Leather products and their manufacturing methods

Abstract

To provide a leather product having a new leather part pattern on the leather part and a manufacturing method thereof. [Solution] Leather products (10, 110, 210) having at least a part of a leather part (14, 114, 214) made of natural leather, the leather part having photodiscoloration parts (31D, 22g, 122g, 24, 26, 227d) that have undergone a color change due to irradiation with processing light (LV, LVu, LVs), and non-photodiscoloration parts (32N, 22p, 122p, 227n) that have not undergone a color change due to not being irradiated with processing light, and the photodiscoloration parts and non-photodiscoloration parts form at least a part of the leather part pattern provided on the leather part.

Description

[Technical Field]

[0001] The present invention relates to a leather product having at least a leather portion made of leather, and a method for producing the same. [Background technology]

[0002] It is known that natural leather, such as cowhide, discolors (so-called sunburn) when exposed to sunlight or other light containing ultraviolet rays. In leather products such as wallets and bags made of undyed, unpainted, tanned genuine leather (so-called tanned leather), some buyers enjoy the change in color of the leather from beige to a glossy brown due to aging, such as sunburn. Even dyed leather undergoes color changes due to sunburn. As the degree of sunburn progresses, the color gradually changes from the original color (before sunburn), for example, from bright red to dark red, to a dark color that is a mixture of the original color and brown.

[0003] Patent Document 1 also discloses a three-dimensionally patterned natural leather having a three-dimensional pattern on the surface of the natural leather, which is made of a resin portion cured by irradiating an ultraviolet-curable resin with ultraviolet light, and a method for producing the same. Other known methods for forming patterns on leather include dyeing and embossing. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2008 / 044515 Summary of the Invention [Problem to be solved by the invention]

[0005] However, discoloration due to sun exposure was not considered desirable during the manufacturing and retail stages of leather products with leather parts made from natural leather. Furthermore, no consideration was given to utilizing discoloration of leather caused by ultraviolet light irradiation as a pattern to be applied to the leather part. The ultraviolet irradiation in the technology of Patent Document 1 is only for a very short time to harden the ultraviolet-curable resin, and does not discolor the leather.

[0006] The present invention has been made in view of the above circumstances, and provides a leather product having a new leather part pattern on the leather part, and a method for manufacturing the same. [Means for solving the problem]

[0007] (1) One aspect of the present invention for solving the above problem is a leather product having at least a leather part made of natural leather, the leather part having a photodiscoloration part that has undergone a color change due to irradiation with processing light and a non-photodiscoloration part that has not undergone the color change due to not being irradiated with the processing light, and the photodiscoloration part and the non-photodiscoloration part form at least a part of a leather part pattern provided on the leather part. The leather part has a light-processed, drawn part having an outer discoloration part and an inner non-discoloration part, the light-processed part includes the outer discoloration part of the light-processed drawn part, and the non-light-discolored part includes the inner non-discoloration part of the light-processed drawn part. It is a leather product.

[0008] The leather product described above has a photodiscolored portion and a non-photodiscolored portion in the leather part, and these together form at least a part of the leather part pattern. Thus, the leather product has a new leather part pattern that cannot be obtained by dyeing or the like.

[0009] The "photodiscolored areas" of the leather are areas that have undergone a color change due to exposure to processing light. However, color changes due to processing light do not include color changes caused by carbonization (burning) of the leather due to temperature increases caused by exposure to infrared or visible light. On the other hand, "non-photodiscolored areas" are areas that have not been exposed to processing light and have not undergone a color change due to processing light. The pattern formed by the photodiscoloring and non-photodiscoloring portions may be present over the entire leather portion, or may be present only on a portion of the leather portion. Furthermore, the boundary between the photodiscoloring and non-photodiscoloring portions does not need to be clear, and a gradation pattern may be created in which the degree of color change in the photodiscoloring portion gradually decreases toward the non-photodiscoloring portion. The leather portion of a leather product may be provided with only a leather portion pattern consisting of photodiscoloring and non-photodiscoloring portions. Alternatively, in addition to the leather portion pattern consisting of the photodiscoloring and non-photodiscoloring portions, the leather portion may be provided with a leather portion pattern created by color change through dyeing or bleaching (bleaching, discharge printing), shape change through shaping, embossing, or tying, or a scorching process using heat or laser light, such as branding.

[0010] "Leather products" include tote bags, shoulder bags, handbags, and attaché cases. Bags such as jackets, pants, skirts and other clothing, writing implements, document holders and other stationery Accessories such as hats, belts, necklaces, brooches, wallets, business card holders, etc. Fur, chairs and other furniture, etc., used independently by consumers and users, and made entirely or partially of natural materials Leather products include the "leather part" of leather. The front body part member, the outer surface part member of the belt main body part, the crown part member of the hat, Brim parts, furniture coverings such as sofas and chairs, interior parts of vehicles and buildings Material with leather parts Made by used in a product and constituting at least a part of this product This also includes products that are components that have a "leather part" in at least one part.

[0011] The "natural leather" that forms the leather portion can be leather (leather fabric) such as cowhide, horsehide, sheephide, pigskin, or deerskin. Furthermore, leather fabrics that have undergone known tanning processes, such as tannin tanning, chrome tanning, combination tanning, or aldehyde tanning, can be used as the tanning process applied to the leather. Among these, it is preferable to use natural leather that has undergone tannin tanning or combination tanning, which are prone to color changes when exposed to processing light.

[0012] The "processing light" may be any light that can cause a color change in leather when irradiated, and depending on the leather material, blue light, violet light, ultraviolet light, etc. Examples of light sources include sunlight (sunlight), as well as ultraviolet lamps that emit light that mimics sunlight, such as xenon arc lamps, ultraviolet fluorescent lamps, and high-pressure mercury lamps, as well as ultraviolet LEDs and ultraviolet laser diodes. In addition, the "color changes" that occur in the photodiscolored areas of the leather due to irradiation with processing light include discoloration of the leather surface due to the transformation of tannins contained in the leather, fading of dyes applied to the leather, and discoloration of the dyed areas due to the combination of these.

[0014] The leather part of this leather product has a light-drawn processed part with an outer discolored part and an inner non-discolored part. Moreover, the light-drawn part includes the outer discolored part, and the non-light-drawn part includes the inner non-discolored part. Therefore, it is possible to obtain a leather product having a leather part with a unique light-drawn pattern in which, of the light-drawn processed part that has been irradiated with processing light after pleats have been formed in the leather part by a drawing process, at least a part of the outer discolored part becomes a light-drawn part and the inner non-discolored part becomes a non-light-drawn part. The narrowed light processed portion may be provided on the entire leather portion, or may be provided on only a part of the leather portion.

[0015] The "light-squeezed processed portion" provided on the leather portion is a portion formed by performing a "light-squeezed processed portion" on the leather portion through a "light-squeezed processed portion" and then performing a light processing operation in which processing light is irradiated onto the "light-squeezed processed portion," and then the squeezing is released and the leather is unfolded. The degree of unfolding of the "light-squeezed processed portion" can be selected as appropriate. For example, in order to retain the texture of the squeezing process, it is advisable to unfold it to the extent that the three-dimensional shape of the unevenness, such as folds and creases, formed by the squeezing process remains. Alternatively, it is also possible to unfold it by ironing or pressing until the unevenness, such as folds and creases, that have occurred in the squeezing process portion are flattened.

[0016] "Light-processing tying" is a process performed on leather to form "light-processing tying sections." This process forms creases or other irregularities in the leather (leather fabric) by sewing, wrapping, tying, folding, tightening, etc. Examples include the following: a) The leather (leather fabric) is sewn flat along a predetermined pattern, and then the sewing thread is pulled and tightened to form multiple folds in the leather that overlap along the pattern. b) A single fold or multiple folds formed in the leather are bound and tied with tying thread, rubber in the form of a line, tape, or ring. Alternatively, a flexible metal wire such as copper wire or aluminum wire, or a metal wire with a resin coating on the outer periphery, is wound around the fold to maintain the shape. c) The leather is folded to form creases, and the center of the folded leather is held in place by sandwiching it between compression plates in the stacking direction. d) Part of the tying process performed in a) to c) is covered with a shielding material that blocks the processing light. e) With part of the leather covered with a light-blocking material, the squeezing processes a) to c) are carried out.

[0017] The "light-processed, squeezed area" is a "light-processed squeezed area" that has been subjected to "light-processing squeeze processing" on leather (leather fabric). It includes an "external discolored area" that is exposed to the outside and has undergone a color change due to exposure to processing light, and an "internal non-discolored area" that is located inside the pleats formed by the squeezing process, or inside the binding thread, compression plate, or shielding material, and is therefore not exposed to the processing light and has not undergone a color change due to the processing light. The "external discolored area" is included in the "light-processed area," and the "internal non-discolored area" is included in the "non-light-processed area." Depending on the method, direction, and range of irradiation of the processing light, the "light-squeezed processed portion" may include not only the "outer discolored portion" and the "inner non-discolored portion," but also the "outer non-discolored portion" of the light-processing squeezed portion that was exposed to the outside by the squeezing process and could be irradiated with processing light, but that was not actually irradiated with processing light and did not undergo a color change. This "outer non-discolored portion" is included in the "non-light-discolored portion."

[0018] ( 2 )( 1 ) The leather product described in the above, wherein the light-grained processed portion is preferably a leather product having a grained three-dimensional shape in which the uneven shape formed by the graining process is fixed.

[0019] This leather product has a three-dimensional, drawn, and light-processed part formed on the leather, where the uneven shape created by the drawing process is fixed. Moreover, the outer discolored part of the drawn and light-processed part also undergoes a color change due to the light processing, resulting in a leather product with a unique three-dimensional leather pattern.

[0020] The shape-fixing treatment, which fixes the uneven shape created by the wringing process on the leather part, can be carried out before or after the light processing. For example, the shape-fixing treatment involves immersing the entire leather part or a part to be fixed in water or hot water at 20 to 80°C, and then drying to fix the shape. It is also possible to combine dyeing and shape-fixing treatment by immersing the leather part in a dyeing solution at 20 to 80°C.

[0021] ( 3 )Furthermore(1) or (2) In the leather product described above, the leather part has a tie-dyed part having an outer dyed part and an inner undyed part, and at least one of the outer dyed part and the inner undyed part of the tie-dyed part is preferably a leather product including the photodiscoloration part. (4) Alternatively, a leather product may be provided having at least a leather part made of natural leather, the leather part having a photodiscolored part that has undergone a color change due to irradiation with processing light, and a non-photodiscolored part that has not undergone the color change due to not being irradiated with the processing light, the photodiscolored part and the non-photodiscolored part forming at least a part of a leather part pattern provided on the leather part, the leather part having a tie-dyed part having an outer dyed part and an inner undyed part, and at least one of the outer dyed part and the inner undyed part of the tie-dyed part including the photodiscolored part.

[0022] The leather part of this leather product further has a tie-dyed section, so the leather part pattern can include a unique dyed tie-dye pattern formed by tying and dyeing the outer dyed section and the inner undyed section. Moreover, at least one of the outer dyed section and the inner undyed section includes a photodiscoloration section. In other words, because part or all of the outer dyed section or the inner undyed section is a photodiscoloration section, the dyed tie-dye pattern formed in the tie-dyed section is overlapped by the pattern formed by the photodiscoloration section and the non-photodiscoloration section, resulting in a leather product with a leather part with an even more complex pattern. The tie-dyed section may be provided over the entire leather part, or may be provided only on a portion of the leather part.

[0023] The "tie-dyed portion" is a portion formed by further dyeing the "tie-dyed portion for dyeing" formed by subjecting the leather portion to "tie-dyeing processing for dyeing," and then releasing the tie-dyeing and unfolding the leather. The degree of unfolding of the "tie-dyed portion" can also be selected as appropriate. For example, to retain the texture of the tie-dyeing processing, it is recommended to unfold it to the extent that the three-dimensional shape of the unevenness, such as folds and creases, formed by the tie-dyeing processing remains. Alternatively, it can be unfolded by ironing or pressing until the unevenness, such as folds and creases, that have occurred in the tie-dyed portion are flattened.

[0024] The "dyeing tie-down process" applied to leather to form a "dyeing tie-down" is a process that forms pleats or other irregularities in the leather (leather fabric) by sewing, wrapping, tying, folding, tightening, etc., and examples include the following techniques: a) The leather (leather fabric) is flat-stitched along a predetermined pattern, and then the sewing thread is pulled and tightened to form multiple pleats in the leather that fold over in the desired shape; b) A single pleat formed in the leather, or multiple pleats formed by gathering them together, is bound and tied with a binding thread, a rubber wire, a tape, or a ring; or a flexible metal wire such as copper wire or aluminum wire, or a metal wire with a resin coating on the outer periphery, is wound and tied; c) The leather is folded to form pleats, and the center of the folded leather is held between two compression plates in the stacking direction; d) A portion of the area that has been tied down in a) to c) is covered with a penetration-preventing material to prevent the dye solution from penetrating into the interior.

[0025] The "tied and dyed portion" has an "outer dyed portion" that is dyed when the "tied portion for dyeing" is dyed because it is exposed to the outside or located near an exposed portion and the dye seeps in, and an "inner undyed portion" that is not dyed because it is located inside the pleats formed and compressed by the tied processing, or is located inside the binding thread, compression plate, or penetration prevention material and is compressed, so the dye does not reach it. The dyeing applied to the tie-dyed parts includes not only dyeing the leather (leather fabric) but also decolorizing the already dyed parts or the color-changed parts caused by light processing using a discharge liquid (decolorizing liquid, bleaching liquid). Furthermore, the "tie-dyed portion" may include not only the "outer dyed portion" and the "inner non-dyed portion," but also the "outer non-dyed portion" that was exposed to the outside by the tie-dyeing process and could have been dyed, but was not actually brought into contact with the dye solution and therefore was not dyed.

[0026] (5) Furthermore, the leather product according to any one of (1) to (4) may be a leather product in which an ultraviolet absorbing agent is applied to at least the non-photodiscoloring portion of the leather portion.

[0027] In this leather product, an ultraviolet absorber is applied to at least the non-photodiscolored parts of the leather, which makes it difficult for the non-photodiscolored parts to tan even when exposed to sunlight or light from a lamp during display or use, thereby slowing the progression of changes (such as a decrease in contrast) in the pattern formed by the photodiscolored and non-photodiscolored parts of the leather.

[0028] Examples of ultraviolet absorbers include benzotriazole-based, benzophenone-based, and hydroxyphenyltriazine-based ultraviolet absorbers. More specific examples include diethylaminohydroxybenzoylhexylbenzoate, t-butylmethoxydibenzoylmethane, and the like, which absorb UVA; octyl methoxycinnamate, ethylhexyl methoxycinnamate, and the like, which absorb UVB; and bisethylhexyloxyphenol methoxyphenyltriazine, octocrylene, oxybenzone-3, and the like, which absorb both UVA and UVB. The ultraviolet absorber can be applied to the leather by painting, spraying, immersion, or the like.

[0029] The UV absorber may be applied not only to the non-photodiscoloring parts but also to the entire leather part, which makes it difficult for both the photodiscoloring parts and the non-photodiscoloring parts to change color due to sun exposure, thereby suppressing color changes in both.

[0030] (6) Another aspect of the present invention for solving the above-mentioned problems is a method for manufacturing a leather product having at least a leather part made of natural leather, the leather part having a photodiscolored part that has undergone a color change due to irradiation with processing light and a non-photodiscolored part that has not undergone the color change due to not being irradiated with the processing light, the photodiscolored part and the non-photodiscolored part forming at least a part of a leather part pattern of the leather part, the method comprising: an irradiation step of irradiating the photodiscolored part that will become the photodiscolored part with the processing light without irradiating the non-photodiscolored part that will become the non-photodiscolored part of a leather member for leather part that will become the leather part with the processing light to form the photodiscolored part and the non-photodiscolored part. and a process for forming the photodiscoloration portion and the non-photodiscoloration portion on the leather member for leather part prior to the irradiation process. It would be a good idea to use this as a manufacturing method for leather products.

[0031] In this method of manufacturing leather products, the processing light is irradiated onto the intended photodiscoloration portion of the leather member for leather part in the irradiation step to form a non-photodiscoloration portion in addition to the photodiscoloration portion, thereby enabling the appropriate manufacture of a leather part in which the photodiscoloration portion and the non-photodiscoloration portion form at least a part of the leather part pattern, and a leather product having the same.

[0032] "Leather components for leather parts" are leather components that will be used as leather parts, and include not only leather parts themselves, but also leather components for leather parts that are larger than leather parts and have a specified shape (such as a rectangular shape) from which one or more leather parts can be obtained, and leather (leather fabric) for leather parts from which multiple leather parts can be obtained.

[0033] In the irradiation process, the method of irradiating the intended photocolor changing portion with processing light without irradiating the intended non-photocolor changing portion with processing light may be selected depending on the light source that emits the processing light, and examples thereof include the following methods. A) A photomask having a predetermined pattern of light-transmitting and light-shielding areas is placed on the leather material for leather part, or unevenness such as folds or creases is formed on the leather material for leather part in advance, thereby forming areas for photodiscoloration and areas for non-photodiscoloration on the leather material for leather part. Then, in the irradiation process, processing light is irradiated onto the areas for photodiscoloration on the leather material for leather part. B) In the leather part for leather part, the irradiation optical system is configured so that the processing light is not irradiated onto the non-photodiscoloration portion-intended portion, but the processing light of a predetermined irradiation pattern is irradiated onto the photodiscoloration portion-intended portion, and in the irradiation step, the processing light of the predetermined irradiation pattern is irradiated onto the photodiscoloration portion-intended portion. More specifically, for example, the following can be mentioned. B1) By arranging a light source for the processing light, a reflective material such as a mirror, and a shielding material with a light-transmitting portion and a light-blocking portion, the processing light is irradiated in a predetermined irradiation pattern, and in the irradiation process, the processing light is irradiated onto the intended photodiscoloration portion of the leather material for the leather part. B2) Projection: A processing light of a predetermined irradiation pattern is irradiated onto the leather material for the leather part through a projector and an optical scanner. C) A combination of A) and B) above.

[0034] The leather pattern formed on the leather part may not only be a pattern formed by photodiscoloring parts and non-photodiscoloring parts, but also a pattern formed by other known techniques, such as dyeing (including bleaching), printing, embossing, foil stamping, tie-dyeing, and charring.

[0036] This method for manufacturing leather products includes the aforementioned planned portion forming step, and by forming planned photodiscoloration portions and planned non-photodiscoloration portions in advance, it is possible to manufacture leather portions and leather products having such leather portions with leather portion patterns that include unique designs made up of photodiscoloration portions and non-photodiscoloration portions.

[0037] The planned portion forming step may be any step that allows a planned photocolor change portion and a planned non-photocolor change portion to be formed in the leather material for leather part prior to the irradiation step, and examples thereof include the following. i) The leather material for the leather part is subjected to a squeezing process to form a "squeezed part for light processing" which is a squeezing part for light processing (squeezing process for light processing). ii) A photomask having a predetermined shape of light-transmitting portion and light-shielding portion is placed on the leather material for the leather part to form areas through which the processing light passes and areas where the processing light is blocked (photomask placement process). The "transparent area" of the photomask includes areas that transmit the processing light without blocking it, as well as semi-transparent areas that block part of the processing light and transmit only the remaining part. Photomasks can be made from materials such as metal plates, metal foils, paper, cloth, and resin films (opaque, transparent, or semi-transparent). The photomask can be simply placed on the leather material for the leather part, or it can be peelably attached after the irradiation process. iii) A light processing unevenness forming process in which the leather material for the leather part is placed on a table with unevenness, and the leather material for the leather part is deformed or bent along the unevenness to form unevenness such as folds and creases in the leather material for the leather part, thereby forming areas to be photodiscolored that are exposed to processing light and areas to be non-photodiscolored that are not exposed to processing light. iv) A process combining the above steps i) to iii).

[0038] ( 7 )moreover( 6 ) is a method for manufacturing a leather product described in the above, wherein the planned portion forming step includes a light processing tightening step of providing a light processing tightening portion having an outer exposed portion and an inner light-shielding portion for at least a portion of the leather member for the leather portion, and the planned portion for the light-discoloring portion includes at least a portion of the outer exposed portion, and the planned portion for the non-light-discoloring portion includes the inner light-shielding portion.

[0039] This method of manufacturing leather products includes a light processing tightening step in which a light processing tightening portion having an outer exposed portion and an inner light-shielding portion is provided as the step of forming the intended light-discoloring portion and the intended non-light-discoloring portion. As a result, within the unique tightening pattern formed by the tightening process, at least a part of the outer exposed portion becomes an outer discolored portion that has undergone a color change due to light processing, and the inner light-shielding portion becomes an inner non-discolored portion that does not undergo a color change, making it possible to produce a leather part and a leather product having the same that have a unique leather part pattern.

[0040] The "wrapping portion for light processing" provided on the leather material for leather part is a portion of the leather material for leather part that has undergone the aforementioned "wrapping process for light processing," such as sewing, binding, and folding, and is a portion that becomes a "wrapping light processing portion" after being irradiated with processing light in the irradiation process. The "wrapping portion for light processing" that has been subjected to the wrapping process has an outer exposed portion and an inner light-shielding portion. The "outer exposed portion" of the "wrapping portion for light processing" is a portion that is exposed to the outside and can be hit by processing light. At least a portion of this "outer exposed portion" is a portion that becomes an outer discolored portion when irradiated with processing light. On the other hand, the "inner light-shielding portion" is a portion that is shielded from processing light because it is located inside the pleats formed by the wrapping process, or inside the binding thread, compression plate, or shielding material, and is therefore a portion that is not irradiated with processing light and becomes an inner non-discolored portion.

[0041] ( 8 )moreover( 7 ) is a method for manufacturing a leather product described in the above, which preferably comprises either a pre-irradiation shape fixing process for fixing the shape of at least a part of the constricted portion for light processing after the constricting process for light processing and before the irradiation process, or a post-irradiation shape fixing process for fixing the shape of at least a part of the constricted light processing portion, which is the constricted portion for light processing irradiated with the processing light, after the irradiation process.

[0042] In this manufacturing method, the shape of at least a portion of the light-processed wringing portion is fixed in a pre-irradiation shape-fixing step, or the shape of at least a portion of the light-processed wringing portion is fixed in a post-irradiation shape-fixing step, making it possible to produce a leather part and a leather product having the same, which have a wringed three-dimensional shape in which the shape of the light-processed wringing portion is fixed, and which also have a leather part pattern that includes the unique pattern formed by the outer discolored portion and the inner non-discolored portion described above due to the light processing.

[0043] The pre-irradiation shape fixing step and post-irradiation shape fixing step may be any method capable of fixing the three-dimensional shape of the light-processed wringing portion or light-processed wringing portion that has been wringed in the leather material for leather part. Specifically, for example, the leather material for leather part may be immersed in water or hot water at 20 to 80°C for 20 to 60 minutes while maintaining the wringing of the light-processed wringing portion or the like, and then dried at room temperature, such as 10 to 30°C.

[0044] ( 9 )Furthermore (6)~( 8 ) The method for manufacturing a leather product described in any one of the above may preferably include an accelerator application step of applying a tanning accelerator to at least a portion of the intended photodiscoloration portion prior to the irradiation step.

[0045] In this manufacturing method, a tanning accelerator is applied to at least a portion of the intended photodiscoloration area in an accelerator application step prior to the irradiation step. Therefore, when the intended photodiscoloration area to which the tanning accelerator has been applied is irradiated with processing light in the irradiation step, the color change that occurs in the photodiscoloration area occurs more quickly and more deeply, allowing the irradiation step to be completed in a shorter time. Alternatively, a photodiscoloration area in which the color change caused by irradiation with processing light is more profound can be obtained.

[0046] If the photodiscolored parts continue to contain tanning accelerators even after the leather product is manufactured, the color change of the photodiscolored parts will progress when the leather product is exposed to sunlight during use. This also has the effect of preventing the color change (tanning change) that occurs in the non-photodiscolored parts from reducing the contrast of the leather pattern formed by the photodiscolored parts and non-photodiscolored parts, and preventing changes in color tone. The tanning accelerator can be applied to the area to be photodiscolored by painting, spray painting, immersion, etc. An example of a tanning accelerator is neatsfoot oil. [Brief explanation of the drawings]

[0047] [Figure 1] 1A and 1B are explanatory diagrams of a bag according to an embodiment and a first modified embodiment. [Figure 2]10 is an explanatory diagram illustrating a pattern provided on a pattern portion in the front body of the bag according to the embodiment. FIG. [Figure 3] 1 is a flowchart showing the manufacturing process of the bag according to the embodiment and the first and second modified embodiments. [Figure 4] 10A and 10B are explanatory views showing the state of the squeezing process for optical processing in the embodiment and modified embodiments 1 and 2. FIG. [Figure 5] 10A and 10B are explanatory diagrams of a leather member on which a light-processing tightening portion is formed, and an irradiation step of irradiating the leather member with processing light to form a light-processed tightening portion, according to the embodiment and modified embodiment 2. [Figure 6] 10 is an explanatory diagram showing how a constricted light-processing portion is formed by irradiating a processing light onto the optical processing constriction portion according to the embodiment and modified embodiment 2. FIG. [Figure 7] 10 is an explanatory diagram illustrating a pattern provided on a pattern portion of the front body of the bag of modified embodiment 1. FIG. [Figure 8] FIG. 10 is an explanatory diagram showing a state in which processing light is irradiated onto the pinched portion to form a pinched light-processed portion, and further, a tip side portion of the pinched portion is dyed to form a pinched dyed portion, according to the first modified embodiment. [Figure 9] FIG. 10 is an explanatory diagram of a bag according to a second modified embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0048] (Embodiment) A bag 10, which is an example of a leather product according to an embodiment of the present invention, and a method for manufacturing the same will be described below with reference to the drawings. The bag 10 shown in FIG. 1 is entirely made of natural leather, specifically cowhide. The bag 10 comprises a roughly bottomed, rectangular, tubular main body 11 that forms a storage compartment, and a pair of handles 12 attached to the top of the main body 11. The outer periphery of the main body 11 comprises a rectangular bottom 13, a front body 14 that rises from the bottom 13 and faces the front of the bag 10, a rear body 15 that faces the rear opposite the front body 14, and a pair of gussets 16 connecting the front body 14 and the rear body 15. The front body 14 is made of tanned, natural leather, while the bottom 13, rear body 15, gusset 16, and handles 12 are made of tanned, deep red oil leather.

[0049] As shown in Figures 1 and 2, this bag 10 has a pattern section 21 that forms a leather pattern on the front body 14 in a portion of the front body 14 (a portion roughly to the left of the center of the front body 14 in Figure 1). This pattern section 21 is made up of a flower-shaped flower pattern section 22, a leaf pattern section 23 in the shape of a stem and two leaves extending downward from the flower-shaped section, and a peripheral pattern section 24 that surrounds these. The flower pattern section 22 is made up of a plurality of petal-shaped petals 22p and gaps 22g. The gaps 22g are made up of a number of island-like sections located in the gaps between the petals 22p, which are shown with dark hatching in Figure 2, and have an overall radial shape.

[0050] In the pattern portion 21, the petal portions 22p of the flower pattern portion 22 are non-photocolor changing portions 32N that are not irradiated with processing light LV and do not undergo a color change due to processing light LV, as will be described later, while the gap portions 22g are photocolor changing portions 31D that undergo a color change due to irradiation with processing light LV.

[0051] The petal portion 22p, which is the non-photodiscoloring portion 32N, is beige, the natural base color of the tanned leather. Meanwhile, the gap portion 22g, which is the photodiscoloring portion 31D, was originally the same beige as the petal portion 22p, but has undergone a color change to a brown hue. Thus, the floral pattern portion 22, consisting of the petal portion 22p, which is the non-photodiscoloring portion 32N, and the gap portion 22g, which is the photodiscoloring portion 31D, form part of the leather pattern of the pattern portion 21. Thus, the bag 10 of this embodiment has a front body 14 that utilizes the color change caused by the presence or absence of irradiation with processing light LV, resulting from the presence of the photodiscoloring portion 31D and the non-photodiscoloring portion 32N, as part of the pattern of the pattern portion 21. Thus, the bag 10 is composed of the photodiscoloring portion 31D and the non-photodiscoloring portion 32N, and has a new leather pattern, such as the floral pattern portion 22, that cannot be obtained by conventional dyeing techniques.

[0052] As will be described later, the floral pattern portion 22 of the front body 14 is a region where a light processing constriction portion 43 was formed by a light processing constriction process (see Figs. 4 to 6). The floral pattern portion 22 is a light processing constriction portion 33 that is formed by performing light processing by irradiating the light processing constriction portion 43 with processing light LV, and then releasing the constriction and expanding the leather.

[0053] The gaps 22g in the floral pattern portion 22 correspond to the outer exposed portions 43O of the optical processing constriction portion 43 that was used to constrict the leather. The gaps 22g also correspond to the outer portions 33O of the optical processing constriction portion 33 that were exposed to the outside and were irradiated with the processing light LV, as well as the outer discolored portions 33OD that underwent a color change due to the processing light LV. In this embodiment, as described below, the optical processing constriction portion 43 was irradiated with the processing light LV from all directions during the optical processing, so the entire outer portion 33O became the outer discolored portion 33OD. Furthermore, the gaps 22g underwent a deep color change due to the strong irradiation with the processing light LV, resulting in a deeper brown hue than the surrounding pattern portion 24 described below.

[0054] Meanwhile, petal portions 22p of floral pattern portion 22 correspond to inner light-shielding portion 43I of light-processing wringing portion 43, which is shielded from the processing light LV because it is located inside the pleats formed by the wringing process or inside the binding thread. Also, petal portions 22p correspond to inner non-discoloring portion 33IN of light-processing portion 33, which is shielded from the processing light and therefore does not undergo a color change due to the processing light LV. Thus, in this embodiment, bag 10 is obtained, which has a front body 14 with floral pattern portion 22 having a unique light-shielded pattern, in which outer portion 33O (outer discoloring portion 33OD) is photodiscoloring portion 31D and inner non-discoloring portion 33IN is non-photodiscoloring portion 32N.

[0055] In addition, as described below, the floral pattern portion 22, which is the light-squeezing-processed portion 33, is irradiated with processing light LV and has a three-dimensional squeezed shape 33C in which the uneven shape formed on the front body 14 by the squeezing process is fixed. Specifically, the three-dimensional squeezed shape 33C protrudes like a mountain, with the center 22gc of the gap 22g as the peak, the gap 22g forming a ridge, and the petal 22p forming a valley. Furthermore, as shown linearly in FIG. 2, wrinkles 25 caused by the squeezing process are generated in a generally radial pattern on the petal 22p and other portions. That is, in this bag 10, the light-squeezing-processed portion 33 is formed on the front body 14, having the three-dimensional squeezed shape 33C in which the uneven shape formed by the squeezing process is fixed. Furthermore, as mentioned above, the outer discoloration portion 33OD (gap portion 22g) of the outer portion 33O has undergone a color change due to light processing, resulting in the bag 10 having a front body 14 with a unique three-dimensional pattern portion 21 (leather pattern) that combines the presence or absence of light discoloration with the mountain-like three-dimensional shape created by the squeezing process.

[0056] As described above, in the bag 10 of this embodiment, the gap 22g, i.e., the entire outer portion 33O, is the outer discoloration portion 33OD. However, when irradiating the processing light LV, the processing light LV is irradiated only from a biased direction, such as irradiating the processing light LV only from one direction toward the light processing constriction portion 43. As a result, a portion of the outer portion 33O may be made into the outer discoloration portion 33OD, which has undergone a color change, while the remaining portion may be made into an outer non-discoloration portion (not shown), which is the outer portion 33O but is not irradiated by the processing light LV and has not undergone a color change. The outer non-discoloration portion formed in this manner is included in the non-photodiscoloration portion 32N.

[0057] On the other hand, leaf pattern portion 23 in the shape of a stem and two leaves of pattern portion 21 is embossed to form a concave shape, and the inside of the concave portion is dyed green to form concave dyed portion 36. This concave dyed portion 36, which is leaf pattern portion 23, is also photocolor changing portion 31D, but because it is dyed green, the color change caused by irradiation with processing light LV is not very noticeable, and the green color is slightly deeper than the original green color produced by dyeing alone.

[0058] In this embodiment, the entire leaf pattern portion 23 is dyed green, and the entire leaf pattern portion 23 is discolored by processing light LV to form photodiscoloration portion 31D. However, it is also possible to form a pattern within leaf pattern portion 23 that differs in color tone between photodiscoloration portion 31D and non-photodiscoloration portion 32N by forming a portion of leaf pattern portion 23 as photodiscoloration portion 31D and the remaining portion as non-photodiscoloration portion 32N that is not discolored by processing light LV.

[0059] In addition, in this embodiment, the peripheral pattern portion 24 of the pattern portion 21 that surrounds the floral pattern portion 22 and the leaf pattern portion 23, and the unpatterned portion 26 of the front body 14 that is roughly to the right of the center in Figure 1, also become photocolor-changing portions 31D in which a color change has occurred due to the processing light LV.

[0060] In Figure 2, the difference in the degree of color change is indicated by the difference in hatching. The color change in the peripheral pattern portion 24 is somewhat milder than that in the gap portion 22g of the floral pattern portion 22, which has a deep color change. In addition, the degree of color change due to irradiation with processing light LV varies depending on the location in the peripheral pattern portion 24. For example, in the intermediate discoloration portion 24m, such as the portion of the peripheral pattern portion 24 extending radially from the gap portion 22g, the color change is not as strong (deep) as that in the gap portion 22g, but the color change is relatively large (darker). On the other hand, the weak discoloration portion 24l has a relatively small color change (lighter discoloration) compared to the intermediate discoloration portion 24m. Therefore, the intermediate discoloration portion 24m and the weak discoloration portion 24l create a wavy pattern of light and dark discoloration (from ochre to brown) in the peripheral pattern portion 24. As will be described later, the front torso leather material 40 from which the front torso 14 is obtained is provided with a light processing tightening portion 43 that will become the floral pattern portion 22 through light processing tightening, so that the leather in the area of ​​the front torso leather material 40 surrounding the light processing tightening portion 43 that will become the peripheral pattern portion 24 is deformed into an uneven, wavy shape (see Figures 5 and 6). This is because the processing light LV is not irradiated uniformly, causing variations in the degree of color change.

[0061] On the other hand, the non-patterned portion 26 undergoes a generally uniform color change due to irradiation with the processing light LV; specifically, a color change intermediate between the moderately discolored portion 24m and the weakly discolored portion 24l of the peripheral pattern portion 24. The portion of the front torso leather member 40 that will become the non-patterned portion 26 is located away from the light processing constriction portion 43 that will become the floral pattern portion 22, allowing the leather to be flattened and uniformly irradiated with the processing light LV. Although not shown, the portion of the front torso leather member 40 that is away from the light processing constriction portion 43 is intentionally maintained in a wavy shape and irradiated with the processing light LV. This allows the right side of the front torso 14 to be a portion that has a shading pattern formed by color change, instead of the non-patterned portion 26.

[0062] Next, the manufacturing process of the bag 10 will be described with reference to the flowchart of FIG. First, in the front body preparation step S10, a front body leather member 40 is prepared, which will be used to obtain the front body 14. The front body leather member 40 is made of tannin-tanned vegetable tanned leather and has planar dimensions slightly larger than those of the front body 14. Separately, in the other member preparation step S30, leather members (not shown) are prepared to form the handle 12, as well as the bottom 13 of the main body 11, the back body 15, and the gusset portion 16.

[0063] In the subsequent dyeing step S11, a mask (not shown) having perforations in the shape of a stem and two leaves is placed in a predetermined position on the prepared unprocessed front body leather material 40, and a green dye is used to create dyed areas in the shape of a stem and two leaves.

[0064] In the subsequent drawing step S12, as shown in FIG. 4, the tip BRs of a rod BR is pressed from the back side against the position of the front torso leather member 40 that will become the center 22gc of the floral pattern portion 22, forming multiple pleats that radiate from the center 22gc, and gathering the pleated leather around the rod BR. Next, a binding thread ST is spirally wound around the pleated leather gathered around the rod BR to bind it. Thus, the front torso leather member 40 is subjected to a drawing process for light processing, forming a bamboo-like protruding light processing binding portion 43 (see FIGS. 5 and 6). This light processing binding portion 43 has an outer exposed portion 43O that is exposed to the outside and can be hit by the processing light LV, and an inner light-shielded portion 43I that is located inside the leather pleats formed in the light processing binding portion 43 and inside the binding thread ST, and is therefore shielded from the processing light LV.

[0065] The rod BR may be removed when wrapping the binding thread ST around the gathered leather, or it may be tightened together with the leather and left in the optical processing tightening unit 43. In the latter case, the rod BR can be used to irradiate the optical processing tightening unit 43 with the processing light LV while maintaining the desired orientation in the irradiation step S14 described below. For example, as shown in FIG. 5, by inserting and fixing a straight rod-shaped rod BR into an insertion hole (not shown) pre-formed in the mounting table TB, the orientation of the optical processing tightening unit 43 can be maintained upright relative to the mounting table TB, and the processing light LV can be irradiated while reliably maintaining the orientation and position of the optical processing tightening unit 43 at a desired angle, direction, and position. The rod BR can be made of, for example, wood, bamboo, paper tube, plastic, or metal such as stainless steel. On the other hand, a rod BR made of a flexible and deformable metal material such as a copper rod or an aluminum rod can be used as the core material of the optical processing constriction portion 43, and the rod BR, which is in a straight rod shape when constricted, can be deformed appropriately by bending it together with the optical processing constriction portion 43, and the processing light LV can be irradiated while maintaining the optical processing constriction portion 43 in its bent shape.

[0066] Furthermore, instead of the binding thread ST, flexible metal wire such as copper wire or aluminum wire or resin-coated metal wire such as resin-coated copper wire may be wound around the gathered leather to form the light processing binding portion 43, which maintains the bound state. Instead of the binding thread ST, a rubber band or rubber line may be wound around the leather to maintain the bound state.

[0067] Furthermore, the peripheral portion 44 of the front body leather member 40 around the bamboo-like protruding optical processing constricting portion 43 also has an uneven shape influenced by the pleats formed in the optical processing constricting portion 43. For this reason, when the front body leather member 40 is irradiated with processing light LV in the irradiation step S14, for example, as shown in Fig. 5, if the front body leather member 40 is placed on a flat table TB with the optical processing constricting portion 43 standing upright, a plurality of ridges 44T are formed radially in the peripheral portion 44, continuing to the pleats forming the outer exposed portion 43O of the optical processing constricting portion 43, as shown in Fig. 6. In addition, recesses 44R are formed between the ridges 44T. The uneven shape of the peripheral portion 44 of the front body leather material 40 placed on the placing table TB can be varied in various ways depending on the unevenness caused by the aforementioned convex ridge portion 44T and concave portion 44R connected to the light processing tightening portion 43, as well as the arrangement of pleats and unevenness intentionally formed on the front body leather material 40 by the worker.

[0068] Furthermore, in the front torso leather member 40, the inner light-shielding portion 43I of the light-processing gathered portion 43 is a non-photodiscoloration portion-intended portion 42N that is not irradiated with the processing light LV and does not undergo a color change, and becomes a non-photodiscoloration portion 32N (specifically, the petal portion 22p).On the other hand, the remaining portion of the front torso leather member 40, i.e., the outer exposed portion 43O and the peripheral portion 44 of the light-processing gathered portion 43, is a photodiscoloration portion-intended portion 41D that undergoes a color change due to irradiation with the processing light LV (specifically, the gap portion 22g, the leaf pattern portion 23, the peripheral pattern portion 24, and the non-pattern portion 26).

[0069] Next, in the accelerator application step S13, a tanning accelerator AC is applied to the portion of the prospective photocoloration portion 41D where the color change that occurs in the irradiation step S14 described below is desired. In this embodiment, the tanning accelerator AC (specifically, neatsfoot oil) is first soaked into fabric and then applied thinly and uniformly to the outer exposed portion 43O of the light-processing constriction portion 43. This accelerates the color change in the outer exposed portion 43O due to irradiation with the processing light LV, allowing the irradiation step S14 to be completed in a short time. Furthermore, a deep color change can be effectively produced in the gap portion 22g of the floral pattern portion 22 corresponding to the outer exposed portion 43O (see FIG. 2).

[0070] 5 and 6, in the irradiation step S14, the photodiscoloration portion-intended portion 41D of the front torso leather member 40 is irradiated with the processing light LV for 5 to 100 hours (48 hours in this embodiment), causing a color change in the photodiscoloration portion-intended portion 41D to become the photodiscoloration portion 31D. Specifically, the processing light LV is irradiated onto the photodiscoloration portion-intended portion 43 and the peripheral portion 44 of the front torso leather member 40. As a result, the processing light LV causes a color change in the gap portion 22g, the leaf pattern portion 23, the peripheral pattern portion 24, and the non-pattern portion 26 of the floral pattern portion 22. Note that the processing light LV is not irradiated onto the non-photodiscoloration portion-intended portion 42N, which becomes the non-photodiscoloration portion 32N (specifically, the petal portion 22p).

[0071] Therefore, according to this embodiment, the front body 14 in which the photocolor changing portion 31D and the non-photocolor changing portion 32N form at least a part of the pattern portion 21 (leather pattern) and the bag 10 having the same can be appropriately manufactured. Furthermore, in the drawing step S12, the photocolor changing portion-intended portion 41D and the non-photocolor changing portion-intended portion 42N are formed in advance. Specifically, the drawing process for light processing forms the drawing portion 43 for light processing, which has the outer exposed portion 43O and the inner light-shielding portion 43I. This makes it possible to produce a front body 14 and a bag 10 having the same, which have a unique leather pattern including the photocolor changing portion 31D and the non-photocolor changing portion 32N, and further have a unique leather pattern in which the outer exposed portion 43O becomes the outer color changing portion 33OD (gap portion 22g) and the inner light-shielding portion 43I becomes the inner non-photocolor changing portion 33IN (petal portion 22p) within the unique drawn pattern formed by the drawing process.

[0072] In this embodiment, as shown in FIG. 5, the processing light LV is emitted from multiple light sources LSh so as to travel in a generally horizontal direction, and is irradiated generally evenly in the circumferential direction from the periphery of the upright optical processing constricting portion 43 toward the optical processing constricting portion 43. Therefore, the processing light LV is most intensely and evenly irradiated in the circumferential direction onto the outer exposed portion 43O of the optical processing constricting portion 43 of the front torso leather member 40. Meanwhile, the processing light LV is also irradiated onto the peripheral portion 44 of the front torso leather member 40, extending over the mounting table TB, but not as intensely as onto the outer exposed portion 43O. As described above, the peripheral portion 44 has a ridge portion 44T and a recess portion 44R. Therefore, the processing light LV is irradiated more intensely onto the ridge portion 44T of the peripheral portion 44 than onto the recess portion 44R.

[0073] As a result, the outer exposed portion 43O of the light processing gathered portion 43 in the front body leather member 40 becomes the gap portion 22g (outer discolored portion 33OD) where a strong (deep) color change has occurred (see Figure 2). Thus, a leather pattern can be obtained in the flower pattern portion 22, where a clear contrast in the shade of color change occurs between the petal portion 22p and the gap portion 22g. Furthermore, the convex portion 44T of the peripheral portion 44 becomes the medium discolored portion 24m of the peripheral pattern portion 24 where a somewhat strong color change has occurred. On the other hand, the concave portion 44R of the peripheral portion 44 undergoes a relatively weak color change, becoming the weak discolored portion 24l of the peripheral pattern portion 24. In this way, by providing the peripheral portion 44 with irregularities, it is possible to form the peripheral pattern portion 24 where a shade of color change has occurred.

[0074] The light source of the processing light LV used in this irradiation step S14 may be a light source that emits processing light LV that can cause a color change in the intended photocolor changing portion 41D of the front torso leather member 40, depending on the material of the leather used (differences in tanning), etc. Specifically, sunlight can be used, but light sources that generate light that imitates sunlight, such as xenon arc lamps, ultraviolet fluorescent lamps, ultraviolet LEDs, and ultraviolet laser diodes, can also be used. In this embodiment, a light source LSh was used, which is composed of an array of multiple ultraviolet LEDs that emit processing light LV that is mainly light in the UVA region of ultraviolet rays.

[0075] In this embodiment, multiple light sources LSh are used to surround the optical processing constricting portion 43, and the processing light LV is irradiated evenly from the periphery in the circumferential direction toward the optical processing constricting portion 43. However, instead of the stationary mounting table TB shown in Fig. 5, for example, the front body leather material 40 may be placed on a rotating table and gradually rotated around the optical processing constricting portion 43 while the processing light LV is irradiated using a single or a small number of light sources LSh. Furthermore, the irradiation time may be set according to the intensity of the processing light LV emitted from the light source LSh, and may be set to the time required for the color change occurring in the gap portion 22g (photodiscoloration portion) to reach a desired degree.

[0076] In this embodiment, multiple light sources LSh were used to irradiate the optical processing constriction portion 43 with the processing light LV evenly from the periphery in the circumferential direction. However, the processing light irradiation pattern is not limited to this. For example, as shown by the two-dot chain line in FIG. 5 , a light source LSu disposed above the front waist leather member 40 can be used to irradiate the front waist leather member 40 with downward processing light LVu from above. In this case, the processing light LVu does not strike the outer exposed portion 43O, excluding the top portion 43T of the optical processing constriction portion 43, so that the color change in the gap portion 22g of the floral pattern portion 22 is slight, resulting in a pattern with a faint contrast between the petal portion 22p and the gap portion 22g. On the other hand, the downward processing light LVu strikes the convex portion 44T and concave portion 44R of the peripheral portion 44, resulting in a strong color change in the portions of these portions directly facing the light source LSu. In this way, by changing the irradiation direction of the processing light LV, etc., it is possible to create a shading pattern in the floral pattern portion 22 and the peripheral pattern portion 24 that is different from that of the embodiment (see FIG. 2).

[0077] Alternatively, as shown by the dashed-dotted line in FIG. 5 , a single light source LSs positioned diagonally above the front torso leather member 40 (diagonally above and to the right in FIG. 5 ) can be used to irradiate the front torso leather member 40 with processing light LVs from the diagonally above and to the right. In this case, the processing light LVs is strongly irradiated onto the right-hand portion of the optical processing constriction portion 43 in FIG. 5 . However, the processing light LVs is weakly irradiated onto the left-hand portion of the optical processing constriction portion 43 in FIG. 5 , or the processing light LVs is not irradiated onto the left-hand portion of the optical processing constriction portion 43, resulting in a shadow (an outer non-discolored portion). As a result, the gaps 22g themselves in the floral pattern portion 22 exhibit varying shades of color change, and the contrast between the petals 22p and the gaps 22g also changes. Meanwhile, the processing light LVs is strongly irradiated onto many of the ridges 44T of the peripheral portion 44. In contrast, the processing light LVs is weakly irradiated onto the recesses 44R, or the processing light LVs is not irradiated onto the recesses 44R. Therefore, in this case as well, it is possible to create a shading pattern in the floral pattern portion 22 and the peripheral pattern portion 24 that is different from that in the embodiment (see FIG. 2).

[0078] After the irradiation step S14, in the shape fixing step S15, the front body leather material 40 that has been irradiated with the processing light LV is immersed in water or warm water at 20 to 80°C for 20 to 60 minutes, and then dried at 10 to 30°C to fix the bamboo-shoot-like three-dimensional shape including the numerous pleats of the squeezed light-processed portion 33.

[0079] For this reason, even when the drawing process is released and the light-drawn drawn portion 33 is unfolded in the drawing release step S16 described below, the floral pattern portion 22 having the drawn three-dimensional shape 33C in which the shape of the light-drawn drawn portion 33 (light-drawn drawn portion 43) is fixed is formed in the front body leather member 40. Thus, according to the manufacturing method of this embodiment, it is possible to manufacture a front body 14 in which the floral pattern portion 22 has the drawn three-dimensional shape 33C and which has a pattern portion 21 (leather portion pattern) including a unique pattern formed by the outer discolored portion 33OD (gap portion 22g) caused by the light process and the inner non-discolored portion 33IN (petal portion 22p), and a bag 10 having the same.

[0080] In this embodiment, as described above, the irradiation step S14 is followed by the shape fixing step S15 for fixing the three-dimensional shape of the constricting light-processing portion 33. However, as shown by the dashed line in Fig. 3, after the constricting portion 43 for light processing is formed in the constricting step S12, a shape fixing step S25 for fixing the three-dimensional shape of the constricting light-processing portion 43 is performed before the irradiation step S14 and further before the accelerator application step S13. Then, the accelerator application step S13 and the irradiation step S14 may be performed.

[0081] Next, in the tightening release step S16, the tightening process applied to the tightening light-processed portion 33 is released. Specifically, the binding thread ST is removed, and the fixed shape of the tightening light-processed portion 33 is unfolded. This results in the front body leather member 40 having the pattern portion 21 shown in Figure 2. Moreover, as described above, the floral pattern portion 22 has a tightened three-dimensional shape 33C that presents a three-dimensional pattern in which a mountain-like three-dimensional shape with the center 22gc of the gap portion 22g as its peak is fixed.

[0082] Thereafter, in the embossing step S17, a press mold is pressed against the dyed portion in the shape of the stem and two leaves that was previously dyed green in the dyeing step S11, forming depressions and forming the leaf pattern portion 23.

[0083] Furthermore, in the sunburn prevention step S18, an ultraviolet absorber UA is applied to at least the petal portions 22p (non-photodiscoloration portions 32N) of the front body leather member 40. Specifically, a solution containing the ultraviolet absorber UA is impregnated into a cloth or brush and applied to at least the petal portions 22p. This makes the petal portions 22p less susceptible to sunburn, even if sunlight or light from a lamp hits the front body leather member 40 or the front body 14 of the bag 10 during the subsequent manufacturing process of the bag 10, or when the bag 10 is on display or in use. This makes it possible to slow the progression of changes (such as a decrease in contrast) in the shading pattern formed by the gap portions 22g and the petal portions 22p (photodiscoloration portions 31D and non-photodiscoloration portions 32N) of the pattern portion 21 (leather pattern).

[0084] The ultraviolet absorber UA may be applied to the entire surface of the front torso leather member 40. For example, a solution containing the ultraviolet absorber UA may be sprayed onto the entire surface of the front torso leather member 40. This also suppresses color changes due to exposure to light and slows the progression of changes in the shading pattern formed by the photodiscoloration areas 31D and non-photodiscoloration areas 32N on the front torso 14. A specific example of a product containing the ultraviolet absorber UA that is applied to at least the petal portions 22p or the entire surface of the front torso leather member 40 is Columbus Protect Spray.

[0085] In the cutting step S19, the front body 14 including the pattern portion 21 is cut out from the front body leather member 40 manufactured as described above.

[0086] Next, in the sewing process S40, the main body 11 is sewn together using the front body 14 as well as the bottom 13, rear body 15, and gusset 16 that were separately prepared in the other member preparation process S30. Furthermore, the handle 12 is sewn to this main body 11. In this way, the bag 10 (see Figures 1 and 2) having the patterned portion 21 and the non-patterned portion 26 on the front body 14 is completed.

[0087] In this embodiment, the three-dimensional shape of the optically narrowed processed portion 33 is fixed in the shape fixing step S15 (or shape fixing step S25). However, conversely, the shape fixing steps S15 and S25 can be eliminated, and a flattening step S20 can be performed after the un-constricting step S16, as shown by the dashed line in Figure 3, in which the three-dimensional shape created in the optically narrowed processed portion 33 is flattened. In this case, a front body leather member 40 can be obtained that has a flat pattern created by the photodiscoloration portion 31D and the non-photodiscoloration portion 32N created by the irradiation step S14. Also, the bag 10 can have a front body 14 that has a flat pattern created by the photodiscoloration portion 31D and the non-photodiscoloration portion 32N.

[0088] (Variation 1) Next, a description will be given of a bag 110 of modified embodiment 1 and a method for manufacturing the same. The bag 10 of the above-described embodiment has a floral pattern portion 22 or the like in the pattern portion 21 of the front body 14, which has gap portions 22g that have undergone a color change due to irradiation with processing light LV and petal portions 22p that have not undergone a color change (see Figs. 1 and 2). To form this floral pattern portion 22 or the like, a light processing tightening portion 43 was formed in the front body leather member 40, and this light processing tightening portion 43 was irradiated with processing light LV (see Figs. 3 to 6).

[0089] In contrast, bag 110 of modified embodiment 1 has, like the embodiment, petal portions 122p and gaps 122g that have not undergone color change in floral pattern portion 122 of pattern portion 121 in front torso 114. However, unlike gaps 22g in the embodiment, gaps 122g in modified embodiment 1 have gap photodiscolored portions 122gd that have undergone a color change (but are not dyed) due to irradiation with processing light LV, as well as gap dyed portions 122gs that have undergone a color change and are dyed (see FIGS. 1 and 7). To form gap dyed portions 122gs of floral pattern portion 122, a squeezing portion 143 that serves as both a light processing squeezing portion and a dyeing squeezing portion is formed in front torso leather member 140, and processing light LV is irradiated onto this squeezing portion 143, like the embodiment. However, in this modified embodiment 1, in addition to this, the front side portion 143S of the gathered portion 143 is dyed (see FIGS. 3 and 8). Therefore, the following description will mainly focus on the parts that are different from the embodiment, and the description of the similar parts will be omitted or simplified.

[0090] The bag 110 of this first modified embodiment will now be described. As described above, the bag 110 includes a pattern portion 121 on the left side of the front body 114 in FIG. 1, which includes a floral pattern portion 122, a leaf pattern portion 23, and a surrounding pattern portion 24 (see FIG. 7). The floral pattern portion 122 includes multiple petals 122p that are beige and have a petal-like shape because they have not undergone a color change, and radial gaps 122g located between the petals 122p. The gaps 122g are located on the outside and, like the gaps 22g in the embodiment, have gap photodiscoloration portions 122gd that have undergone a color change due to irradiation with processing light LV and exhibit a generally brown hue. In addition, the gaps 122g are located on the inside, are centered on a center portion 122gc, and include gap dyeing portions 122gs that have undergone a color change due to irradiation with processing light LV, and are dyed. In the bag 110 of the first modified embodiment, the gap dyed portions 122gs are dyed red, and a color change due to light processing is added to give them a deep red color.

[0091] As in the embodiment, the floral pattern portion 122 of the pattern portion 121 is the light-drawn and unfolded portion 33 formed by applying light processing to the drawn portion 143 that has been subjected to a drawing process and then unwrapping the drawn portion. The petal portions 122p of this floral pattern portion 122 are non-photodiscoloring portions 32N that have not undergone a color change due to the processing light LV. Meanwhile, the gap portions 122g are photodiscoloring portions 31D that have undergone a color change due to the irradiation of the processing light LV. Therefore, in the floral pattern portion 122 of this modified embodiment 1, the petal portions 122p, which are non-photodiscoloring portions 32N, and the gap portions 122g, which are photodiscoloring portions 31D, form part of the pattern formed by the pattern portion 121. Thus, the bag 110 of this modified embodiment 1 also has a front body 114 that is composed of the photodiscoloring portions 31D and the non-photodiscoloring portions 32N and has a leather pattern, such as the floral pattern portion 122, that cannot be obtained by conventional dyeing or other techniques.

[0092] Furthermore, the floral pattern portion 122 of the pattern portion 121 is a squeezed light-processed portion 33 formed by unwrapping a squeezed portion 143 that has been subjected to a squeeze process for light processing, which also serves as a squeeze process for dyeing, and then performing light processing on the squeezed portion 143, and then unfolding the squeezed portion 138. The floral pattern portion 122 is also a tie-dyed portion 138 formed by dyeing a tip portion 143S of the squeezed portion 143 and then unwrapping the squeezed portion 138. Therefore, among the gap portions 122g of the floral pattern portion 122, the gap-dyed portion 122gs near the center portion 122gc is an outer dyed portion 138O of the tie-dyed portion 138 that has undergone a color change due to irradiation with processing light LV and has been dyed. Meanwhile, among the multiple petal portions 122p, the portion adjacent to the gap-dyed portion 122gs is an inner undyed portion 138I of the tie-dyed portion 138 that has not undergone a color change due to irradiation with processing light LV and has not been dyed.

[0093] This bag 110 has a dyed and pinched section 138 overlapping the pinched light-processed section 33, so that the dyed and pinched pattern formed by the outer dyed section 138O (gap dyed section 122gs) and the inner non-dyed section 138I (petal section 122p) is also overlapped with the pattern formed by the photodiscoloration section 31D (gap photodiscoloration section 122gd) and the non-photodiscoloration section 32N (petal section 122p), resulting in a bag 110 having a front body 114 with an even more complex pattern than the embodiment.

[0094] Next, a manufacturing method of the bag 110 of this modified embodiment 1 will be described (see FIGS. 3, 7, and 8). The manufacturing of the bag 110 is substantially the same as the manufacturing of the bag 10 of the embodiment. However, the pinched portion 143 formed in the pinching step S12 is a pinched portion for light processing similar to the embodiment, and also serves as a pinched portion for dyeing that produces a pattern by dyeing. Furthermore, in this modified embodiment 1, a pinched portion dyeing step S111, indicated by a dashed line, is provided after the irradiation step S14 and before the shape fixing step S15. After the pinched portion dyeing step S111, the same steps as in the embodiment are performed.

[0095] Therefore, the irradiation step S14 and the crimped portion dyeing step S111 will be described with reference to Figures 7 and 8. The crimped portion 143 (see Figure 8) formed by the crimping process (see Figure 4) in the crimping step S12 consists of an outer exposed portion 143O exposed to the outside and an inner portion 143I. The inner portion 143I is a portion located inside the pleats formed by the crimping process and inside the binding thread ST. As in the embodiment, an uneven peripheral portion 44 consisting of protruding ridges 44T and recessed portions 44R is formed around the crimped portion 143.

[0096] Therefore, after the irradiation step S14, as in the embodiment, the outer exposed portion 143O of the constricted portion 143 becomes the outer portion 33O, and the entire portion becomes the outer discolored portion 33OD, which has undergone a color change due to irradiation with the processing light LV. On the other hand, the inner portion 143I becomes the inner non-discolored portion 33IN, which has not been irradiated with the processing light LV and does not undergo a color change. Also, as in the embodiment, the peripheral portion 44 (the convex ridge portion 44T, the concave portion 44R) is irradiated with the processing light LV, which causes a color change, forming the moderately discolored portion 24m and the weakly discolored portion 24l.

[0097] In this modified embodiment 1, after the irradiation step S14, the tip portion 143S of the squeezed portion 143, including the apex portion 143T, is immersed in a dyeing solution (not shown) to form the squeezed-dyed portion 138. This squeezed-dyed portion 138 is composed of an outer dyed portion 138O and an inner undyed portion 138I. The outer dyed portion 138O is included in the outer exposed portion 143O of the squeezed portion 143 and is a portion dyed with the dyeing solution. The outer dyed portion 138O is a portion of the outer discolored portion 33OD that has been dyed, and as described above, exhibits a color tone (deep red in this modified embodiment) in which the color change due to the processing light LV is superimposed with the dyeing color. On the other hand, the inner undyed portion 138I is included in the inner portion 143I of the squeezed portion 143 and is a portion that was not dyed because the dyeing process prevented the dyeing solution from penetrating into it, and is also part of the inner undiscolored portion 33IN (petal portion 22p).

[0098] Therefore, in the tightening release step S16, the tying thread ST is removed, the tightening process is released, and the tightened light-processed portion 33 is unfolded. As shown in Figure 8, the inner non-discolored portion 33IN and the inner non-dyed portion 138I become petal portions 122p that do not change color or are not dyed. On the other hand, the outer discolored portion 33OD becomes gap light-discolored portions 122gd that have undergone a color change. Furthermore, the outer dyed portion 138O becomes gap dyed portions 122gs that have undergone a color change and are dyed.

[0099] (Variation 2) In the embodiment, the front body leather member 40 is subjected to a tightening process for light processing to form a bamboo-shoot-shaped tightened portion for light processing 43. As a result, an outer exposed portion 43O of the tightened portion for light processing 43 is provided as a planned photocolor changing portion 41D to be irradiated with processing light LV, and an inner light-shielding portion 43I is provided as a planned non-photocolor changing portion 42N.

[0100] However, the method of providing the leather material for leather part with the photodiscoloration portion and the non-photodiscoloration portion is not limited to the drawing process. For example, as described above, a photomask having a predetermined shape of light-transmitting portion and a light-blocking portion is placed on the leather material for leather part to provide the photodiscoloration portion and the non-photodiscoloration portion on the leather material for leather part. Then, the processing light LV may be irradiated to form the photodiscoloration portion and the non-photodiscoloration portion.

[0101] For example, in addition to forming the light-processing squeezing portion 43 in the squeezing step S12, a photomask placement step S212, indicated by a two-dot chain line in Fig. 3, places a checkered photomask PM, in which rectangular light-transmitting portions and light-shielding portions are alternately arranged, on the front body leather material 40 (leather material for leather part), as indicated by a dashed line in Fig. 5, to provide the front body leather material 40 with the photodiscoloration portion-intended portions 241D and the non-photodiscoloration portion-intended portions 242N arranged in a checkered pattern. Thereafter, in the irradiation step S14, the front body leather material 40 is irradiated with processing light LV, and the same steps as those in the embodiment are carried out.

[0102] As a result, as shown in Figure 9, a part of the front body 214 can be provided with a flower-shaped floral pattern portion 22, a leaf pattern portion 23, and a surrounding pattern portion 24, similar to the bag 10 of the embodiment (see Figure 1), and it is also possible to manufacture a bag 210 having a checkered discoloration pattern portion 227 consisting of a rectangular rectangular discoloration portion 227d (photodiscoloration portion 31D) and a rectangular non-photodiscoloration portion 227n (non-photodiscoloration portion 32N).

[0103] The present invention has been described above in accordance with the embodiment and modified embodiments 1 and 2. However, it goes without saying that the present invention is not limited to the embodiment, etc., and can be appropriately modified and applied without departing from the spirit of the present invention.

[0104] For example, in the embodiments, the front torso leather member 40 is subjected to a wringing process for light processing, in which bamboo-shoot-shaped wringing portions 43 for light processing and wringing portions 143 are formed by wringing (see Figs. 4 to 6 and 8). Then, processing light LV is irradiated onto the wringing portions 43 for light processing, etc., to form the flower pattern portions 22, 122, which are made up of gap portions 22g, 122g (parts of the photodiscoloration portion 31D) that have undergone a color change and petal portions 22p, 122p (non-photodiscoloration portion 32N) that have not undergone a color change.

[0105] However, as for the light processing squeezing process that can be applied to leather parts for leather parts such as the front body leather part 40, in addition to the squeezing process described above, various squeezing processes can be used to form a light processing squeezing part having an outer exposed part and an inner light-shielding part by sewing, wrapping, tying, folding, tightening, etc. to form pleats in the leather (leather fabric), as exemplified above.

[0106] In modified form 1, the front body leather member 140 is subjected to a drawing process to form a drawing portion 143 that serves both as a drawing portion for light processing and a drawing portion for dyeing, and the drawing portion 143 is irradiated with processing light LV to form a light drawing pattern consisting of the photocolor changing portion 31D and the non-photocolor changing portion 32N. In addition, the tip portion 143S of the drawing portion 143 is dyed to form a drawing dye pattern consisting of the outer dyed portion 138O and the inner non-dyed portion 138I superimposed thereon.

[0107] However, for example, a light-processing wringing portion may first be formed on the leather material for the leather part, and then a processing light may be irradiated onto it, and then a dyeing wringing portion may be formed at a position separate from or partially overlapping the light-processing wringing portion, and then dyed. Conversely, a dyeing wringing portion may first be formed on the leather material for the leather part, and then a light-processing wringing portion may be formed at a position separate from or partially overlapping the dyeing wringing portion, and then irradiated with processing light. It is also possible to form multiple wringing portions, irradiate some of them as light-processing wringing portions with processing light, and dye other portions as dyeing wringing portions, and provide the light-processing wringing portion and the dyeing wringing portion at positions separate from each other or at positions partially overlapping, and perform light processing and dyeing separately.

[0108] In addition, when forming a pattern on a leather material for leather parts, an example has been shown in which the area to be dyed is dyed (colored) with a dyeing solution. However, all or part of the leather material for leather parts can be dyed in advance. Then, part of the dyed area can be bleached (decolorized) with a bleaching solution, and a pattern can be formed with the dyed and bleached areas. Furthermore, a light processing tightening section can be formed or a photomask can be placed on the bleached area formed on the leather material for leather parts, and then processing light LV can be irradiated to form photo-discolored areas and non-photo-discolored areas in the bleached area, thereby creating a pattern using these. [Explanation of symbols]

[0109] 10,110,210 Bags (leather products) 14,114,214 Front body (leather part) 21,121 Pattern part (leather part pattern) 22,122 Floral pattern section 22p, 122p Petal part (non-photodiscolored part) 22g, 122g Gap area (photodiscoloration area) 122gd Gap light discoloration part 122gs Gap Dyed Section 227 Discoloration pattern part 227d Rectangular discoloration area (photodiscoloration area) 227n Rectangular non-discoloring area (non-photodiscoloring area) 31D Photochromic area 32N Non-photodiscoloring part 33 Optical diaphragm processing section 33C constricted three-dimensional shape 33O outer part 33OD Outer discolored area 33IN Non-discolored inner part 138 Tie-dyeing section 138O Outer staining area 138I Inner unstained area 40,140 Leather material for front body (leather material for leather part) 41D, 241D Photodiscoloration area 42N, 242N Non-photodiscoloring part planned part 43 Optical processing constriction section 143 String section (light processing section, dyeing section) 43O External exposed part 143O External exposed part (dyeable part) 43I Inner light shielding part 143I Inner part (internal light-shielding part, undyable part) 43T,143T top S11 Dyeing process S12 Squeezing process (squeezing process for optical processing, planned portion formation process) S13 Accelerator application process AC tanning accelerator S212 Photomask placement process (planned portion formation process) PM Photomask S14 Irradiation process LSh,LSu,LSs light source LV,LVu,LVs processing light S15 Shape fixing process (shape fixing process after irradiation) S25 Shape fixing process (shape fixing process before irradiation) S18 Sun protection process UA Ultraviolet absorber S111 Chopped area dyeing process

Claims

1. A leather product having at least a portion made of natural leather, The leather part is a photodiscoloration portion that has undergone a color change due to irradiation with processing light; a non-photocolor changing portion that is not irradiated with the processing light and does not undergo the color change; the photochromic portion and the non-photochromic portion form at least a part of a leather part pattern provided on the leather part, The leather part is a light-constricting processed portion having an outer discolored portion and an inner non-discolored portion; the photochromic portion includes the outer photochromic portion of the optically processed portion; The non-photodiscoloring portion includes the inner non-photodiscoloring portion of the optically narrowed portion. Leather products.

2. A leather product according to claim 1, The optically narrowed processed portion has a three-dimensional narrowed shape in which a concave-convex shape formed by the narrowing process is fixed. Leather products.

3. The leather product according to claim 1 or claim 2, The leather part is A tie-dyed portion having an outer dyed portion and an inner undyed portion, At least one of the outer dyed portion and the inner undyed portion of the tie-dyed portion includes the photochromic portion. Leather products.

4. A leather product having at least a portion made of natural leather, The leather part is a photodiscoloration portion that has undergone a color change due to irradiation with processing light; a non-photocolor changing portion that is not irradiated with the processing light and does not undergo the color change; the photochromic portion and the non-photochromic portion form at least a part of a leather part pattern provided on the leather part, The leather part is A tie-dyed portion having an outer dyed portion and an inner undyed portion, At least one of the outer dyed portion and the inner undyed portion of the tie-dyed portion includes the photochromic portion. Leather products.

5. A leather product according to any one of claims 1, 2 or 4, An ultraviolet absorbing agent is applied to at least the non-photodiscolored portion of the leather portion. Leather products.

6. At least a portion of the leather part is made of natural leather, The leather part is a photodiscoloration portion that has undergone a color change due to irradiation with processing light; a non-photocolor changing portion that is not irradiated with the processing light and does not undergo the color change; The photodiscoloring portion and the non-photodiscoloring portion form at least a part of the leather part pattern of the leather part. A method for manufacturing a leather product, comprising: Among the leather parts for leather parts, without irradiating the processing light to the non-photocolor changing portion-planned portion that will become the non-photocolor changing portion, Irradiating the processing light to a portion to be the photocolor changing portion, an irradiation step for forming the photochromic portion and the non-photochromic portion; a process for forming the photodiscoloration portion and the non-photodiscoloration portion on the leather member for leather part prior to the irradiation process. Leather product manufacturing method.

7. A method for manufacturing a leather product according to claim 6, The planned portion forming step includes: The method includes a light processing squeezing step of providing a light processing squeezing portion having an outer exposed portion and an inner light-shielding portion for at least a part of the leather part for leather part, the prospective photochromic portion includes at least a part of the outer exposed portion, The non-photocolorable portion-prospective portion includes the inner light-shielding portion. Leather product manufacturing method.

8. A method for manufacturing a leather product according to claim 7, A pre-irradiation shape fixing process for fixing the shape of at least a part of the optical processing constriction portion after the optical processing constriction process and prior to the irradiation process; and a post-irradiation shape fixing step of fixing the shape of at least a part of the optical processing constriction portion irradiated with the processing light after the irradiation step. Leather product manufacturing method.

9. A method for manufacturing a leather product according to any one of claims 6 to 8, Prior to the irradiation step, an accelerator application step is provided in which a tanning accelerator is applied to at least a part of the prospective photodiscoloration portion. Leather product manufacturing method.

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