FR2744141A1 - PROCESS FOR OLEOPHOBIC AND HYDROPHOBIC TREATMENT OF PAPER OR BOARD - Google Patents

Abstract

To accelerate the curing of paper or cardboard treated with a fluorinated acrylic copolymer and a starch or a polyvinyl alcohol, a crosslinking agent such as glyoxal or a polyamide-epichlorohydrin resin is incorporated into the treatment bath.

Description

DESCRIPTION

  The present invention relates to a method for hydrophobic treatment and

oleophobic paper and cardboard.

  Different products have been proposed in the past for this type of treatment. In particular, in patent application EP 542 598, the content of which is incorporated here by reference, fluorinated acrylic copolymers have been proposed comprising by weight: (a) 50 to 92%, preferably 70 to 90%, of one or several polyfluorinated monomers of general formula: O II Rf-BOCC = CH-R (I)

1

  R 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

  bone, B represents a bivalent chain linked to O by a car atom

  bone and possibly comprising one or more oxygen, sulfur and / or nitrogen atoms, one of the symbols R represents 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:

R1 O

\ Il N-B'-O-C-C = CH2 (Il) I

R2 R '

  in which B 'represents an alkylene radical, linear or branched, containing 1 to 4 carbon atoms, R' represents a hydrogen atom or an alkyl radical containing 1 to 4 carbon atoms, R1 and R2, identical or different, represent each a hydrogen atom, an alkyl radical

  linear or branched containing 1 to 18 carbon atoms or a hy-

  droxyethyl or benzyl, or R1 and R2 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: -2- R "-CH = CH2 (Ill) in which R" can be an alkylcarboxylate or alkylether group containing 1 to 18 carbon atoms; (d) 0 to 10%, preferably 0 to 8%, of any monomer other than the

  monomers of formulas 1, II and III.

  These fluorinated products, perfectly dilutable with water, can be applied to paper using different techniques (in size-press or in the mass) and give it, without the need for additives (sequestrants, retention agents, fixing resins, etc.). .) excellent hydrophobic and oleophobic properties, in particular a spectacular resistance to liquids of aqueous origin, to fatty substances as well as to solvents.

low surface tension.

  Such papers are used in the packaging of wet and / or fatty food products in markets as varied as the biscuit / pastry sector, fast food, the margarine and butter market, the meats and poultry, chocolate, products

  frozen, the dry food market for dogs and cats (pet food).

  In the case of animal feed, the fluorinated treatment must be able to ensure a barrier to particularly aggressive fats (free fatty acids)

  to prevent the appearance of spots linked to the migration of these fats, in particular

  in the corners or folds of the packaging.

  The fluorinated products, described in patent application EP 542 598, used alone, simply diluted in water and applied superficially to the paper at a normal dose (0.05 to 0.2% of fluorine relative to the weight of paper ), born

  do not always lead to a good result in the packaging of "pet foods", that is to say

  say that the fats manage to diffuse through the paper and stain it.

  To obtain an improvement in the barrier effect to fats, it is advantageous to

  gous to associate the fluorinated acrylic polymers described in patent application EP 542 598 with a starch or a polyvinyl alcohol. The starches used can be cationic, oxidized or amphoteric, and are generally used at a concentration of the order of 5 to 60 g / l in the aqueous solution containing the

  fluorinated acrylic polymer. Cationic starches are preferred.

  The different types of polyvinyl alcohols can be used at a concentration of the order of 1 to 40 g / l in the aqueous solution containing the fluorinated acrylic polymer. It is preferable to use a polyvinyl alcohol with a low ester index (less than 30, ie a hydrolysis rate greater than 98%) and high viscosity

  (viscosity between 22 and 32 mPa.s for an aqueous solution at 4% by weight).

  -3- In the case where the fluorinated acrylic polymers simply diluted in pure water fail to ensure a good result in the packaging of pet foods, the incorporation in the same aqueous solution of a starch or a polyvinyl alcohol significantly improves the grease barrier and helps prevent greasy stains from appearing on paper. However, this result is generally obtained only after a fairly long time for the paper to mature, by simple storage at room temperature for two to three weeks. The need to store paper before using it to make packaging, the impossibility of controlling the quality of its production when it leaves its machine and the need to manage delivery times to its customers, poses significant problems. to the stationer. It has now been found that this drawback can be remedied and the desired performance of the grease barrier effect obtained after only a few days (less than a week) by adding to the previous formulations a

  third compound having several groups capable of reacting chemically-

  with the cellulose fibers that make up the paper, so as to create crosslinking points. As examples of reactive groups, mention may more particularly be made of epoxy or aldehyde groups. The reactive compound can in particular be chosen from condensates or precondensates of urea formaldehyde or melamine formaldehyde, epoxy derivatives such as diglycidyl-glycerol or

  epoxypropyltrialkyl (aryl) ammonium halides such as (epoxy-2,3- chloride)

  propyl) trimethylammonium and N-methyl-N chloride (2,3-epoxy-propyl) morpho-

  linium, polyamide resins treated with epichlorohydrin, and glyoxal.

  Preferably, glyoxal and polyamideepichlorohydrin resins are used.

  The process according to the invention is advantageously carried out by means of an aqueous composition comprising: (a) from 1 to 10 g / I, preferably from 1.5 to 5 g / I of a fluorinated acrylic copolymer; (b) from 5 to 60 gAl, preferably from 10 to 50 g / I, of a starch, or from 1 to 40 g / l, preferably from 5 to 20 g / I of a polyvinyl alcohol; and

  (c) from 0.1 to 20 g / l, preferably from 0.5 to 10 g / l, of a crosslinking agent.

  Organic solvents, miscible with water, may optionally be present in the composition according to the invention. They come from the synthesis of the fluorinated acrylic copolymer and are, for example, those mentioned in the application

EP 542 598.

  Mention may more particularly be made of acetone, tetrahydrofuran, dioxane, dimethylformamide, N-methyl-pyrrolidone-2, dimethylsulfoxide, -4- ethanol, isopropanol, ethylene glycol and propylene glycol. Their concentrations

can vary from 0 to 12.5 g / I.

  The compositions according to the invention can be prepared by simple

  mixture of the various products presented in aqueous solution.

  The pre-solution of polyvinyl alcohol or starch in

  the water is produced according to methods well known to those skilled in the art.

  The compositions according to the invention are applied to paper or cardboard

  in surfacing by the well-known size-press technique.

  To evaluate the performance of the substrates treated according to the invention, the Applicant used the following test: In a climatic oven at 60 ° C. and 65% relative humidity, 200 g of treated paper are deposited on a surface of 100 cm 2. brand dog food

YAM'S (EUKANUBA PUPPY quality).

  The whole is placed on an untreated, absorbent paper (type filter paper) of the same surface. After which, we put on the whole a weight of 3, 5 kg and we leave to

the oven for 3 days.

  The diffusion of greases is evaluated by measuring the total surface of the spots which appeared on the absorbent paper. The fat barrier is considered to be effective when the stained area is less than 10% of the area

total absorbent paper.

  The following examples illustrate the invention without limiting it.

EXAMPLE41

  A solution of fluorinated acrylic copolymer containing 25% dry matter is used as described in Example 4 of patent application EP 542 598 (solution

  S4), a cationic starch (Hi Cat 145 from the company Roquette), and glyoxal.

  With these different compounds, we prepare the size-press baths described

in the table below.

  Constituents of the Bath number (g / I) 2 3 4 Solution S4 20 20 20 20 Starch - 10 - 10 Glyoxal - - 2 2 Water 980 970 978 968

TOTAL 1000 1000 1000 1000

  -5- The different compositions are applied in size-press on a paper composed of bleached pulp, not glued, of 70 g / m2. The breeding rate is around 110%. After drying for two minutes at 110 ° C., the papers thus treated and an untreated paper are stored for a variable time at room temperature, then subjected to the kibble test. The results obtained are grouped in the following table: Stained area Paper treated with the bath n Paper (in%) 1 2 3 4 untreated After 5 days of 100 100 100 O 100 storage After 3 weeks of storage 100 0 100 0 100 L examination of the table shows that, at a constant fluorine content, only the paper treated with the bath 4 according to the invention constitutes an effective barrier to migration

  fats that do not require significant ripening time.

EXAMPLE 2

  In the same way as in Example 1, the size baths are prepared

  press described above in which glyoxal is replaced by a resin

  polyamide-epichlorohydrin (Hercosett 57 from the company Hercules).

  Components of the bath Number of the bath (g / l) 5 6 S4 solution 20 20 Starch 10 Polyamide-epichlorohydrin resin 0.5 0.5 Water 979.5 969.5

TOTAL 1000 1000

  After applying the various compositions in size-press under the same conditions as in Example 1, the following results are obtained: 6 - Stained surface Paper treated with the bath n Paper (in%) 1 2 5 6 not treated After 5 days of storage 100 100 100 O 100 After 3 weeks of storage 100 0 100 0 100 Only the paper treated with bath No. 6 according to the invention constitutes a barrier

  effective at migrating fats without requiring maturing.

EXAMPLE 3

  The procedure is the same as in Example 1, replacing

  starch with a polyvinyl alcohol (Rhodoviol 30/5 from the Rhône Poulenc Company).

  The following aqueous solutions are obtained: Constituents of the bath Number of the bath (gl) 7 8 Solution S4 20 20 Polyvinyl alcohol 20 20 Glyoxal - 2 Water 960 958

TOTAL 1000 1000

  After applying the various compositions in size-press, under the same conditions as in Example 1, the following results are obtained: Stained surface Paper treated with the bath n Paper (in%) I 7 3 8 untreated After 5 days of storage 100 100 100 0 100 After 3 weeks of storage 100 0 100 0 100 Only paper treated with bath No. 8 according to the invention constitutes a barrier

  effective at migrating fats without requiring maturing.

EXAMPLE_4

  The procedure is the same as in Example 2, replacing the starch with polyvinyl alcohol. The following composition is obtained: Constituents of the bath Number of the bath (g / I) 9 Solution S4 20 Polyvinyl alcohol 20 Polyamide-epichlorohydrin resin 0.5 Water 959.5

TOTAL 1000

  After application in size-press under the same conditions as in Example 1, the following results are obtained: Stained surface Paper treated with the bath n Paper (in%) I 7 5 9 untreated After 5 days of storage 100 100 100 0 100 After 3 weeks of storage 100 0 100 0 100 Only the paper treated with bath No. 9 according to the invention constitutes a barrier

  effective at migrating fats without requiring maturing.

-8-

Claims (10)

  1. Process for oleophobic and hydrophobic treatment of paper or cardboard by means of an aqueous composition comprising a fluorinated acrylic copolymer and a starch or a polyvinyl alcohol, characterized in that the aqueous composition   further contains at least one crosslinking agent.   2. Method according to claim 1, in which the crosslinking agent is chosen from condensates or precondensates of urea formaldehyde or melamine formaldehyde,   epoxy derivatives, polyamide resins treated with epichlorohydrin and glyoxal.   3. Method according to claim 1 or 2 wherein the acrylic copolymer   that fluorinated comprises by weight: (a) 50 to 92% of one or more polyfluorinated monomers of general formula: II Rf-B-O-C-C = CH-R (I) R   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   bone, B represents a bivalent chain linked to O by a car atom   bone and possibly comprising one or more oxygen, sulfur and / or nitrogen atoms, one of the symbols R represents a hydrogen atom and the other a hydrogen atom or an alkyl radical containing 1 to 4 carbon atoms; (b) 1 to 25% of one or more monomers of general formula: R1 O \ Il N-B'-O-C-C = CH2 (Il) I R2 R '   in which B 'represents an alkylene radical, linear or branched, containing 1 to 4 carbon atoms, R' represents a hydrogen atom or an alkyl radical containing 1 to 4 carbon atoms, R1 and R2, identical or different, represent each a hydrogen atom, an alkyl radical   linear or branched containing 1 to 18 carbon atoms or a hy-   droxyethyl or benzyl, or R1 and R2 together with the nitrogen atom to which they are linked form a morpholino, piperidino or pyrrolidinyl1 radical; -9 (c) 1 to 25% of a vinyl derivative of general formula: R "-CH = CH2 (111)   in which R "can be an alkylcarboxylate or alkyl ether group containing from 1 to 18 carbon atoms; (d) 0 to 10% of any monomer other than the monomers of formulas I, II and III.   4. The method of claim 3 wherein the fluorinated copolymer comprises by weight 70 to 90% of polyfluorinated monomer (s) of formula (I), 8 to 18% of monomer (s) of formula (II) , 2 to 10% of monomer (s) of formula (111) and   from 0 to 8% of another monomer (d).   5. Method according to one of claims 1 to 4 wherein a cationic starch.   6. Method according to one of claims I to 5 in which a   polyvinyl alcohol having an ester number less than 30 and having a solution   aqueous at 4% by weight has a viscosity at 20 C of between 22 and 32 mPa.s.   7. Method according to one of claims I to 6 wherein one applies by   size-press on the paper or the cardboard to be treated an aqueous composition comprising: (a) from 1 to 10 g / A, preferably from 1.5 to 5 g / I, of fluorinated acrylic copolymer; (b) from 5 to 60 g / l, preferably from 10 to 50 g / A, of starch, or from 1 to 40 g / I, preferably from 5 to 20 g / l, of polyvinyl alcohol; and   (c) from 0.1 to 20 g / l, preferably from 0.5 to 10 g / l, of crosslinking agent.   8. The method of claim 7, wherein the crosslinking agent is   glyoxal or a polyamide-epichlorohydrin resin.   9. The method of claim 7 or 8, wherein the aqueous composition further contains up to 12.5 g / i of one or more organic solvents miscible with water.   10. Paper or cardboard treated by a process according to one of the claims 1 to 9.