JP2015199792A - Method for manufacturing genuine leather product having penetration hole, and genuine leather product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a genuine leather product having a penetration hole, optimally used for a vehicle interior purpose, which sufficiently prevents fraying fiber around the penetration hole and having an excellent texture.SOLUTION: A method for manufacturing a genuine leather product includes: a step of cutting fiber on a back surface of a genuine leather base material; an application step of applying a back spray resin layer whose main component is synthetic resin on the back surface of the genuine leather base material; a coating step of applying a base coat resin layer on a surface of the genuine leather base material; an embossing step of applying an uneven pattern on a surface of the base coat resin layer; a staking step for adjusting a texture of the genuine leather base material; a coating step of applying a coat resin layer on the surface of the base coat resin layer; and a hole opening step of forming a penetration hole in the genuine leather base material and the resin layer.

Description

  The present invention relates to a method for manufacturing a genuine leather product having a through-hole and a genuine leather product.

Genuine leather products are usually called finish layers in order to emphasize the beauty of the appearance with color and gloss on genuine leather base materials that have been tanned or dyed, and to improve the durability of genuine leather. A resin layer is laminated on the surface of the silver surface layer.
For this reason, the surface of the genuine leather base material is covered with a resin layer, and when used for vehicle interior materials, particularly on the seating surface, sweating and stickiness may occur due to sweating when sitting for a long time. was there. In order to solve this problem, a breathing process is performed to form fine holes in a genuine leather product whose surface is covered with a resin layer by a conventionally known method such as needle punching, electric discharge, or laser irradiation, thereby imparting air permeability. .

  However, when the perforation process as described above is performed, the fiber layer of the genuine leather is composed of a plurality of fiber bundles, so that the fibers around the hole are likely to fray, and the frayed fiber covers the hole. Therefore, when the hole was looked into from the surface of the genuine leather product, the hole was closed, and there was a problem that it looked bad.

  In order to solve such a problem, in Patent Document 1, in a leather having a silver surface layer and a fiber layer, the fiber layer is coated with a resin layer, and then a through hole is formed by mechanical means or optical means. Discloses a drilling method for preventing or reducing fraying of fibers around the through hole.

  However, although the method of Patent Document 1 can reduce fraying of fibers around the hole, there is a problem that the texture of the resulting genuine leather becomes coarse because the fibers are hardened with resin in the final process. It was.

JP 2009-249422 A

  An object of the present invention is to provide a genuine leather product that can sufficiently prevent fraying of fibers around a through hole and has a through hole with a good texture.

  The method for producing a genuine leather product having through-holes according to the present invention includes a step of cutting fibers on the back surface of a leather base material, and a coating step of applying a back-blown resin layer mainly composed of a synthetic resin on the back surface of the leather base material. And a coating step for applying a base coat resin layer to the surface of the leather base material, an embossing step for providing an uneven pattern on the surface of the base coat resin layer, a staking step for adjusting the texture of the leather base material, and a base coat It includes an application step of providing a coat resin layer on the surface of the resin layer, and a punching step of providing through holes in the leather base material and the resin layer.

  Further, the leather product having a through hole of the present invention is a leather product having a through hole in which a resin layer having a concavo-convex pattern is formed on the surface of the leather base material, and is a fiber on the back surface layer of the leather base material. However, in the cut state, they are fixed to each other by a back-blown resin layer mainly composed of a synthetic resin, and a base coat resin layer and a coat resin layer are sequentially laminated on the surface of the leather base material. The BLC value is 3.0 or more.

  Further, the leather product having a through hole of the present invention is a leather product having a through hole in which a resin layer having a concavo-convex pattern is formed on the surface of the leather base material, and is a fiber on the back surface layer of the leather base material. However, in the cut state, they are fixed to each other by the back-blown resin layer mainly composed of a synthetic resin, and the base coat resin layer and the coat resin layer are sequentially laminated on the surface of the leather base material. It has a concavo-convex pattern on the surface and is steaked.

  ADVANTAGE OF THE INVENTION According to this invention, the fray of the fiber around a through-hole can fully be prevented, and the genuine leather product which has a through-hole with a favorable texture can be provided.

  Hereinafter, embodiments of the present invention will be described in detail.

  The leather base material used in the present invention is not particularly limited, and examples of raw materials include mammals such as cattle, horses, pigs, goats, sheep, deer, kangaroos, birds such as ostriches, sea turtles, monitor lizards, and pythons. And those derived from reptiles such as crocodiles. Of these, cowhide is preferred because of its high versatility and large area. Raw hides or those that have been salted to prevent decay are called raw hides, and those in this state are used in the leather making process.

  The leather (raw leather) is used to impart durability (heat resistance, rot resistance, chemical resistance, etc.), and the leather-like material is called “leather” (simply called “leather”). It is distinguished from “skin” which is called and not hesitated.

The leather making process is roughly divided into a tanning process, a dyeing process, and a finishing process, and is further divided into the following.
Moistening process: Raw leather, soaking / back splitting, lining, hair removal / lime pickling, splitting, remineralization, decalcification / fermentation, soaking, tanning dyeing process;・ Greasing, setting out, drying, taste-removing, staking (kneading, tapping), tension drying, silver peeling Finishing process: painting, ironing, polishing

  Although the individual steps are being improved, it can be said that the steps are technically determined and are well known in the art. However, the order may be partially changed, omitted, or replaced with another process.

In order to eliminate fraying around the through-hole, which is the subject of the present invention, before the coating process in the finishing process, that is, after the silvering of the dyeing process, the fiber cutting process and the back-blowing application process on the back side of the leather base material It is important to perform in order.
Genuine leather that has gone through silver peeling is used as the genuine leather base material. In the present specification, genuine leather before painting is referred to as “genuine leather base material”, and genuine leather after painting is referred to as “genuine leather product” and is distinguished for convenience.

  By performing a fiber cutting step on the back surface of the genuine leather base material, long fibers that cause fraying of the through holes are cut. By cutting the fibers floating on the back surface layer of the leather base material and removing the fibers that may float from the fiber layer surface layer on the back surface of the leather base material, the resin layer does not leak during back spray coating. Since the fibers adhere to each other and the fibers are firmly fixed to each other, a fraying prevention effect is obtained.

  The fiber length of the fibers that fall off from the back surface of the genuine leather substrate after the fiber cutting step is preferably 5.0 mm or less. This is because the back-blown resin easily spreads between the fibers and the fibers are firmly fixed.

In addition, the fiber length of the fiber to drop in the present invention is measured by the following method.
Adhere an adhesive tape (Nichiban Co., Ltd. cloth adhesive tape <LS> No. 121) with a size of 5 cm x 10 cm on the back of the leather base material, and the length of the fibers attached to the tape when peeled off. taking measurement.

  Specific methods of the fiber cutting step of the present invention include combing and buffing.

The whispering can be performed with a knife machine using a band knife.
The clearance for spreading is appropriately set depending on the desired thickness and fiber length, but is preferably 1.1 to 1.2 mm. If the thickness is less than 1.1 mm, the leather base material becomes thin and the strength may be impaired. If it exceeds 1.2 mm, the fiber length cannot be shortened sufficiently, and fraying may occur.

Buffing can be performed with a buffing machine using sandpaper.
The sandpaper used for buffing is preferably 320 to 800, and more preferably 400 to 600. If it is less than 320, fibers on the back surface of the leather base material are scraped too much, destroying the structure around the silver surface, and the entangled state of the fibers becomes loose, so that there is a risk that wrinkles will occur. If it exceeds 800, the fibers on the surface layer on the back side of the leather base material are not sufficiently cut, and the fraying prevention effect may not be obtained.

  The buffing processing speed is preferably 3 to 8 m / min. Further, the number of times of buffing is not particularly limited. You may perform once or several times until the fiber of the back surface of a genuine leather base material becomes a desired state. When performing a plurality of times, it is preferable to use a coarse sandpaper for the first buffing and a finer sandpaper for the final buffing.

  Next, the fibers on the back surface of the base material are bonded to each other by the back blowing resin composed of a resin mainly composed of a synthetic resin by performing a back spray coating step of applying the resin to the back surface of the genuine leather base material after the fiber cutting step. . Thereby, since the fibers of the back surface layer of the genuine leather base material are cut and fixed to each other by the back-blown resin layer, fraying around the through hole is suppressed.

It does not specifically limit as a synthetic resin used for a back spray coating process, A conventionally well-known synthetic resin can be used and an acrylic resin is used preferably from a versatility viewpoint.
The acrylic resin is not particularly limited. For example, acrylic acid alkyl esters such as methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, isobutyl acrylate, 2-ethylhexyl acrylate; methacrylic acid Methacrylic acid alkyl esters such as methyl, ethyl methacrylate, propyl methacrylate, butyl methacrylate, isobutyl methacrylate, 2-ethylhexyl methacrylate; 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxy acrylate Hydroxy group-containing acrylic esters such as butyl; hydroxy group-containing methacrylates such as 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 4-hydroxybutyl methacrylate, etc. It can be mentioned coalescence. These can be used alone or in combination of two or more.
A commercially available acrylic resin can be used, and an emulsion type is preferably used from the viewpoint of environmental load.

  The resin used in the back spray coating step may contain various additives such as a functional agent such as a matting agent, an anti-tacking agent, and a formalin catcher agent, if necessary.

The coating amount of the resin by the back-blown coating step, in terms of solid content, preferably 3 to 15 g / ^{m 2,} preferably further is 5 to 10 g / ^{m 2.} If it is less than 3 g / m ² , the adhesion between the fibers on the back of the leather base material is weak, and fraying of the through holes may occur. If it exceeds 15 g / m ² , the texture of the obtained genuine leather product may become coarse.

  In the back spray coating process, for example, a reverse roll coater, a spray coater, a roll coater, a gravure coater, a kiss roll coater, a knife coater, a comma coater and the like can be used without particular limitation. Among these, it is preferable to use a spray coater because the resin can be applied only to the back surface of the leather base material and a small amount can be applied.

  After the back spray coating process, heat treatment is performed to evaporate the solvent in the paint and dry the resin to form a coating film. In order to prevent excessive moisture evaporation of the leather base material, the heat treatment is preferably performed so that the leather base material itself does not reach a temperature of 80 ° C. or higher. Therefore, it is preferable that the heat processing temperature is 90-130 degreeC, More preferably, it is 100-120 degreeC. The heat treatment time is preferably 1 to 5 minutes, more preferably 2 to 3 minutes. If the heat treatment temperature or heat treatment time is less than the lower limit, drying may be insufficient. If the heat treatment temperature or the heat treatment time exceeds the upper limit, the texture and feel may become hard.

  Next, a base coat resin layer (hereinafter also simply referred to as “base coat layer”) is formed on the surface of the genuine leather substrate.

  The resin used for forming the base coat resin layer is not particularly limited as long as it is a synthetic resin, and examples thereof include a polyurethane resin, an acrylic resin, an epoxy resin, and a silicone resin. These can be used alone or in combination of two or more. Among these, a polyurethane resin is preferable from the viewpoint of texture and strength, and an acrylic resin is preferable from the viewpoint of texture, moldability (formability in embossing) and versatility, and it is more preferable to use these in combination.

  The polyurethane resin is not particularly limited, and examples thereof include a polycarbonate polyurethane resin, a polyether polyurethane resin, and a polyester polyurethane resin. These can be used alone or in combination of two or more. Of these, polycarbonate polyurethane resins are preferable from the viewpoint of durability, and polyether polyurethane resins are preferable from the viewpoint of texture, and it is more preferable to use them in combination.

  In addition, a one-pack type resin can be used as the polyurethane resin. The one-component resin is usually marketed in the form of emulsified dispersion in water (emulsion type) or dissolved in an organic solvent, but the emulsion type is preferably used from the viewpoint of environmental burden.

The acrylic resin is not particularly limited, and may be appropriately selected from known resins. For example, a polymer of acrylic ester (acrylate) or methacrylic ester (methacrylate), for example, methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, isobutyl acrylate, 2-ethylhexyl acrylate Acrylic acid alkyl esters such as methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, isobutyl methacrylate, 2-ethylhexyl methacrylate, etc .; 2-hydroxyethyl acrylate, acrylic acid Hydroxy group-containing acrylic esters such as 2-hydroxypropyl and 2-hydroxybutyl acrylate; 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 4-methacrylic acid 4- It can be mentioned polymers such as hydroxy group-containing methacrylic acid esters such as Dorokishibuchiru. These can be used alone or in combination of two or more.
From the viewpoint of environmental load, an emulsion type is preferably used.

  For the resin forming the base coat layer, pigments, matting agents, smoothing agents, surfactants, fillers, leveling agents, thickeners, cross-linking agents can be used as long as they do not impair the physical properties of the base coat layer. Various additives such as may be added. Moreover, you may contain solvents, such as water, as needed.

  The thickness of the base coat layer is preferably 15 to 45 μm, more preferably 24 to 36 μm. When the thickness is less than 15 μm, the defects of the leather base material cannot be sufficiently concealed, and the surface of the leather product may have uneven color feeling or physical properties such as wear resistance may be deteriorated. If the thickness exceeds 45 μm, the texture and feel may become hard, or the appearance unique to genuine leather may be impaired.

The base coat layer is formed by applying a base coat layer forming paint and then performing a heat treatment.
In order to apply the base coat layer-forming coating material, for example, a reverse roll coater, spray coater, roll coater, gravure coater, kiss roll coater, knife coater, comma coater and the like can be used without particular limitation. Of these, application by a reverse roll coater or spray coater is preferable because a uniform and thin coating film can be formed.
In addition, what is necessary is just to set an application | coating thickness or a wet application quantity suitably according to the thickness of the desired base coat layer.

  The heat treatment is performed to evaporate the solvent in the paint and dry the resin. Moreover, when a crosslinking agent is added, a crosslinking reaction is accelerated | stimulated and the coating film which has sufficient intensity | strength can be formed. In order to prevent excessive moisture evaporation of the leather base material, the heat treatment is preferably performed so that the leather base material itself does not reach a temperature of 80 ° C. or higher. Therefore, it is preferable that the heat processing temperature is 90-130 degreeC, More preferably, it is 100-120 degreeC. The heat treatment time is preferably 1 to 5 minutes, more preferably 2 to 3 minutes. If the heat treatment temperature or heat treatment time is less than the lower limit, drying may be insufficient. If the heat treatment temperature or the heat treatment time exceeds the upper limit, the texture and feel may become hard.

  Thus, a base coat resin layer can be formed.

  Next, an uneven pattern is formed on the surface of the base coat resin layer by embossing. Embossing on the surface of the base coat resin layer is better because the color will change depending on the presence or absence of the uneven pattern, so it is easier to adjust the color with the coat resin layer if embossed before applying the coat resin layer described later. .

  A known embossing device can be used for embossing without limitation. The emboss mold may be a roll (emboss roll) or a flat (emboss plate). Furthermore, even if the concavo-convex pattern is manufactured so that the concavo-convex patterns overlap each other in the facing portion (male type and female type), one may have a concavo-convex pattern and the other may have a flat surface. Among them, an embossing device including a roll having a concavo-convex pattern and a roll having a flat surface is preferable in that it is excellent in continuous processability and does not impair the texture of the fabric.

  The shape of the concavo-convex pattern is not particularly limited, and examples thereof include a texture pattern, a geometric pattern such as a point, a straight line, a curve, a dotted line, a circle, an ellipse, a triangle, a quadrangle, and a polygon. The pattern which combined the seed | species or more may be sufficient.

What is necessary is just to set suitably the heating temperature (namely, it corresponds to the heat processing temperature at the time of embossing) of the roll or flat plate which has an uneven | corrugated pattern. Preferably, it is preferably performed at a temperature at which the base coat resin layer does not melt. Therefore, it is preferable that heating temperature is 60-120 degreeC.
What is necessary is just to set suitably about conditions, such as the pressure at the time of a press, speed, and the introduction | transduction tension | tensile_strength of a leather base material.

  Next, a staking process for adjusting the texture of the leather base material is performed. By performing the staking process, the texture of the obtained genuine leather product is good and flexible while the back blowing resin is applied to the back surface. In addition, since the color seems to change due to staking, it is better to perform the staking process on the surface of the base coat resin layer because it is easier to adjust the color with the coat resin layer if the staking process is performed before applying the coat resin layer. .

  Specific examples of equipment used in the staking process include a milling machine that puts leather in a drum and rotates it to knock the leather from top to bottom to give it flexibility. And a vibration staking machine that imparts smoothness. These may be used alone or in combination. Since it is easy to obtain flexibility and surface smoothness, it is preferable to use a vibration staking machine in combination in the order of use after the milling machine.

  As processing conditions for the milling machine, the rotational speed is preferably 10 to 20 rpm. There exists a possibility that the softness | flexibility of leather may become inadequate that rotation speed is less than 10 rpm. If the rotational speed exceeds 20 rpm, there is a risk of embossing. The processing time is preferably 5 to 120 minutes. If the processing time is less than 5 minutes, the leather may have insufficient flexibility. If the processing time exceeds 120 minutes, there is a risk that the texture will float.

  As processing conditions of the vibration staking machine, the processing speed is preferably 4 to 8 m / min. If the processing speed is less than 4 m / min, pin marks may remain. When the processing speed exceeds 8 m / min, the flexibility and smoothness of the leather may be insufficient. It is preferable that the driving depth of the pin is 0.5 to 3.0 mm. If the driving depth is less than 0.5 mm, the flexibility and smoothness of the leather may be insufficient. If the driving depth exceeds 3.0 mm, pin marks may remain on the leather surface and the design may be impaired. Further, the driving with a pin may be combined not only with one condition but also with a plurality of conditions. When changing the driving depth, it is preferable that the depth is set in the deep order (for example, 2.0 mm, 1.5 mm, and 1.0 mm in order) from the viewpoint of smoothing without damaging the texture.

  Next, a coat resin layer such as a color coat resin layer and a top coat resin layer is formed on the surface of the base coat resin layer. The coat resin layer is preferably composed of two layers, a color coat resin layer and a top coat resin layer, but may be one layer or three layers.

  As the resin used for forming each coat resin layer, a conventionally known resin can be used as in the case of the base coat resin layer, but a polyurethane resin is preferably used from the viewpoint of durability. Moreover, you may add the additive similar to a basecoat resin layer to resin which forms a coat resin layer.

As with the base coat resin layer, each coat resin layer is formed by applying a resin layer forming paint and then performing a heat treatment.
In addition, it is preferable that the resin which forms a topcoat resin layer has added the crosslinking agent. Thereby, physical properties such as wear resistance can be improved.

  The thickness of the color coat resin layer is preferably 3 to 15 μm, more preferably 6 to 9 μm. If the thickness is less than 3 μm, it is difficult to form a uniform coating film, and color unevenness may occur or physical properties such as wear resistance may deteriorate. If the thickness exceeds 15 μm, the texture and feel may become hard, or the appearance unique to genuine leather may be impaired.

  The thickness of the top coat resin layer is preferably 3 to 17 μm, more preferably 6 to 14 μm. If the thickness is less than 3 μm, it is difficult to form a uniform coating film, and physical properties such as wear resistance may be deteriorated. If the thickness exceeds 17 μm, the texture and feel may become hard.

  Next, a perforating process is performed to form a through hole to obtain the genuine leather product of the present invention.

  As the hole forming method, conventionally known means such as needle punching, electric discharge, laser irradiation and the like can be used. From the viewpoint of versatility, needle punching is preferable.

The shape of the through hole is not particularly limited, and a geometric pattern such as a circle, a triangle, or a square can be selected. Among these, a round shape is preferable from the viewpoint of strength. The area of the opening is preferably 0.19 to 7.07 mm ² . If it is less than the lower limit, even a slight fraying may block the hole, which may impair the appearance or impair air permeability. If the upper limit is exceeded, the strength of the resulting genuine leather product may be impaired.

  Moreover, 0.5-3.0 mm is preferable as an average hole diameter of an opening part. If it is less than the lower limit value, even a slight fraying may block the hole, impairing the appearance or impairing air permeability. If the upper limit is exceeded, the strength of the resulting genuine leather product may be impaired.

  Thus, a genuine leather product having the through hole of the present invention is obtained.

The genuine leather product of the present invention is soft and good in texture. Specifically, the BLC value of the genuine leather product is 3.0 or more, more preferably 3.5. Moreover, it is preferable that the BLC value is 5.0 or less because it is difficult to cause embossing of the concavo-convex pattern, and more preferably 4.0 or less.
In addition, the BLC value in this invention says the distortion measured value when pushing in with the load of 500g.

  In the genuine leather product of the present invention, the fiber length of the fibers falling off from the back surface of the genuine leather product is preferably 5.0 mm or less. When the fiber length is 5.0 mm or less, the fibers on the back surface are difficult to fray, and the leather product is less likely to fray through holes. More preferably, it is 3.0 mm or less.

The fiber length of the fiber falling off from the back side of the leather product in the present invention is measured by the following method.
Adhere a 5cm x 10cm adhesive tape (cloth adhesive tape <LS> No. 121 made by Nichiban Co., Ltd.) to the back of the leather product and measure the length of the fibers attached to the tape when peeled off. .

EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to a following example. In the examples, “%” and “parts” are based on weight.
In addition, evaluation with respect to the genuine leather products obtained in the examples was according to the following method.

[Fraying]
Fiber that adheres to the tape when the adhesive tape (fabric adhesive tape <LS> No. 121, manufactured by Nichiban Co., Ltd.) of 5 cm × 10 cm size is applied to the back of the genuine leather product obtained in the examples and peeled off. Observe. This was performed at arbitrary five locations, and the tape having the largest number of fibers of 3.0 mm or more attached to the tape was evaluated according to the following criteria.
A: 5 or less fibers of 3.0 mm or more attached to the tape ○: 6 or more fibers of 3.0 mm or more attached to the tape 10 or less Δ: 3.0 mm or more attached to the tape 11 or more fibers and 15 or less fibers ×: 16 or more fibers of 3.0 mm or more attached to the tape

[Texture]
One test piece having a size of 150 mm square was sampled, and a strain measurement value (BLC value) was measured when the test piece was pushed in with a load of 500 g using ST300 Laser Softness Tester (manufactured by BLC Laser Technology Center Ltd.).
A larger strain measurement value indicates a softer texture.
◎: Strain measurement value is 3.5 mm or more ○: Strain measurement value is 3.0 mm or more and less than 3.5 mm △: Strain measurement value is 2.5 mm or more and less than 3.0 mm ×: Strain measurement value is less than 2.5 mm

[Longest fiber length of fallen fiber]
Adhesive tape of 5cm x 10cm size (cloth adhesive tape <LS> No. 121 made by Nichiban Co., Ltd.) is applied to the back of the test piece, and the longest of the fibers that adhere to the tape when peeled off. The length was measured.

[Example 1]
(1) Preparation of Genuine Leather Base Adult cowhide was used as the raw leather, and it was subjected to silvering by passing through a normal tanning process and a dyeing process. The dyeing was performed so as to have the same color as the base coat resin layer.

(2) Fiber cutting step The back side of the genuine leather base material obtained in (1) was subjected to a boring process with a clearance of 1.1 mm using a band knife machine as a boring machine.
The longest fiber length of the fallen fibers on the back surface of the obtained leather base material was 2.5 mm.

In addition, the longest fiber length of the falling fibers is obtained by the following method.
Adhesive tape (fabric adhesive tape <LS> No. 121 made by Nichiban Co., Ltd.) with a size of 5cm x 10cm is attached to the back of the leather base material, and the longest of the fibers attached to the tape when peeled off. Measure the length of things.

(3) Back blowing application process [Prescription A1]
1) Product name “PRIMAL SB-150”; 150 parts (acrylic resin emulsion type, solid content 35%)
2) Product name “EUDERM Nappa Softs”; 50 parts (matting agent, solid content 25%)
3) Water; 800 parts All raw materials except LAN are manufactured by LANXESS.
According to prescription A1, each raw material was mixed with the mixer, and the coating material for back blowing resin layer formation was prepared.
Using the spray coater ("TU ROT.3400 / 1.41", manufactured by BARNINI Srl) on the back surface of the leather base material obtained in (2), for forming the back-blown resin layer obtained in (3) The paint was applied so that the wet coating amount was 110 g / m ^2, and was left to stand in a dryer adjusted to 110 ° C. for 3 minutes for heat treatment.
The dry coating amount in the formed back-blown resin layer was 7.2 g / m ² .

(4) Formation of base coat resin layer [prescription B1]
1) Product name “BAYDERM Bottom DLV”; 160 parts (polycarbonate polyurethane resin, solid content 40%)
2) Product name “BAYDERM Bottom 51UD”; 200 parts (polyether polyurethane resin, solid content 35%)
3) Product name "PRIMAL SB-300"; 200 parts (acrylic resin, solid content 34%)
4) Trade name “EUDERM White CB-N”; 118.6 parts (pigment, solid content 60%)
5) Product name “EUDERM Caramel C—N”; 0.9 parts (pigment, solid content 35%)
6) Trade name “EUDERM Bordo CB-N”; 0.3 parts (pigment, solid content 40%)
7) Trade name “EUDERM Black BN”; 0.2 parts (pigment, solid content 23%)
8) Trade name “EUDERM Nappa Softs”; 110 parts (matting agent, solid content 25%)
9) Product name “EUDERM Matching Agent SN-C”; 120 parts (filler, solid content 23%)
10) Trade name “EUDERM Paste DO”; 40 parts (filler, solid content 52%)
11) Trade name “AQUADERM Fluid H”; 10 parts (leveling agent, solid content 100%)
12) Product name “ACRYSOL RM-1020”; about 10 parts (thickener, solid content 20%)
13) Water; 150 parts

All raw materials except LAN are made by LANXESS. The total amount is about 1120 parts.
In accordance with Formula B1, each raw material was mixed with a mixer to prepare a paint for forming a base coat layer. At this time, it adjusted with the thickener so that a viscosity might be set to 50 seconds using the cup viscometer (Anest Iwata Co., Ltd. make, NK-2 model).
Using a reverse roll coater (trade name “JUMBOSTAR-SR”, manufactured by Ge.Ma.Ta.SpA) on the surface of the leather base material obtained in (3), the base coat layer forming coating material is applied in a wet amount. Was applied at a rate of 100 g / m ² and left in a dryer adjusted to 110 ° C. for 3 minutes for heat treatment.
The formed base coat layer had a thickness of 32 μm and a dry coating amount of 32.3 g / m ² .

(5) Embossing Step For the intermediate product obtained in (4), using an embossing machine (trade name “KOMBIPRESS-1800NE”, manufactured by BERGI ofb spa), a roll temperature of 90 ° C. and a pressure of 150 kgf / m. ^2. Embossing was performed under conditions of a processing speed of 5 m / min to give a texture pattern.

(6) For the intermediate product obtained in the staking step (5), using a milling machine (trade name “N2500 × 1200TS”, manufactured by BAGGIO Technology srl) at room temperature (20 ° C.), The kneading process was performed for 30 minutes under the condition of a rotational speed of 15 rpm.
Next, using a vibration staking machine (trade name “3H3200A”, manufactured by CARTIGLIANO SpA), conditions for changing the machining speed 6 m / min and the implantation depth in the order of 2.0 mm, 1.5 mm, and 1.0 mm The tapping process was performed.

(7) Formation of color coat resin layer [prescription C1]
1) Product name “BAYDERM Bottom DLV”; 160 parts (polycarbonate polyurethane resin, solid content 40%)
2) Product name “BAYDERM Bottom 51UD”; 200 parts (polyether polyurethane resin, solid content 35%)
3) Product name "PRIMAL SB-300"; 200 parts (acrylic resin, solid content 34%)
4) Trade name “EUDERM White CB-N”; 118.6 parts (pigment, solid content 60%)
5) Product name “EUDERM Caramel C—N”; 0.9 parts (pigment, solid content 35%)
6) Trade name “EUDERM Bordo CB-N”; 0.3 parts (pigment, solid content 40%)
7) Trade name “EUDERM Black BN”; 0.2 parts (pigment, solid content 23%)
8) Trade name “EUDERM Nappa Softs”; 110 parts (matting agent, solid content 25%)
9) Product name “EUDERM Matching Agent SN-C”; 120 parts (filler, solid content 23%)
10) Trade name “EUDERM Paste DO”; 40 parts (filler, solid content 52%)
11) Trade name “AQUADERM Fluid H”; 10 parts (leveling agent, solid content 100%)
12) Trade name “ACRYSOL RM-1020”; about 5 parts (thickener, solid content 20%)
13) Water; 150 parts

All raw materials except LAN are made by LANXESS. The total amount is about 1115 parts.
According to the prescription C1, each raw material was mixed with a mixer to prepare a paint for forming a color coat resin layer. At this time, the viscosity was adjusted with a thickener using a cup viscometer (Anest Iwata Co., Ltd., NK-2 model) so that the viscosity would be 25 seconds.
Using a spray machine (trade name “TU ROT.3400 / 1.41”, manufactured by BARNINI Srl) on the surface of the intermediate product that has undergone the process of (6), the coating amount for forming the color coat resin layer is It apply | coated so that it might become 25 g / m < ² >, and it heat-processed by leaving still for 3 minutes in the dryer adjusted to 110 degreeC.
The formed color coat resin layer had a thickness of 8.0 μm and a dry coating amount of 8.1 g / m ² .

(8) Formation of topcoat resin layer [prescription D1]
1) Product name “HYDRHOLAC UD-2”; 340 parts (polycarbonate polyurethane resin, solid content 25%)
2) Product name "HYDRHOLAC Finish HW-2"; 120 parts (polycarbonate polyurethane resin, solid content 35%)
3) Product name “AQUADERM Finish HAT”; 200 parts (polycarbonate polyurethane resin, solid content 40%)
4) Trade name “EUDERM White CB-N”; 22.4 parts (pigment, solid content 60%)
5) Trade name “EUDERM Caramel C—N”; 3.1 parts (pigment, solid content 35%)
6) Trade name “EUDERM Bordo CB-N”; 2.7 parts (pigment, solid content 40%)
7) Trade name “EUDERM Black B-N”; 1.8 parts (pigment, solid content 23%)
8) Product name “Rosilk 2229”; 70 parts (smoothing agent, solid content 60%)
9) Trade name “AQUADERM Additive SF”; 30 parts (smoothing agent, solid content 50%)
10) Product name “AQUADERM Fluid H”; 10 parts (leveling agent, solid content 100%)
11) Product name “AQUADERM XL-50”; 150 parts (crosslinking agent, solid content 50%)
12) Product name “ACRYSOL RM-1020”; about 10 parts (thickener, solid content 20%)
13) Water; 150 parts

All raw materials except LAN are made by LANXESS. The total amount is about 1110 parts.
According to prescription D1, each raw material was mixed with the mixer, and the resin liquid for topcoat layer formation was prepared. At this time, the viscosity was adjusted with a thickener using a cup viscometer (Anest Iwata Co., Ltd., NK-2 model) so that the viscosity would be 25 seconds.
Using the spray coater (trade name “TU ROT.3400 / 1.41”, manufactured by BARNINI Srl) on the surface of the intermediate product obtained in (7), the coating amount for forming the top coat resin layer is wet applied. Was applied at 50 g / m ² and left in a drier adjusted to 110 ° C. for 3 minutes for heat treatment.
The formed topcoat resin layer had a thickness of 8.0 μm and a dry coating amount of 8.3 g / m ² .

(9) Hole making process (needle punching)
Using the punching machine (NK-CK155, manufactured by NEKON), punch the intermediate product obtained in (8) at the surface side of the intermediate product with a pin hole of 1.5 mm, a pin-shaped cylinder, and a pitch distance of 5 mm. By processing, an opening having an opening area of 1.3 mm ² and an average hole diameter of 1.3 mm was formed.

Thus, a genuine leather product of Example 1 was obtained.
The obtained leather product had a BLC value of 3.7 and was evaluated as ◎. The frayed state was 0 fibers of 3.0 mm or more, and the evaluation was 評 価.
Moreover, as for the state of the fiber of the obtained genuine leather product back surface, the longest fiber length of the fallen fiber was 2.8 mm.

  Other examples and comparative examples were produced in the same manner as in Example 1 except that the fiber cutting process conditions and the staking process were changed according to Table 1 to produce genuine leather products.

The details of buffing in Table 1 are as follows.
Using the buffing machine (machine name: ENDLESS BAND BUFFFING MACHINE SN180, manufactured by ALETTI) on the back of the leather base material obtained in (1), using a 400th sandpaper, clearance 0.8 mm, processing speed Buffed once at 5.0 m / min.

Evaluation of the genuine leather products produced in the examples and comparative examples was made by the method described above, and the results are shown in Table 1.
As shown in Table 1, the genuine leather products of the examples were not frayed even in the state having through holes, and the evaluation of the texture was good.
On the other hand, the genuine leather product of the comparative example had a poor fraying evaluation or a poor texture evaluation.

Claims (3)

Cutting the fibers on the back of the genuine leather substrate;
An application step of providing a back-blown resin layer mainly composed of a synthetic resin on the back side of the genuine leather substrate;
An application step of providing a base coat resin layer on the surface of the genuine leather substrate;
An embossing process for imparting a concavo-convex pattern to the surface of the base coat resin layer
A staking process for adjusting the texture of the leather base material,
An application step of providing a coat resin layer on the surface of the base coat resin layer;
A method for producing a genuine leather product having a through hole, comprising: a step of forming a through hole in a leather base material and a resin layer. A leather product having a through-hole, in which a resin layer having an uneven pattern is formed on the surface of a leather base material,
The fibers on the back surface layer of the genuine leather base material are fixed to each other by a back-blown resin layer mainly composed of a synthetic resin in a cut state.
A base coat resin layer and a coat resin layer are sequentially laminated on the surface of the leather base material.
And the genuine leather product which has a through-hole characterized by the BLC value of a genuine leather product being 3.0 or more. A leather product having a through-hole, in which a resin layer having an uneven pattern is formed on the surface of a leather base material,
The fibers on the back surface layer of the genuine leather base material are fixed to each other by a back-blown resin layer mainly composed of a synthetic resin in a cut state.
A base coat resin layer and a coat resin layer are sequentially laminated on the surface of the leather base material.
A genuine leather product having a through hole, wherein the base coat resin layer has a concavo-convex pattern on a surface and is staking.