous substrate with a view to giving it properties of oleophobia and hydrophobia.

This composition contains at least one cationic binder, at least one oleophobic and hydrophobic fluorinated acrylic copolymer and at least glyoxal or a compound comprising it.

The dilution and the composition of this composition are adapted as a function of the capacity of the fibrous substrate to absorb this composition and of the conditions of implementation of the process for preparing the substrate.

• 2 à 5 % en poids sec d'au moins un liant cationique,
• 0,3 à 1 % en poids sec d'au moins un copolymère acrylique fluoré oléophobe et hydrophobe et
• 0,2 à 1,5 % en poids de glyoxal ou d'au moins un composé en comprenant,
• des solvants aqueux et/ou organiques et éventuellement des adjuvants nécessaires à la mise en oeuvre de la composition, en quantité suffisante pour obtenir un pourcentage de 100 en poids total.

This composition advantageously contains:

• 2 to 5% by dry weight of at least one cationic binder,
• 0.3 to 1% by dry weight of at least one oleophobic and hydrophobic fluorinated acrylic copolymer and
• 0.2 to 1.5% by weight of glyoxal or of at least one compound comprising,
• aqueous and / or organic solvents and optionally adjuvants necessary for the implementation of the composition, in an amount sufficient to obtain a percentage of 100 by total weight.

In the compositions, each of the three synergistic components is preferably in one of the forms previously described in the context of the description of the substrate.

EXAMPLES:

Embodiments of the invention are described in Examples 5 and 6 and Examples 8 and 9.

Examples 1 to 4 and 7 are comparative examples which do not correspond to the invention.

The examples are all carried out in the same way, only the nature and the quantities of the products used for the treatment composition differ. Tables 1 and 2 specify the products included in the treatment baths and their respective quantities as well as the characteristics of the papers treated with these compositions.

Table 3 gives the concentrations in percentages by dry weight of the three synergistic constituents in the paper obtained after treatment and then drying according to Examples 8 and 9; such paper containing a final humidity of about 5% by weight.

The values for Cobb and KIT TEST are given for each face of the substrate. Certain data are expressed at different times counted from the end of the manufacture of the substrate (t = 0).

The cationic starch used is a quaternized starch having a degree of cationicity characterized by its nitrogen content on dry matter of at least 0.14%.

FORAPERLE 321 is a fluorinated acrylic copolymer, it is cationic and it has a dry extract of 25%, it is manufactured and marketed by the company ELF ATOCHEM.

DRYOL XF is a wax intended to reduce the hydrophilicity of the substrate, marketed by PROTEX.

AQUAPEL 34B is a bonding agent, it is an alkyl ketene dimer marketed by HERCULES

BOZEFIX TSI is a compound comprising glyoxal and urea, with 42% active ingredients, manufactured and marketed by HOESCHT.

Glyoxal used alone is diluted to 40% by weight with water.

The quantities expressed in Tables 1 and 2 below are given by weight of the product in its marketed form except for starch which is expressed by dry weight.

Realization of the examples:

A treatment composition is produced according to the components and the respective amounts of each example, the composition being supplemented with water in sufficient quantity so as to obtain a percentage of 100 by total weight; the starch has been previously cooked.

This composition is placed in the size press of a pilot machine.

On this pilot machine, a paper is produced from cellulose fibers and a wet resistance agent diluted in an aqueous medium. The wet sheet is pressed and then it is treated in a size press with the treatment composition.

The recovery of the composition by the paper is approximately 75% by wet weight.

RESULTS:

Comparative examples 2 to 4 show that the addition of a sizing agent has no significant effect on improving the greasiness, on the contrary they decrease it while these products are known for their barrier effect.

TABLEAU 3 EXEMPLE 8 EXEMPLE 9 Amidon cationique 2,18 2,17 Foraperle 321 0,36 0,36 Bozefix TSI 0,61 0,87 Comparative examples 1 and 7 in comparison with the examples according to the invention 5, 6, 8 and 9 show the synergy of the mixture of the three components in order to have a good result in the "TESTED CROQUETTES" immediately after the manufacture of the fibrous substrate. Furthermore, results obtained with the test kit show that the solvanophobic nature of the substrate treated according to the invention is good.

TABLE 3 EXAMPLE 8 EXAMPLE 9 Cationic starch 2.18 2.17 Foraperle 321 0.36 0.36 Bozefix TSI 0.61 0.87

DESCRIPTION OF THE "CROQUETTES TEST":

This test is derived from a test developed by the company 3M.

On a grid allowing the ambient atmosphere to pass (humid and hot air), an untreated paper is placed.

On this paper the substrate to be tested is placed.

Above this substrate, place 250 ml of kibble for dogs, of the CROQ MIX brand marketed by QUAKER, these kibbles being kept inside a wooden frame of 10 cm x 10 cm and 5 cm high .

Corrugated cardboard is placed on these kibbles and over a weight of 2.5 kg.

This set is placed in an oven at 60 ° C and whose relative humidity is 65%, for 3 days.

On the side in contact with the test paper, untreated paper, the stained surface is determined using a graph paper. The exposed surface being 100 cm ² , the percentage of stained surface is directly obtained.

Claims (12)

Oleophobic and hydrophobic fibrous substrate, characterized in that it contains at least one cationic binder, at least one oleophobic and hydrophobic fluorinated acrylic copolymer and at least glyoxal or a compound comprising glyoxal. Fibrous substrate according to claim 1, characterized in that it contains: - 1 to 5% by dry weight of at least one cationic binder, 0.25 to 1.25% by dry weight of at least one oleophobic and hydrophobic fluorinated acrylic copolymer and - 0.1 to 1.5% by weight of glyoxal or of at least one compound comprising glyoxal. Substrate according to one of claims 1 or 2, characterized in that the compound comprising glyoxal is a compound of glyoxal and urea. Substrate according to one of claims 1 to 3, characterized in that the cationic binder is a cationic starch. Fibrous substrate according to one of claims 1 to 4, characterized in that it comprises fibers chosen from natural organic fibers, in particular cellulose fibers, synthetic organic fibers. Fibrous substrate according to Claim 5, characterized in that the fibers are cellulose fibers. Method for manufacturing a fibrous substrate by paper according to one of claims 1 to 6, characterized in that: - the fibers and optionally adjuvants are mixed in an aqueous medium, - we send this mixture on the canvas of a paper machine - the wet sheet obtained is pressed, the sheet is treated using a size press or an impregnator with a composition containing at least one cationic binder, at least one oleophobic and hydrophobic fluorinated acrylic copolymer and at least glyoxal or a compound comprising it, - the sheet is dried. Oleophobic and hydrophobic packaging, in particular grease-resistant packaging, characterized in that it is manufactured from a fibrous substrate according to one of claims 1 to 6 or obtained according to claim 7. Composition in particular intended to confer oleophobicity and hydrophobicity properties, characterized in that it contains at least one cationic binder, at least one oleophobic and hydrophobic fluorinated acrylic copolymer and glyoxal or at least one compound comprising it. Composition according to Claim 9, characterized in that it contains: - 2 to 5% by dry weight of at least one cationic binder, - 0.3 to 1% by dry weight of at least one oleophobic and hydrophobic fluorinated acrylic copolymer and 0.2 to 1.5% by weight of glyoxal or of at least one compound comprising, - Aqueous and / or organic solvents and optionally adjuvants necessary for the implementation of the composition, in an amount sufficient to obtain a percentage of 100 by total weight. Composition according to Claim 9 or 10, characterized in that the compound comprising glyoxal is a compound of glyoxal and urea. Composition according to one of Claims 9 to 11, characterized in that the cationic binder is a cationic starch.