CN1177941C - A transfer element for finishing leather - Google Patents

Abstract

A transfer part for finishing leather. The transfer element has at least one glossy film supported on a carrier for glossy finishing of the leather. The transfer element may additionally comprise a foil on said film, said foil being coloured, printed or metallized.

Description

A transfer element for finishing leather

The invention relates to a transfer element for treating leather to impart its lustrous properties.

current technology

It is generally known that the production of leather involves chemical treatment of raw hides and hides. However, it has hitherto been necessary to subject the leather to an additional chemical treatment step in order to give it a glossy appearance if its finish or appearance is desired. Obviously, the disadvantage of this known method lies in the additional chemical treatment step.

Another disadvantage of the known technology is associated with dividing the hide. According to known techniques, the split hides are subjected to steps of lamination, coloring or foil transfer in order to increase or improve the quality of the split hides. For this purpose, the split leather is impregnated with adhesive and wax so that it releases from the flat panel when compressed. After impregnation, it is laminated, colored or treated with a transfer foil. Its disadvantage is that the fiber bundle is not concealed, but it is still in an upright position.

Still another disadvantage is the attachment of chemical reagents to the plates.

Regarding the many defects that exist in the above prior art, you can refer to the following public documents: Handbook on Leather Technology (Handbook of Leather Technology), J.H.Sharphouse; Technology of Leather Manufacture (Leather Production Technology), K.T.Sarkar; and Principles of Leather Manufacture ( Principles of Leather Production), S.S. Dutta.

purpose of invention

An object of the present invention is to propose a transfer element for treating leather and thereby imparting glossy properties to it.

Another object of the invention is to propose a transfer element for treating leather and thus providing a uniform feel to the leather.

Yet another object of the present invention is to propose a transfer unit for the treatment of hides that provides good flat sheet peeling properties.

Yet another object of the invention is to propose a transfer element for treating hides and providing a good closure of the fibers.

A further object of the present invention is to propose a transfer element for treating leather and providing grain smoothness.

Another object of the invention is to propose a transfer element that imparts gloss to the leather while coloring, printing or metallizing it.

Description of the invention

According to the present invention there is provided a transfer element for imparting glossy properties to leather comprising a glossy film of at least two coextruded layers, and wherein the inner layer is the active or glossy layer and the outer layer is the common layer, releasably A carrier or substrate layer attached to said outer layer.

The glossy film preferably comprises three coextruded layers where the inner layer has glossy properties, the middle layer is a common layer that contributes to the bulk properties of the film and is also a storage layer for the migration of chemicals, and a common The outer layer of the layer. A carrier such as paper is adhered to the outer layer.

The inner layer comprises a resin layer of isotactic polypropylene alone or in combination with an ethylene propylene random copolymer content of 0 to 40% by weight. The intermediate layer includes isotactic polypropylene and migratory additives, which are antistatic and slip agents. The outer layer also includes isotactic polypropylene and an additive which is an antiblocking agent. A backing such as paper is adhered to the outer layer with an adhesive.

The inner layer may additionally contain a migrating chemical agent at a content of 0-5%. The migrating chemical agent is an antistatic agent and a slip agent selected from erucamide, stearylamide, silicone oil which may be used alone or in any combination , stearic acid and stearates. In addition, the inner layer may include a release agent in an amount of 500-4000 ppm. The antiblocking agent is selected from silicon dioxide, silicate, clay, talc and quartz alone or in any combination. The haze or gloss of the inner layer is varied by varying the thickness of the inner layer, the amount of migrating chemical and release agent in the composition.

The content of the migration chemical agent including the antistatic agent and the slip agent in the intermediate layer is 500-10000 ppm by weight.

The outer layer is the same as the inner layer and comprises isotactic polypropylene combined with ethylene propylene random copolymer, wherein the ethylene propylene copolymer content is 0-40% by weight. The film also includes a paper layer adhered to the outer layer. The paper layer is a cellulose paper, such as cromo art paper, having a grammage of 30-100 g/m2.

The isotactic polypropylene present in the layer has an average molecular weight of 25,000 to 1,000,00, a melt flow index of 1-25 g/10 min at 230°C/2.16 kg, and a density of 0.892-0.92 g/cm ³ .

As mentioned above, the outer layer is provided with a release agent. However, in the case of films having three layers, a release agent may or may not be provided on the outer layers. According to another embodiment, a detackifying agent is provided on the outer layer as well as on the inner layer. The outer layer may be subjected to corona treatment, flame treatment or chemical treatment in order to apply an adhesive thereon to secure the paper layer. The paper layer acts as a hard lining and absorbs waste heat during the smoothing process of the leather.

The conveying member of the present invention has a thickness of 8-45 microns. If the thickness is greater than 45 microns, it will have no effect on the handling or properties of the film, but will not be beneficial, and will only increase the final cost of the film. If the thickness is less than 8 microns, the desired quality and properties cannot be obtained. In the case of a two-layer film, both the inner and outer layers should be of sufficient thickness to store and release the chemical reagents therein. Also in the three-layer structure, the inner layer, the middle layer and the outer layer should all have sufficient thickness to store and release the chemical agent. Preferably, the conveying member has a thickness of 12-45 microns, but without any limitation thereto.

The thickness of the inner layer, the middle layer and the outer layer is 2-8 microns, preferably 2-5 microns. If the inner layer thickness is less than 2 microns, the gloss may be reduced. If the thickness is above 8 microns, and the outer, middle and inner layers are extruded, then co-extrusion of the layers can be problematic.

In the table below, the properties of the glossy film are given in relation to the predetermined specification.

Comparative Properties of Gloss Films

No. Properties Units Specification Value Actual Results Specification Value Actual Results

1. Average Size Micron 15 14.9 20 20.1

2. Turbidity % 1.5(Max) 1.2 1.5(Max) 1.3

3. Gloss 95(Min) 98 95(Min) 97

4. Coefficient of friction

Static 0.55 0.50 0.45 0.56

Dynamic 0.55 0.48 0.55 0.54

5. Shrinkage MD% 4.0 3.5 4.0 3.0

TM% 2.0(Max) 1.0 2.0(Max) 0.5

6. Treatment Dyne/cm 38(Min) 40 38(Min) 40

This relates to transfer elements comprising only a glossy film on a carrier or substrate. The conveyor element according to the invention also relates to a conveyor element which, in addition to the glossy film, has a foil selected from a colored, printed or metallized foil.

In this embodiment, the transfer element comprises a carrier or substrate having a glossy film on which the foil is provided.

In each case, the foil comprises multiple layers, at least one outermost layer being an adhesive layer adapted to contact the leather surface, one innermost layer being a release layer in contact with the film and a layer provided in between Active layer, where the active layer is a printed, colored or metallized layer.

The colored foil further comprises a layer of feel modifier with or without an outer protective coating on said release coating, said colorant layer being provided on said feel modifier layer.

In the case of a metallized transfer foil, the metallized foil comprises an overcoat layer on said release layer, said metallized layer being provided on said overcoat layer to provide a metallic finish to the leather. In another embodiment, a print coating is provided between said metallized layer and the outer coating.

The printed foil interlayer comprises a layer of feel modifier provided on said release layer and a printed coating layer provided on said layer of feel modifier. An overcoat may or may not be provided on top of the feel modifier layer.

The feel modifier layer itself comprises multiple layers, one of which is the feel modifier layer and the other layer is an overcoat or covercoat. According to one embodiment, the feel modifier layer comprises at least two layers. One of the layers is a mixture of feel modifier and topcoat, or a feel modifier and covercoat.

According to another embodiment, the feel modifier layer comprises three layers, namely a feel modifier layer adjacent to the release layer, an overcoat layer adjacent to the feel modifier layer, and a layer adjacent to the feel modifier layer. The outer coating is adjacent to the covering layer.

The feel modifier layer includes a combination of waxes or just a single wax, such as microcrystalline wax, paraffin wax, natural or synthetic wax, in solution or emulsion. The wax added to the feel modifier imparts a waxy feel to the leather.

According to one embodiment, the feel modifier layer also includes oils, polydialkylsiloxane, olefin-modified siloxane, cyclobutane-modified silicone oil, epoxy-modified silicone oil, alcohol-modified silicone oil, alone or in combination. Sexual silicone oil.

According to another embodiment, the feel modifier layer comprises a combination of wax and lubricant, since this also improves the wear resistance. If a waxy feel is desired, the feel modifier layer contains more wax than lubricant. And if a silky touch is desired, the lubricant content in the feel modifier layer is greater than the wax content. The feel modifier layer may consist of a combination of wax and lubricant, or a separate layer of wax and lubricant.

The top coat is a protective coating that protects the cover coat. The coating consists of lacquers and lacquer emulsions of different resins, such as nitrocellulose copolymers of vinyl chloride and vinyl acetate, polyurethanes and polyamides, with or without crosslinkers, with or without fillers, such as dioxide silicon.

Covercoats mainly consist of natural resins such as shellac, casein, albumin and gelatin or plasticizers. In addition, the cover coat may be selected from natural or synthetic resins such as acrylic, methacrylic, synthetic rubber, vinyl, nitrocellulose resin or polyurethane. According to another embodiment, the natural resin can be present together with a synthetic resin.

According to another embodiment, the cover coat may also include colorants, with or without dispersants, with or without crosslinking or curing agents. The colorant can be selected from metallic pigments, organic or inorganic pearlescent pigments, or dyes.

Claims (24)

1, a kind of transfer member of giving leather gloss character, the gloss film that comprises a kind of at least two layers of coextrusion layer, and wherein internal layer comprise separately or with the isotatic polypropylene resin of content 0-40 weight % ethylene, propylene random copolymers combination, the molecular-weight average of described isotatic polypropylene is 25,000-100,000, the melt flow index under 230 ℃/2.16kg is 1-25g/10min, and density is 0.892-0.9g/cm ³Skin comprises described isotatic polypropylene and is the additive of release agent; This drive disk assembly also comprises and depends on described outer field carrier or substrate layer; And the thickness of this drive disk assembly is the 8-45 micron.

2, according to the transfer member of claim 1, wherein said gloss film comprises three layers, promptly described internal layer, middle layer and described skin.

3, according to the transfer member of claim 1, wherein said internal layer also is included as the additive of static inhibitor and slippage agent, and its content is the 0-5 weight % of isotatic polypropylene weight.

4, according to the transfer member of claim 1, wherein said internal layer also is included as the additive of release agent, and its content is the 500-4000ppm of isotatic polypropylene weight.

5, according to the transfer member of claim 2, wherein said middle layer comprises isotatic polypropylene and is the additive of static inhibitor and slippage agent, the molecular-weight average of described isotatic polypropylene is 25,000-100,000 melt flow index under 230 ℃/2.16kg is 1-25g/10min, and density is 0.892-0.92g/cm ³, and described additive level is the 500-10000ppm of isotatic polypropylene weight.

6, according to the transfer member of claim 3 or 5, wherein said static inhibitor and slippage agent are selected from separately or its arbitrary combination is used erucicamide, stearylamide, silicone oil, stearic acid and stearate.

7, according to the transfer member of claim 1 or 3, wherein said release agent is selected from separately or silicon-dioxide, silicate, clay, talcum and the quartz of its arbitrary combination.

8, according to the transfer member of claim 1, wherein said internal layer and outer layer thickness respectively are the 2-8 micron.

9, according to the transfer member of claim 1, a kind of paper tinsel that provides on the described film is provided, described paper tinsel is selected from printing, painted or metallized foils.

10, according to the transfer member of claim 9, wherein each described paper tinsel comprises multilayer, at least one deck outermost layer is the release layer that contacts with this film for binder layer, one deck innermost layer that is fit to the contact leather surface, one deck active coating that provides betwixt, wherein this active coating is that one deck is printed, painted or metal layer.

11, according to the transfer member of claim 10, wherein said printing and painted paper tinsel respectively are included in one deck sense of touch activator layer on the described release layer, this sense of touch activator layer comprises multilayer, and wherein one deck is that sense of touch activator layer and another layer are external coating (EC) or seal coat.

12, according to the transfer member of claim 10, wherein this printing and painted paper tinsel respectively have one deck to comprise multiwalled sense of touch activator layer, and wherein one deck is that sense of touch activator layer, one deck adjacent with release layer is that external coating (EC) and one deck adjacent with this sense of touch activator layer is the tectum adjacent with this external coating (EC).

13, according to 10 transfer member of claim, wherein this metallized foils is included in the external coating (EC) on the described release layer.

14, according to the transfer member of claim 11 or 12, wherein this sense of touch activator comprises single wax or wax combination.

15, according to the transfer member of claim 14, wherein said wax is selected from Microcrystalline Wax, paraffin, the natural or synthetic wax of solution or emulsion-type.

16, according to the transfer member of claim 11 or 12, wherein said sense of touch activator layer comprises that also the oils of independent use or oils are used in combination with polydialkysiloxane, olefin-modified siloxanes.

17, according to each transfer member among the claim 11-13, wherein said external coating (EC) comprises the pyroxylin(e)finish and the pyroxylin(e)finish emulsion of different resins.

18, according to the transfer member of claim 17, wherein said resin is selected from nitrocotton multipolymer, urethane and the polymeric amide of vinylchlorid and vinyl acetate, has or cross-linking agent-free, has or do not have filler.

19, according to the transfer member of claim 11 or 12, wherein said seal coat mainly comprises natural resin.

20, according to the transfer member of claim 11 or 12, wherein said seal coat comprises synthetic resins.

21, according to the transfer member of claim 20, wherein said resin is selected from acrylic acid or the like, methacrylic, synthetic rubber, Vinylite, nitrocellulose resin or urethane.

22, according to the transfer member of claim 11 or 12, wherein said seal coat comprises natural and combination synthetic resins.

23, according to the transfer member of claim 11 or 12, wherein said seal coat optionally comprises tinting material, has or do not have dispersion agent, has or does not have crosslinked or solidifying agent.

24,, wherein between described metal layer and external coating (EC), provide one deck to print coating according to the transfer member of claim 13.