EP1065070A2 - Ink-jet recording material containing a thermoplastic copolymer having polyether groups - Google Patents

Abstract

Ink jet recording material comprising at least one polymer layer on a base material, in which the polymer layer is an extruded layer containing a thermoplastic copolymer with polyether groups (I).

Description

The invention relates to a recording material for the Ink jet recording process.

Those with the general spread of electronic Media related manufacturing technology of color printing has been going on in recent years Gained meaning. The aim of this technology is Adaptation of the image quality of the color printouts to the Level of silver salt photography.

bleed"), kurze Trocknungszeiten der Tinte, Lichtstabilität sowie Dimensionsstabilität. Eine weitere wichtige Anforderung für kommerzielle Anwendungen stellt der Oberflächenglanz dar. Dies ist insbesondere bei der Herstellung von Kunstgraphiken wichtig, aber auch bei der Erzeugung von Bildern, bei denen ein fotoähnlicher Eindruck verlangt wird. An important technology is the ink jet recording process, which has delivered an increasingly better image quality in recent years. In the ink jet process, tiny droplets of ink are applied to a recording material using various techniques that have been described several times. High demands are placed on the recording materials used in this technology. These include, for example, high resolution and high color density of the generated image, no color bleeding (

bleed "), short drying times of the ink, light stability and dimensional stability. Another important requirement for commercial applications is surface gloss. This is particularly important in the production of art graphics, but also in the production of images in which a photo-like impression is required .

EP 0 650 850 A2 is a recording material known that from a polyolefin coated Base paper and a receiving layer. The Material enables the production of images with high Resolution, color density and high gloss, which in the Overall impression with conventional photographic images are comparable. A disadvantage of this receiving material are its poor drying properties.

JP 10-119424 uses a recording paper high gloss suggested a hydrophobic carrier and two layers containing porous silica contains, with the silica of the upper layer has smaller particles than the silica lower layer. Disadvantage of this Recording material is the long drying time.

In some other fonts, glossy ones Claimed recording materials in which the Receiving layer in a cast coating process against a heated mirror smooth Cylinder surface is pressed, which the Recording material has a high-gloss surface receives.

The object of the present invention is a high-gloss recording material for ink jet recording processes provide with the pictures high color density and a low mottle (Cloudiness) can be generated and a good one Has smudge resistance.

The task is solved by a recording material, which is a carrier material and at least one polymer layer includes. The polymer layer can be directly on the carrier arranged and applied by extrusion. The The polymer layer contains a polyether group thermoplastic copolymer.

Draw the recording materials according to the invention by high gloss, which is achieved by treatment in one Calender or increased even further with a chill roll can be. They have a high smudge resistance excellent color density and excellent mottle values on. The recording material according to the invention has more well-known compared to the polyolefin layers Ink-jet recording materials an improved Ink absorption capacity.

The polymer layer can also be a mixture of the Copolymer containing polyether groups and others Polymers. The proportion of the other polymer in the Mixture with those to be used according to the invention Copolymers can be about 1 to 50% by weight, preferably up to 40% by weight, based on the mass of the mixture.

In a particular embodiment of the invention contains the polymer layer is a polyether amide block copolymer, being a block polymer with a number of Polyether groups from 2 to 20 in each themselves repeating copolymer segment particularly good Delivers results.

worin PA ein Polyamidsegment und PE ein Polyethersegment bedeutet. Die einzelnen Segmente können durch Carboxylgruppen miteinander verbunden sein. Ein Polyethersegment kann 2 bis 30, vorzugsweise 5 bis 20 Etherfunktionen aufweisen.Polyetheramide block copolymers suitable according to the invention are, for example, those of the general formula

where PA is a polyamide segment and PE is a polyether segment. The individual segments can be connected to one another by carboxyl groups. A polyether segment can have 2 to 30, preferably 5 to 20 ether functions.

In a further preferred embodiment of the invention is the copolymer containing polyether groups Polyetherester copolymer.

Suitable as additional polymers in a mixture with the are to be used according to the invention thermoplastic polymers such as polyolefins, Ethylene copolymers, polyesters, polycarbonates, polyurethanes and / or extrudable polyvinyl alcohol homopolymers or Polyvinyl alcohol copolymers.

Other auxiliaries such as White pigments, color pigments, fillers, in particular absorptive fillers and pigments such as aluminum oxide, Aluminum hydroxide and / or silicas, as well Color fixatives, dispersing aids, plasticizers and optical brighteners may be included. Can be used as a white pigment Titanium dioxide can be used. Other fillers and Pigments are calcium carbonate, magnesium carbonate, clay, Zinc oxide, aluminum silicate, magnesium silicate, ultramarine, Cobalt blue and soot or mixtures of these. The fillers and / or pigments are in an amount from 1 to 40% by weight, in particular 5 to 20% by weight, used. The quantities given relate to the mass the polymer layer.

The application weight of the extruded polymer layer can be 5 to 50 g / m ² , preferably 10 to 30 g / m ² . The polymer layer can be applied as a single layer to the front of the carrier material using an extrusion process known to those skilled in the art or in multiple layers using a coextrusion process. However, it can also be applied to the back of the carrier material.

A zone temperature of 160 to 340 ° C, in particular 180 to 320 ° C, set. It has proven to be particularly advantageous in particular proven the use of single inch extruders that used resins and other additives Mixing screw speeds from 70 to 150 rpm and to extrude the mixtures obtained. Become others The extruder used is said to be the screw speed preferably be adjusted so that the viscosity of the mass to be extruded in a single inch screw extruder at speeds of more than 70 rpm and corresponds to a temperature of 160 to 320 ° C.

In order to achieve the highest possible gloss values, it is advantageous, a high gloss in the extrusion process Use cooling roller.

In principle, any base paper can be used as a carrier material be used. Surface-sized, calendered or non-calendered or heavily glued Base papers. The paper can be acid or neutral sized his. The base paper is said to have high dimensional stability have and should be capable of being in the ink contained liquid without absorbing waves. Papers with high dimensional stability Pulp mixtures of softwood pulps and Eucalyptus pulps are particularly suitable. In this respect, the disclosure of DE 196 02 793 B1 which is a raw paper for an ink jet recording material describes. The base paper can other auxiliaries common in the paper industry and Additives such as dyes, optical brighteners or Defoamers included. The use of Reject pulp and recycled waste paper is possible. However, one-sided can also be used as the carrier material or on both sides with polyolefins, in particular with Polyethylene coated paper can be used.

In a further embodiment of the invention, the Recording material contain another layer. This additional layer can function as a Have an ink-receiving layer. This layer can be made an aqueous dispersion or solution. The additional layer can be a single layer or can also be applied in multiple layers. she can hydrophilic or water-soluble binders, dye-fixing agents, dyes, optical Brighteners, crosslinking agents and inorganic and / or contain organic pigments.

Polymers, for example, can be used as binders become like polyvinyl alcohol and its modifications, Starch and starch derivatives, gelatin, casein, cellulose derivatives, Styrene / butadiene latex, vinyl copolymers, Polyvinyl pyrrolidone and acrylic esters.

In order not to increase the gloss of the recording material as a pigment can be a fine particle inorganic pigment with a particle size of 0.01 to 1.0 µm, in particular 0.02 to 0.5 µm, in the Ink receiving layer used. Is particularly preferred however, a particle size of 0.1 to 0.3 µm. The pigment can be selected from the group of oxides, Carbonates, silicates or sulfates of alkali metals, Alkaline earth metals such as silica, aluminum oxide, Barium sulfate, calcium carbonate and magnesium silicate. Silicic acid and aluminum oxide are particularly suitable with an average particle size of less than 0.3 µm. But also a mixture of silica and aluminum oxide an average particle size of less than 0.3 microns can be used.

The quantitative ratio of pigment to binder can be 20: 1 to 1: 5. The application weight of the layer can be 0.5 to 40 g / m ² , preferably 1 to 30 g / m ² .

Any of the following can be used to apply the ink-receiving layer (s) any well-known order and Dosing methods are used like roller application, Engraving, nipping and air brushing or Roller doctor dosage. This is particularly preferred Apply with the help of a cascade coating system or a slot caster.

For setting the curl behavior, antistatic and the back of the printer can be transported in the printer be provided with a separate functional layer. Suitable backing layers are in the DE 43 08 274 A1 and DE 44 28 941 A1 the disclosure of which is incorporated by reference.

The following examples are provided for further explanation the invention.

Examples Base paper A

A paper with a basis weight of 83 g / m ² and a thickness of 87 μm was produced with a Fourdrinier paper machine (base paper A). The pulp had a freeness of 29 according to Schopper / Riegler. About 42% by weight of pine sulfate pulp and about 54% by weight of eucalyptus cellulose were used as cellulose. In addition, 4% by weight of clay was added as a pigment. 0.1% by weight of alkyl ketene dimer, 0.05% by weight of starch and 0.5% by weight of polyamide / polyamine-epichlorohydrin resin as wet strength agent were added. A 7.0% by weight polyvinyl alcohol solution was used for surface sizing. The paper had a roughness according to Sheffield of 98.

Base paper B

A paper with a basis weight of 130 g / m ² and a thickness of 138 μm was produced with a Yankee paper machine. The pulp had a freeness of 27 according to Schopper / Riegler. About 24.5% by weight of pine sulfate pulp and about 67% by weight of eucalyptus pulp were used as pulps. Clay was added as a pigment in an amount of 8.5% by weight. 0.55% by weight of alkyl ketene dimer was added as the sizing agent and 0.6% by weight of polyamide / polyamine-epichlorohydrin resin as the wet strength agent. A 1.97% by weight starch solution was used for the surface sizing. The paper had a Sheffield roughness of 120.

The weights of the pulps and pigments refer on the pulp input of these substances Weight of the sizing agents and wet strength agents refer to the dry fiber content.

example 1

The front of base paper A was coated with a polyether amide block polymer, PEBAX® MV 6100 SL 01, using a 1 '' extruder. A temperature profile of 190 to 280 ° C was set in the extruder. The screw speed was set above 70 revolutions / minute (rpm) to improve the adhesion of the layer. The laminate obtained was then passed over a high-gloss cooling cylinder. The application weight of the extruded polymer layer was 20 g / m ² .

The back of base paper A was coated with clear polyethylene, which was a mixture of LDPE and HDPE (35% HDPE with a density d = 0.963 g / cm ³ , MFI = 8; 65% LDPE with d = 0.923 g / cm ³ , MFI = 4.4).

Example 2

The base paper A was treated under the same conditions as in Example 1 with a mixture of 98% by weight polyether amide block polymer, PEBAX® MV 6100 SL 01 and 2% by weight of a 50% TiO ₂ masterbatch (50% by weight anatase TiO ₂ , 1.5 wt.% Zn stearate, 48.5 wt.% LDPE) coated by extrusion. The application weight was 23 g / m ² . The back was coated with a clear polyethylene as in Example 1.

Example 3

The base paper A was subjected to the same conditions as in Example 1 with a mixture of 90% by weight polyether amide block polymer, PEBAX® MV 6100 SL 01 and 10% by weight of a 50% TiO ₂ masterbatch (as in Example 2) Extrusion coated. The application weight was 23 g / m ² . The back was coated with a clear polyethylene as in Example 1.

Example 4

The front of the base paper B was coated under the same conditions as in Example 1 with a polyether amide block polymer, PEBAX® MV 3000 by extrusion. The application weight was 20 g / m ² . The back was coated with a clear polyethylene as in Example 1.

Example 5

The base paper B was coated under the same conditions as in Example 1 with a mixture of 98% by weight polyether amide block polymer, PEBAX® MV 3000 and 2% by weight of a 50% TiO ₂ masterbatch (as in Example 2) by extrusion . The application weight was 23 g / m ² . The back was coated with a clear polyethylene as in Example 1.

Example 6

The base paper B was coated under the same conditions as in Example 1 with a mixture of 90% by weight polyether amide block polymer, PEBAX® MV 3000 and 10% by weight of a 50% TiO ₂ masterbatch (as in Example 2) by extrusion . The application weight was 23 g / m ² . The back was coated with a clear polyethylene as in Example 1.

Example 7

An ink-receiving layer composed of an aqueous dispersion was applied to the front of the paper coated according to Example 1. This ink receiving layer was composed as follows: Polyvinyl alcohol 6.5% by weight Degree of saponification: 98% Viscosity: 62.72 cP (4% aq. Solution, at 20 ° C) Alumina 93.0% by weight middle Particle size: 130 to 140 nm, specific Surface: 50 to 60 m ² / g Boric acid 0.5% by weight

The weight data relate to the dried one Layer.

Example 8

On the front of the coated according to Example 4 Paper was made up of an ink receiving layer aqueous dispersion applied as in Example 7.

Comparative Example 1

A base paper coated on both sides with polyethylene served as a comparative example. For this purpose, the paper A was coated on the front with a low-density polyethylene (LDPE) with a TiO ₂ content of 10% by weight and on the back with a clear LDPE by extrusion. The front application was 19 g / m ² , the back application was 22 g / m ² .

Comparative Example 2

On the coated front of the according Comparative Example 1 prepared polyethylene coated paper became one Ink receiving layer applied according to Example 7.

Testing of according to the examples and comparative examples produced recording papers

The recording papers were made using the Inkjet printer HP 890 at 1440 dpi (dots per inch) printed.

The test print images obtained were checked for color density, Bleed ", smudge resistance and mottle were examined.

shine

The gloss was on unprinted material with the laboratory Reflectometer RL3 from Dr. Long according to DIN 67530 measured at a measuring angle of 60 °.

Color density

The color density was determined using an X-Rite densitometer 428 on the colors cyan, magenta, yellow and black measured.

Bleed

Bleeding of the inks at the edges of color areas lying together was visually matched with the Grades 1 to 5 (very good to very bad).

Smudge resistance

The smudge resistance was achieved by rubbing the printed image checked with a white rag. This exam was made for each color carried out and graded individually. The grade 1 stands for very good smudge resistance (no paint residue recognizable by the rag) and the grade 5 stands for poor smudge resistance (significant paint residues on the Lobes recognizable).

Mottle

The unrest or cloudiness (mottle) in one Color area was visually rated 1 to 5 (very good to very bad).

The test results are summarized in Table 1. Exam results Color density shine Bleed note Smudge resistance Mottle cyan magent yellow black 1 1.70 1.20 1.34 1.25 56.2 2 2 2 2 1.68 0.71 1.15 1.49 50.0 2 2 2 3rd 2.28 1.26 1.42 1.01 52.6 2 2.5 2 4th 2.25 1.35 1.46 2.45 68.0 2 2 2 5 1.80 1.35 1.16 2.50 51.3 2 2 2.5 6 1.82 1.35 1.21 2.44 49.2 2 2 2 7 2.41 1.38 1.65 2.25 36.2 2 1 1 8th 2.35 1.36 1.76 2.30 36.9 2 1 1.5 V1 1.59 1.45 1.39 1.20 80.3 4th 5 3rd V2 2.39 1.37 1.78 2.35 20.5 3rd 2 1.5

As can be seen from the table, using the extrudable copolymers according to the invention high-gloss Ink-jet recording papers are made that too in terms of color density, smudge resistance, bleed and mottle overall have good results.

Claims (8)

Recording material for the ink jet printing process, which comprises a carrier material and a polymer layer, characterized in that at least one polymer layer is arranged on the carrier, the polymer layer is an extruded layer and contains a thermoplastic copolymer having polyether groups. Recording material according to claim 1, characterized in that the copolymer is a polyether amide block copolymer. Recording material according to claim 1 or 2, characterized in that the number of polyether groups in each repeating copolymer segment is 2 to 20. Recording material according to one of the preceding claims, characterized in that the polymer layer contains a mixture of a copolymer containing polyether groups and a thermoplastic polymer. Recording material according to claim 4, characterized in that the thermoplastic polymer is selected from the group of polyolefins, ethylene copolymers, polyesters, polycarbonates and polyurethanes. Recording material according to one of the preceding claims, characterized in that the amount of the thermoplastic polymer is 1 to 50% by weight, based on the polymer mixture. Recording material according to one of the preceding claims, characterized in that the polymer layer contains approximately 40% by weight of pigment. Recording material according to one of the preceding claims, characterized in that an ink-receiving layer is arranged over the polymer layer.