Release product

Abstract

A release product including a basic substrate and a siliconized release layer. The basic substrate has a first side and a second side. The siliconized release layer has been applied on the first side of the basic substrate. The release product includes a coating layer which has been applied directly on either the first side of the basic substrate, or the second side of the basic substrate. The coating layer includes silica particles and a binder.

Claims

1. A release product for self-adhesive labels, consisting of: a glassine paper comprising a first side and a second side, a silicone coating applied only on the first side of the glassine paper, and a coating layer which has been applied directly on only the second side of the glassine paper, the coating layer comprising porous silica particles, a cross-linking agent and a binder, wherein the release product is structured to be removable from a self-adhesive label, and wherein the porous silica particles have an average diameter of 0.3 to 10 m, a surface area of at least 300 m.sup.2/g and a bulk density of at least 0.15 g/cm.sup.3.

2. The release product according to claim 1, wherein the binder comprises natural polymers or their derivatives.

3. The release product according to claim 2, wherein the binder comprises starch, carboxymethyl cellulose, or their mixture.

4. The release product according to claim 1, wherein the coating layer comprises kaolin or talc.

5. The release product according to claim 1, wherein the silica particles have a bulk density of at least 0.30 g/cm.sup.3.

6. A release product for self-adhesive labels, consisting of: a glassine paper comprising a first side and a second side, a silicone coating as a release layer applied on the first side of the glassine paper, and a coating layer which has been applied directly on the second side of the glassine paper, the coating layer comprising porous silica particles, a cross-linking agent and a binder; wherein the release product is structured to be removable from a self-adhesive label, and wherein the porous silica particles have an average diameter of 0.3 to 10 m, a surface area of at least 300 m.sup.2/g and a bulk density of at least 0.15 g/cm.sup.3.

Description

EXAMPLE

(1) Release papers were coated by using the coating recipes listed in table 1. The typical composition of the coating composition comprises at least silica particles and a binder comprising starch or its derivatives, cmc, or their mixtures. There is usually also a cross-linking agent in order to prevent dusting and sticking to calender rolls. The coating composition may also comprise inorganic particles different from the silica particles, such as kaolin.

(2) TABLE-US-00001 TABLE 1 Coating compositions. Samples Typical composition Specific composition 1 2 3 4 5 6 Starch Raisamyl 21221 65 65 72 76 76 91 Cross-linking agent BIM SU-6040 3 3 3 4 4 4 CMC CP Kelco FF-801 2 2 PVA KSE Moviol 10-98 10 10 5 5 5 Clay Imerys ND 9321 10 15 10 10 10 Silica Formapol FP348 10 5 10 5 5 5

(3) The numbers in the table are weight percents of the total amount (=100 wt.-%). The base paper was a glassine paper having a grammage of 64 g/m.sup.2. The grammage of the coating layer was 1.1 g/m.sup.2.

(4) The used silica particles had an average particle size of about 4 m, a surface area of about 340 m.sup.2/g, and a bulk density of about 1.77 g/cm.sup.3.

(5) The coating compositions were applied on the second side of the release paper. All the coating layers showed desired properties, i.e. the coating layers were efficient to absorb contaminants.