Transfer paper for sublimation printing, comprising an alkaline earth salt

Abstract

The invention relates to transfer paper for sublimation printing, having one or more alkaline earth salts on at least one face thereof.

Claims

1. Transfer paper comprising a fibrous substrate and directly applied on at least one side of the fibrous substrate, a composition comprising an alkaline earth salt selected from calcium dichloride, calcium nitrate, magnesium sulphate and magnesium chloride wherein the transfer paper is a sublimation printing transfer paper and is free of calcium sulfate and barium sulfate.

2. Transfer paper according to claim 1, the alkaline earth salt(s) being present on the said side in a quantity equal to or greater than 0.2 g/m.sup.2.

3. Transfer paper according to claim 1 lacking other surface treatment formulation ingredients on the side containing the alkaline earth salt(s).

4. Transfer paper according to claim 1, wherein the transfer paper is printable by inkjet printing.

5. Transfer paper according to claim 1 having a Bendtsen air permeability equal to or greater than 100 ml/min (ISO 5636-3).

6. Transfer paper according to claim 1 having a paper weight between 25 and 150 g/m.sup.2.

7. Manufacturing process for a transfer paper for sublimation printing, according to claim 1, wherein a surface treatment is used to deposit, on at least one side of a fibrous substrate, one or more alkaline earth salts or one or more compounds which, in the presence of one or more other compounds carried by the fibrous substrate, form one or more alkaline earth salts in situ.

8. Manufacturing process for a transfer paper according to the preceding claim, wherein the fibrous substrate is manufactured and the surface treatment applied in-line or off-line.

9. Manufacturing process for a transfer paper according to claim 7, wherein surface treatment deposits a composition containing alkaline earth salt(s) on the said side of the fibrous substrate.

10. Manufacturing process for a transfer paper according to the preceding claim, wherein the quantity of the composition deposited on the side of the fibrous substrate is between 0.2 and 15 g/m.sup.2 by dry weight, preferably between 0.5 and 8 g/m.sup.2.

11. Manufacturing process for a transfer paper according to claim 7, wherein the surface treatment is applied using a size press, a film transfer press or a coating system, in particular a knife coating, air knife coating, crayon or curtain, or by engraved cylinder.

12. Transfer paper printed by sublimation printing, containing a transfer paper according to claim 1 and wherein at least one print on the side of the transfer paper contains the alkaline earth salt(s).

13. Process for printing transfer paper for sublimation printing, in which at least one ink is used to print, in particular by inkjet printing, the side containing the alkaline earth salt(s) of a transfer paper according to claim 1.

14. Process for decorating a support, wherein the printing on a transfer paper printed according to claim 12 is transferred to the support by sublimation.

15. Transfer paper according to claim 1 wherein the composition containing the alkaline earth salt is free of binder.

16. Transfer paper according to claim 1 wherein the composition containing the alkaline earth salt is free of mineral filler.

17. Transfer paper according to claim 1 wherein the composition containing the alkaline earth salt comprises 10 to 100 weight percent of the alkaline earth salt.

18. Transfer paper according to claim 1 wherein the composition containing the alkaline earth salt comprises 40 to 100 weight percent of the alkaline earth salt.

Description

EXAMPLES

Examples 1 to 6

(1) The compositions described in the table below are each deposited by Mayer rod on one side of a fibrous substrate of the composition and properties described below. The fibrous substrates treated by these compositions for transfer papers.

(2) Basic Paper Before Coating Fibrous composition: 30% softwood+70% mixed short fibres Basis weight=60 g/m.sup.2 Cobb value 60 s=15 g/m.sup.2 Bendtsen porosity=1500 ml/min

(3) Coating formulations: composition and coating according to the table below.

(4) The printing test is carried out on paper using a SAWGRASS SG400 printer, and transfer is by press at 200° C. for one minute on polyester fabric.

(5) Black ink (SAWGRASS Sublijet black) is deposited on the side of the fibrous substrate treated by the composition. A solid black area of colour is thereby obtained. The transfer papers treated by the ink form printed transfer papers.

(6) The optical density after transfer to the polyester fabric is measured with an X-rite 500 spectrodensitometer.

(7) Proportions are expressed as dry weight.

(8) The quantities of calcium carbonate, aluminium silicate, polyvinyl alcohol, sorbitol, polyDADMAC and alkaline earth salt are expressed in percentage as dry weight (% dry).

(9) TABLE-US-00001 Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Salt - type CaCI2 MgSO4 CaNO3 CaCI2 CaCI2 — Calcium carbonate % dry 0 0 0 76 0 18 Aluminium silicate % dry 0 0 0 0 0 71 Polyvinyl alcohol % dry 0 0 0 10 40 11 Sorbitol % dry 0 0 0 0 20 0 Polydadmac % dry 0 0 0 4 0 0 Alkaline earth salt % dry 100 100 100 10 40 0 Dry deposit (g/m.sup.2) 1.05 0.99 0.91 6.1 0.85 1.36 Dry salt weight (g/m.sup.2) 1.05 0.99 0.91 0.61 0.34 0 Optical density (solid 2.34 2.37 2.12 2.46 2.18 1.86 black area of colour) Bendtsen air permeability (ml/min) >100 >100 >100 >100 >100 >100

(10) The printed transfer papers described in examples 1, 2, 3, 4 and 5, which are papers according to the invention, have an optical density greater than the printed transfer paper according to example 6 which is not according to the invention.

Examples A, B and C

(11) The black ink in examples 1, 2 and 3 has been replaced by a solid red area of colour formed by printing yellow and magenta (SAWGRASS Sublijet), respectively in examples A, B and C. The results are given in the table below.

(12) TABLE-US-00002 Example Example Example A B C Salt-type CaCI2 MgSO4 CaNO3 Calcium carbonate % dry 0 0 0 Aluminium silicate % dry 0 0 0 Polyvinyl alcohol % dry 0 0 0 Sorbitol % dry 0 0 0 Polydadmac % dry 0 0 0 Salt % dry 100 100 100 Dry deposit (g/m.sup.2) 1.05 0.99 0.91 Dry salt weight (g/m.sup.2) 1.05 0.99 0.91 Optical density 1.99 1.58 1.56 (solid red area of colour) Bendtsen air (ml/min) >100 >100 >100 permeability

(13) Calcium dichloride gives and excellent optical density with the solid red area of colour.