JP2014055210A - Pattern formation leather - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pattern formation leather excellent in rubbing resistance and feeling by using an ultraviolet rat curable ink.SOLUTION: The pattern formation leather is obtained by laminating a base coat layer and a pattern layer on a leather base material in this order, an urethane resin contained in the base coat layer is constituted by a polycarbonate-based polyurethane resin and a polyether-based polyurethane resin, the pattern layer is constituted by a monofunctional acrylate monomer having at least dioxolane group, a monofunctional acrylate monomer having a hexahydrophthalimide group and a cured product of an ultraviolet ray curable ink having a polymerization initiator, and further the polymerization initiator is a photo-radical polymerization initiator.

Description

  The present invention relates to a pattern-formed leather, and more particularly to a pattern-formed leather in which a pattern is formed using an ultraviolet curable ink.

  Conventionally, leather products made of natural leather or synthetic leather have been used in various fields such as clothing, bags, shoes, interior materials, and vehicle interior materials because of their unique soft texture and luxury. Among these, the vehicle interior material is required to have a high degree of durability because it is placed in a severe use situation. In particular, in the case of a car seat skin material, etc., where there are many opportunities to come into direct contact with the human body, there is a strong demand for wear resistance, particularly sag resistance, against friction caused by people getting on and off.

  On the other hand, conventional leather products are often plain colored products, and examples of design imparting are mainly patterning by screen printing and concave processing by embossing after pigment resin coating.

  Furthermore, since natural leather has a characteristic that it is particularly susceptible to heat, when a chemical that requires heat treatment or the like must be used, the chemical and the processing temperature are limited.

  Natural leather is mostly painted to conceal flaws and maintain physical properties, and it consists of pigments and other colorants and resins for natural leather that has been subjected to tanning and other chemical and physical treatments. A plain colored film is formed using a paint. In this case, the paint used is either water-based or solvent-based, but the resin used at this time has a very low film-forming temperature in order to increase curability because it cannot be heat-treated at high temperatures. In many cases, a resin having a low glass transition point or softening point is used, and it is difficult to perform heat treatment at a high temperature.

  The application of an ink jet method as a means for imparting design properties to natural leather and synthetic leather is also being studied. However, when using ink added with a resin to impart design properties, film formation is performed for the reasons described above. It is necessary to prepare an ink having a low temperature or a cross-linking agent, which is very difficult to implement when handling is considered. When water-based ink or the like is used, a step of applying an ink receiving layer on the leather coated with the pigment paint is required.

Therefore, in recent years, an inkjet system using an ultraviolet curable ink has been proposed as an inkjet system that does not require application of an ink receiving layer or heat treatment during resin curing.
For example, Patent Document 1 discloses a pattern-formed leather imparted with design properties by painting or coating a pigment resin on natural or synthetic leather using an ultraviolet curable ink jet method. Moreover, according to this, the pattern formation leather which follows a tension | tensile_strength without a cured film breaking can be provided, maintaining the softness | flexibility peculiar to leather.

  However, the pattern-formed leather described in Patent Document 1 has a comparatively useful effect on the followability of the cured film with respect to tension, but does not take into account the sag resistance.

  Furthermore, it has been extremely difficult to impart sag resistance while maintaining the soft texture of the leather.

JP 2007-284466 A

  The present invention has been made in view of the present situation, and an object of the present invention is to provide a pattern-formed leather that uses an ultraviolet curable ink and has excellent stagnation resistance and texture.

  The present invention is a patterned leather in which a base coat layer and a pattern layer are sequentially laminated on a leather base material, and the urethane resin contained in the base coat layer is composed of a polycarbonate-based polyurethane resin and a polyether-based polyurethane resin. The pattern layer is made of a cured product of an ultraviolet curable ink containing at least a monofunctional acrylate monomer having a dioxolane group, a monofunctional acrylate monomer having a hexahydrophthalimide group, and a polymerization initiator, The pattern forming leather is characterized in that the polymerization initiator is a radical photopolymerization initiator.

  The content of the monofunctional acrylate monomer having a dioxolane group in the ultraviolet curable ink is 30 to 50% by weight, and the content of the monofunctional acrylate monomer having a hexahydrophthalimide group is 30 to 50% by weight. Is preferred.

  It is preferable that the urethane resin contained in the base coat layer is composed of polycarbonate polyurethane resin: polyether polyurethane resin = 92 to 108: 28 to 42.

  ADVANTAGE OF THE INVENTION According to this invention, the pattern formation leather excellent in the sag resistance and the texture can be provided.

  The present invention is a patterned leather in which a base coat layer and a patterned layer are sequentially laminated on a leather base material that is natural or synthetic leather.

  As the leather base material used in the present invention, either synthetic leather or natural leather can be used, and it is not particularly limited. Hereinafter, embodiments of the present invention will be described in detail by taking natural leather as an example, but these contents can also be applied when natural leather is changed to synthetic leather.

  Examples of natural leather base materials used in the present invention include mammal leather such as cattle, horses, pigs, sheep, deer, kangaroos, bird leather such as ostriches, reptile leather such as sea turtles, monitor lizards, pythons, crocodiles, etc. Known natural leather can be mentioned. Of these, cowhide having high versatility and a large area is preferable.

  The raw leather of natural leather is usually soaked, lined, depigmented / lime pickled, divided, scaled out, recalcified, decalcified / fermented, soaked, chromed, neutralized, dyed / greased, water squeezed, By going through the steps of stretching, drying, seasoning, staking and tension drying, it becomes a semi-finished leather called crust. Next, silver stripping (buffing) is performed on the surface of the silver surface layer of the obtained semi-finished leather. Silver stripping is performed to smooth the leather surface by scraping the surface of the silver layer, and to remove and equalize the factors affecting the appearance quality, such as individual differences, site differences, worms, and scratches. The natural leather base material in the present invention usually refers to a state after such treatment.

  The base coat layer contains a urethane resin, and the urethane resin needs to be composed of a polycarbonate-based polyurethane resin and a polyether-based polyurethane resin. By including the two types of urethane resins, it is possible to satisfy the sag resistance of the base coat layer without impairing the soft texture peculiar to natural leather.

  The polycarbonate-based polyurethane resin and the polyether-based polyurethane resin are particularly preferably used in a ratio of polycarbonate-based polyurethane resin: polyether-based polyurethane resin = 92 to 108: 28 to 42. If the blending ratio of the polycarbonate-based polyurethane resin is increased, the texture may be coarse. On the contrary, if the blending ratio of the polyether-based polyurethane resin is increased, sufficient stagnation resistance may not be obtained.

  The polycarbonate-based polyurethane resin is obtained by reacting a polycarbonate diol component and a diisocyanate component.

  Examples of the polycarbonate diol component include polyalkylene polycarbonate diols such as polyethylene carbonate diol, polybutylene carbonate diol, and polyhexamethylene carbonate diol. These can be used alone or in combination of two or more.

  Examples of the diisocyanate component include aromatic diisocyanates such as phenylene diisocyanate, tolylene diisocyanate (TDI), 4,4′-diphenylmethane diisocyanate (MDI), 2,4′-diphenylmethane diisocyanate, naphthalene diisocyanate, xylylene diisocyanate, and hexamethylene. Examples thereof include aliphatic diisocyanates or alicyclic diisocyanates such as diisocyanate, lysine diisocyanate, cyclohexane diisocyanate, isophorone diisocyanate (IPDI), dicyclohexylmethane diisocyanate, and tetramethylxylylene diisocyanate. These can be used alone or in combination of two or more.

  The polyether-based polyurethane resin is obtained by reacting a polyether diol component and a diisocyanate component.

  Examples of the polyether diol component include polyalkylene glycols such as polytetramethylene glycol and polypropylene glycol. These can be used alone or in combination of two or more. Moreover, as a diisocyanate component, the component similar to the diisocyanate component of the polycarbonate-type polyurethane resin mentioned above can be mention | raise | lifted.

  Commercially available one-component resins can be used as the polycarbonate-based polyurethane resin and the polyether-based polyurethane resin. The one-component resin is usually marketed in a form emulsified and dispersed in water (emulsion type) or a form dissolved in an organic solvent, but the emulsion type is preferably used from the viewpoint of environmental load.

  In addition to the polyurethane resin, the base coat layer may contain other resin components as long as the physical properties of the base coat layer are not impaired. In addition, various additives such as colorants (pigments, dyes), matting agents, cross-linking agents, smoothing agents, surfactants, fillers, leveling agents, thickeners, etc., can be used alone or as needed. Two or more kinds may be used in combination.

The thickness of the base coat layer is preferably 15 to 60 μm, and more preferably 24 to 36 μm. If the thickness is less than 15 μm, sufficient stagnation resistance may not be obtained, and if the thickness exceeds 60 μm, the texture may become coarse. Moreover, the dry coating amount (solid content weight per unit area) of the base coat paint necessary for providing the thickness is usually 15 to 60 g / m ² , more preferably 24 to 36 g / m ² . is there.

  As a method for applying the base coat paint, various conventionally known methods can be adopted and are not particularly limited. Examples thereof include a method using a reverse roll coater, spray coater, roll coater, gravure coater, kiss roll coater, knife coater, comma coater, and the like. Of these, application with a reverse roll coater is preferred from the viewpoint that a uniform and thin film can be formed.

  The base coat paint is dried after being applied. At this time, in order to prevent excessive moisture evaporation of the natural leather substrate, the drying treatment is preferably performed so that the natural leather substrate itself does not reach a temperature of 80 ° C. or higher. Therefore, the drying treatment temperature is preferably 90 to 130 ° C, and more preferably 100 to 120 ° C. If the drying treatment temperature is less than 90 ° C., the resin is not sufficiently crosslinked and the stagnation resistance may not be sufficiently obtained. On the other hand, when the drying treatment temperature exceeds 130 ° C., the texture may become coarse. Moreover, it is preferable that drying processing time is 1 to 5 minutes, and it is more preferable that it is 2-3 minutes. If the drying time is less than 1 minute, crosslinking of the resin may be insufficient, and if it exceeds 5 minutes, the texture may become coarse.

  The pattern layer is composed of an ultraviolet curable ink cured product. Here, the ultraviolet curable ink used in the present invention must contain at least a monofunctional acrylate monomer having a dioxolane group, a monofunctional acrylate monomer having a hexahydrophthalimide group, and a polymerization initiator, and further polymerization. The initiator needs to be a photo radical polymerization initiator.

  The monofunctional acrylate having a dioxolane group has different reacting portions in photocationic polymerization and photoradical polymerization. That is, in photocationic polymerization, a dioxolane group is ring-opening polymerized, whereas in photoradical polymerization, an acrylate group is polymerized. In the present invention, leaving the dioxolane group unreacted by photoradical polymerization is important in obtaining stagnation resistance. That is, the presence of a dioxolane group in the ultraviolet curable ink cured product constituting the pattern layer can improve the flexibility of the pattern layer. On the other hand, when a dioxolane group is reacted by photocationic polymerization, the cured film has poor flexibility.

  In addition, the monofunctional acrylate having a dioxolane group is excellent in adhesion to the base coat layer used in the present invention, and also has a function of suppressing the peeling of the pattern layer from the base coat layer.

  Furthermore, in the present invention, the combined use with a monofunctional acrylate monomer having a hexahydrophthalimide group is also important in obtaining stagnation resistance. A monofunctional acrylate having a dioxolane group can form a flexible cured film, but is inferior in durability. Only in combination with a monofunctional acrylate monomer having a hexahydrophthalimide group, it becomes possible to obtain excellent sag resistance.

  In addition, monofunctional acrylates having hexahydrophthalimide groups have high viscosity when used alone and are not suitable for inkjet systems, but can be used in combination with monofunctional acrylate monomers having dioxolane groups to reduce viscosity. The use by the method becomes possible.

  The monofunctional acrylate having a dioxolane group is preferably contained in a proportion of 30 to 50% by weight in the ultraviolet curable ink. If the content is less than 30% by weight, the adhesion with the base coat layer may be lowered, or the viscosity of the ultraviolet curable ink may be increased, which may cause a discharge failure when the ink jet method is used. On the other hand, if it exceeds 50% by weight, the pattern layer after the ultraviolet curable ink is cured becomes too flexible, so that the durability is lowered and sufficient stagnation resistance may not be obtained.

  Specific examples of the monofunctional acrylate monomer having a dioxolane group include MEDOL-10 and CHDOL-10 manufactured by Osaka Organic Chemical Industry Co., Ltd., but are not limited thereto.

  The monofunctional acrylate having a hexahydrophthalimide group is preferably contained in an amount of 30 to 50% by weight in the ultraviolet curable ink. If it is less than 30% by weight, the durability of the patterned layer after the ultraviolet curable ink is cured may be lowered, and sufficient stagnation resistance may not be obtained. On the other hand, when the amount exceeds 50% by weight, the viscosity of the ultraviolet curable ink increases, and there is a possibility that ejection failure may occur when the ink jet method is used.

  Specific examples of the monofunctional acrylate monomer having a hexahydrophthalimide group include Aronix M-140 manufactured by Toagosei Co., Ltd., but are not limited thereto.

  In the present invention, the polymerization initiator used for the ultraviolet curable ink needs to be a radical photopolymerization initiator as described above. Examples of the radical photopolymerization initiator include benzoin-based, thioxanthone-based, benzophenone-based, ketal-based, and acetophenone-based, and these can be used singly or in combination of two or more.

  The addition amount of the photo radical polymerization initiator is preferably 1 to 10% by weight, more preferably 3 to 7% by weight, based on the total amount of the ultraviolet curable ink. If it is less than 1% by weight, the polymerization may not proceed sufficiently and the pattern layer may be uncured. On the other hand, if it exceeds 10% by weight, no further improvement in curing rate or curing speed can be expected, resulting in high costs.

  In addition to those described above, a colorant, a reactive diluent, an oligomer component, a dispersant, various additives, and the like can be appropriately added to the ultraviolet curable ink used in the present invention as necessary.

  As the colorant, both pigments and dyes can be used.

  When weather resistance and light resistance are required for the patterned leather, it is preferable to use a pigment, and any one of organic and inorganic is selected.

  Organic pigments include, for example, nitroso, dyed lakes, azo lakes, insoluble azos, monoazos, disazos, condensed azos, benzimidazolones, phthalocyanines, anthraquinones, perylenes, quinacridones, dioxazines , Isoindolines, azomethines, pyrrolopyrroles and the like.

  Inorganic pigments include oxides, hydroxides, sulfides, ferrocyanides, chromates, carbonates, silicates, phosphates, carbons (carbon black), metal powders, etc. can give.

  The content of the colorant in the ultraviolet curable ink is preferably 0.01 to 10% by weight, and more preferably 0.05 to 5% by weight. If the content of the colorant is less than 0.01% by weight, sufficient coloring may not be performed. On the other hand, if it exceeds 10% by weight, ejection failure may occur when the inkjet method is used.

  In addition, when the weather resistance and light resistance are not so important, it is possible to use a dye, and the dye at that time is not particularly limited, and an arbitrary one is selected.

  Examples of the dye include oil-soluble dyes such as azos, anthraquinones, indigoids, phthalocyanines, carboniums, quinoneimines, methines, xanthenes, nitros, nitrosos, disperse dyes, acid dyes, reactive dyes , Cationic dyes and direct dyes.

  Examples of reactive diluents include hexafunctional acrylates such as dipentaerythritol hexaacrylate and modified products thereof; pentafunctional acrylates such as dipentaerythritol hydroxypentaacrylate; pentaditrimethylolpropane tetraacrylate, ethoxylated pentaerythritol tetraacrylate, penta Tetrafunctional acrylate such as erythritol tetraacrylate; trifunctional such as trimethylolpropane triacrylate, ethylene oxide modified trimethylolpropane triacrylate, pentaerythritol triacrylate, tris (2-hydroxyethyl) isocyanurate triacrylate, propoxylated glyceryl triacrylate Acrylate; Hydroxypivalate neopentyl glycol diacrylate , Polytetramethylene glycol diacrylate, trimethylolpropane acrylic acid benzoate, diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethylene glycol (200) diacrylate, polyethylene glycol (400) diacrylate , Polyethylene glycol (600) diacrylate, neopentyl glycol diacrylate, propoxy-modified neopentyl glycol diacrylate, 1,3-butanediol diacrylate, 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, 1,9-nonanediol diacrylate, dimethylol-tricyclodecane diacrylate, bisphenol A Bifunctional acrylates such as tylene oxide adduct diacrylate; and caprolactone acrylate, tridecyl acrylate, isodecyl acrylate, isooctyl acrylate, isomyristyl acrylate, isostearyl acrylate, 2-ethylhexyl-diglycol diacrylate, 2-hydroxybutyl Acrylate, 2-acryloyloxyethyl hexahydrophthalic acid, neopentylglycol acrylic acid benzoate, isoamyl acrylate, lauryl acrylate, stearyl acrylate, butoxyethyl acrylate, ethoxy-diethylene glycol acrylate, methoxy-triethylene glycol acrylate, methoxy- Polyethylene glycol acrylate, methoxydipropylene glycol Coal acrylate, phenoxyethyl acrylate, phenoxy-polyethylene glycol acrylate, nonylphenol ethylene oxide adduct acrylate, tetrahydrofurfuryl acrylate, isobornyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxy-3-phenoxypropyl acrylate Monoacrylic acrylates such as 2-acryloyloxyethyl-succinic acid, 2-acryloyloxyethyl-phthalic acid, 2-acryloyloxyethyl-2-hydroxyethyl-phthalic acid. Furthermore, a reactive diluent in which a functional group such as phosphorus or fluorine is added to these can be mentioned. These reactive diluents can be used alone or in combination of two or more.

  The reactive diluent can be added within a range that does not affect the stagnation resistance obtained by the monofunctional acrylate monomer having a dioxolane group and the monofunctional acrylate having a hexahydrophthalimide group. % Or less is preferable.

  However, the polyfunctional acrylate in the reactive diluent is preferably 15% by weight or less, more preferably 10% by weight or less in the ultraviolet curable ink. If it exceeds 15% by weight, flexibility may be lost and the sag resistance may not be satisfied.

  Examples of the oligomer component include urethane acrylate, polyester acrylate, epoxy acrylate, silicon acrylate, and polybutadiene acrylate, which can be used alone or in combination. Of these, urethane acrylate is particularly preferable because of its excellent adhesiveness and flexibility. The upper limit of addition is not particularly limited, but if it is too large, the viscosity of the ink may become too high and ink discharge may not be possible, and is preferably 10% by weight or less, more preferably 5% by weight or less. preferable.

  As the dispersant, for example, a polymer type is preferable, and a dispersant having an acidic adsorbing group or a basic adsorbing group at the end group is more preferable. The addition amount of the dispersant is preferably 0.01 to 1 and more preferably 0.1 to 0.5 with respect to the weight of the colorant to be added. If it is less than 0.01, a sufficient dispersion effect may not be obtained. On the other hand, when it exceeds 1, the viscosity of the ink increases, and there is a possibility that a problem may occur in the discharge property when the ink jet method is used.

  In addition, additives such as heat stabilizers, antioxidants, preservatives, pH adjusters, antifoaming agents, penetrants, and the like can be added as additives. Further, an auxiliary agent such as a sensitizer can be used in combination in order to promote the initiation reaction of the photo radical polymerization initiator.

  As a method for applying the ultraviolet curable ink, it is preferable to use an ink jet method in that various patterns can be expressed.

Preferably the amount of ink applied is 1-200 g / ^{m 2,} and more preferably 5 to 150 g / ^{m 2.} When it is less than 1 g / m ² , sufficient coloring cannot be expressed, and when it exceeds 200 g / m ² , the stagnation resistance tends to deteriorate.

  The UV curable ink is cured by UV irradiation after application. As the ultraviolet irradiation conditions, an output of 80 to 200 W / cm and an irradiation time of 0.1 to 5 seconds are preferable.

  The patterned leather according to the present invention may further have a top coat layer. By having the top coat layer, itching resistance can be further improved.

  The top coat layer is preferably a polycarbonate-based polyurethane resin in terms of excellent sag resistance, but is not particularly limited. Examples of the polycarbonate-based polyurethane resin used for the top coat layer include those similar to those used for the base coat layer.

  In addition to the polycarbonate-based polyurethane resin described above, the topcoat layer may contain other resins, colorants, matting agents, cross-linking agents, smoothing agents, surfactants, fillers, leveling agents, and thickeners as necessary. Various additives such as an agent can be used singly or in combination of two or more.

The thickness of the top coat layer is preferably 6 to 27 μm, and more preferably 12 to 18 μm. If the thickness is less than 6 μm, sufficient stagnation resistance may not be obtained. On the other hand, when it exceeds 27 μm, the texture may become coarse. Moreover, the dry coating amount of the top coat paint necessary for imparting the above thickness is usually 6 to 27 g / m ² , more preferably 12 to 18 g / m ² .

  The method for applying the top coat paint is not particularly limited, and the top coat paint can be applied by the same method as described for the method for applying the base coat paint. Of these, application by a spray coater is preferable because a uniform film can be formed.

  The drying process after applying the top coat paint may be performed by the same method as the drying process after applying the base coat paint.

  The pattern-formed leather according to the present invention may be further subjected to various processing treatments such as embossing, kneading, and tapping as needed. These processings are usually performed after the base coat layer is formed.

  The present invention will be described with reference to examples. The present invention is not limited to these examples.

The evaluation of Examples and Comparative Examples was performed as follows.
[Evaluation of itch resistance]
In accordance with JIS K 6404-6, using a Scott type grinder, the load was 1 kg, the stroke was 40 mm, the grip interval was 15 mm, and the sample width was 25 mm. The state was confirmed and judged according to the following criteria.
<Criteria>
○: No breakage / peeling is observed in both base coat layer and pattern layer Δ: Breakage / peeling is observed in either basecoat layer or pattern layer ×: Breakage / peeling is observed in both basecoat layer and pattern layer

[Texture evaluation]
Strain measurement when a test piece having a size of 150 mm square was collected and pushed in with a load of 500 g using a tactile sensation measuring instrument (trade name “ST300 Laser Softness Tester”, manufactured by BLC Leather Technology Center Ltd.). The value (BLC value) was measured and the result was determined according to the following criteria. A larger BLC value means a softer texture.
<Criteria>
○: BLC value is 3.0 or more Δ: BLC value is 2.5 or more and less than 3.0 ×: BLC value is less than 2.5

[Example 1]
(1) Natural leather base material Crust was obtained by using a raw leather of adult cowhide and a usual process such as chrome bran. Subsequently, silvering and dyeing were performed to obtain a natural leather base material.

(2) Formation of base coat layer According to the following prescription, each raw material was mixed with a mixer to prepare a base coat paint A1.

<Base coat paint formulation: A1>
250 parts by weight of BAYDERM Bottom DLV (polycarbonate polyurethane resin, solid content 40%)
BAYDERM Bottom 51UD 100 parts by weight (polyether polyurethane resin, solid content 35%)
PRIMAL SB-300 150 parts by weight (acrylic resin, solid content 34%)
120 parts by weight of EUDERM BLACK BN (pigment, solid content 23%)
110 parts by weight of EUDERM Nappa Softs (matting agent, solid content 25%)
120 parts by weight of EUDERM Matting Agent SN-C (filler, solid content 23%)
EUDERM Paste DO 40 parts by weight (filler, solid content 52%)
AQUADERM Fluid H 10 parts by weight (leveling agent, solid content 100%)
ACRYSOL RM-1020 10 parts by weight (thickener, solid content 20%)
150 parts by weight of water

All the prescription ingredients except LAN are manufactured by LANXESS. The total amount is 1060 parts by weight.
Among these, the compounding ratio (solid content weight basis) of polycarbonate type polyurethane resin and polyether type polyurethane resin is 100: 35.

Using a reverse roll coater (trade name “JUMBOSTAR-SR”, manufactured by Ge.Ma.Ta.SpA) on the surface of the natural leather base material, the base coat paint A1 is applied so that the wet coating amount is 130 g / m ^2. And left in a dryer adjusted to 110 ° C. for 3 minutes. The formed base coat layer had a thickness of 39 μm and a dry coating amount of 39 g / m ² .

(3) Formation of pattern layer According to the following prescription, after mixing each material with a mixer, it disperse | distributed for 3 minutes with the beads mill, and obtained ultraviolet curable ink B1 by filtering.
<Ultraviolet curable ink formulation: B1>
MEDOL-10 37 parts by weight (Osaka Organic Chemical Industry Co., Ltd. (2-methyl-2-ethyl-1,3-dioxolan-4-yl) methyl acrylate)
Aronix M-140 35 parts by weight (Toagosei Co., Ltd. 2- (1,2-cyclohexanedicarboximide) ethyl acrylate)
IRGALITE BLUE GLNF 2 parts by weight (Ciba Specialty Chemicals Co., Ltd. Pigment copper phthalocyanine)
1 part by weight of Florene DOPA-33 (Kyoeisha Chemical Co., Ltd. Dispersant modified acrylic copolymer)
5 parts by weight of Ebecryl 270 (Daicel Cytec Co., Ltd. Aliphatic urethane acrylate oligomer)
SR489 10 parts by weight (Sartomer tridecyl acrylate)
Darocur 1173 5 parts by weight (BASF Japan K.K. photoradical polymerization initiator 2-hydroxy-2-methyl-1-phenyl-propan-1-one)

The ultraviolet curable ink B1 was applied to a natural leather substrate provided with a base coat layer using an inkjet printer. The application conditions and curing conditions of the ultraviolet curable ink were set as follows.
<Granting conditions>
Head heating temperature 50 ℃
Nozzle diameter 70μm
Applied voltage 50V
Pulse width 20μs
Drive frequency 1kHz
Resolution 360 x 360 dpi
Ink application amount 100 g / m ²
5mm x 5mm lattice pattern

<Curing conditions>
Lamp type Metal halide lamp Output 80W / cm
Irradiation time 1 second Irradiation height 10 mm

The pattern formation leather of Example 1 was obtained by the above process.

[Example 2]
In Example 1, after forming the pattern layer, a top coat layer was further formed on the pattern layer side.
(4) Formation of topcoat layer According to the following prescription, each raw material was mixed with the mixer, and topcoat coating material C1 was prepared.
<Topcoat paint formulation: C1>
HYDRHOLAC UD-2 400 parts by weight (polycarbonate polyurethane resin, solid content 25%)
60 parts by weight of HYDRHOLAC Finish HW-2 (polycarbonate polyurethane resin, solid content 35%)
AQUADERM Finish HAT 200 parts by weight (polycarbonate polyurethane resin, solid content 40%)
EUDERM BLACK BN 10 parts by weight (pigment, solid content 23%)
70 parts by weight of Rosilk 2229 (smoothing agent, solid content 60%)
AQUADERM Additive SF 30 parts by weight (smoothing agent, solid content 50%)
AQUADERM Fluid H 10 parts by weight (leveling agent, solid content 100%)
AQUADERM SL-50 150 parts by weight (crosslinking agent, solid content 50%)
RM1020 10 parts by weight (thickener, solid content 20%)
150 parts by weight of water

All the prescription ingredients except LAN are manufactured by LANXESS. The total amount is 1090 parts by weight.

Using a spray machine (“TU ROT.3400 / 1.41”, manufactured by BARNINI Srl) on the pattern layer forming side of the natural leather base material, the wet coating amount of the top coat paint C1 is 50 g / m ^2. Applied. Then, it left still in the dryer adjusted to 110 degreeC for 3 minutes, and dried.

  The pattern-formed leather of Example 2 was obtained through the above steps.

[Comparative Example 1]
In Example 1, the base coat paint used for forming the base coat layer was changed to the following base coat paint A2. Other than that was carried out similarly to Example 1, and obtained the pattern formation leather of the comparative example 1.
<Base coat paint formulation: A2>
250 parts by weight of BAYDERM Bottom DLV (polycarbonate polyurethane resin, solid content 40%)
PRIMAL SB-300 100 parts by weight (acrylic resin, solid content 34%)
120 parts by weight of EUDERM BLACK BN (pigment, solid content 23%)
110 parts by weight of EUDERM Nappa Softs (matting agent, solid content 25%)
120 parts by weight of EUDERM Matting Agent SN-C (filler, solid content 23%)
EUDERM Paste DO 40 parts by weight (filler, solid content 52%)
AQUADERM Fluid H 10 parts by weight (leveling agent, solid content 100%)
ACRYSOL RM-1020 10 parts by weight (thickener, solid content 20%)
150 parts by weight of water

[Comparative Example 2]
In Example 1, the base coat paint used for forming the base coat layer was changed to the following base coat paint A3. Other than that was carried out similarly to Example 1, and obtained the pattern formation leather of the comparative example 2. FIG.
<Base coat paint formulation: A3>
BAYDERM Bottom 51UD 100 parts by weight (polyether polyurethane resin, solid content 35%)
PRIMAL SB-300 150 parts by weight (acrylic resin, solid content 34%)
120 parts by weight of EUDERM BLACK BN (pigment, solid content 23%)
110 parts by weight of EUDERM Nappa Softs (matting agent, solid content 25%)
120 parts by weight of EUDERM Matting Agent SN-C (filler, solid content 23%)
EUDERM Paste DO 40 parts by weight (filler, solid content 52%)
AQUADERM Fluid H 10 parts by weight (leveling agent, solid content 100%)
ACRYSOL RM-1020 10 parts by weight (thickener, solid content 20%)
150 parts by weight of water

[Comparative Example 3]
In Example 1, the ultraviolet curable ink used for forming the pattern layer was changed to the following ultraviolet curable ink B2. Other than that was carried out similarly to Example 1, and obtained the pattern formation leather of the comparative example 3.
<UV curable ink formulation: B2>
MEDOL-10 37 parts by weight (Osaka Organic Chemical Industry Co., Ltd. (2-methyl-2-ethyl-1,3-dioxolan-4-yl) methyl acrylate)
IRGALITE BLUE GLNF 2 parts by weight (Ciba Specialty Chemicals Co., Ltd. Pigment copper phthalocyanine)
1 part by weight of Florene DOPA-33 (Kyoeisha Chemical Co., Ltd. Dispersant modified acrylic copolymer)
5 parts by weight of Ebecryl 270 (Daicel Cytec Co., Ltd. Aliphatic urethane acrylate oligomer)
SR489 10 parts by weight (Sartomer tridecyl acrylate)
40 parts by weight of IBXA (Kyoeisha Chemical Co., Ltd. Reactive Diluent Isobonyl Acrylate)
Darocur 1173 5 parts by weight (BASF Japan K.K. photoradical polymerization initiator 2-hydroxy-2-methyl-1-phenyl-propan-1-one)

[Comparative Example 4]
In Example 1, the ultraviolet curable ink used for forming the pattern layer was changed to the following ultraviolet curable ink B3. Other than that was carried out similarly to Example 1, and obtained the pattern formation leather of the comparative example 4.
<Ultraviolet curable ink formulation: B3>
IRGALITE BLUE GLNF 2 parts by weight (Ciba Specialty Chemicals Co., Ltd. Pigment copper phthalocyanine)
1 part by weight of Florene DOPA-33 (Kyoeisha Chemical Co., Ltd. Dispersant modified acrylic copolymer)
5 parts by weight of Ebecryl 270 (Daicel Cytec Co., Ltd. Aliphatic urethane acrylate oligomer)
SR489 10 parts by weight (Sartomer tridecyl acrylate)
37 parts by weight of IBXA (Kyoeisha Chemical Co., Ltd. Reactive Diluent Isobonyl Acrylate)
SR9003 40 parts by weight (Sartomer reactive diluent propoxy-modified neopentyl glycol diacrylate)
Darocur 1173 5 parts by weight (BASF Japan K.K. photoradical polymerization initiator 2-hydroxy-2-methyl-1-phenyl-propan-1-one)

  As shown in Table 3, the patterned leathers of Examples 1 and 2 were excellent in both sag resistance and texture.

On the other hand, in Comparative Example 1, although the sag resistance was excellent, the texture was coarse. In Comparative Example 2, although the texture was excellent, the base coat layer was broken in the stagnation resistance evaluation, and the ink layer was also broken accordingly. In Comparative Example 3, the texture and the sag resistance of the base coat were excellent, but breakage occurred in the ink layer. In Comparative Example 4, the texture of the ink layer was hard and the stagnation resistance was not sufficient.

Claims (3)

  A pattern-forming leather in which a base coat layer and a pattern layer are sequentially laminated on a leather base material, wherein the urethane resin contained in the base coat layer is composed of a polycarbonate-based polyurethane resin and a polyether-based polyurethane resin, The pattern layer is composed of a cured product of an ultraviolet curable ink containing at least a monofunctional acrylate monomer having a dioxolane group, a monofunctional acrylate monomer having a hexahydrophthalimide group, and a polymerization initiator, and further, the polymerization initiation A pattern-forming leather, wherein the agent is a radical photopolymerization initiator.   The content of the monofunctional acrylate monomer having a dioxolane group in the ultraviolet curable ink is 30 to 50% by weight, and the content of the monofunctional acrylate monomer having a hexahydrophthalimide group is 30 to 50% by weight. The patterned leather according to claim 1, wherein:   The pattern-formed leather according to claim 1, wherein the urethane resin contained in the base coat layer is constituted by a ratio of polycarbonate-based polyurethane resin: polyether-based polyurethane resin = 92 to 108: 28 to 42.