FR2675405A1 - METHOD FOR MAKING A PLANAR SUPPORT WITH ONE OF THE SIDES PRESENTING ANTI-SLIP PROPERTIES AND THE OTHER OF WHICH PRESENTS ADHESIVE PROPERTIES AND THE SUPPORT THUS OBTAINED. - Google Patents

Abstract

Process for continuously producing an adhesive anti-slip flat support, characterized in that it consists in: - unwinding under low mechanical tension a flexible flat support (2); - in coating at room temperature one of the two main faces of said support (2) with a coating composition (3) consisting of a thermoplastic resin (27), supplemented with hollow microspheres (28), the envelope of which (29) is made of a polymer which is also thermoplastic, and the core (30) of which contains a volatile fluid; - heating the support (2) thus coated; - Then, in subjecting the support on the other main face opposite to the coating by means of a natural or synthetic adhesive (15); - And finally, after drying of said adhesive, in storing the product thus obtained. The invention also relates to the non-slip adhesive papers thus obtained. Application: packaging.

Description

METHOD FOR MAKING A PLANAR SUPPORT OF WHICH ONE OF

  FACES PRESENTS ANTI-SLIP PROPERTIES AND THE SAME FACE HAS ADHESIVE PROPERTIES AND THE SUPPORT THUS OBTAINED. 5

  The invention relates to an improved method for producing a planar support, presenting on

  one of its faces anti-slip properties, and on the other side adhesive properties It also relates to the supports thus obtained.

  "Anti-slip properties" means the properties developed by certain supports, such as, in particular, paper, non-woven films, etc. which, although lacking glue or any other similar adhesive system, exhibit a certain resistance when

  positioned on their flat on any coating, they are subject to displacement on this coating. In fact, these properties are generally necessary when the supports are positioned on a smooth coating.

  It has been known for a very long time to use adhesive paper such as, for example, adhesive paper.

  In the particular field of packaging, it is desirable to use paper or paperboard having glide30 in order, especially during the palletization of packaged products, to give greater stability to

  pallets obtained, especially during transport.

  However, in the packaging production chains, it is not possible to use paper with

  anti-slip properties, considering that just because

  If these anti-slip properties are present, there is a risk of the installation blocking at the levels where the packaged product is likely to slide on surfaces originally intended for this purpose. The invention aims at overcoming these various disadvantages. It proposes a process capable of continuously producing a planar support, one of whose faces has anti-slip properties and the other of which has adhesive properties. unrolling under a low mechanical tension a flexible plane support and in particular a strip of paper; to coat at ambient temperature one of the two main faces of said support with a coating composition consisting of a thermoplastic resin, added with hollow microspheres whose envelope is

  made of a thermoplastic polymer and whose core contains a volatile fluid; to heat the support thus coated to a temperature of

  greater than the softening temperature of the constituent polymer of the microspheres, and of the resin, and greater than the volatilization temperature of the volatile fluid; then, to subject the support thus coated on one of its two main faces to a second coating on the opposite face by means of a natural glue

  or synthetic; and finally, storing the product thus obtained, after drying said glue.

  In other words, the method consists in producing a support, one of whose faces has anti-slip properties and the other of which has properties

  In this way, when the packaging is closed,

  Using a support made in accordance with the process of the invention, the package is closed by the face having adhesive properties, the other side being external to the package, allowing the anti-mold properties to be overcome. -glisse wanted. Advantageously in practice, the softening point of the constituent resin and polymer of the microspheres is between

  and 150 C; indeed, if this temperature is below

  at 60 ° C, the diltation of the internal fluid as well as the softening of the constituent polymer of the microparticles.

  spheres are insufficient to result in a significant swelling of the latter, and consequently, to anti-slip properties interesting In revenge, if this temperature exceeds 150 C, micro-spheres burst under the action of the dilation of the fluid

  they contain; the coating resin is a resin selected from the group consisting of styrene-butadiene copolymers, vinyl acetate, ester vinyl acetate copolymer

  maleic, polyvinylidene chloride, acrylic copolymer

  acrylonitriles, and acrylic polymers;

  the envelope of the microspheres is made of a copolymer of polyvinylidene chloride and acrylonitrile

  Trile; the volatile fluid contained in the core of the microspheres is selected from the group consisting of isobutane and neopentane; the glue is a natural glue or a resin

acrylic or vinyl.

  The invention also relates to the support thus obtained. This support is characterized in that it is

  formed of a sheet of flexible material and typically selected from the group consisting of papers, cartons, plastic films such as polyethylene, polyester, polypropylene etc, and nonwovens, one of whose faces comprises a coating constituted by a plurality of microspheres made of a polymer having a low softening point and containing a volatile fl uid, and having a diameter of between 5 and microns, adhered to said support by means of a low softening point resin between 60 and OC, and the other side is coated with glue

natural or synthetic.

  Advantageously in practice, the relative amount of microspheres per unit area is between

0.3 and 1 gram per square meter.

  The manner in which the invention can be realized and the advantages which result therefrom will emerge more clearly from the following exemplary embodiment, given as an indication and not a limitation to the accompanying figures. FIG. schematic representation of the device adapted to implement the method according to the invention. FIG. 2 is a schematic sectional view of the support coated on one of its faces but beforehand

  to its treatment according to the process according to the invention.

  Figure 3 is a schematic sectional view of the support according to the invention after treatment.

  The installation for carrying out the process according to the invention as represented in FIG. 1 basically comprises a reeling roll (1) on which is mounted a reel of a support (2) and typically kraft paper. in scrolling (2) is kept under mechanical tension and by means of conventional system not shown The paper (2) is then fed through the positive delivery roller (23) at a coating zone (6) comprising respectively return rollers (7 and 8) and a coating roll (5), immersed in a coating tank (4) containing the coating composition (3) This latter is typically made of an acrylic resin

  in the aqueous phase with a softening point of about 70 ° C. It also contains microspheres made of a copolymer of polyvinylidene chloride and acrylic acid.

  nitrile of typical diameter between 2 and 10 micrometers The microspheres contain a volatile gas and typically isobutane or neopentane. The excess of coating composition on the paper

  (2) is removed by means of an air gap (9) which can be adjusted to obtain a layer of

  more or less significant thickness and constant dough, the excess of composition falling into the tray (4) According to the invention, the paper (2) thus coated through a furnace (10) by For example, the infrared is used to evaporate the water contained in the coating composition. In addition, the oven is thus adjusted so that, taking into account the speed of travel of the coated support and the length of the path in this, the temperature of the paper (2) reaches about 90 ° C. In this way, under the effect of the temperature, the constituent copolymer of the microspheres softens. In addition, the gas contained in said

  microspheres dilates, inducing, in view of the softening

  The microsphere casing, the swelling thereof, results in microspheres whose diameter varies between 20 and 40 micrometers.

see more.

  Given the softening point also low of the coating resin, these microspheres well

  that having inflated, remain attached to the support.

  At the furnace outlet, the temperature drop induces a hardening of the microsphere casing, as well as of the coating resin. In this way, the size of the microspheres is stabilized to a size corresponding substantially to that obtained.

in the oven.

  The paper thus coated on one of these faces is returned by means of a return roller (12) to a second coating zone (13) comprising, as for the first, two sets of rollers (16 and 17) and a coating roll (18) dipping in the coating composition

  (15), the latter being contained in a tray (14).

  This coating composition (15) consists of

  acrylic or vinyl resin, even natural glue type glue to bone After coating also at room temperature

  on the other side of the support (2), the excess coating composition is removed by means of an air gap (19). The support thus coated passes through another furnace.

  (21), in order to eliminate the water contained in this second coating (for example at 900 ° C.).

  FIGS. 2 and 3 show a cross section schematizing the coated support before passing through the oven (10) and the coating zone (14) and after passing through the oven (21). The support (25) consisting of for example as already said by kraft paper35 of neighboring grammage of 60 g / m 2, corresponding approximately to a thickness close to 60 micrometers, is coated

  a coating layer (26) of 5 micrometers thick

  This layer as already mentioned contains an aqueous resin emulsion (27) and microspheres (28) whose typical outer diameter is between 2 and 10 micrometers. After passing through the oven (10), the microspheres

  (28) are expanded to

  from 20 to 30 or even 40 micrometers, their envelope (29)

  being secured to the support (25) by the resin (27) The core (30) is itself dilated In fact, these microspheres

  res (28) protrude from the resin plane (27), but remain secured to the support (25) by the resin (27) The paper thus coated has on this face a very inhomogeneous aspect under the microscope, inherent in

  the random distribution of the microspheres on its surface. In addition, it is non-tacky to the touch and develops anti-slip characteristics corresponding to the goal sought-20.

  These characteristics are due to the presence of the microspheres, which protrude from the surface of the paper. These microspheres advantageously act as dampers, thus further developing the anti-slip characteristics of the resulting paper.

  Moreover, the other side being coated with a natural or synthetic glue, giving adhesive properties, the paper thus obtained stored in the form of a coil can be used for many applications and especially

packaging.

  The anti-slip coating is devoid of any

  adhesive properties, and given its inhomogeneity, it is not created by storage in the form of a reel

  of the paper obtained, between the adhesive side of the roll-

  upper and the anti-slip side of the sticky bridge lower winding, so that these coils are

  easily unwindable, and therefore usable.

  When packaging is carried out, in order to close the packaging on the packaged product,

  strips of paper coated on both sides, fixing the

  proper ballasting by the adhesive side, the face

  anti-glide being turned outwards, and

  to confer on the packaging thus obtained

  anti-slips particularly sought after especially when packaged products are paletized, and

  In fact, the pallets are very stable during transport.

Claims (5)

  1 / A process for continuously producing a planar support, one side of which has anti-slip properties and the other of which has adhesive properties, characterized in that it consists of:   to unroll under low mechanical tension a sup-   port (2) flexible plan; to coat at room temperature one of the   two main faces of said support (2) of a coating composition (3) consisting of a thermoplastic resin   tick (27), added with hollow microspheres (28) whose envelope (29) is made of a polymer also thermoplastic, and whose core (30) contains a volatile fluid;   to heat the support (2) thus coated at a temperature above the softening temperature.   the polymer constituting the envelope (30) of the microspheres (28) and the resin (27), and the volatilization temperature of the fluid;   then, to subject the support thus coated on one of its two main faces to a second coating.   on the other opposite main face by means of a natural or synthetic glue (15), and finally, after drying of said glue, to store the product thus obtained.   2 / A method according to claim 1, characterized in that the softening point of the resin and the   constituent polymer microspheres (28) is between 60 and 150 OC.   3 / A method according to one of claims 1 and 2, characterized in that the coating resin (3,27) is.   a resin selected from the group consisting of copolymers   styrene-butadiene matrices, vinyl acetate, maleic vinyl acetate copolymer, polyvinylidene chloride, acrylonitrile acrylate copolymer, and acrylic polymers. 5   4 / A method according to one of claims 1 to 3, characterized in that the envelope (29) microspheres   (28) is made of a copolymer of polyvinylidene chloride and acrylonitrile   / Method according to one of claims 1 to 4, characterized in that the volatile fluid contained in the   core (30) of the microspheres (28) is selected from the group consisting of isobutane and neopentane.   6 / A method according to one of claims 1 to 5, characterized in that the coating glue of the second   The face of the support (2) is a natural adhesive or an acrylic or vinyl resin. 7 / Sheet of a material developing on one of its faces anti-slip properties and on the other side adhesive properties, characterized in that it consists of a support (2, 25) of flexible material and typically selected from the group consisting of papers, cartons, plastic films, nonwoven fabrics, of which one of the faces receives a coating   constituted by a plurality of microspheres (28)   in a polymer with a low softening point and containing a volatile fluid, and whose diameter is   between 5 and 100 micrometers, a member of the said   using a resin with a low softening point between 60 and 80 ° C., the other side of which receives   a layer of natural or synthetic glue.   8 / sheet according to claim 7, characterized in that the relative amount of microspheres (28) per unit area is between 0.3 and 1 gram per square meter.