JP7112213B2 - Grain-finished leather-like sheet and bag handle using the same - Google Patents

Description

TECHNICAL FIELD The present invention relates to a grain-finished leather-like sheet and a bag handle using the same.

A grain-finished leather-like sheet having a grain-finished appearance resembling natural leather, which is used as a surface material for bags, clothing, shoes, etc. A grain-finished leather-like sheet comprising a resin layer of

For example, Patent Document 1 below describes an artificial leather for a steering wheel cover with improved durability, a fiber base material containing a long-fiber type high-density ultrafine yarn nonwoven fabric, a urethane pore layer having fine pores, a urethane pore layer and polyurethane. It contains a urethane adhesive layer containing a urethane-based adhesive for bonding the skin layer, and a polyurethane resin produced by polymerizing an isocyanate compound and a polyol compound including a polycarbonate-based polyol, a fluorine-based polyol and an ester-based polyol. Disclosed is an artificial leather for a steering wheel cover, in which polyurethane skin layers are laminated in this order.

JP 2016-8932 A

A grain-finished leather-like sheet has been used as a cover material for bags. In such bags, there is a problem of deterioration over time in which the polyurethane skin film forming the skin of the grain-finished leather-like sheet used for the handle peels off as if it melted during use.

An object of the present invention is to provide a grain-finished leather-like sheet which is less susceptible to the problem that the polyurethane surface film of the grain-finished leather-like sheet melts and peels off during use due to deterioration over time.

The present inventors analyzed compounds attached to the handles of bags that have deteriorated over time. As a result, we identified that the handles that peeled off over time had a large amount of various phthalates, especially mono(2-ethylhexyl) phthalate, attached to them compared to the handles that did not peel off. However, the inventors were able to identify that one of the causes of deterioration over time of peeling is the adhesion of phthalates such as mono(2-ethylhexyl) phthalate, leading to the present invention.

That is, one aspect of the present invention is a grain-finished article comprising a fiber base material, a polyurethane porous layer laminated on the fiber base material , and a polyurethane surface film laminated on the polyurethane porous layer via an adhesive layer . A leather-like sheet in which the polyurethane surface film is obtained by polymerizing urethane monomer components containing an aromatic diisocyanate as an organic polyisocyanate and at least one of a polycarbonate diol and a polyether diol as a polymer polyol. , aromatic-polycarbonate-based polyurethane or aromatic-polyether-based polyurethane, mono (2-ethylhexyl) phthalate is dropped on the surface of the polyurethane surface film, and after standing at room temperature for 336 hours, the polyurethane surface film peels off. It is a grain-finished leather-like sheet that does not have grain. Such a grain-finished leather-like sheet has a high resistance to phthalates such as mono(2-ethylhexyl) phthalate. Therefore, even if the phthalate ester adheres to the product using the grain-finished leather-like sheet, it is suppressed from deteriorating and peeling off over time as if the polyurethane surface film had melted. It is believed that the origin of mono(2-ethylhexyl) phthalate is an internal metabolite of di(2-ethylhexyl) phthalate, which is known as a plasticizer for cosmetics and plastic products.

In the above grain-finished leather-like sheet, the polyurethane surface film contains an aromatic polyisocyanate as the organic polyisocyanate and a polycarbonate-based diol as the polymer polyol, an aromatic-polycarbonate obtained by polymerizing urethane monomer components. It is preferable to contain a poly-based polyurethane from the viewpoint of easily obtaining a grain-finished leather-like sheet having higher resistance to phthalates such as mono(2-ethylhexyl) phthalate. In addition, when the polyurethane surface film is laminated on the polyurethane porous layer laminated on the fiber base material and includes the polyurethane intermediate layer and the polyurethane outermost layer coated on the polyurethane intermediate layer, the polyurethane intermediate layer and the polyurethane outermost layer are laminated. Any of the surface layers preferably comprise an aromatic-polycarbonate polyurethane.

Moreover, one aspect of the present invention is a bag handle including any of the grain-finished leather-like sheets described above. Even if phthalates such as mono(2-ethylhexyl) phthalate adhere to such bag handles, it is possible to prevent them from deteriorating and peeling off over time as if the polyurethane surface film had melted.

Another aspect of the present invention includes a step of dropping a phthalate on the surface of the grain-finished leather-like sheet, and a step of leaving the grain-finished leather-like sheet to which the phthalate has been dropped for a predetermined time. and observing the appearance of the portion of the grain-finished leather-like sheet to which the phthalate ester has been dropped, which has been allowed to stand for a predetermined time. According to such an evaluation method, it is possible to select a grain-finished leather-like sheet that does not easily deteriorate and peel off even if the phthalate ester adheres thereto.

According to the present invention, it is possible to obtain a grain-finished leather-like sheet in which the problem of delamination due to deterioration over time as if the polyurethane surface film had melted does not easily occur.

FIG. 1 is a schematic cross-sectional view of the grain-finished artificial leather of the embodiment. 2 is a photograph showing evaluation results in Example 1. FIG. 3 is a photograph showing evaluation results in Example 2. FIG. 4 is a photograph showing evaluation results in Comparative Example 1. FIG. 5 is a photograph showing evaluation results in Comparative Example 2. FIG. 6 is a photograph showing evaluation results in Comparative Example 3. FIG.

The grain-finished leather-like sheet according to the present invention is a grain-finished leather-like sheet comprising a fiber base material and a polyurethane skin film laminated on the surface layer of the fiber base material directly or via another polyurethane layer. After dropping mono(2-ethylhexyl) phthalate on the surface of the polyurethane surface film and allowing it to stand at room temperature for 336 hours, it is a grain-finished leather-like sheet in which the polyurethane surface film does not peel off.

FIG. 1 is a schematic cross-sectional view illustrating the layer structure of a grain-finished leather-like sheet 10, which is one embodiment of the grain-finished leather-like sheet according to the present invention. The grain-finished leather-like sheet 10 comprises a fiber substrate 1, a polyurethane porous layer 2 laminated on the fiber substrate 1, a polyurethane intermediate layer 4a, and a polyurethane outermost layer 4b coated on the polyurethane intermediate layer 4a. and a polyurethane adhesive layer 3 for bonding the polyurethane porous layer 2 and the polyurethane skin 4 together .

As the fiber base material, nonwoven fabrics, woven fabrics, knitted fabrics, or base materials impregnated with polymer elastic bodies such as polyurethane and acrylic elastic bodies are used for conventionally known artificial leathers and synthetic leathers. There is no particular limitation on the fiber base material. Although the thickness of the fiber base material is not particularly limited, it is preferably about 300 to 3000 μm, more preferably about 500 to 1500 μm. Also, the type of fiber forming the fiber base material is not particularly limited, and examples thereof include nylon-based fibers, polyester-based fibers, polyolefin-based fibers, polyurethane-based fibers, and the like.

Also, the fineness and form of the fibers are not particularly limited. For example, the fineness may be regular fibers with a fineness of more than 1 dtex, or ultrafine fibers with a fineness of less than 1 dtex. The form of the fibers may be solid fibers or fibers with voids such as hollow fibers and lotus root-like fibers.

Polyurethane is obtained by polymerizing a urethane monomer component containing organic polyisocyanate, polymeric polyol, and chain extender in a predetermined molar ratio. Polyurethane is prepared, for example, as an organic solvent solution (for example, a solution in an organic solvent such as dimethylformamide, methyl ethyl ketone, acetone, toluene), an aqueous solution, or an emulsion when producing a grain-finished leather-like sheet.

Specific examples of organic polyisocyanates include non-yellowing diisocyanates including aromatic diisocyanates such as 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate and xylylene diisocyanate. non-yellowing diisocyanates such as aliphatic or alicyclic diisocyanates such as hexamethylene diisocyanate, isophorone diisocyanate, norbornene diisocyanate, and 4,4'-dicyclohexylmethane diisocyanate; Moreover, you may use polyfunctional isocyanate, such as a trifunctional isocyanate and a tetrafunctional isocyanate, together as needed. These may be used alone or in combination of two or more.

Specific examples of polymer polyols include polycarbonate-based diols such as polyhexamethylene carbonate diol, poly(3-methyl-1,5-pentylene carbonate) diol, polypentamethylene carbonate diol, and polytetramethylene carbonate diol. Polyols; polyether-based polyols such as polyethylene glycol, polypropylene glycol, polytetramethylene glycol, and poly(methyltetramethylene glycol); polyethylene adipate diol, polybutylene adipate diol, polypropylene adipate diol, polybutylene sebacate diol, polyhexamethylene adipate Polyester polyols such as diol, poly(3-methyl-1,5-pentylene adipate) diol, poly(3-methyl-1,5-pentylene sebacate) diol, polycaprolactone diol, or copolymers thereof etc. These may be used alone or in combination of two or more.

Specific examples of chain extenders include diamines such as hydrazine, ethylenediamine, propylenediamine, hexamethylenediamine, nonamethylenediamine, xylylenediamine, isophoronediamine, piperazine and its derivatives, adipic acid dihydrazide, and isophthalic acid dihydrazide. triamines such as diethylenetriamine; tetramines such as triethylenetetramine; ethylene glycol, propylene glycol, 1,4-butanediol, 1,6-hexanediol, 1,4-bis(β-hydroxyethoxy)benzene, 1 ,4-cyclohexanediol; triols such as trimethylolpropane; pentaols such as pentaerythritol; aminoalcohols such as aminoethyl alcohol and aminopropyl alcohol; These may be used alone or in combination of two or more. In addition, during the chain elongation reaction, along with the chain elongation agent, monoamines such as ethylamine, propylamine, and butylamine; carboxyl group-containing monoamine compounds such as 4-aminobutanoic acid and 6-aminohexanoic acid; Monools may be used in combination.

The polyurethane for forming the polyurethane porous layer is formed, for example, by applying a polyurethane solution that is wet-coagulated to the surface of the fiber base material and then immersing it in a water-based coagulation bath to solidify the porous polyurethane. be. In addition, the polyurethane porous layer may be impregnated inside for the purpose of imparting shape stability to the fiber base material. In this case, the fiber base material is impregnated with a polyurethane solution in advance, and the polyurethane solution is coated thereon, and then immersed in a water-based coagulation bath to solidify the polyurethane solution. can also impart polyurethane porosity.

The thickness of the polyurethane porous layer is, for example, preferably about 100 to 600 μm, more preferably about 200 to 400 μm.

As the polyurethane surface film, mono(2-ethylhexyl) phthalate is dropped on the surface of the polyurethane surface film of the grain-finished leather-like sheet, and the polyurethane surface film does not peel off after being left at room temperature for 336 hours. It is not limited to vaping. The 336 hours is two weeks, and is a period during which the polyurethane surface film of the grain-finished leather-like sheet according to the present invention can be clearly identified. If it is too short than 336 hours, for example, about 5 days (120 hours), the exfoliated polyurethane skin cannot be identified. In order to form such a polyurethane surface film, an aromatic-polycarbonate-based polyurethane obtained by polymerizing a urethane monomer component containing an aromatic diisocyanate as an organic polyisocyanate and a polycarbonate-based diol as a polymer polyol, It is particularly preferred in that it is difficult to swell with phthalates such as mono(2-ethylhexyl) phthalate, so that the polyurethane surface film is difficult to peel off.

When producing a grain-finished leather-like sheet having a layer structure like the grain-finished leather-like sheet of the present embodiment, as a method of adhering a polyurethane skin film to the surface of a polyurethane porous layer or a polyurethane non-porous layer, For example, a method using the following dry surface forming method can be mentioned.

A polyurethane film is formed to form a polyurethane skin on the release paper. When the polyurethane surface film has a laminated structure including a polyurethane intermediate layer and a polyurethane outermost layer coated on the polyurethane intermediate layer, for example, a film of the outermost polyurethane layer is formed on a release paper, and the polyurethane outermost layer is By forming a polyurethane film for forming a polyurethane intermediate layer on the film, a polyurethane surface film having a laminate structure of a polyurethane outermost layer and a polyurethane intermediate layer is formed. A polyurethane adhesive is then applied to the polyurethane skin film and dried with complete or partial solvent removal.

The thickness of the polyurethane adhesive layer is preferably 5 to 200 μm, more preferably 30 to 70 μm. If the polyurethane adhesive layer is too thick, the flex resistance tends to decrease and the adhesive strength of the polyurethane surface film tends to decrease. The total thickness of the polyurethane surface film and the polyurethane adhesive layer should be 10 to 300 μm, more preferably 30 to 200 μm, particularly about 50 to 100 μm, to maintain a balance between mechanical properties and texture. It is preferable because it is possible.

Then, the polyurethane adhesive laminated on the polyurethane skin film formed on the release paper is adhered to the surface of the polyurethane porous layer and pressed, and then the polyurethane adhesive is cured to form a polyurethane adhesive layer. Glue the polyurethane skin through. Then, by peeling off the release paper from the surface of the polyurethane surface film, a grain-finished leather-like sheet having a polyurethane surface film on the surface of the porous layer, such as the grain-finished leather-like sheet of the present embodiment, is obtained.

Alternatively, instead of the dry surface making method as described above, a resin liquid containing polyurethane is applied to the surface of the polyurethane porous layer or the polyurethane nonporous layer by a gravure method, a reverse coating method, a direct coating method, or the like, A polyurethane surface film may be formed by wet coagulation or dry coagulation of an elastic polyurethane polymer. The polyurethane skin can be non-porous or porous.

The thickness of the polyurethane surface film is preferably 10 to 100 μm, more preferably 20 to 50 μm. If the polyurethane surface film is too thin, the abrasion resistance tends to decrease, and if it is too thick, the texture tends to be hard and the flex resistance tends to decrease.

The grain-finished leather-like sheet according to the present invention is produced by dripping mono(2-ethylhexyl) phthalate on the surface of the polyurethane surface film and allowing it to stand at room temperature for 336 hours. is. Such a grain-finished leather-like sheet was obtained by the following evaluation method.

A phthalate such as mono(2-ethylhexyl) phthalate is dropped onto the surface of the grain-finished leather-like sheet. It should be noted that resistance to phthalate esters can be similarly evaluated when other phthalate esters are added dropwise instead of mono(2-ethylhexyl) phthalate. Specific examples of other phthalates include dibutyl phthalate (DBP), benzyl butyl phthalate (BBP), di(2-ethylhexyl) phthalate (DEHP), dioctyl phthalate (DNOP), diisononyl phthalate ( DINP), diisodecyl phthalate (DIDP), and the like.

The drop amount of the phthalate ester is not particularly limited as long as it penetrates into the fiber base material over time and sufficiently remains on the surface even after 2 weeks, but is, for example, about 0.1 to 0.5 cc. is preferred.

Then, the grain-finished leather-like sheet to which the phthalate ester has been dropped is left for a predetermined period of time. The time for standing is appropriately adjusted according to the resistance of the grain-finished leather-like sheet to be evaluated to phthalates, and is, for example, 100 to 400 hours, preferably 336 hours.

Then, the appearance of the portion of the grain-finished leather-like sheet to which the phthalate ester has been dropped is observed. Specifically, after wiping off the phthalate ester remaining on the surface of the grain-finished leather-like sheet with a wiping cloth or the like, whether or not the polyurethane surface film was peeled off was examined. Detachability is evaluated based on criteria such as whether or not the polyurethane surface film was swollen. In addition, it can be determined that the grain-finished leather-like sheet in which the polyurethane surface film is not peeled off is difficult to peel off due to deterioration of the polyurethane resin layer over time due to the phthalate ester. In addition, the phrase "the polyurethane surface film does not peel off" means that it does not peel off when lightly touched.

As described above, the grain-finished leather-like sheet according to the present invention has a grain-finished leather-like sheet having a grain-finished appearance resembling natural leather, which is used as a covering material for bags, clothing, shoes, and the like. It is preferably used. In particular, for example, when it is used as a surface material for a handle of a bag, even if the phthalate ester adheres, the polyurethane surface film is prevented from deteriorating with age and peeling off as if it melted during use.

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples. However, the scope of the present invention is not limited to these examples.

[Preliminary experiment]
A bag with a handle using a grain-finished leather-like sheet, in which the polyurethane surface film of the grain-finished leather-like sheet of the handle deteriorated and peeled off as if it melted during use, was collected from the market. Then, a sample cut out from the peeled portion and a sample cut out from the portion where peeling did not occur were prepared, and the components adhering to each sample were analyzed as follows. Specifically, each flask containing 0.5 g of each sample and 5 ml of acetonitrile was heated at 60° C. for 4 hours to extract the adhering components. Then, each measurement sample was prepared by filtering the extract with a PTFE filter having a pore size of 0.45 μm. Then, the contained components were specified by performing gas chromatography mass spectrometry (GCMS analysis) on the components in each measurement sample. As a result, it was confirmed that the sample cut from the peeled portion contained significantly more mono(2-ethylhexyl) phthalate than the sample cut from the portion where peeling did not occur. A relatively large amount of mono(2-ethylhexyl) phthalate was also detected in the sample cut from the portion where peeling did not occur. As other components, a slightly larger amount of cetanol and stearic acid was detected in the sample cut from the portion where peeling did not occur than in the sample where peeling did not occur. Preliminary experiments were conducted using each of the detected components, and as a result, it was found that mono(2-ethylhexyl) phthalate easily exfoliated the polyurethane surface film of the grain-finished leather-like sheet.

[Example 1]
A sea-island composite fiber composed of 45 parts by mass of 6-nylon (sea component) and 55 parts by mass of polystyrene (island component) is melt-spun, drawn 3 times, applied with a fiber oil, and mechanically crimped. Dried. The resulting crimped fibers were cut into 51 mm lengths to form staples of 3 decitex to form a web, which was alternately combined from both sides and subjected to needle punching at about 500 punches/cm ² to obtain an entangled nonwoven fabric. This entangled nonwoven fabric had a basis weight of 350 g/m ² and an apparent specific gravity of 0.17. This entangled nonwoven fabric was treated with a 4% aqueous solution of polyvinyl alcohol, compressed and fixed to a thickness of about 1.3 mm, and buffed to smooth the surface. Then, it was impregnated with a dimethylformamide (hereinafter referred to as DMF) solution of polyurethane mainly composed of polyester polyurethane at a concentration of 13%. Further, the same polyurethane elastomer solution was coated on the surface in an amount of 100 g/m ² in terms of solid content, and then immersed in a mixture of DMF/water to wet-coagulate the polyurethane into a porous state. Then, the island component was eluted and removed in hot toluene to convert the composite fibers into hollow fibers, thereby obtaining a fiber base material laminated with a polyurethane porous layer. The thickness of the polyurethane porous layer was 300 μm.

Next, on release paper (R-70 manufactured by Lintec Co., Ltd.), an aromatic-polycarbonate-based polyurethane containing an aromatic diisocyanate as an organic polyisocyanate unit and a polycarbonate-based polyol as a polymer polyol unit. 100 parts by mass of a non-yellowing polycarbonate-based polyurethane 30% solution (ME8210LP, manufactured by Dainichiseika Co., Ltd.), a polyurethane coloring agent in which a pigment is dispersed in a polyurethane vehicle (Rezamin BS012 (manufactured by Dainichiseika Kogyo Co., Ltd.)) A solution containing 6 parts by mass, 3 parts by mass of a polyurethane coloring agent (Rezamin BS181 (manufactured by Dainichiseika Kogyo Co., Ltd.)), 30 parts by mass of DMF, and 30 parts by mass of methyl ethyl ketone was dried so that the thickness thereof would be 15 μm. A polyurethane outermost layer was formed by coating and drying. Then, on the polyurethane outermost layer, a DMF solution containing 100 parts by mass of a non-yellowing polycarbonate polyurethane 30% solution (ME8210LP) containing the same aromatic-polycarbonate polyurethane and 25 parts by mass of a polyurethane colorant (Rezamin BS012) was dried. A polyurethane intermediate layer was formed by coating and drying so that the final thickness would be 20 μm.

Then, 130 g/m ² of a polyurethane adhesive solution was applied to the surface of the polyurethane intermediate layer, dried at 120° C. for 15 seconds to evaporate the solvent, and then laminated to the polyurethane porous layer. The polyurethane-based adhesive solution contains, as an adhesive component, TA205FT (manufactured by DIC Corporation), which is a cross-linkable polycarbonate-based polyurethane-based adhesive, with a cross-linking agent and a cross-linking accelerator added to 100 parts by mass, A solvent containing 5 parts by mass of DMF and 10 parts by mass of ethyl acetate was used. Then, the obtained laminated intermediate is pressed with a roll having a clearance of about 65% of the total thickness of 1.55 mm of the porous polyurethane layer and the fiber base material, and the polyurethane adhesive is applied to the polyurethane porous layer. penetrated the layer. Then, after drying at 130° C. for 3 minutes and aging treatment at 50° C. for 3 days, the release paper was peeled off to obtain a grain-finished artificial leather as a grain-finished leather-like sheet.

Then, 0.3 cc of mono(2-ethylhexyl) phthalate was dropped on the surface of the polyurethane surface film of the grain-finished artificial leather, and left at room temperature for 120 hours (5 days) and 336 hours (2 weeks). Then, the mono(2-ethylhexyl) phthalate on the polyurethane surface film of the grain-finished artificial leather was wiped off after each standing, and the appearance was observed. As a result, there was no significant change in appearance and the fiber base layer did not swell after 5 days. On the other hand, after 2 weeks, the fiber base layer was swollen, but the polyurethane surface film did not come off or peel off. Fig. 2 shows a photograph taken at that time.

[Example 2]
A grain-finished artificial leather was obtained and evaluated in the same manner as in Example 1, except that the polyurethane intermediate layer, the polyurethane outermost layer and the adhesive layer were formed as follows.

On release paper (R-70 manufactured by Lintec Co., Ltd.), an aromatic-polyether polyurethane containing an aromatic diisocyanate as an organic isocyanate unit and a polyether polyol as a polymer polyol unit. 100 parts by mass of a 30% modified polyether-based polyurethane solution (ME8116 manufactured by Dainichiseika Co., Ltd.), 1.5 parts by mass of a polyurethane colorant (Rezamin DUT4181 (manufactured by Dainichiseika Kogyo Co., Ltd.)), pearl pigment ink KW120 A solution containing 8 parts by mass (manufactured by Dainichiseika Kogyo Co., Ltd.), 30 parts by mass of DMF, and 30 parts by mass of methyl ethyl ketone is coated so that the thickness after drying is 15 μm, and dried to form the outermost polyurethane layer. formed. Then, on the polyurethane outermost layer, 100 parts by mass of a 30% solution of a non-yellowing polyether polyurethane containing a similar aromatic-polyether polyurethane (ME8116 manufactured by Dainichiseika Co., Ltd.) and a polyurethane colorant (Rezamin DUT4094 ) was applied so that the thickness after drying was 20 μm, and dried to form a polyurethane intermediate layer.

Then, 130 g/m ² of a polyurethane adhesive solution was applied to the surface of the polyurethane intermediate layer, dried at 120° C. for 15 seconds to evaporate the solvent, and then laminated to the polyurethane porous layer. The polyurethane-based adhesive solution is a cross-linkable polyether-based polyurethane-based adhesive, UD8310 (manufactured by Dainichiseika Kogyo Co., Ltd.) of 100 parts by mass to which a cross-linking agent and a cross-linking accelerator are added. and containing 5 parts by mass of DMF and 10 parts by mass of ethyl acetate as solvents. Then, the obtained laminated intermediate is pressed with a roll having a clearance of about 65% of the total thickness of 1.55 mm of the porous polyurethane layer and the fiber base material, and the polyurethane adhesive is applied to the polyurethane porous layer. penetrated the layer. Then, after drying at 130° C. for 3 minutes and aging treatment at 50° C. for 3 days, the release paper was peeled off to obtain a grain-finished artificial leather as a grain-finished leather-like sheet.

As a result, the fiber base layer was found to swell after 5 days, but the polyurethane surface film did not swell. Moreover, in two weeks, although the polyurethane surface film was swollen, it did not come off or peel off. A photograph taken at that time is shown in FIG.

[Comparative Example 1]
Grain-finished artificial leather was obtained and evaluated in the same manner as in Example 1 except that the polyurethane intermediate layer and the polyurethane outermost layer were formed as follows.

On release paper (R-70 manufactured by Lintec Co., Ltd.), non-yellowing containing aliphatic-polycarbonate polyurethane containing aliphatic diisocyanate as organic isocyanate unit and polycarbonate polyol as polymer polyol unit Polycarbonate-based polyurethane 30% solution (NY324 manufactured by DIC Corporation) 100 parts by mass, polyurethane colorant (Rezamin DUT4181 (manufactured by Dainichiseika Kogyo Co., Ltd.)) 1.5 parts by mass, pearl pigment ink KW120 (Dainichiseika A polyurethane outermost layer was formed by applying a solution containing 8 parts by mass of Kogyo Co., Ltd., 20 parts by mass of DMF, and 20 parts by mass of toluene to a thickness of 15 μm after drying, followed by drying. Then, on the polyurethane outermost layer, 100 parts by mass of a 30% non-yellowing polycarbonate-based polyurethane solution (NY324 manufactured by DIC Corporation) containing a similar aliphatic polycarbonate-based polyurethane and 25 parts by mass of a polyurethane colorant (Lezamin DUT4094) A polyurethane intermediate layer was formed by applying a DMF solution containing the above to a thickness of 20 μm after drying and drying.

As a result, the polyurethane surface film swelled in 5 days, and after 2 weeks, the polyurethane surface film was completely peeled off and the polyurethane porous layer was exposed. A photograph taken at that time is shown in FIG.

[Comparative Example 2]
A grain-finished artificial leather was obtained and evaluated in the same manner as in Example 1, except that the polyurethane intermediate layer, the polyurethane outermost layer and the adhesive layer were formed as follows.

A non-yellowing polycarbonate containing an aliphatic-polycarbonate-based polyurethane containing an aliphatic diisocyanate as an organic isocyanate unit and a polycarbonate-based polyol as a polymer polyol unit on a release paper (R-70 manufactured by Lintec Co., Ltd.) Polyurethane 30% solution (NY324 manufactured by DIC Corporation) 100 parts by mass, polyurethane colorant (Rezamin DUT4181 (manufactured by Dainichiseika Kogyo Co., Ltd.)) 1.5 parts by mass, pearl pigment ink KW120 (Dainichiseika Kogyo Co., Ltd.) A polyurethane outermost layer was formed by applying a solution containing 8 parts by weight of Co., Ltd., 20 parts by weight of DMF, and 20 parts by weight of toluene to a thickness of 15 μm after drying, followed by drying. Then, the polyurethane outermost layer contains an aromatic-polyether polyurethane containing an aromatic diisocyanate as an organic isocyanate unit and a polyether polyol as a polymer polyol unit, and a 30% solution of a non-yellowing polyether polyurethane ( A DMF solution containing 100 parts by mass of ME8116) manufactured by Dainichiseika Kogyo Co., Ltd. and 25 parts by mass of a polyurethane coloring agent (Rezamin DUT4094) was applied so that the thickness after drying was 20 μm, and dried. , forming a polyurethane interlayer.

Then, 130 g/m ² of a polyurethane adhesive solution was applied to the surface of the polyurethane intermediate layer, dried at 120° C. for 15 seconds to evaporate the solvent, and then laminated to the polyurethane porous layer. The polyurethane-based adhesive solution is a cross-linkable polyether-based polyurethane-based adhesive, UD8310 (manufactured by Dainichiseika Kogyo Co., Ltd.) of 100 parts by mass to which a cross-linking agent and a cross-linking accelerator are added. and containing 5 parts by mass of DMF and 10 parts by mass of ethyl acetate as solvents. Then, the obtained laminated intermediate is pressed with a roll having a clearance of about 65% of the total thickness of 1.55 mm of the porous polyurethane layer and the fiber base material, and the polyurethane adhesive is applied to the polyurethane porous layer. penetrated the layer. Then, after drying at 130° C. for 3 minutes and aging treatment at 50° C. for 3 days, the release paper was peeled off to obtain a grain-finished artificial leather as a grain-finished leather-like sheet.

As a result, the polyurethane surface film swelled in 5 days, and after 2 weeks, the polyurethane surface film was completely peeled off and the polyurethane porous layer was exposed. FIG. 5 shows a photograph taken at that time.

[Comparative Example 3]
A grain-finished artificial leather was obtained and evaluated in the same manner as in Example 1 except that the polyurethane intermediate layer and the polyurethane outermost layer were formed as follows.

On release paper (R-70 manufactured by Lintec Co., Ltd.), non-yellowing containing aliphatic-polycarbonate polyurethane containing aliphatic diisocyanate as organic isocyanate unit and polycarbonate polyol as polymer polyol unit Polycarbonate-based polyurethane 30% solution (NY324 manufactured by DIC Corporation) 100 parts by mass, polyurethane colorant (Rezamin DUT4181 (manufactured by Dainichiseika Kogyo Co., Ltd.)) 1.5 parts by mass, pearl pigment ink KW120 (Dainichiseika A polyurethane outermost layer was formed by applying a solution containing 8 parts by mass of Kogyo Co., Ltd., 20 parts by mass of DMF, and 20 parts by mass of toluene to a thickness of 15 μm after drying, followed by drying. Then, on the polyurethane outermost layer, 100 parts by mass of a 30% non-yellowing polycarbonate-based polyurethane solution containing a similar aliphatic polycarbonate-based polyurethane (NY324 manufactured by DIC Corporation) and 25 parts by mass of a polyurethane coloring agent (Rezamin DUT4094). A polyurethane intermediate layer was formed by applying a DMF solution containing the above to a thickness of 20 μm after drying and drying.

Then, 130 g/m ² of a polyurethane adhesive solution was applied to the surface of the polyurethane intermediate layer, dried at 120° C. for 15 seconds to evaporate the solvent, and then laminated to the polyurethane porous layer. The polyurethane-based adhesive solution is a cross-linkable polyether-based polyurethane-based adhesive, UD8310 (manufactured by Dainichiseika Kogyo Co., Ltd.) of 100 parts by mass to which a cross-linking agent and a cross-linking accelerator are added. and containing 5 parts by mass of DMF and 10 parts by mass of ethyl acetate as solvents. Then, the obtained laminated intermediate is pressed with a roll having a clearance of about 65% of the total thickness of 1.55 mm of the porous polyurethane layer and the fiber base material, and the polyurethane adhesive is applied to the polyurethane porous layer. infiltrated into the layers. Then, after drying at 130° C. for 3 minutes and aging treatment at 50° C. for 3 days, the release paper was peeled off to obtain a grain-finished artificial leather as a grain-finished leather-like sheet.

As a result, the polyurethane surface film swelled in 5 days, and after 2 weeks, the polyurethane surface film was completely peeled off and the polyurethane porous layer was exposed. A photograph taken at that time is shown in FIG.

From the above results, the grain-finished leather-like sheet of Example 1 provided with a polyurethane skin layer containing an aromatic-polyether polyurethane and the silver of Example 2 provided with a polyurethane skin layer containing an aromatic-polyether-based polyurethane The textured leather-like sheet was hard to swell with mono(2-ethylhexyl) phthalate and hard to peel off. Further, the grain-finished leather-like sheet of Example 1 having a polyurethane skin layer containing an aromatic-polycarbonate polyurethane was particularly difficult to swell in mono(2-ethylhexyl) phthalate and was difficult to peel off. On the other hand, Comparative Examples 1 and 3 provided with a polyurethane skin layer containing an aliphatic-polycarbonate polyurethane, a polyurethane containing an outermost layer containing an aliphatic-polycarbonate-based polyurethane and an intermediate layer containing an aromatic-polyether-based polyurethane In all of the grain-finished leather-like sheets of Comparative Example 2 having a skin layer, the polyurethane skin swelled after 5 days, and the polyurethane skin was completely peeled off after 2 weeks.

Reference Signs List 1 Fiber base material 2 Polyurethane porous layer 3 Polyurethane adhesive layer 4 Polyurethane surface film 4a Polyurethane intermediate layer 4b Polyurethane outermost layer 10 Grain-finished leather-like sheet

Claims (5)

A grain-finished leather-like sheet comprising a fiber base material, a polyurethane porous layer laminated on the fiber base material , and a polyurethane surface film laminated on the polyurethane porous layer via an adhesive layer ,
The polyurethane surface film is an aromatic-polycarbonate-based polymer obtained by polymerizing a urethane monomer component containing an aromatic diisocyanate as an organic polyisocyanate and at least one of a polycarbonate-based diol and a polyether-based diol as a polymer polyol. Polyurethane or aromatic-polyether polyurethane,
A grain-finished leather-like sheet characterized in that, after dropping mono(2-ethylhexyl) phthalate on the surface of said polyurethane surface film and allowing it to stand at normal temperature for 336 hours, said polyurethane surface film does not peel off. 2. The grain-finished leather-like sheet according to claim 1, wherein the fiber base material is a non-woven fabric of nylon fibers . The polyurethane epidermis is
The grain-finished leather-like according to claim 1 , comprising a polyurethane intermediate layer and a polyurethane outermost layer adhered to the polyurethane intermediate layer, wherein the polyurethane intermediate layer and the polyurethane outermost layer contain the aromatic-polycarbonate-based polyurethane. sheet. The grain-finished leather-like sheet according to any one of claims 1 to 3, which is used as a material for a handle for a bag. A bag handle comprising the grain-finished leather-like sheet according to any one of claims 1 to 4.

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