FR2519883A1 - Masking prod. comprising bi:oriented plastic sheet - coated with adhesive on surface with specified linear surface tension - Google Patents

Abstract

A masking prod. comprises (a) a support formed by a bioriented plastic sheet one surface of which has a linear surface tension (LST) of 4 x 10 power -4 to 5.5 x 10 power -4 N/cm, while the other surface has an LST of 3 x 10 power -4 to 3.5 x 10 power -4 and (b) an adhesive layer applied to the surface with the higher LST. The prod. is used for D.I.Y. jobs and protecting surfaces such as walls, glass, when painting. The adhesive anchors strongly to the support; paint 'slip' on the non-adhesive part of the prod. is avoided and the prod. can be rolled on itself and then unwound without damaging the adhesive layer.

Description

19883

  Masking product of the plastic support type provided with an adhesive layer, and its application in particular in the

  do-it-yourself and surface protection.

  The present invention relates, as a new industrial product, to a masking product of the plastic support type provided with an adhesive layer. This product is useful in particular in the field of DIY and that of surface protection, such as walls, windows, woodwork, during removal

  a coat of paint or varnish.

  In the field of masking products, there are known in particular American patents Nos. 3,032,181 and No. 1,726,744, embodiments (presented in the form of a roll) constituted by a paper support, one of the faces of which is partially or

  completely with an adhesive layer, and the other side of which is, respectively

  tively, partially or completely coated with an anti-

  adherent (for example a silicone layer).

  It turns out that these old realizations have a certain number of disadvantages: the paper support is not perfectly waterproof.

  this fact, when in use, there are penetrations of paint

  ture staining the hidden surfaces that one wanted to protect (this case is frequently encountered because modern quick-drying paints are water-based paints); the paper support being "fragile" vis-à-vis water

  (humidity or water in the paints), the risk of seeing (i) the product-

  cache curl and (ii) the adhesive mass deteriorate or detach, is relatively large;

  paints or varnishes slide on the anti-

  adherent, this phenomenon being due to the large difference in surface tension existing between a non-stick layer used in the field of adhesive tapes having a linear surface tension less than 2.5 × 10 N / cm (ie 25 dynes / cm) and paints or varnishes with a linear surface tension of -4

  general 3.5 x 10 N / Cm, as is the case for paints

  aqueous tures which are more and more used, for reasons

  security sounds, in the building sector; moreover, it is impossible for paper supports to conform to variations in orientation of the surfaces to be protected which require elongations greater than or equal to 20%, while said paper supports only allow elongations. order of 5 Z; finally, the adhesive mass of a paper support cannot

  not adhere to the non-stick layer of said support, when a che-

  vauchement is necessary (as happens in the case of a

change of direction).

  To overcome these drawbacks, we recommend, according to the

  vention, a new technical solution that uses support

  plastic material whose face intended to receive the adhered mass

  sive has a linear surface tension between 4 x 10-4

  N / cm and 5.5 x 1074 N / cm, and the other side of which has a super tension

  linear form of the order of 3 x i 0-4 N / cm to 3.5 x 10-4 N / cm,

  so as to allow (i) the attachment to the support of the adhered mass

  sive deposited in particular by coating, (ii) to avoid a significant "sliding" of paint or varnish on the non-adherent face of the support at the time of use, and (iii) the winding of the product

  masking on itself, then the subsequent course without dete

improvement of the adhesive coating.

  The masking product according to the invention, which comprises a plastic support provided with an adhesive layer, is characterized in that it comprises: a) a support constituted by a plastic sheet

  bioriented, one of the faces of which has a surface tension-

  the linear between 4 x 10 N / cm and 5.5 x 10 N / cm and the other side of which has a linear surface tension

-4 1-4

  on the order of 3 x 10-4 N / cm to 3.5 x 104 N / cm, and

  b) an adhesive mass arranged in a layer on at least one part

  tie of the surface of the support having the surface tension

highest linear.

  Furthermore, it is advantageously recommended to provide on at least one of the edges of the support a means for initiating the transverse tear of the masking product. This means which can be a serrated cut constitutes a primer for the tear, due to the cracking that '' it realizes, from the macromolecular network of the plastic material constituting the support This primer can be microscopic (in this case it can be indifferently provided on one or both edges of the support) or macroscopic (in this case it is provided on the edge of the support not in contact

with the adhesive).

  Biorientation (in the length direction and the width direction, that is to say in the running direction

  and the cross direction) and the means to initiate the transverse tear

  dirty cooperate to tear the masking product to size

  required, at the time of use The biorientation ensures a

  clean rure, it also allows the modeling and the extensibility of the support. Preferably the support to be used will have one side

  (that intended to receive the adhesive mass) having a sufficient tension

  linear imperfection of the order of 4.5 x 10 N / cm, the other face having a linear surface tension of the order of 3 x 10-4 at

3.5 x 10 4 N / cm.

  Other advantages and characteristics of the invention are-

  will be better understood on reading the following description of

  attached drawings, in no way limitative, but given by way of illustration

tration, o

  Fig 1 shows a perspective view of a pro-

  masking product according to the invention, and FIG. 2 is a section on II-II of the product of the

fig 1.

  The support 1 is a sheet of plastic material (which

  may in particular have a thickness of 20 to 100,) which is biorien-

  which is coated on a portion of its surface 5 by a

  adhesive layer 2 The support has a clear edge 4

  held in particular by cutting with a smooth wheel and an edge 3

  bearing a sawtooth cut obtained by cutting with a notched wheel Of course, it is possible to envisage a microscopic cut 3 which would be clear on the macroscopic scale; in the

  case where the cutout 3 serving as a tear initiator would be micros-

  copic, we could easily swap edges 3 and 4

  so that said cutout is on the side of the mass at 4 hesitatively.

  Among the plastics which are suitable for

  read support 1, we can notably mention the substances

  thermoplastics such as polyalkylenes, in particular poly-

  ethylene and polypropylene It is important that the support 1 is bioriented and has a different linear surface tension on each face, the face having to receive the adhesive layer by coating having a linear surface tension between -4 55 x 17 / m 4 x 104 N / cm and 5.5 104 N / cm, the other side having a tension

  linear surface of the order of 3 x 104 N / cm to 3.5 x 104 N / cm.

  To obtain such a surface tension, a sheet of material may be treated before deposition of the adhesive layer 2 by coating.

  plastic with surface tension on each side of the gold-

  dre of 3 x 10-4 N / cm (i) in order to subject it to hot micro-

  graining by means of one or more cylinders, (ii) in order to make it undergo a heat treatment with a row of flames, or

  preferably (iii) in order to subject him to an electrical treatment

that ("CORONA" or ionizing system)

  Such treatment offers the advantage of avoiding the use of

  tion of an intermediate layer of varnish ("primer") for attaching the adhesive mass 2 to the surface 5 of the support 1 when the initial surface tension on each face is of the order of

3 x 104 N / cm.

  The best way to prepare a masking product

  ge according to the invention, consists in using a support 1 biorien-

  polypropylene tee that is subjected to a treatment in an electric field ("CORONA" system) Polypropylene sheet is a substance which has a linear surface tension on

25.19883

  each face of the order of 3 xl O 4 N / cm and which, by treatment according to the "CORONA" system, sees one of its faces having a linear surface tension of the order of 4 x 10 N / cm at, 5 x 10-4 N / cm, the other side having an unmodified or very slightly modified linear surface tension (increase in

10 to 2 x 10 N / cm).

  When we have increased the surface tension, we deposit

  then the adhesive mass 2 by coating ("size-press" or "reverse-

  roll "in particular) on the surface of the support 1 which has been subjected to

  said treatment A final product is obtained which can be wound on itself, the adhesive mass 2 deposited by coating on at least a portion of the face 5 which can then adhere to the face 6

  but can be subsequently detached from the face 6 without destruction

  tion of the bonding of said adhesive mass with the face 5, the fa-

  this 6 playing the role of a non-stick face.

  The adhesive layer 2 can, if necessary, be dyed in the mass, either to have an aesthetic appearance, or even to facilitate the positioning of the masking product. This adhesive mass is advantageously an acrylic mass, in particular chosen from polymers and copolymers of acrylic acid and

  alkyl acrylate Preferably, this adhesive mass will be felt

  pressure sensitive; a non-acrylic adhesive mass would imply the use of a bonding "primer" The adhesive mass according to the invention can be colored (in particular in yellow) After drying the adhesive mass (a deposit of 25 to 50 g / is obtained m 2 dry weight of adhesive mass) the net edge 4 and edge are cut

serrated 3.

  If we used a support with a superficial tension

  -4 skies on each face of 2.5 x 10 N / cm which one side 5 was treated so that it has a surface tension of the order of 4 x 10 N / cm at 5.5 x 10-4 N / cm to receive the adhesive mass, it would be seen that the paints (in particular water-based paints) having a surface tension of the order of 3.5 × 1074

  N / cm, would form drops on the face 6 On the other hand,

  according to the invention, with a face 6 having a surface tension t 883 linear of 3 x 10-4 N / cm at 3.5 x 10-4 N / cm and a face 5 having a surface tension of 4 x 10-4 N / cm at 5.5 x 10-4 N / cm, we observe (i) good adhesion of said paints on said face 6, (ii) good adhesion of the adhesive mass 2 on face 5 and (iii) the possibility of making said adhesive mass adhere to the non-stick face 4 during a change of direction at

time of employment.

EXAMPLE

  A biaxially oriented polypropylene ("PROPAFILM" manufactured by the company ICI) having a thickness of 30 to 40) and a linear surface tension of 3 × 10 −4 N / cm, is subjected to a "CORONA" treatment on one side only. that this face has a linear surface tension -4 of 4.5 x 104 N / cm and that the other face has 1-4 x 1-4 a linear surface tension of 3 x 10 N / cm at 3.1 x 104 N / cm We submit the face having the linear surface tension

  the highest to a coating on at least a portion of its over-

  face with an acrylic adhesive mass ("ACRONAL", manufactured by the Company B A S F) to obtain, after drying, a deposit of 25 to

  g / m 2 dry weight of adhesive, the adhesive layer having been previously

  enamelled in the mass by means of 1 to 1000 ppm by weight

dye.

  We then proceed to cutting into strips, by means of a cutting device (in particular a machine of the KAMFT type or of the PELISSIER type) equipped with either knobs having irregularities

  on the cutting edge, or notched knurls.

  It is observed that the product thus obtained is not sensitive to water: the water absorption in 24 hours of the polypropylene support is less than or equal to 0.01% by weight relative to the weight of said support.

Claims (5)

  1 Masking product comprising a material support   plastic provided with an adhesive layer, said product being characterized   laughed at in that it comprises: a) a support constituted by a sheet of biaxially oriented plastic material, one of the faces of which has a surface tension - the linear between 4 x 1074 N / cm and 5.5 x 1074 N / cm and the other side of which has a linear surface tension of the order of 3 x 10-4 N / cm to 3.5 x 1074 N / cm, and   b) a layer of adhesive mass placed on at least one part   O 10 tie of the surface of the support having surface tension highest linear.   2 Masking product according to claim 1, charac-   terized in that the support has at least one of its edges   a means for initiating the transverse tear.   3 Masking product comprising a material support   plastic with at least a portion of one of its faces covered   kills with an adhesive layer, said product being characterized in that it comprises a support constituted by a sheet of material   biaxially oriented plastic, one side of which has a superficial tension   linear sky between 4 x 10-4 N / cm and 5.5 x 104 N / cm and the other side of which has a linear surface tension of the order of 3 x 10-4 N / cm at 3.5 x 10-4 N / cm, and a layer of adhesive mass placed on at least part of the face of the support having the highest linear surface tension, at least one of the edges of the support having a means for initiating the tearing   transverse, in particular a serrated cutout.   4 Masking product according to any one of the resales   dications 1 to 3, characterized in that the face of the material support   re plastic receiving the adhesive layer has a surface tension-   the linear of the order of 4.5 x 10-4 N / cm.   Masking product according to any one of claims 1 to 4, characterized in that the bi-oriented support is polypropylene. 6 Masking product according to any one of   claims 1 to 4 characterized in that the adhesive layer   is obtained by coating with an acrylic adhesive mass.   7 Masking product according to any one of   Claims 1 to 6, characterized in that it comprises 25 to   g / m 2 dry weight of a pressure sensitive adhesive layer   sion and deposited on at least a portion of one of the faces support.