JP6542436B2 - Skin material and method of manufacturing the same - Google Patents

Description

  The present invention relates to a skin material in which natural leather is adhered to a resin foam, and a method of manufacturing the same.

  Conventionally, as a skin material of a seat such as a car, a railway, an aircraft, a furniture, or an interior material, there is a skin material in which a natural leather is adhered to a polyurethane foam.

  As a bonding method of polyurethane foam and natural leather, polyurethane foam and natural leather are laminated with a non-woven hot melt adhesive interposed, and the hot melt adhesive is melted under pressure and heat, and natural leather and polyurethane foam are formed. There is a thing which adheres a body (patent documents 1).

  Also, as another bonding method, a powdery hot melt adhesive is applied on one side of a polyurethane foam to form a bonding layer, natural leather is laminated on the bonding layer, and pressed with a hot platen. No. 4,648,095, which melts a hot melt adhesive and bonds a natural leather and a polyurethane foam.

  However, in the method of using a non-woven hot melt adhesive or a powdered hot melt adhesive, when bonding a natural leather and a polyurethane foam, when heating from the polyurethane foam side, the feel of the surface material is improved. If the thickness of the polyurethane foam is 10 mm or more, sufficient heat is not transmitted to the hot melt adhesive between the polyurethane foam and the natural leather by the heat insulation effect of the polyurethane foam, and the polyurethane foam and the natural leather can be bonded reliably. It disappears. In addition, when the heating temperature is increased to improve the adhesion, there is a problem that the polyurethane foam may be thermally deteriorated. Furthermore, when the back base fabric made of nylon tricot or the like is bonded in advance to the back surface of the polyurethane foam in order to improve the sewing work of the surface material, problems such as shrinkage of the back base fabric due to heat occur.

  Also, in order to ensure the adhesion between the natural leather and the polyurethane foam by the hot melt adhesive, if heat is easily transmitted to the hot melt adhesive from the natural leather side, the heat is directly applied to the natural leather, so natural The natural emboss (fine asperity) on the surface of the leather grows by heat and becomes a flat surface, and the original design of the natural leather is impaired, or the heat shrinks due to heat. A good skin material can not be obtained.

In addition, natural leather holds moisture because of natural materials, and the water in natural leather evaporates by heating, which causes a problem of impairing hot melt adhesion.
Furthermore, in the method of using a non-woven hot melt adhesive, the continuous fiber structure remains in a small amount between the natural leather and the polyurethane foam, so the flexibility and the flexibility of the surface material are impaired, and the problem of hardening becomes difficult. There is.
Incidentally, if the heating temperature is lowered to prevent the above-mentioned problems caused by heating, then the adhesion of the hot melt adhesive is lowered to cause adhesion failure between natural leather and polyurethane foam.

Unexamined-Japanese-Patent No. 2006-110960 JP-A-3-247446

  The present invention has been made in view of the above-mentioned point, and an object of the present invention is to provide a surface material having strong adhesion between natural leather and a resin foam and having good natural leather texture and a method for producing the same.

The invention of claim 1 is a moisture-curable type in which a resin foam made of a soft slab polyurethane foam and a cell skeleton of the resin foam are cut to form asperities and which are applied and applied in a molten state to the exposed surface. The present invention relates to a skin material comprising a water-containing natural leather bonded with a hot melt adhesive.

  According to the invention of claim 2, in the case of claim 1, the natural leather is laminated on the surface of the resin foam with the moisture-curable hot melt adhesive applied in a molten state interposed between the natural leather and the moisture in the air. The moisture-curable hot melt adhesive is cured by curing with the moisture naturally released from the natural leather.

  The invention according to claim 3 is characterized in that, in claim 1 or 2, the moisture-curable hot melt adhesive is a solventless urethane-based reactive hot-melt resin.

  The invention of claim 4 is characterized in that, in any one of claims 1 to 3, a back base cloth is provided on the surface of the resin foam which is not adhered to the natural leather.

According to the invention of claim 5, the moisture curable hot melt adhesive melted by heating is applied to the surface of the resin foam exposed by cutting the cell skeleton and becoming uneven, and the moisture curable hot melt in a molten state A method for producing a skin material, comprising: laminating a water-containing natural leather on the surface of the resin foam with an adhesive interposed between the natural leather and the step of compressing at normal temperature after the lamination of the natural leather; And D. curing the moisture-curable hot melt adhesive with moisture naturally released from the natural leather.

  The invention of claim 6 is characterized in that, in claim 5, a back base cloth is provided in advance on the surface of the resin foam which is not adhered to the natural leather.

According to the invention of claim 7, in the method according to claim 5 or 6, the resin foam is fed in one direction by a feed roll positioned on the lower surface side of the resin foam when the moisture-curable hot melt adhesive is applied. The hot melt adhesive in a molten state supplied and stored between the adhesive supply roll and the application roll from the discharge part of the adhesive storage tank in the above state is at a temperature lower than the melting temperature of the adhesive. The step of engaging the hot melt adhesive in a molten state with the unevenness exposed on the upper surface of the resin foam is performed by supplying and applying the upper surface of the resin foam by rotation of the supply roll and the application roll, and After the resin foam to which the hot melt adhesive in a molten state is applied is placed on the upper surface of the lower mold when laminating the natural leather, the natural leather is placed on the hot melt adhesive in a molten state. Backside performs the step of the laminated body by laminating such that the downward upon the compression, the upper die, and a step of compressing the laminated body at room temperature, the hot melt adhesive, moisture in the air And curing with the moisture naturally released from the natural leather.

According to the invention of claim 1, since the hot melt adhesive in a molten state is applied to the surface of the resin foam made of the soft slab polyurethane foam, it is for melting the hot melt adhesive after lamination of natural leather. The adhesion between the resin foam and the natural leather becomes good without heating, and the emboss of the surface of the natural leather is not elongated by the heating, and the original design property of the natural leather is not impaired. It is possible to obtain a skin of a good texture. Furthermore, since heating after lamination of natural leather is unnecessary, there is no fear of thermal deterioration or deformation of the resin foam due to heating, and a skin material of good quality can be obtained.
According to the invention of claim 1, since the cut portion of the cell skeleton is exposed as irregularities on the surface of the resin foam, the hot melt adhesive is engaged with the surface of the resin foam to form the resin foam Adhesive strength of natural leather is increased.
According to the first and second aspects of the invention, since the hot melt adhesive is made of a moisture curing type hot melt adhesive, the curing of the moisture curing type hot melt adhesive proceeds even with the moisture evaporating from the natural leather, and resin foaming Adhesion between the body and the natural leather will be good.

  According to the invention of claim 3, since the moisture-curable hot melt adhesive is a solventless urethane-based reactive heat melting resin, it is preferable in order to pass VOC standards and the like in vehicle applications.

  According to the invention of claim 4, the back base cloth provided on the surface of the resin foam which is not adhered to the natural leather has no fear of thermal deterioration such as shrinkage because the resin foam is not heated, Good quality can be maintained, and the back base cloth can make the surface material sewing operation good.

According to the invention of claim 5, the resin foam and the natural leather can be well adhered to each other without heating for melting the hot melt adhesive after lamination of the natural leather, and the natural leather is heated by the heating. The surface texture of the surface does not extend, and the original design of the natural leather is not impaired, and a skin material having a good texture can be obtained. Furthermore, since heating after lamination of natural leather is unnecessary, there is no fear of thermal deterioration or deformation of the resin foam due to heating, and a skin material of good quality can be obtained.
According to the invention of claim 5, since the hot melt adhesive is made of a moisture curing type hot melt adhesive, the curing of the moisture curing type hot melt adhesive proceeds even by the moisture evaporating from the natural leather, and the resin foam Adhesion of natural leather will be good. Furthermore, since the cut part of the cell skeleton is exposed as irregularities in the surface of the resin foam, the hot melt adhesive engages with the surface of the resin foam and the adhesive strength between the resin foam and the natural leather is high. Become.

  According to the invention of claim 6, the back base cloth provided on the surface of the resin foam which is not adhered to the natural leather has no fear of thermal deterioration such as shrinkage because the resin foam is not heated, Good quality can be maintained, and the sewing operation of the obtained skin material can be made good by the back base fabric.

It is sectional drawing of the surface material which concerns on 1st Embodiment of this invention. It is sectional drawing which shows application | coating of the hot melt adhesive of a molten state. It is sectional drawing which shows lamination | stacking of natural leather. It is a sectional view showing compression. It is sectional drawing of the skin material which concerns on 2nd Embodiment of this invention.

Hereinafter, embodiments of the present invention will be described.
The surface material 10 of the first embodiment shown in FIG. 1 is suitable as a surface material of a seat such as a car, a railway, an aircraft, furniture, etc. and an interior material, and it is a resin foam 11 and the resin foam 11 The natural leather 31 is laminated and bonded to the surface of the resin foam 11 with the hot melt adhesive 21 applied in a molten state on the surface of the resin foam 11.

  It does not specifically limit as said resin foam 11, For example, a soft polyurethane foam, a polyethylene foam, a polypropylene foam etc. can be mentioned. In particular, a flexible slab polyurethane foam obtained by cutting a block-like flexible polyurethane foam produced by slab foaming continuously foaming at normal temperature and normal pressure into a sheet is suitable as the resin foam 11. In the soft slab polyurethane foam, since the cut portion of the cell skeleton is exposed as unevenness on the cut surface, the hot melt adhesive 21 is engaged with the surface of the soft slab polyurethane foam and the resin foam 11 The adhesive strength of the natural leather 31 is increased.

In addition, since the skin material 10 is not heated to a high temperature when the skin material 10 is manufactured, a polyethylene foam or the like having a low melting point can also be used as the resin foam 11.
Although the thickness of the said resin foam 11 is suitably set according to the use of the said surface material 10, 2-20 mm is mentioned as an example.

  On the surface of the resin foam 11 which is not bonded to the natural leather 31, the back base fabric 15 is bonded in advance by a frame laminate, an emulsion adhesive or the like. The back base fabric 15 suppresses the expansion of the surface material 11 at the time of sewing or the like of the surface material 11, makes the surface of the surface material 11 slip well, and facilitates the cloth feeding on the sewing machine stand. Alternatively, it has the function of protecting the back surface when the surface material 11 is used, and examples thereof include cloth materials (knit, fabric), non-woven fabrics and the like.

  The hot melt adhesive 21 applied in a molten state to the surface to which the natural leather 31 is adhered in the resin foam 11 may be a normal one made of a thermoplastic plastic such as vinyl acetate resin, or may be melted by heating. Such as a moisture-curable type which reacts and cures with moisture. In particular, since the curing of a moisture curing type hot melt adhesive is promoted not only by the moisture in the air but also by the moisture naturally contained in the natural leather 31, the moisture contained in the natural leather 31 It is preferable as the hot melt adhesive 21 because the adhesiveness is not impaired and the adhesiveness can be rather improved. As the moisture curing type hot melt adhesive, there are urethane type, polyester type, acrylic type and the like, and the urethane type moisture curing type adhesive is preferable from the viewpoint of easy handling, availability and the like. Specifically, a non-solvent reactive hot-melt resin which is a urethane-based reactive hot melt adhesive and does not contain a diluent such as an organic solvent is preferable in order to pass VOC standards and the like in vehicle applications. This adhesive is mainly composed of an isocyanate group-terminated urethane polymer, and as the polyol component, polyester polyols, polyether polyols and the like are generally used, but other polyols may be used. It may be a urethane compound having an isocyanate group as a reactive group. The heat melting temperature is 70 ° C to 200 ° C, preferably 80 ° C to 160 ° C.

  The type and thickness of the natural leather 31 such as cowhide, pig leather, kangaroo, ostrich, crocodile and reptiles are determined according to the application of the surface covering material 10. In particular, natural leather made of cowhide is preferable because it is excellent in durability. The thickness of the natural leather is 0.5 to 3 mm.

  The method of manufacturing the surface material 10 will be described. The surface material 10 is manufactured by a hot melt adhesive application process, a natural leather lamination process, and a compression curing process.

  In the hot melt adhesive application step, the hot melt adhesive 21 melted by heating is applied to one surface of the resin foam 11 by a coating device. The resin foam 11 is previously formed into a sheet having a predetermined thickness, and in the case where the back base cloth 15 is adhered to the lower surface (back side), the resin foam 11 of the resin foam 11 on the opposite side to the back base cloth 15 The hot melt adhesive 21 is applied to the surface.

  The case where a roll coater is used as the coating device is shown in FIG. The roll coater 40 includes a feed roll 41, a supply roll 42, an application roll 43, and a hot melt adhesive reservoir 44.

The feed roll 41 is disposed below the resin foam 11 and rotates in one direction while being in contact with the back base cloth 15 of the lower surface of the resin foam 11, and the resin foam 11 is rotated by one rotation thereof. Send in the direction.
The supply roll 42 and the application roll 43 are disposed above the resin foam 11 with their rotational axes parallel to each other and with a gap provided between their outer peripheral surfaces. The supply roll 42 rotates in the direction opposite to the feeding direction of the resin foam 11 without the outer peripheral surface being in contact with the upper surface of the resin foam 11. On the other hand, the application roll 43 rotates in the feed direction of the resin foam 11 with a predetermined distance (clearance) between the outer peripheral surface and the upper surface of the resin foam 11. Further, the outer peripheral surface of the supply roll 42 and the application roll 43 can be heated.

  The hot melt adhesive storage tank 44 is disposed such that the discharge portion 45 at the lower end is located above the supply roll 42 and the application roll 43, and the hot melt adhesive 21 contained therein is heated or the like It stores in a molten state by heating with the heating means of

  The molten hot melt adhesive 21 stored in the hot melt adhesive storage tank 44 is fed from the discharge unit 45 while the resin foam 11 is fed in one direction by the feed roll 41. It is supplied between the supply roll 42 and the application roll 43. The molten hot melt adhesive 21 supplied between the supply roll 42 and the application roll 43 is supplied to the upper surface of the resin foam 11 by the rotation of the supply roll 42 and the application roll 43. The molten hot melt adhesive 21 supplied to the upper surface of the resin foam 11 is applied to the upper surface of the resin foam 11 in contact with the lower end of the outer peripheral surface of the rotating application roll 43.

  The application amount of the hot melt adhesive 21 to the resin foam 11 is the melt viscosity of the hot melt adhesive 21 depending on the heating temperature of the hot melt adhesive storage tank 44, the supply roll 42 and the application roll 43. Adjustment by adjusting the rotational speed of the supply roll 42 and the application roll 43, the distance between the outer peripheral surface of the application roll 43 and the upper surface of the resin foam 11 (clearance), and the feed speed of the resin foam 11 it can.

  In the step of laminating natural leather, as shown in FIG. 3, the natural leather 31 is laminated on the surface of the resin foam 11 with the hot melt adhesive 21 in a molten state interposed therebetween. In the embodiment shown in FIG. 3, after the resin foam 11 to which the hot melt adhesive 21 in a molten state is applied is placed on the upper surface of the lower die 51 of the press, the hot melt adhesive 21 in the molten state is The natural leather 31 is laminated on top of the other with the back surface facing downward. In addition, the code | symbol 52 is an upper mold | type of a press apparatus.

  In the compression curing step, as shown in FIG. 4, the laminated body 10A in which the natural leather 31 is laminated is compressed by sandwiching the hot melt adhesive 21 in a molten state on the upper surface of the resin foam 11; The adhesive 21 is cured to form the skin material 10 in which the natural leather 31 and the resin foam 11 are bonded. The compression is performed at a temperature lower than the melting point of the hot melt adhesive 21. For example, it carries out at normal temperature. In addition, normal temperature means the range of 20 +/- 15 degreeC prescribed | regulated by Japanese Industrial Standard. Further, the degree of compression is not particularly limited, and for example, compression is performed so as to be 40 to 80% of the total thickness.

  The hot melt adhesive 21 is naturally cooled and hardened during the compression to bond the natural leather 31 and the resin foam 11. Further, in the case of a moisture curing type hot melt adhesive, the curing of the hot melt adhesive 21 proceeds by natural cooling, moisture in the air, and moisture naturally released from the natural leather 31, and the natural leather 31 and the above-mentioned natural leather 31 Adhesion of the resin foam 11 becomes strong.

  In the compression step, high temperature heating for melting the hot melt adhesive 21 is not performed, so that the emboss of the surface of the natural leather 31 does not extend, and the original design property of the natural leather 31 is not lost. The skin material 10 with a good texture is obtained. Furthermore, the back base fabric 15 is not deteriorated by heat, and the skin material 10 of good quality can be obtained.

The skin material 60 of 2nd Embodiment is shown in FIG. The skin material 60 of the second embodiment does not have the back base cloth 15 of the skin material 10 of the first embodiment, and the other structure is the same as the skin material 10 of the first embodiment. The code | symbol 61 is a resin foam, 71 is a hot-melt-adhesive agent, 81 is a natural leather.
The method of manufacturing the skin material 60 of the second embodiment is the same as the method of manufacturing the skin material 10 of the first embodiment except that the back base cloth 15 is not adhered to the lower surface of the resin foam 11. It is the same as that of the manufacturing method of skin material 10 of a 1st embodiment.

Examples 1 to 3 (moisture curing type hot melt adhesive, with back base cloth)
Density 30 kg / m ³ Hardness (JIS K 6400-2: 2012) 50 N Cell number (JIS K 6400-1: 2004) 42 pieces / 25 mm, product number: EL-68WS, polyether-based soft slab manufactured by Inoac Corporation The polyurethane foam was used as a resin foam in a size of 250 × 400 mm × thickness 10 mm, and was adhered to the back with an acrylic emulsion adhesive using 15 denier nylon tricot as a back base.

  As a hot melt adhesive, a urethane-based moisture-curable adhesive, a polyurethane-based hot-melt moisture-curable resin manufactured by Hitachi Chemical Polymer Co., Ltd., HIBON, a melt coating temperature: 150 ° C., 150 ° C. by the roll coater 40 It was made to apply and adhere on the surface on the opposite side to the back base cloth of the resin foam in the state which was heated and fuse | melted. The temperature of the hot melt adhesive stored in the hot melt adhesive storage tank 44, the temperature of the supply roll 42 and the temperature of the application roll 43 are all 80 ° C., and the rotational speeds of the supply roll 42 and the application roll 43 The value of the clearance was fixed, and the feed rate of the resin foam was changed at 4 to 6 m / min to obtain the adhesion amount (application amount) of Examples 1 to 3 shown in Table 1.

  Next, the resin foam is placed on the press lower mold with the hot melt adhesive facing upward, the natural leather (cowhide) is laminated on the resin foam with the hot melt adhesive on the surface of the resin foam, and the press is performed. The upper mold was lowered and compressed to form the skin materials of Examples 1 to 3 shown in Table 1. The compression was performed at normal temperature for 40 seconds, and the amount of compression was set to 60%.

・ Reference example 4 (normal type hot melt adhesive, with back base cloth)
As a hot melt adhesive, using a vinyl acetate-based hot melt adhesive manufactured by Aika Kogyo Co., Ltd., product name: A-QNJ, the resin foam and the back base cloth are made the same as in Examples 1 to 3, and the hot melt adhesive storage tank 44. The temperature of the hot melt adhesive stored in 44 and the temperature of the supply roll 42 and the application roll 43 are 95 ° C., the rotational speed of the supply roll 42 and the application roll 43 and the value of the clearance are fixed. The feed rate of the body was adjusted to obtain the adhesion amount (application amount) of Reference Example 4 in Table 1. The skin material of Reference Example 4 shown in Table 1 was formed in the same manner as in Examples 1 to 3 except for the above.

Comparative example 1 (non-woven type hot melt adhesive, with back base cloth)
As a web-like hot melt adhesive (non-woven type hot melt adhesive), spun bond non-woven fabric, fabric weight: 25 g / m ² , melting point: 115 ° C., product number: DINAC LNS 1225, manufactured by Toha Tech Co., Ltd., resin foam and The back base cloth is made the same as in Examples 1 to 3, and the resin foam is placed on the press lower mold so that the back base cloth is on the lower side, and the hot melt adhesive is placed on the upper surface of the resin foam. Then, natural leather (cowhide) was laminated on both sides of the hot melt adhesive, and the upper die was lowered and heated and compressed to form the skin material of Comparative Example 1 shown in Table 1. The press mold was at normal temperature, the upper mold was at 190 ° C. for 40 seconds, and the compression was set to 50%.

Examples 5 to 7 (moisture-setting hot melt adhesive, without back backing)
Density 30 kg / m ³ , hardness (JIS K 6400-2: 2012) 70 N, cell number (JIS K 6400-1: 2004) 25/25 mm, part number: WF-18, soft polyether-based slab made by Inoac Corporation The polyurethane foam was used as a resin foam in a size of 250 × 400 mm × thickness 10 mm and no backing cloth was provided. The same hot melt adhesive as in Examples 1 to 3 is used, and the hot melt adhesive in a molten state is applied to one side surface of the resin foam in the same manner as in Examples 1 to 3, in Examples 5 to 7 in Table 2. It adhered (coated) by the adhesion amount shown.

  Next, the resin foam is placed on the press lower mold with the hot melt adhesive facing upward, the natural leather (cowhide) is laminated on the resin foam with the hot melt adhesive on the surface of the resin foam, and the press is performed. The upper mold was lowered and compressed to form the skin materials of Examples 5 to 7 shown in Table 2. In addition, compression was performed at normal temperature for 40 seconds, and the amount of compression was set to 50%.

Reference Example 8 (Normal Type Hot Melt Adhesive, No Back Base Cloth)
As a hot melt adhesive, using a vinyl acetate-based hot melt adhesive manufactured by Aika Kogyo Co., Ltd., product name: A-QNJ, the resin foam was made the same as in Examples 5 to 7, and stored in the hot melt adhesive storage tank 44. The temperature of the hot melt adhesive and the temperature of the supply roll 42 and the application roll 43 are set to 130 ° C., the rotational speed of the supply roll 42 and the application roll 43 and the value of the clearance are fixed. The coating amount (coating amount) of Reference Example 8 in Table 2 was set to 5 m / min. The skin material of Reference Example 8 shown in Table 2 was formed in the same manner as in Examples 5 to 7 except for the above.

・ Comparative example 2 (non-woven fabric hot melt adhesive, without back backing)
As a web-like hot melt adhesive, spun bond non-woven fabric, fabric weight: 25 g / m ² , melting point: 115 ° C., product number: Dynak LNS 1225, manufactured by Toha Tech Co., Ltd., resin foam is the same as Examples 5 to 7 Place the resin foam on the press lower mold, place the hot melt adhesive on the surface of the resin foam, laminate the natural leather (cowhide) with the hot melt adhesive, and press it on the press The mold was lowered and heated and compressed to form a skin material of Comparative Example 2 shown in Table 2. The pressing was performed at room temperature for the lower die and at 190 for the upper die for 40 seconds, and the amount of compression was set to 50%.

  Peeling strength, hardness, appearance, shrinkage, and heat resistant adhesive strength were measured for the skin materials of Examples, Reference Examples, and Comparative Examples. The measurement results are shown in Tables 1 and 2.

Peeling strength (unit N / 25 mm) was measured based on JIS K 6854-2 (adhesive-peeling adhesive strength test method, part 2: 180 degree peeling). The number of tests n is three. The surface material was cut into 250 mm × 400 mm, but the direction of 400 mm was vertical and the direction of 250 mm was horizontal. The symbol “*” attached to the measured values indicates that the adhesive strength is high and the peeling surface is broken.
The hardness (unit N) was measured based on a push-pull gauge (FS probe). The larger the number, the harder it is. The hardness is measured by using a push-pull gauge (SUNTEX, FS100), which has a 50-mm diameter hollow disk with a push-pull shaft with a semi-spherical abutment of 10 mm in diameter, centered on a 50-cm diameter hollow disk. The above contact part was pushed down to the sample side to read the numerical value.
The appearance was visually observed whether the surface of the natural leather had wrinkles reduced or unsightly avatars (concave and convex) were generated. The “x” in the “shrinking reduction” observation indicates that a clear reduction in embossing was observed, and the “o” means that no embossing reduction was observed. "△" in the observation result of "avatar" indicates that unsightly avatar (concave and convex) was partially observed, and "o" indicates that unsightly avatar (concave and convex) was not observed.

  Shrinkage (mm) was measured for the amount of shrinkage of the actually molded sample. In both the example and the comparative example, the amount of shrinkage of the raw material leather on which the resin foam is laminated after preparing the raw material leather before molding cut into a predetermined shape as a standard, melt-applying the adhesive and pressing at normal temperature Was measured. As a size of the surface material which becomes a standard, it cut out to 250 mm x 400 mm, made the direction of 400 mm vertical, and made the direction of 250 mm horizontal. “O” in the measurement result indicates that the shrinkage is less than 3 mm in the usable range as a laminated skin material in any of the vertical direction and the horizontal direction, and “x” is the standard raw material leather as a standard On the other hand, the shrinkage difference generated in the laminated skin material is a shrinkage exceeding 3 mm or more.

  Heat resistant adhesive strength prepares a test piece for peeling test, width 25 mm, length 175 mm, peels leaving 75 mm, attaches a 10 g weight to the end of peeled skin material, and does not peel the test piece The heat-resistant adhesive strength was measured by hanging down with one end as an upper end and leaving it to stand in a thermostat at 140 ° C. for 24 hours. Those who passed the test were marked with "o", and the peeled distance was less than 5 mm, and the weight remained at the bottom. Those that failed the test were marked "x", and at the end of the test, the test piece peeled off and the weight dropped.

As shown in Tables 1 and 2, the surface material of each example in which the hot melt adhesive is melted and attached to the resin foam side has high peel strength between natural leather and resin foam, and the hardness is also soft, and the natural leather It has a good appearance, a small shrinkage, and is suitable as a seat material for automobiles, railways, aircraft, furniture, etc., and as a skin material for interior materials and the like. In addition, Examples 1 to 3 and Reference Example 4 having the back base cloth had no deterioration due to heat in the back base cloth, and were of good quality. Furthermore, when a moisture curing type adhesive was used, the peel strength (heat resistant adhesive strength) under high temperature environment was strong and durable.
On the other hand, each comparative example which uses a non-woven fabric as a hot melt adhesive and heat-presses after laminating natural leather has low peel strength between natural leather and resin foam, hard hardness, and reduced emboss on the surface of natural leather In addition, an unsightly avatar is generated to impair the texture of natural leather, and the shrinkage is large, which is unsuitable as a surface material such as a seat for car, railway, aircraft, furniture, etc. and an interior material.

Reference Signs List 10, 60 skin material 10A laminate 11, 61 resin foam 15 back base fabric 21, 71 hot melt adhesive 31, 81 natural leather 40 roll coater 41 feed roll 42 supply roll 43 application roll 44 hot melt adhesive storage tank

Claims (7)

The resin foam made of soft slab polyurethane foam is bonded with a moisture-curable hot-melt adhesive applied and engaged in a molten state on the surface exposed by cutting the cell skeleton of the resin foam. A skin material made of wet natural leather.   The natural leather is laminated on the surface of the resin foam with the moisture-curable hot melt adhesive applied in a molten state, and is formed by moisture in the air and moisture naturally released from the natural leather. The skin material according to claim 1, which is adhered by curing of the moisture curing type hot melt adhesive.   The skin material according to claim 1 or 2, wherein the moisture curing type hot melt adhesive is a solventless urethane reactive hot-melt resin.   The surface material according to any one of claims 1 to 3, wherein a back base fabric is provided on a surface of the resin foam which is not adhered to the natural leather. The moisture curable hot melt adhesive melted by heating is applied to the surface of the resin foam exposed by cutting the cell skeleton and becoming uneven, and the resin is sandwiched between the moisture curable hot melt adhesive in a molten state. A method for producing a skin material, comprising laminating a water-containing natural leather on the surface of a foam, comprising:
Compressing at normal temperature after laminating the natural leather;
Curing the moisture-curable hot melt adhesive with moisture in the air and moisture spontaneously released from the natural leather during the compression.   The method for producing a skin material according to claim 5, wherein a back base fabric is provided in advance on the surface of the resin foam which is not adhered to the natural leather. At the time of application of the moisture-curable hot melt adhesive, from the discharge portion of the adhesive storage tank, in a state where the resin foam is fed in one direction by a feed roll positioned on the lower surface side of the resin foam. A hot-melt adhesive in a molten state supplied and stored between an adhesive supply roll and an application roll is made of the resin foam by rotation of the supply roll and the application roll at a temperature lower than the melting temperature of the adhesive. The step of causing the hot melt adhesive in a molten state to engage with the asperities exposed on the upper surface of the resin foam is performed by supplying and applying the upper surface.
After the resin foam to which the hot melt adhesive in a molten state is applied is placed on the upper surface of the lower mold when laminating the natural leather, the natural leather is placed on the hot melt adhesive in a molten state. Performing a process of laminating to form a laminate so that the back surface is facing downward,
At the time of the compression, a step of compressing the laminate at a normal temperature by an upper mold and a step of curing the hot melt adhesive by moisture in the air and moisture spontaneously released from the natural leather are performed. The manufacturing method of the surface material of Claim 5 or 6 characterized by the above-mentioned.

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