JP2014118637A - Synthetic leather and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a wet-process synthetic leather, in which the amount of solvent used is reduced by using PUD, and material cost is reduced and a drying time is shortened by reducing the amount of resin used, while maintaining characteristics such as flexibility of the wet-process synthetic leather.SOLUTION: A base layer 13 is obtained from a fiber base material 11 by a wet process, in which an organic solvent solution of polyurethane resin is impregnated into or applied onto the fiber base material 11, and the fiber base material 11 with the resin solution is passed through water or warm water to solidify the resin, and then the fiber base material 11 with the resin is dried to obtain the base layer 13. A facing layer 15 that is a bored film is formed by a dry process using aqueous polyurethane dispersion solution. The base layer 13 and the facing layer 15 are joined to each other via an adhesive agent layer 14 having foamed aqueous polyurethane dispersion solution.

Description

  The present invention relates to synthetic leather and a method for producing the same.

  Synthetic leather includes dry synthetic leather and wet synthetic leather. In dry synthetic leather, a polyurethane solution for a skin layer containing a pigment is coated on a release paper having an embossed pattern, and dried to form a film. The polyurethane film for the adhesive layer is coated on the polyurethane film of the skin layer, and this is bonded to a woven or knitted fabric as a fiber base material by pressure bonding. And after evaporating (volatilizing) the solvent of the polyurethane solution for adhesive layers with a dryer, this curing reaction is completed by aging (curing). Finally, the release paper is peeled to obtain dry synthetic leather having an embossed pattern.

  On the other hand, wet synthetic leather has a soft texture and volume feeling similar to natural leather by forming a porous layer (microporous layer) on the fiber base material of the dry synthetic leather. That is, a polyurethane resin solution containing dimethylformamide (DMF), which is an organic solvent, is coated on a fiber base material and immersed in warm water as a coagulating liquid. By this immersion, the solvent of the polyurethane solution is replaced with water and extracted (water bath replacement), and the polyurethane resin is precipitated and solidified to form a porous layer. Thereafter, similar to the above-described dry synthetic leather, wet synthetic leather is obtained by pressing the polyurethane film for the skin layer onto the porous layer using the polyurethane solution for the adhesive layer.

  FIG. 5 shows a cross-sectional configuration of a conventional wet synthetic leather 30. The synthetic leather 30 has a breathable base fabric 31 as a fiber base material and a breathable porous layer 32 formed on the base fabric 31. A base layer 33 is formed by integrating the base fabric 31 and the porous layer 32. A film-like skin layer 35 having a leather-like uneven surface containing urethane resin is laminated on the base layer 33 with an adhesive layer 34 interposed therebetween.

  6A to 6C show a part of the manufacturing process of the conventional wet synthetic leather 30, and FIG. 6A shows the process of forming the skin layer 35. A film material 38 to be the skin layer 35 is supplied onto the release paper 39 delivered by the metal roller 36. The release paper 39 has a concavo-convex shape obtained by inverting the leather-like concavo-convex surface. A blade 37 is provided on the roller 36 at a predetermined interval, and a film material 38 is applied onto the release paper 39 by the blade 37.

  By drying the release paper 39 to which the film material 38 is applied, a skin layer 35 having a leather-like uneven shape is obtained on the release paper 39 as shown in FIG. Thereafter, an adhesive layer 34 is applied on the skin layer 35, and the skin layer 35 is bonded onto the porous layer 32 of the base layer 33 via the adhesive layer 34, as shown in FIG. After drying, the release paper 39 is peeled off to obtain the synthetic leather 30 shown in FIG.

  Since the conventional wet synthetic leather 30 does not have the air permeability of the adhesive layer 34 and the skin layer 35, there is a problem that when it is used as leather shoes or the like, it is steamed as compared with natural leather. Further, since the adhesive layer 34 and the skin layer 35 have a considerable thickness, there is also a problem that they are finished hard.

  In addition, dimethylformamide (DMF) used for forming the porous layer 32 by wet synthetic leather, dimethylformamide (DMF) used for forming the skin layer 35 and the adhesive layer 34 by dry processing, and methyl ethyl ketone (MEK). ), Organic solvents such as toluene (TOL) are highly flammable and more toxic. Therefore, there is a risk of fire, as well as problems such as deterioration of the working environment and environmental pollution such as air and water quality.

  As for the organic solvent, DMF dissolved in warm water can be easily recovered in the wet process, but the organic solvent such as DMF, MEK, and TOL evaporated in the drying furnace is captured and recovered in the dry process. It is difficult, and there are problems with collection costs and labor.

  Therefore, the present applicant has proposed a new synthetic leather in Patent Document 1 (Patent No. 2955847) and Patent Document 2 (Patent No. 4024019). Patent Document 1 relates to a synthetic leather 40 having a cross-sectional structure shown in FIG. In the figure, 31 is a base fabric, 32 is a porous layer, 33 is a base layer, 43 is a leather-like skin layer, 44 is a convex portion, and 45 is a concave portion. Since this synthetic leather 40 has a skin layer 43 formed in a perforated state on the convex portion 44 of the porous layer 32, it has the same breathability and flexibility as natural leather, and is used for shoes, etc. Moreover, the same feeling of use as natural leather can be obtained. Patent Document 2 relates to a synthetic leather using an aqueous polyurethane dispersion solution (PUD) instead of the solvent-based polyurethane resin used for the porous layer 32.

Japanese Patent No. 2,954,847 Japanese Patent No. 4024019

  However, the water-based resin used in the invention of Patent Document 2 is generally more expensive than the solvent-based resin, and requires large evaporation energy. For this reason, if all the solvent-based resins of the porous layer 32, the adhesive layer 34, and the skin layer 35 of the conventional wet synthetic leather are replaced with water-based resins, the cost increase becomes excessive. That is, if the adhesive layer 34 and the skin layer 35 are formed of a water-based resin, the material cost and the drying heat energy cost are increased, and the manufacturing speed must be reduced to increase the drying time. Although moisture in the adhesive layer 34 and the skin layer 35 is evaporated through the porous layer 32, the drying time may be further extended depending on the air permeability of the porous layer 32. In this case, the production rate is further reduced. I do not get.

  On the other hand, the porous layer 32 of the base layer 33 is replaced with a water bath when wet-formed with a solvent-based resin. Therefore, even if the solvent-based resin is changed to a water-based resin, the evaporation energy hardly changes. Since there are many compared with the layer 35, there exists a problem that the influence of material cost increase is large. In addition, since about 95% of DMF dissolved in warm water by water bath replacement can be recovered even at present, there is little environmental improvement effect even if water-based resin is used at high cost.

  Therefore, the object of the present invention is to use a low-cost solvent-based resin for the base layer of wet synthetic leather with a large amount of resin as before and use a water-based resin for the skin layer and adhesive layer with a small amount of resin. The purpose is to avoid cost increase as much as possible, and at the same time to shorten the drying time and reduce the amount of solvent released to the environment.

  In order to solve the above-mentioned problems, the present invention provides the fiber base material by a wet method in which a fiber base material impregnated or coated on a fiber base material is solidified through water or warm water and then dried. A step of forming a skin layer formed into a dry and perforated film using an aqueous polyurethane dispersion solution, and bonding the base layer and the skin layer with a foamed aqueous polyurethane dispersion solution A method for producing wet synthetic leather, comprising the steps of joining each other with an agent layer.

  When the skin layer is formed by a dry process using a foamed polyurethane dispersion solution, air permeability is obtained, so that it is not always necessary to form a perforated film. Further, when the skin layer is formed into a dry and perforated film using an aqueous dispersion solution of thermoplastic polyurethane, the adhesive layer is not necessarily required because it can be bonded to the base layer by thermal fusion.

  In the present invention, since the resin used in the skin layer and adhesive layer of the wet synthetic leather is changed from a solvent system to an aqueous system, the solvent that has been released into the air in the drying process of the conventional skin layer and adhesive layer is removed. Can be eliminated. Further, by increasing the concentration of the aqueous resin solution, it is possible to reduce the thermal energy for drying and shorten the drying time by reducing the amount of water used, thereby reducing the manufacturing cost.

It is sectional drawing of the synthetic leather which concerns on embodiment of this invention. It is the schematic which shows the base layer formation process of the manufacturing method of the synthetic leather which concerns on embodiment of this invention. It is the schematic which shows the skin layer formation process of the manufacturing method of the synthetic leather which concerns on embodiment of this invention. It is the schematic which shows the bonding process of the base layer and skin layer of the manufacturing method of the synthetic leather which concerns on embodiment of this invention. It is a figure which shows the quantity of resin of a skin layer, and a solvent. It is a figure which shows the quantity of resin of an adhesive bond layer, and a solvent. It is sectional drawing of the conventional wet synthetic leather. It is sectional drawing which shows the manufacturing method of the conventional wet synthetic leather. It is sectional drawing of the conventional wet synthetic leather which has air permeability.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. Fig.1 (a)-(e) is sectional drawing of the five types of wet synthetic leather 10 which concerns on embodiment of this invention. In the figure, 11 is a base fabric as a fiber substrate, 12 is a porous layer formed of a solvent-based resin, 13 is a base layer, 14 is an adhesive layer formed of a foamed water-based resin, and 15 is a skin formed of a water-based resin. 15a is a skin layer formed of a foamed water-based resin, 15b is a skin layer formed of a thermoplastic water-based resin, 16 is a release paper, and 18 is a porous coating layer.

  In the synthetic leather 10 shown in FIGS. 1A, 1B, 1D, and 1E, the skin layer 15 is bonded to the porous layer 12 using a thin adhesive layer 14 of about 10 μm, for example. In the synthetic leather 10 of (c), the adhesive layer 14 is omitted, and a skin layer 15b formed of a thermoplastic water-based resin is directly bonded to the porous layer 12 by heat fusion. In addition, the synthetic leather 10 of FIGS. 1 (a), (c), (d), and (e) has a perforated film layer 15 and 15b, but the synthetic leather 10 of FIG. By forming 15a with a foamed water-based resin, air permeability is provided without making a perforated film.

  1 (a), (b) and (c), a solvent-based resin is applied on a base fabric 11 to form a porous layer 12 having a thickness of about 0.3 to 0.4 mm, for example. However, the synthetic leather 10 shown in FIGS. 1D and 1E has a base layer 11 a in which a base fabric 11 is impregnated with a solvent-based resin and a porous layer is formed on the internal structure of the base fabric 11. In FIG. 1D, a coating layer 18 is formed on the surface of the base layer 13a in order to improve the familiarity with the adhesive layer 14, and the coating layer 18 is made porous. What is not subjected to the coating treatment is the synthetic leather 10 of FIG. 1 (e), and this synthetic leather 10 is formed with a thick adhesive layer 14 such as about 150 μm so as to absorb irregularities on the surface of the base fabric 11. doing.

  The surface of the porous layer 12 is composed of an outer skin 12a and a hole 12b. The porous layer 12 is formed by water bath substitution with solvent-based resin and drying, but the surface of the finished porous layer 12 is covered with a cuticle-like skin 12a, so that the adhesive layer 14 can be dried and ventilated as it is. Be disturbed. Therefore, a large number of holes 12b are formed by subjecting the skin 12a to a porous treatment using, for example, a polishing roll. The porous treatment can be performed by partially melting the skin 12a with an organic solvent.

  The skin layer 15 is a breathable leather-like film layer having innumerable micropores by filling the film material only into the recesses of the release paper in the same manner as in Patent Document 1 (Japanese Patent No. 2,954,847, FIG. 7). (Perforated film). The skin layer 15 and the adhesive layer 14 are formed using PUD. The PUD used for the skin layer 15 is not subjected to foaming treatment in order to maintain strength, and air permeability is ensured by the formation of the perforated film. On the other hand, the PUD of the adhesive layer 14 is foamed at a predetermined magnification so that a sufficient thickness of the adhesive layer 14 and a predetermined air permeability can be obtained. In addition, if the PUD used for the skin layer 15 is foamed at a low magnification (about 1.2 to 2.0 times), the minimum breathability and strength can be ensured. Filming is not always necessary (synthetic leather in FIG. 1 (b)).

  The adhesive layer 14 can be composed of open cells having a bubble diameter in the range of 20 to 250 μm. When the bubble diameter is larger than 250 μm, there is no problem in air permeability, but the scratch resistance of the skin layer 15 is inferior, and the peel strength of the adhesive layer 14 is weak, which is not suitable as the wet synthetic leather 10. On the other hand, when the bubble diameter is 20 μm or less, the skin layer 15 has good scratch resistance but poor air permeability, and in addition, making the bubble diameter 20 μm or less itself increases the cost with technical difficulties. The bubble diameter can be adjusted by the expansion ratio of the PUD used as the material of the adhesive layer 14, and in order to set the bubble diameter to 20 to 250 μm, the expansion ratio is 1.25 to 2.5 times the volume of the PUD. And

The wet synthetic leather 10 of FIG. 1A can be manufactured, for example, by the manufacturing process of FIGS. 2A to 2C. 2A is a process of manufacturing the base layer 13 by a wet process using a solvent-based resin, FIG. 2B is a process of forming a skin layer 15 by a dry process using a water-based resin, and FIG. This is a step of bonding the skin layer 15 with the adhesive layer 14 of the water-based foamed resin.
In the figure, 1 is a base fabric supply roll, 2a to 2c are resin supply pods, 3 is a water tank, 4 is a first drying furnace, 5 is a polishing roll, 6a is a release paper supply roll, 6b is a skin roll, and 6c is a release paper. Winding roll, 8a is a second drying furnace, 8b is a third drying furnace, 9a is a base layer roll, 9b is a product roll, 17 is a blade, R1-9, R12-14 are guide rolls, R10, 11 are back rolls It is.

  As shown in FIG. 2A, the underlayer 13 is formed by forming the porous layer 12 on the fiber substrate 11 by a wet method. That is, a solution obtained by dissolving a polyurethane resin in DMF is applied onto the fiber base 11 by the resin supply pod 2a. The fiber base material 11 to which the organic solvent solution of the polyurethane resin is applied is passed through water (or hot water) as a coagulating liquid in the water tank 3, so that the organic solvent in the solution is replaced with water, and the polyurethane resin. Precipitates and solidifies, and a porous layer 12 (microporous layer) is formed on the fiber substrate 11. The fiber substrate 11 is then washed with water and dried in the first drying furnace 4.

  When the fiber substrate 11 is dried, a thin film of polyurethane resin is formed on the surface of the porous layer 12. If this film is left as it is, the evaporation and breathability of moisture and solvent will be hindered, so that a large number of holes are formed in the film by polishing with the polishing roll 5 (porosification treatment). The ground fiber substrate 11 is wound around the underlayer roll 9a.

  The skin layer 15 is formed as shown in FIG. 2B. That is, the PUD is applied to the release paper 16 fed from the release paper supply roll 6 by the resin supply pod 2b. The release paper 16 coated with PUD is scraped off excess PUD between the blade 17 and the back roll R10. And it is dried with the 2nd drying furnace 8a in the state made into the perforated film which hold | maintained PUD only in the recessed part of the release paper 16, and is wound up by the skin roll 6b after that.

  The base layer 13 and the skin layer 15 are bonded together as shown in FIG. 2C. That is, the foamed aqueous PUD serving as an adhesive is applied onto the release paper 16 with the skin layer 15 fed from the skin roll 6b on the back roll R11 by the resin supply pod 2c. On the adhesive layer 14 formed by the application, the fiber base material 11 with the porous layer 12 fed out from the base layer roll 9a is pressed and bonded between the guide rolls R12 and R13. The bonded fiber base material 11 is heated to a heat-sensitive coagulation temperature (40 to 130 ° C.) of urethane in the third drying furnace 8b, and then the release paper 16 is peeled downstream of the guide roll R14. Then, the upper part of the release paper 16 is wound around the product roll 9. The wet synthetic leather 10 is manufactured as described above.

  As described above, the adhesive layer 14 is heated and solidified in the third drying furnace 8b. At this time, the moisture contained in the PUD becomes vapor, and the surface of the porous layer 12 is made porous. It goes out to the base fabric 11 side through the formed hole 12b. Therefore, the drying time of the adhesive layer 14 can be shortened, and the production speed can be improved. In addition, since the opposite side of the adhesive layer 14 is covered with the release paper 16 having no air permeability, water vapor cannot be released to the release paper 16 side.

FIG. 3 shows an example of the mixing ratio of the solvent and solute of the resin used for the skin layer 15 by comparing conventional type 1 (using organic solvents such as DMF, MEK, TOL) and type 2 of the present invention (using PUD). It is a thing. In contrast to the conventional type 1 resin solution coating amount of 100 to 150 g / m ² , in the type 2 embodiment of the present invention, the coating amount is significantly reduced to 30 to 60 g / m ^2. The ratio of minutes is increasing. That is, the mass% concentration of the organic solvent solution of the conventional skin layer is 15 to 25%, whereas the mass% concentration of the PUD of the skin layer of this embodiment is 35 to 50%, which is about twice that of the conventional one. It has become.

By using such a high concentration PUD, the amount of water to be evaporated (19.5 to 30 g / m ² ) is reduced while securing the residual resin amount as before. Since the skin layer 15 is an important part that determines the appearance of the wet synthetic leather 10, the amount of residual resin (g / m ² ) remaining in the leather pattern recesses of the release paper 16 is the same as before (10.5 to 30 g). It is necessary to secure it. On the other hand, extending the drying time due to the use of PUD can be minimized by reducing the amount of the solvent (water) to be evaporated by increasing the concentration of the resin solution. The reason why the amount of the residual resin is smaller than the conventional one is the above-described perforated film formation.

FIG. 4 shows an example of the mixing ratio of the solvent and solute of the resin used for the adhesive layer 14 in comparison with the conventional type 1 (using DMF or the like as a solvent) and the type 2 of the present invention (using foamed PUD). It is a thing. While the conventional type 1 has a resin solution application amount of 150 to 200 g / m ² , the type 2 embodiment of the present invention has a very wide application amount range of 74 to 300 g / m ² . This is because the conventional adhesive layer only has an adhesive function, so the upper limit of the necessary amount is naturally determined, but in the case of the present invention, since the foamed PUD is used, the adhesive layer can be made porous, This is because the thickness (residual resin amount, expansion ratio) of the adhesive layer 14 can be adjusted depending on the product application such as surface soft feeling and volume feeling.

  Compared with the minimum application amount, the resin solution application amount is about half that of the conventional embodiment of the present invention, but the ratio of the resin solid content is doubled. That is, the DMF mass% concentration of the conventional adhesive layer is 20 to 25%, whereas the PUD mass% concentration of the adhesive layer of the present embodiment is 40 to 50%, and the concentration is 2 It has doubled. As a result, even with the minimum application amount, the amount of residual resin can be made the same level as before, and the same synthetic leather strength can be obtained.

As described above, when the PUD used in the adhesive layer is made high in concentration, the amount of solvent (water) to be evaporated is compared with the conventional case with the same residual resin amount (30 to 50 g / m ² ). While the evaporation amount of an organic solvent (DMF, MEK, TOL, etc.) is 150 g / m ² , the embodiment of the present invention has an evaporation amount of water of 44 to 50 g / m ² . Thereby, the extension of the drying time by using PUD can be suppressed to the minimum. In addition, by foaming the PUD used for the adhesive layer, the finished adhesive layer 14 becomes porous and bulky like the porous layer 12 of the fiber base material 11, and has a very soft texture. it can. Further, the transfer reproducibility of the skin layer 15 is enhanced by the porous bulky structure. Further, since the amount of resin used in the adhesive layer 14 is larger than that of the skin layer 15, the effect of shortening the drying time is increased by increasing the concentration of PUD and foaming.

In the embodiment of the present invention, as described above, since the thickness (residual resin amount, expansion ratio) of the adhesive layer 14 can be adjusted according to the product application such as surface soft feeling and volume feeling, resin solution application It is also possible to increase the amount up to about 300 g / m ² . When the coating amount is 300 g / m ² , the residual resin amount is 150 g / m ^2, which is three times that of the conventional one, and an extremely bulky porous adhesive layer 14 can be obtained. By using such a bulky porous adhesive layer 14, it is possible to give a very soft texture with the adhesive layer 14 itself, and in some cases, the lower porous layer 12 may be omitted. Even becomes possible. If it does so, the synthetic leather similar to the conventional wet can be obtained only by a dry type, without using a wet process at all.

  In the present embodiment, the amount of resin used can be reduced as compared with the conventional type 1 by forming the skin layer 15 as a perforated film, and the reduced amount can be transferred to the lower adhesive layer 14 without increasing the cost. . For this reason, the thickness of the adhesive layer 14 can be maintained in a porous state and bulky even after the product is finished. Therefore, it is possible to maintain and improve the soft texture and volume feeling close to natural leather of wet synthetic leather. Moreover, the perforated shape of the release paper reflected on the skin layer 15 can be reproduced more sharply than the conventional product in combination with the perforated film of the skin layer 15 and the improved transfer reproducibility of the adhesive layer 14.

  The embodiment of the present invention has been described above, but the present invention is not limited to the above-described embodiment, and it is needless to say that various modifications can be made without departing from the gist of the present invention.

1: base fabric supply rolls 2a to 2c: resin supply pod 3: water tank 4: first drying furnace 5: polishing roll 6a: release paper supply roll 6b: skin roll 6c: release paper winding roll 8a: second drying furnace 8b : Third drying furnace 9a: Underlayer roll 9b: Product roll 10: Wet synthetic leather 11: Fiber base material 12: Porous layer 12a: Skin 12b: Hole 13: Underlayer 14: Adhesive layer 15: Skin layer 16 : Release paper 17: Blade 18: Coating layer R10, 11: Back roll

Claims (11)

A step of using the fiber base material as an underlayer by a wet method in which a fiber base material impregnated or coated with an organic solvent solution of a polyurethane resin is solidified by passing it through water or warm water;
Forming a dry and perforated film skin layer using an aqueous polyurethane dispersion solution; and
Bonding the base layer and the skin layer to each other with an adhesive layer containing a foamed aqueous polyurethane dispersion solution;
A method for producing wet synthetic leather, comprising: A step of using the fiber base material as an underlayer by a wet method in which a fiber base material impregnated or coated with an organic solvent solution of a polyurethane resin is solidified by passing it through water or warm water;
Forming a skin layer dry using a foamed aqueous polyurethane dispersion solution; and
Bonding the base layer and the skin layer to each other with an adhesive layer containing a foamed aqueous polyurethane dispersion solution;
A method for producing wet synthetic leather, comprising: A step of using the fiber base material as an underlayer by a wet method in which a fiber base material impregnated or coated with an organic solvent solution of a polyurethane resin is solidified by passing it through water or warm water;
Forming a dry and perforated film skin layer using an aqueous dispersion solution of thermoplastic polyurethane; and
Bonding the base layer and the skin layer to each other by thermal fusion;
A method for producing wet synthetic leather, comprising:   The method for producing wet synthetic leather according to any one of claims 1 to 3, further comprising a step of subjecting the surface of the base layer to a porous treatment.   5. The method for producing wet synthetic leather according to claim 4, wherein the porous layer is treated with a polishing roll.   The method for producing wet synthetic leather according to any one of claims 1 to 3, wherein a mass% concentration of the aqueous polyurethane dispersion solution of the skin layer is 35 to 50%. A fiber substrate impregnated or coated with an organic solvent solution of a polyurethane resin is solidified by passing through water or warm water and then dried, and then the fiber substrate is used as a base layer.
Forming a perforated film skin layer by dry formation using an aqueous polyurethane dispersion solution,
A wet synthetic leather, wherein the base layer and the skin layer are bonded to each other with an adhesive layer using a foamed aqueous polyurethane dispersion solution. A fiber substrate impregnated or coated with an organic solvent solution of a polyurethane resin is solidified by passing through water or warm water and then dried, and then the fiber substrate is used as a base layer.
Form a skin layer by dry forming using a foamed aqueous polyurethane dispersion solution,
A wet synthetic leather, wherein the base layer and the skin layer are bonded to each other with an adhesive layer using a foamed aqueous polyurethane dispersion solution. A fiber substrate impregnated or coated with an organic solvent solution of a polyurethane resin is solidified by passing through water or warm water and then dried, and then the fiber substrate is used as a base layer.
Using an aqueous dispersion solution of thermoplastic polyurethane to form a dry and perforated film skin layer,
A wet synthetic leather, wherein the base layer and the skin layer are bonded to each other by heat fusion.   The wet synthetic leather according to any one of claims 7 to 9, wherein the surface of the base layer is bonded to the skin layer in a state where the surface is made porous. Forming a dry and perforated film skin layer using an aqueous polyurethane dispersion solution; and
Bonding the skin layer to a fiber substrate with an adhesive layer containing a foamed aqueous polyurethane dispersion solution;
A method for producing synthetic leather, comprising:

Images