TW201937044A - Industrial paper for synthetic leather and method for producing synthetic leather having suitable adherence or release power under micro rugged texture - Google Patents

Abstract

A industrial paper (1) for synthetic leather comprises a base material (2) and a release agent layer (3) formed on the base material (2), on which the specular gloss of the release agent layer (3), based on JIS Z 8741 standard, has the gloss value 30% or less under 20 degree reflection angle, 70% or less under 60 degree reflection angle , and 100% or less under 85 degree reflection angle.

Description

Engineering paper for synthetic leather and manufacturing method of synthetic leather

The invention relates to a synthetic leather engineering paper and a method for manufacturing synthetic leather.

Synthetic leather is based on paper or the like, using engineering paper having a release agent layer composed of a release agent resin composition, and coating the release agent layer with a urethane resin, vinyl chloride resin, etc. A synthetic resin-based coating liquid is dried and then, as required, a base fabric is further bonded via an adhesive, and then the synthetic leather is peeled off from engineering paper.
In this synthetic leather manufacturing method, since the surface state of the release agent layer of engineering paper is transferred to the surface of the synthetic leather, the gloss, matting, or pattern of synthetic leather also varies with the surface state of the engineering paper. different.
Engineering paper for enamel synthetic leather requires high surface smoothness; engineering paper for imitation matte synthetic leather requires high mattness with surface unevenness.
For example, in Document 1 (Japanese Patent Application Laid-Open No. 10-306253), in order to produce a synthetic leather with extremely high gloss, which is called "enamel texture", a silicone-modified alkyd resin is disclosed. Resin composition for engineering paper peeling.
In addition, in Document 2 (Japanese Patent Laid-Open No. 2004-115972), as a composition for forming a matt layer suitable for the production of matte synthetic leather without embossing or embossing, etc., A composition for forming a rough layer comprising porous fine particles as a matting agent is disclosed.
In addition, the synthetic leather with enamel texture is too lustrous, which will produce a dazzling impression, but it has a cheap feel; the synthetic leather with imitation matte texture has a monotonous texture, and they are often regarded as lacking high-quality. In recent years, consumers have demanded synthetic leathers that have a luster and a dark finish.
Synthetic leather with such a "moist luster" cannot be used in engineering leather used in the enamel-textured synthetic leather described in Document 1 or in synthetic paper imitation matte synthetic leather described in Document 2. Obtained during manufacture.
The reason is that the engineering paper for enamel texture or imitation matte does not have a surface state for "moist gloss".
Furthermore, in the manufacture of synthetic leather, engineering paper needs to be finally peeled from synthetic leather, and a moderate peeling force is required.
Especially for the engineering paper with a matte feeling, the surface unevenness is obvious, which makes the contact area between the engineering paper and the synthetic resin larger, and the bonding force (peeling force) becomes higher. Impact on productivity.

An object of the present invention is to provide a synthetic leather engineered paper that has a moderate adhesion (peeling force) due to fine surface irregularities and can produce a desired texture of synthetic leather, and a method for producing a synthetic leather.
The synthetic leather engineering paper of the present invention is a synthetic leather engineering paper having a substrate and a release agent layer formed on the substrate, and is characterized in that the specular gloss of the release agent layer according to JIS Z 8741 is 20, ° gloss value is 30% or less, 60 ° gloss value is 70% or less, 85 ° gloss value is 100% or less.
According to this invention, the specular gloss of the release agent layer can be used to produce synthetic leather using engineering paper having a predetermined gloss value as described above, so that the outer surface of the synthetic leather can have a desired texture called "wet gloss".
In the present invention, it is preferable that the release agent layer is formed of a release agent composition, and the release agent composition contains a filler composed of irregular particles of more than 0% by mass and less than 15% by mass.
According to this invention, an engineering paper having a desired specular gloss can be easily produced by including a filler composed of irregular particles in an amount of more than 0% by mass and less than 15% by mass.
In this invention, it is preferable that the film thickness of the said release agent layer is 3.0 micrometers or more and 12 micrometers or less.
If the film thickness is less than 3.0 μm, too much filler is exposed from the release agent layer to enhance the imitated matte feeling, and it is impossible to produce a synthetic leather having a desired texture. In addition, the filler is not easily fixed to the release agent layer, and the filler is detached from the release agent layer, making it impossible to produce a synthetic leather having a desired texture.
In addition, if the film thickness exceeds 12 μm, the filler is buried in the release agent layer, the amount of filler exposed from the release agent layer is reduced, and the gloss is too strong, so that a synthetic leather having a desired texture cannot be produced.
In the present invention, the average particle diameter D50 of the amorphous particles is preferably 0.5 μm or more and 5.0 μm or less.
Preferably, in the particle size distribution of the amorphous particles, the particle size D10 of the cumulative distribution is 0.8 times or less the average particle size D50, and the particle size D90 is 1.2 times or more the average particle size D50.
According to this invention, the average particle diameter D50 of the irregular particles is in this range, and the particle size distribution of the irregular particles is in this range. Since the irregular particles protrude from the surface of the release agent layer, moderate surface irregularities can be formed, and Suitable for manufacturing synthetic leather with desired texture.
In the present invention, it is preferable that the aforementioned amorphous particles are amorphous silica particles.
According to this invention, the permeation-shaped particles are made of an inorganic material, and even if heated in the production of synthetic leather, they will not be deformed or melted, and a synthetic leather having a desired texture can be produced.
In the present invention, it is preferable that the release agent layer contains a polysiloxane modified alkyd resin.
According to this invention, a polysiloxane modified alkyd resin has heat resistance and can be made into an engineering paper with good peelability from synthetic leather.
The method for producing a synthetic leather of the present invention is characterized by comprising the steps of: applying a coating solution containing a synthetic resin on the release agent layer of the aforementioned synthetic leather engineering paper; and drying the coated coating solution to form A step of synthesizing leather; and a step of peeling the synthetic leather engineering paper from the synthetic leather after drying.
According to this invention, it is possible to enjoy the same actions and effects as described above.

[Form of Implementing Invention]
Hereinafter, an embodiment of the present invention will be described based on the drawings. Fig. 1 shows a synthetic leather engineering paper 1 according to an embodiment of the present invention. The synthetic leather engineering paper 1 includes a base material 2 and a release agent layer 3.

[1] Substrate 2
The base material 2 of the synthetic leather engineering paper 1 can be appropriately selected as long as it can support a release agent layer 3 described later, and examples thereof include a paper base material and a resin film.
Examples of the paper substrate include paper substrates such as dory paper, medium paper, glassine, art paper, coated paper, and cast-coated paper; A laminated paper in which a thermoplastic resin such as polyethylene is laminated on these paper substrates.
Examples of the resin film include polyesters such as polyethylene terephthalate, polyethylene naphthalate, and polybutylene terephthalate, polyethylene, polypropylene, and polymethylpentene. Films made of polyolefin, etc.
In addition, these may be a single layer or a multilayer of two or more layers of the same type or different types.
The thickness of the substrate is not particularly limited, but is preferably 5 to 300 μm, and more preferably 10 to 200 μm.
Among these substrates, from the viewpoint of strength and easy availability, a paper substrate is preferred, and a cast coated paper is more preferred. By using cast coated paper, smoothness, heat resistance, and barrier properties can be ensured.
Examples of the cast coated paper (high-gloss paper) include those manufactured by the direct method, the infiltration method, and the coagulation method. Examples of commercially available products include the Esprit series made by Japan Paper Co., Ltd. and Oji Paper System Mirror Coat series.

[2] Release agent layer 3
As shown in FIG. 1, the release agent layer 3 is formed of a release agent composition 31.

[2-1] Release agent composition 31
The release agent composition 31 forming the release agent layer 3 includes a release main agent and a filler 32 and is formed by blending additives and solvents as required.
Examples of the releasable main agent for forming the release agent composition 31 include:
(1) a polymer compound having a low polarity and exhibiting peelability by itself;
(2) a polymer material imparting releasability by chemical modification;
(3) A composition or the like that imparts a releasability to a polymer material by adding a releasable low molecular or oligomer component.
Examples of polymer compounds that are low in polarity and exhibit peelability include polyorganosiloxane; fluoropolymers; polyolefins such as polyethylene, polypropylene, and polymethylpentene; polybutadiene and polyisocyanate Diene polymers such as pentadiene.
The polymer material that imparts releasability by chemical modification. Examples of chemically modified polymer components include polyvinyl alcohol, partially saponified polyvinyl acetate, hydroxy acrylate copolymer, and urethane. Resin, alkyd resin, amine resin, epoxy resin, phenol resin, etc. Many of these polymer components cannot exhibit peelability without chemical modification.
In addition, as a component for chemical modification, a polymer material that is provided with peelability by chemical modification includes a functional organopolysiloxane or organosiloxane oligomer; a functional group-containing fluorine Carbon compounds; long-chain alkyl compounds with functional groups. Among them, as the long-chain alkyl compound, a compound having an alkyl group having 12 or more carbon atoms such as a lauryl group, a palmyl group, and a stearyl group can be mentioned.
Examples of the functional group of the chemically modified compound include a hydroxyl group, an amino group, a carboxyl group, an epoxy group, an isocyanate group, a (meth) acrylfluorenyl group, a thiol group, and an alkoxysilyl group.
Polymer materials that are chemically modified to impart releasability are commonly referred to as polysiloxane modified resins, fluorine modified resins, long-chain alkyl modified resins, and the like.
As the polymer material to which a peelable low-molecular or oligomer component is added to the polymer material to impart peelability, examples of the polymer material used include polyvinyl alcohol, partially saponified polyvinyl acetate, acrylate copolymer, Urethane resin, polyester resin, polyamide resin, alkyd resin, amine resin, epoxy resin, phenol resin, etc.
Examples of the peelable low-molecular or oligomer component added to these polymer materials include waxes (hydrocarbon compounds); polyorganosiloxanes or organosiloxane oligomers; fluorocarbons; long-chain alkyl groups Examples of the compound include polyether adducts and polyester adducts.
Among these, from the viewpoint that it is easy to improve the peelability or heat resistance, and the affinity with the filler or other additives can be better, a polymer material that imparts peelability by chemical modification is preferably used as the main peelability. The agent is more preferably an alkyd resin chemically modified with polyorganosiloxane, so-called polysiloxane modified alkyd resin. Moreover, the said peelable main agent may be used individually by 1 type, and may use 2 or more types together.

[2-2] Filler 32
Examples of the filler 32 added to the release agent composition 31 include amorphous silicon dioxide, aluminum oxide, titanium oxide, zinc oxide, calcium carbonate, magnesium hydroxide, aluminum hydroxide, kaolin, talc, clay, and the like; From the viewpoint of heat resistance, amorphous silica particles and amorphous alumina particles are preferred; from the viewpoint of economy, amorphous silica is more preferably used.
In addition, these fillers are for the purpose of easily improving dispersibility or imparting reactivity with a release main agent, and the particle surface may be modified with an organic group or a functional group.
In the release agent composition 31, the filler 32 is preferably added with a filler 32 composed of irregular particles exceeding 0% by mass and not more than 15% by mass. The blending ratio of the filler 32 is more preferably more than 1% by mass and less than 12.5% by mass, and particularly preferably more than 2% by mass and less than 10% by mass. By setting it as this range, a desired specular gloss can be obtained, and a moderate peeling force can be obtained.
The average particle diameter D50 of the amorphous particles is preferably 0.5 μm or more and 5.0 μm or less. If the average particle diameter D50 is less than this lower limit, the filler may not be easily exposed from the release agent layer, and the gloss may be enhanced. When the average particle diameter D50 is larger than the upper limit value, the filler may be excessively exposed from the release agent layer, and there is a possibility that the matte feeling is enhanced. In addition, the average particle diameter can be measured by a laser diffraction particle size distribution meter using the release agent composition containing the filler 32 as a measurement object.
The irregular particles used in the release agent composition 31 are preferably those having a wide particle size distribution. That is, the larger the difference between the cumulative distribution particle diameter D10 and the particle diameter D90, the better; specifically, it is preferable that D10 is 0.8 times or less the average particle diameter D50, and D90 is 1.2 times the average particle diameter D50. the above.
The transmission particle size distribution has such a magnitude that rougher and smoother portions of the surface unevenness of the release agent layer 3 are randomly formed, so that the gloss value with respect to the incident angle of light can be converged within a desired range. As a result, a synthetic leather engineering paper 1 having desired glossiness can be obtained. In addition, since the filler 32 is an irregular particle, it is easy to make the particle size distribution have a certain width, so it is preferable to use the irregular particle.
The amorphous particles used in the filler 32 are preferably those in which a bulk body of raw materials such as silicon dioxide and alumina is crushed and pulverized; the specific surface area is 10 m ² / g or more, preferably 20 m ² / g Above 1,000 m ² / g, more preferably between 50 m ² / g and 500 m ² / g.
The release agent composition 31 may further contain additives such as a hardener, a cross-linking agent, a reaction initiator, and a catalyst to the release main agent and the filler, and the release agent composition 31 may be diluted with an organic solvent.
The hardener, the cross-linking agent, and the reaction initiator used in the release agent composition 31 are selected from compounds having a functional group capable of forming a chemical bond with a functional group possessed by the release main agent. The hardening agent, the cross-linking agent, and the reaction initiator form a three-dimensional mesh structure by reacting with the release main agent, which can improve the strength or heat resistance of the film of the release agent layer 3.
The curing agent, crosslinking agent, or reaction initiator used in the release agent composition 31 is not particularly limited as long as it can react with the functional group of the release main agent, and examples thereof include organic compounds containing a polyhydric hydrogen silicon group. Siloxane compounds, melamine compounds, polyisocyanate compounds, polyepoxide compounds, polyaldehyde compounds, polyamine compounds, polyoxazoline compounds, metal complexes, and the like.
The catalyst used in the release agent composition 31 is a compound that accelerates the reaction and causes the curing reaction (crosslinking reaction) of the release agent composition to proceed at a low temperature or in a short time. The compound is selected in accordance with the chemical reaction. For example, when an addition reaction using an organosiloxane compound containing a polyhydric hydrogen silicon group is used, for example, a platinum catalyst is used. In the reaction using dehydration and dealcoholization using a melamine compound, an acid catalyst such as p-toluenesulfonic acid is used.
In the release agent composition 31, the blending ratio of the hardener, the cross-linking agent, or the reaction initiator for the release main agent may be appropriately selected so as to match each physical property required for the engineering paper; for example, relative to the release main agent It is preferably 100 parts by mass or more, preferably 0.1 parts by mass or more and 400 parts by mass or less, and more preferably 10 parts by mass or more and 200 parts by mass or less. In addition, the blending ratio of the catalyst may be similarly selected as long as it is appropriately selected so as to match the required reaction speed of the release agent composition and various physical properties required for the engineering paper; for example, the non-volatile component 100 relative to the release main agent The mass part is preferably 0.01 to 10 parts by mass, and more preferably 0.5 to 5 parts by mass.
The release agent layer 3 is preferably used in the form of a solution containing an organic solvent. As the organic solvent, a well-known solvent having good solubility and volatility in the release agent layer 3 and being chemically inert to each component of the release agent composition 31 can be appropriately selected and used.
Examples of such a solvent include toluene, xylene, hexane, heptane, methanol, ethanol, isopropanol, isobutanol, n-butanol, acetone, methyl ethyl ketone, and tetrahydrofuran. These may be used singly or in combination of two or more kinds.
The nonvolatile matter concentration of the solution of the release agent composition 31 is preferably 5 mass% or more and 60 mass% or less, more preferably 10 mass% or more and 50 mass% or less, from the viewpoint of coating suitability and drying properties. It is preferably 20% by mass or more and 40% by mass or less.

[3] Manufacturing method of synthetic leather engineering paper 1 The synthetic leather engineering paper 1 includes a base material 2 and a release agent layer 3 on the base material 2. The manufacturing method of the synthetic leather engineering paper 1 is not particularly limited. For example, an appropriate amount of filler 32 can be added to a peelable main agent or a hardener to prepare a release agent composition 31, and the release agent composition 31 can be applied to the substrate 2. Then, the coating film is hardened to form a release agent layer 3 on the substrate 2.
Examples of the coating method include a spin coating method, a spray coating method, a bar coating method, a knife coating method, a roll coating method, a roll knife coating method, a blade coating method, a die coating method, Gravure coating method and the like.
When using the said peeling agent composition solution, it is preferable to apply this solution to a base material, and to form a coating film, and to heat and dry this coating film.
The coating film formed on the substrate 2 can also be hardened by heating with drying. When the component has a functional group that reacts through the active energy ray, it can be hardened by irradiation with the active energy ray, or it can be used in combination. It is hardened by heating and irradiation of active energy rays. Examples of the active energy rays include ultraviolet rays and electron beams.
The heating temperature is preferably 80 to 250 ° C, more preferably 100 to 230 ° C; the heating time is preferably 15 seconds to 5 minutes, and more preferably 20 seconds to 3 minutes.
The coating film formed on the substrate 2 may be hardened by heating during drying, or may be hardened by means other than heating, such as irradiation of active energy rays.
In the engineering paper 1 for synthetic leather, the film thickness of the release agent layer 3 after curing is not particularly limited, but is preferably 3.0 μm or more and 12 μm or less, and more preferably 3 μm or more and 8 μm or less.
The synthetic leather engineering paper 1 can also be manufactured by the following manufacturing method instead of the said method. First, a thermoplastic resin is used as a polymer material for the release main agent, and the release agent composition 31 is applied or melt-extruded on the base material 2 to form a release agent layer 3. In addition, an embossing roller having a predetermined shape is prepared, the surface of the release agent layer 3 of the laminate having the release agent layer 3 formed on the substrate 2 is pressed with an embossing roller, and the predetermined release agent layer 3 is transferred. With the uneven shape, a desired synthetic leather engineering paper 1 can be produced.
The synthetic leather engineering paper 1 of the present invention adjusts the composition and processing conditions of the release agent composition 31 during such a manufacturing method so that the specular gloss of the aforementioned release agent layer 3 according to JIS Z 8741 is 20 ° The gloss value is 30% or less, the 60 ° gloss value is 70% or less, and the 85 ° gloss value is 100% or less.
The arithmetic mean roughness Ra of the surface of the release agent layer 3 is in a range of 0.05 μm or more and 0.30 μm or less, and the maximum height Rz is 3.0 μm or less. However, the arithmetic average roughness Ra or the maximum height Rz of the surface of the release agent layer 3 is in this range, and the specular gloss of the release agent layer 3 may not reach 20 ° gloss value 30% or less and 60 ° gloss value 70% or less. The balance of the gloss value at 85 ° is less than 100%. Therefore, it is not suitable as an index for generating "wet gloss".

[4] Method of using synthetic leather engineering paper 1 The synthetic leather engineering paper 1 is used in a manufacturing process of synthetic leather.
As a method for manufacturing synthetic leather using engineering paper 1 for synthetic leather, a urethane resin, a vinyl chloride resin, and a polyamide resin can be coated on the release agent layer 3 of the engineering paper 1 for synthetic leather. After the coating liquid containing synthetic resin as the main component is dried and formed into a resin layer, a base fabric is further bonded and dried via an adhesive as required, and then the synthetic leather is peeled off from the synthetic leather engineering paper 1 and manufactured. .
The synthetic resin used in the above-mentioned synthetic leather manufacturing method is preferably a urethane resin from the viewpoint of texture or durability as a synthetic leather.
Specifically, a urethane resin can be coated on the release agent layer 3 of the synthetic leather engineering paper 1 of the present invention, and the urethane resin layer can be suitably dried to form a urethane resin layer. After the cloth was cured, the urethane resin layer was finally peeled from the synthetic leather engineering paper 1 together with the base cloth to produce a synthetic leather.
The peeling force of the synthetic leather engineering paper 1 from the resin layer of the synthetic leather is preferably 30 to 3000 mN / 30 mm, more preferably 50 to 2000 mN / 30 mm, still more preferably 60 to 1000 mN / 30 mm, and even more preferably 70 to 500mN / 30mm, more preferably 90-200mN / 30mm. If the peeling force is equal to or less than these upper limits, the performance of stable peeling from the synthetic leather can be obtained after repeated use of the synthetic leather engineering paper 1, and a synthetic leather having high gloss can be produced. If these lower limit values are not less than this, the resin layer can be prevented from being inadvertently peeled from the release agent layer 3.

Examples Hereinafter, examples of the present invention will be described. The present invention is not limited to the examples.

[1] Examples
[Example 1]
A polysiloxane modified alkyd resin was used as the peelable main agent, and a melamine resin solution (trade name: Tesfine 309, manufactured by Hitachi Chemical Co., Ltd.) was used as the hardener. The peelable main agent was hardened. Agent = 65:35, solid content concentration 50%) 100 parts by mass, and amorphous silica particles (trade name: Sylysia 420, Fuji Silysia) were added to a mixed solution diluted with 109.2 parts by mass of toluene and 46.9 parts by mass of ethyl acetate. 3.5 parts by mass of Chemical Co., Ltd., and dispersed using a disperser at 3,000 rpm for 30 minutes. To this solution was added 2.5 parts by mass of a p-toluenesulfonic acid methanol solution (solid content concentration: 50% by mass) as a curing catalyst, and the mixture was stirred at 1,500 rpm for 5 minutes using a disperser to prepare a solution of a release agent composition.
This solution was applied to a coated surface of a cast base paper (trade name: Esprit-coat E (UT) 165SW, manufactured by Japan Paper Co., Ltd., basis weight: 150 g / m ² ) to Drying and curing were performed at 210 ° C. for 60 seconds to obtain a synthetic leather engineering paper having a release agent layer having a thickness of about 8.0 μm after curing.

[Example 2]
Except that the amorphous silica particles (trade name: Sylysia 310P, manufactured by Fuji Silysia Chemical Co., Ltd.) were changed, the same release agent composition solution as in Example 1 was prepared, and was prepared by the same method as in Example 1. Synthetic leather manufacturing engineering paper.

[Example 3]
Except that the amorphous silica particles (trade name: Sylysia 430, manufactured by Fuji Silysia Chemical Co., Ltd.) were changed, the same release agent composition solution as in Example 1 was prepared, and prepared in the same manner as in Example 1. Synthetic leather manufacturing engineering paper.

[Example 4]
Except that the addition amount of the amorphous silicon dioxide particles was changed to 1.3 parts by mass, the same release agent composition solution as in Example 1 was prepared, and a synthetic leather manufacturing engineering paper was prepared by the same method as in Example 1.

[Example 5]
Except that the addition amount of the amorphous silica particles was changed to 5.4 parts by mass, the same release agent composition solution as in Example 1 was prepared, and engineering paper for manufacturing synthetic leather was prepared by the same method as in Example 1.

[Example 6]
Except that the same release agent composition solution as that used in Example 1 was used, and the thickness of the cured release agent layer was changed to about 4.0 μm, the engineering paper for manufacturing synthetic leather was obtained by the same method as in Example 1.

[Example 7]
In addition to the releasable main agent, the stearyl modified alkyd resin with a long-chain alkyl group was changed, and the hardener was changed to a solution containing a melamine resin (trade name: Tesfine 303, manufactured by Hitachi Chemical Co., Ltd.). Base agent: hardener = 80: 20, solid content concentration: 48%) The same solution as in Example 1 was prepared with a solution other than that of Example 1, and a synthetic leather manufacturing engineering paper was prepared by the same method as in Example 1.

[2] Comparative Examples
[Comparative Example 1]
Except that the amorphous silicon dioxide particles were not added, the same release agent composition solution as in Example 1 was prepared, and a synthetic leather manufacturing engineering paper was prepared by the same method as in Example 1.

[Comparative Example 2]
Except for using spherical silica particles (trade name: Seahostar KE-P250, manufactured by Nippon Catalysts Co., Ltd.), the same solution as the release agent composition was prepared in the same manner as in Example 1, and was prepared by the same method as in Example 1. Synthetic leather manufacturing engineering paper.

[Comparative Example 3]
Except that the addition amount of the amorphous silicon dioxide particles was changed to 9.0 parts by mass, the same release agent composition solution as in Example 1 was prepared, and a synthetic leather manufacturing engineering paper was prepared by the same method as in Example 1.

[Comparative Example 4]
In addition to using two kinds of spherical silica particles (trade names: Seahostar KE-P250 made by Japan Catalysts Co., Ltd. and Seahostar KE-P100 made by Japan Catalysts Co., Ltd.), the fillers having different particle sizes are mixed in half. In this case, the same solution of the release agent composition as in Example 1 was prepared, and a synthetic leather manufacturing engineering paper was prepared by the same method as in Example 1.
The formulations of the examples and comparative examples are shown in Table 1.


[3] Test and evaluation methods
[3-1] Surface roughness The surface roughness of the release agent layer 3 was measured using a light interference type surface shape measuring device made by Veeco.

[3-2] Mirror gloss Gloss was measured at 20 °, 60 °, and 85 ° using a gloss meter "VG7000" (Nihon Denshoku Kogyo Co., Ltd.).

[3-3] Glossiness As for the evaluation of glossiness, those with gloss and no glare are rated as A; those with only slight gloss and no glare are rated as B; others are rated as C.

[3-4] Peeling force As a coating solution for the resin layer of synthetic leather, a single-liquid polyurethane resin solution (trade name: CRISVON 5516S, manufactured by DIC (strand)) was used, and this solution was applied to The surface of the release agent layer of the engineering paper for synthetic leather manufacturing was dried at 140 ° C. for 2 minutes to form a polyurethane resin layer having a thickness of 25 μm.
Next, a polyester adhesive tape (manufactured by Nitto Denko Corporation, No. 31B) was affixed to the surface of the formed polyurethane resin layer, and placed in a constant temperature room at 23 ° C and a relative humidity of 50% for 30 minutes. , Cut into 30mm wide and 150mm long. Using a tensile tester (device name: Tensilon, manufactured by A & D Co., Ltd.), it was measured when the polyurethane resin layer laminated with the above-mentioned adhesive tape was stretched in a 180 ° direction at a speed of 1000 mm / min and peeled Peeling force.
The results are shown in Tables 2 and 3. In addition, the theoretical calculation value of the specific surface area when a true sphere is assumed is calculated as 6 / (density × particle diameter) (m ² / g), the density of silicon dioxide is 2.2 g / cm ³ , and the average particle diameter is taken as the particle diameter. D50.




In Comparative Example 1, since the silicon dioxide particles were not contained in the release agent layer, the gloss value of the manufactured synthetic leather was too high to produce a "wet glossiness".
In Comparative Example 2 using spherical silica particles, although a slight glare effect was produced, the gloss value of the synthetic leather was similarly high, and a "wet gloss feeling" was not generated.
Furthermore, in Comparative Example 3, because the amount of amorphous silicon dioxide particles was too much, the gloss value of the engineering paper exceeded the scope of the present invention, and the gloss value of the manufactured synthetic leather was too low to form a synthetic leather with a matte feel. It does not produce a "moist luster." Moreover, the peeling force of the synthetic leather was also 510 mN / 30 mm, and it was confirmed that peeling was not easy.
In Comparative Example 4, two types of spherical silica particles having different particle diameters were contained in the release agent layer, but the gloss value of the synthetic leather produced was too high to produce a "moist luster".
On the other hand, in Examples 1 to 7, by setting the gloss value of the release agent layer 3 of the synthetic leather engineering paper 1 to be in the range of the present invention, the gloss value of the manufactured synthetic leather can be felt as ""Moistluster".
In addition, the peeling force of the synthetic leather can also range from 110 mN / 30 mm to 150 mN / 30 mm, and it has been confirmed that the productivity in the peeling step of the synthetic leather can be prevented from being impaired.

1‧‧‧ synthetic leather engineering paper

2‧‧‧ substrate

3‧‧‧ peeling agent layer

31‧‧‧ peeling agent composition

32‧‧‧ filler

FIG. 1 is a cross-sectional view showing the structure of an engineering paper according to an embodiment of the present invention.

Claims (8)

A synthetic leather engineering paper is a synthetic leather engineering paper provided with a base material and a release agent layer formed on the base material, and is characterized in that: The specular gloss of the aforementioned release agent layer according to JIS Z 8741 has a 20 ° gloss value of 30% or less, a 60 ° gloss value of 70% or less, and an 85 ° gloss value of 100% or less. The synthetic leather engineering paper of claim 1, wherein: The release agent layer is formed of a release agent composition containing a filler composed of irregular particles in an amount of more than 0% by mass and less than 15% by mass. The synthetic leather engineering paper of claim 2, wherein: The film thickness of the release agent layer is 3.0 μm or more and 12 μm or less. The synthetic leather engineering paper of claim 2, wherein: The average particle diameter D50 of the amorphous particles is 0.5 μm or more and 5.0 μm or less. The synthetic leather engineering paper of claim 4, wherein: In the particle size distribution of the aforementioned amorphous particles, the particle size D10 of the cumulative distribution is 0.8 times or less the average particle size D50, and the particle size D90 is 1.2 times or more the average particle size D50. The synthetic leather engineering paper of claim 2, wherein: The amorphous particles are amorphous silicon dioxide particles. The synthetic leather engineering paper according to any one of claims 1 to 6, wherein: The release agent layer contains a polysiloxane modified alkyd resin. A method for manufacturing synthetic leather, comprising: A step of applying a coating solution containing a synthetic resin on a release agent layer of a synthetic leather engineering paper as in any one of claim 1 to claim 7; A step of drying the applied coating liquid to form a synthetic leather; and A step of peeling the synthetic leather engineering paper from the synthetic leather after drying.