KR20190090334A - Casting paper for synthetic leather and manufacturing method of synthetic leather - Google Patents

Abstract

Casting paper (1) for synthetic leather is provided with a base material (2) and a release agent layer (3) formed on the base material (2). The specular glossiness of the release agent layer (3) based on JIS Z 8741 is 30% or less at 20°, 70% or less at 60°, and 100% or less at 85°.

Description

TECHNICAL FIELD [0001] The present invention relates to a process for producing synthetic leather and a process for producing synthetic leather,

The present invention relates to a process paper for synthetic leather and a process for producing synthetic leather.

Synthetic leather can be obtained by applying a coating composition containing a synthetic resin such as urethane resin or vinyl chloride resin as a main component onto a release agent layer using a process paper having a release agent layer made of a release agent resin composition on a substrate such as paper and drying Then, if necessary, a base fabric is further adhered thereon with an adhesive agent interposed therebetween, and finally, the synthetic leather is peeled off from the process paper.

In such a method for producing synthetic leather, since the surface state of the release agent layer of the process paper is transferred to the surface of the synthetic leather, the gloss, shine removal or pattern shape of the synthetic leather is different depending on the surface condition of the process paper.

The process paper for the enamel-like synthetic leather is required to have high surface smoothness, and the process paper for the matte-like synthetic leather is required to have a high gloss removability with surface unevenness formed.

For example, Japanese Patent Application Laid-open No. 10-306253 discloses a process for producing a synthetic leather which is generally called a enamel wind with a very high gloss and which comprises a silicone-modified alkyd resin, Discloses a resin composition for peeling.

In addition, Document 2 (Japanese Unexamined Patent Publication (Kokai) No. 2004-115972) discloses a composition for forming a mat layer, which is suitable for the production of a matte-like synthetic leather without embossing or brushed, and which contains porous fine particles A composition for forming a mat layer is disclosed.

However, the enamel-like synthetic leather tends to be perceived as lacking in quality because the gloss is excessively strong, the impression is glaring, and it feels rather inexpensive, or the matte-like synthetic leather has a monotonous texture. BACKGROUND ART [0002] In recent consumer trends, there is a demand for a synthetic leather which combines glossiness with blackness.

Such synthetic leather having such a "calm luster" can not be obtained in the process used in the enamel-like synthetic leather described in Document 1 or in the production of synthetic leather using the process paper used in the matte synthetic leather described in Document 2.

The reason for this is attributed to the fact that the process paper for enamel-like or matte air has no surface state for exhibiting " calm luster. &Quot;

Further, in the production of the synthetic leather, the process sheet needs to be peeled off from the synthetic leather finally, and a suitable peel force is required.

Particularly, in the matte-like processed paper, since the surface irregularities are remarkable, the contact area between the process paper and the synthetic resin is increased to increase the adhesive force (peeling force), and in some cases, it can not be peeled off. I have trouble.

An object of the present invention is to provide a process paper for synthetic leather which can produce a synthetic leather having a desired texture while having a suitable adhesive force (peeling force) by fine surface irregularities, and a method for producing synthetic leather.

The process sheet for synthetic leather according to the present invention is a process paper for synthetic leather having a substrate and a release agent layer formed on the substrate, wherein the surface gloss of the release agent according to JIS Z 8741 is 30 % Or less, a 60 ° gloss value of 70% or less, and an 85 ° gloss value of 100% or less.

According to the present invention, the outer surface of the synthetic leather can be made to have a desired texture of " calm luster " by producing synthetic leather using a process paper in which the mirror surface gloss of the release agent layer is defined by the gloss value as described above have.

In the present invention, it is preferable that the release agent layer is formed of a release agent composition containing a filler composed of amorphous particles exceeding 0 mass% and less than 15 mass%.

According to the present invention, it is easy to produce a process paper having desired mirror gloss by containing a filler composed of amorphous particles exceeding 0 mass% and less than 15 mass%.

In the present invention, the film thickness of the release agent layer is preferably 3.0 m or more and 12 m or less.

If the film thickness is less than 3.0 mu m, the amount of filler exposed from the release agent layer becomes excessively large, and the feeling of matte becomes strong, and synthetic leather having a desired texture can not be produced. Moreover, the filler is hardly fixed to the release agent layer, and the filler is separated from the release agent layer, so that a synthetic leather having a desired texture can not be produced.

On the other hand, if the film thickness exceeds 12 占 퐉, the filler is buried in the release agent layer, and the filler exposed from the release agent layer is reduced, whereby the glossiness is emphasized and synthetic leather having a desired texture can not be produced.

In the present invention, the average particle diameter D50 of the amorphous particles is preferably 0.5 mu m or more and 5.0 mu m or less.

It is preferable that the particle diameter distribution of the amorphous particles is 0.8 times or less of the average particle diameter D50 by the cumulative distribution and the particle diameter D90 is 1.2 times or more of the average particle diameter D50.

According to the present invention, since the average particle diameter D50 of the amorphous particles is in the above range and the particle diameter distribution of the amorphous particles is within the above range, the irregular particles protrude from the surface of the release agent layer, It is suitable for producing synthetic leather having desired texture.

In the present invention, it is preferable that the amorphous particles are amorphous silica particles.

INDUSTRIAL APPLICABILITY According to the present invention, since the amorphous particles are made of an inorganic material, they are not deformed or melted even by heating during the production of synthetic leather, so that a synthetic leather of a desired texture can be produced.

In the present invention, it is preferable that the release agent layer contains a silicone-modified alkyd resin.

According to the present invention, by using a silicone-modified alkyd resin, it is possible to obtain a process paper having heat resistance and good releasability from synthetic leather.

The method for producing a synthetic leather of the present invention comprises the steps of applying a coating liquid containing a synthetic resin on a release agent layer on the above-mentioned synthetic leather processing paper, and a step of drying the applied coating liquid to form a synthetic leather And a step of, after drying, peeling the step paper for synthetic leather from the synthetic leather.

According to the present invention as described above, the same operation and effect as described above can be enjoyed.

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

Hereinafter, one embodiment of the present invention will be described with reference to the drawings. Fig. 1 shows a process paper 1 for synthetic leather according to an embodiment of the present invention. The process paper for synthetic leather (1) comprises a base material (2) and a release agent layer (3).

[1] Description (2)

The base material 2 of the process paper 1 for synthetic leather may be appropriately selected so far as it can support the release agent layer 3 described later, and examples thereof include a paper substrate and a resin film.

Examples of the paper base material include paper base materials such as high temperature paper, heavy paper, glossy paper, art paper, coated paper and cast coated paper, and laminates obtained by laminating thermoplastic resins such as polyethylene Maps.

Examples of the resin film include a film made of polyolefin such as polyethylene, polypropylene, and polymethylpentene, and the like, such as polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate and the like.

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 탆, more preferably 10 to 200 탆.

Of these substrates, paper substrates are preferable from the standpoint of strength and availability, and cast coat sheets are more preferable. By using a cast coating paper, smoothness, heat resistance and barrier property can be ensured.

Examples of commercially available products include commercially available products such as Esprit series manufactured by Nippon Paper Industries Co., Ltd., mirrors manufactured by Oji Paper Co., Ltd., Coat series, and the like.

[2] Release agent layer (3)

The release agent layer 3 is formed of a release agent composition 31 as shown in Fig.

[2-1] Release agent composition (31)

The releasing agent composition 31 forming the releasing agent layer 3 is provided with a peelable subject and a filler 32, and is mixed with an additive and a solvent as required.

As the releasable subject for forming the releaser composition 31,

(1) a polymer compound having low polarity and exhibiting peelability by itself,

(2) a polymer material imparted with releasability by being chemically modified,

(3) a composition in which a releasable low molecular weight or oligomer component is added to a polymer material to give peelability.

Examples of the polymer compound having low polarity and exhibiting its own peelability include polyorganosiloxane; Fluoropolymers; Polyolefins such as polyethylene, polypropylene and polymethylpentene; And diene-based polymers such as polybutadiene and polyisoprene.

Examples of the polymer component to be chemically modified include a polyvinyl alcohol, a partially saponified polyvinyl acetate, a hydroxyl group-containing acrylic ester copolymer, a urethane resin, an alkyd resin, an amino resin, an epoxy resin, Phenol resin and the like. These polymer components often do not exhibit peelability unless chemically modified.

Also, in the polymer material to which the releasability is imparted by chemical modification, the chemical modifying component includes a polyorganosiloxane or organosiloxane oligomer having a functional group; A fluorocarbon compound having a functional group; And long-chain alkyl compounds having a functional group. Examples of the long-chain alkyl compound include compounds having an alkyl group having 12 or more carbon atoms such as a lauryl group, a palmityl group, and a stearyl group.

Examples of the functional group of the compound to be chemically modified include a hydroxyl group, an amino group, a carboxyl group, an epoxy group, an isocyanate group, a (meth) acryloyl group, a thiol group and an alkoxysilyl group.

The polymer material imparted with releasability by chemical modification is commonly referred to as a silicone-modified resin, a fluoro-modified resin, and a long-chain alkyl-modified resin.

Examples of the polymer material to be used include a polyvinyl alcohol, a partially saponified polyvinyl acetate, an acrylic acid ester copolymer, a urethane resin, a polyester resin, a polyvinyl alcohol resin, Polyamide resin, alkyd resin, amino resin, epoxy resin, phenol resin and the like.

Examples of the releasable low-molecular weight or oligomer component added to these polymer materials include wax (hydrocarbon compound); Polyorganosiloxane or organosiloxane oligomer; Fluorocarbons; And long-chain alkyl compounds, and polyether adducts and polyester adducts thereof.

Among them, a polymer material imparted with releasability by chemical modification is preferable as a peelable subject from the viewpoint that the peelability and the heat resistance are easily improved and the affinity with the filler and other additives can be improved, More preferred are alkyd resins chemically modified with organosiloxanes, so-called silicone-modified alkyd resins. The peelable base may be used singly or in combination of two or more kinds.

[2-2] Filler (32)

Examples of the filler 32 added to the release agent composition 31 include amorphous silica, alumina, titanium oxide, zinc oxide, calcium carbonate, magnesium hydroxide, aluminum hydroxide, kaolin, talc and clay. Amorphous silica particles and amorphous alumina particles are preferable, and it is more preferable to employ amorphous silica from an economical viewpoint.

These fillers may be modified with an organic group or a functional group, for example, in order to facilitate the improvement of the dispersibility or to be able to impart reactivity with the peeling agent.

It is preferable that the releasing agent composition 31 contains a filler 32 comprising amorphous particles having a filler 32 of more than 0 mass% and less than 15 mass%. The mixing ratio of the filler (32) is more than 1% by mass, more preferably less than 12.5% by mass, particularly preferably more than 2% by mass and less than 10% by mass. By setting this range, it is possible to obtain a desired surface gloss and a suitable peeling force.

The average particle diameter D50 of the amorphous particles is preferably 0.5 mu m or more and 5.0 mu m or less. If the average particle diameter D50 is smaller than this lower limit value, the filler is less likely to be exposed from the release agent layer, and the glossiness may become strong. If the average particle diameter D50 is larger than the upper limit value, the filler is excessively exposed from the release agent layer, which may result in a strong matte feeling. The average particle size can be measured by a laser diffraction particle size distribution analyzer, in which the release agent composition containing the filler 32 is to be measured.

The amorphous particles used in the release agent composition (31) preferably have a wide particle diameter distribution. More specifically, it is preferable that the difference between the particle diameter D10 and the particle diameter D90 due to the cumulative distribution is large. Specifically, it is preferable that D10 is 0.8 times or less the average particle diameter D50, and D90 is 1.2 times or more the average particle diameter D50.

Since the particle diameter distribution has such a width, the relatively rough portion and the relatively smooth portion of the surface irregularities of the release agent layer 3 are randomly formed, so that the gloss value with respect to the incident angle of light can be made to fall within a desired range, It becomes possible to obtain the process paper 1 for synthetic leather having a desired luster. In addition, since the filler 32 is an amorphous particle, it is easy to make the particle size distribution have a width, so that it is preferable to use the amorphous particle.

The amorphous particles to be used in the filler 32 are preferably those in the form of crushed and pulverized masses of raw materials such as silica and alumina and have a specific surface area of 10 m 2 / g or more, preferably 20 m 2 / g Or more and 1000 m < 2 > / g or less, and more preferably 50 m < 2 > / g or more and 500 m &

The exfoliating composition 31 may be blended with an additive such as a curing agent, a crosslinking agent, a reaction initiator and a catalyst in addition to the exfoliating subject and the filler, and the exfoliating composition 31 may be diluted with an organic solvent.

As the curing agent, crosslinking agent and reaction initiator used in the releasing agent composition (31), a compound having a functional group capable of chemically bonding with a functional group having a peelable subject is selected. The curing agent, crosslinking agent and reaction initiator react with the peeling agent to form a three-dimensional network structure, thereby improving the strength and heat resistance of the coating of the releasing agent layer (3).

The curing agent, crosslinking agent or reaction initiator used in the releasing agent composition (31) is not particularly limited as long as it is capable of reacting with the functional group possessed by the exfoliating theme, and examples thereof include a polyhydrosilyl group-containing organosiloxane compound, a melamine compound, a polyvalent isocyanate compound , Polyvalent epoxy compounds, polyvalent aldehyde compounds, polyvalent amine compounds, polyvalent oxazoline compounds, and metal complexes.

The catalyst used in the release agent composition 31 is a compound which accelerates the reaction so that the curing reaction (cross-linking reaction) of the release agent composition proceeds at a low temperature or in a short time, and a compound according to the chemical reaction is selected. For example, in the case of being used for an addition reaction with an organosiloxane compound containing a polyvalent hydrosilyl group, for example, a platinum catalyst is used. In the reaction involving dehydration and de-alcohol with a melamine compound, for example, an acid catalyst such as p-toluenesulfonic acid is used.

In the releasing agent composition (31), the compounding ratio of the curing agent, the crosslinking agent, or the reaction initiator to the releasable subject may be appropriately selected so as to suit various properties of the required processing paper. For example, Is preferably not less than 0.1 part by mass and not more than 400 parts by mass, and more preferably not less than 10 parts by mass and not more than 200 parts by mass, based on the mass part. The mixing ratio of the catalyst may be appropriately selected so as to suit the reaction rate of the required release agent composition and various physical properties of the required process paper. For example, 0.01 part by mass or more of the catalyst may be added to 100 parts by mass of the non- 10 parts by mass or less, and more preferably 0.5 parts by mass or more and 5 parts by mass or less.

The release agent layer (3) is preferably used in the form of a solution containing an organic solvent. The organic solvent may be appropriately selected from known solvents which are good in solubility and volatility in the release agent layer 3 and chemically inert to each component of the release agent composition 31.

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 concentration of the nonvolatile component in the solution of the release agent composition 31 is preferably 5% by mass or more and 60% by mass or less, more preferably 10% by mass or more and 50% by mass or less, still more preferably 20% Or more and 40 mass% or less.

[3] Manufacturing method of process paper for synthetic leather (1)

The process paper 1 for synthetic leather has a base material 2 and a release agent layer 3 on the base material 2. The method for producing the synthetic leather processing paper 1 is not particularly limited. For example, a filler 32 may be added to a releasing agent or a curing agent in an appropriate amount to form a releasing agent composition 31, (2), and the coating film is cured to form the release agent layer (3) on the substrate (2).

Examples of the application method include spin coating, spray coating, bar coating, knife coating, roll coating, roll knife coating, blade coating, die coating and gravure coating .

When the solution of the releasing agent composition is used, it is preferable that the solution is applied on a substrate to form a coating film, and the coating film is heated and dried.

The coating film formed on the base material 2 may be cured by heating together with drying. When the component has a functional group reactive with an active energy ray, the coating film may be cured by irradiation of an active energy ray. Irradiation may be used in combination. Examples of the active energy ray include ultraviolet rays and electron beams.

The heating temperature is preferably 80 to 250 DEG C, more preferably 100 to 230 DEG C, and the heating time is preferably 15 seconds to 5 minutes, more preferably 20 seconds to 3 minutes.

The coating film formed on the base material 2 may be cured by heating at the time of drying, or may be cured by means other than heating, for example, by irradiation of active energy rays.

In the process sheet 1 for synthetic leather, the thickness of the release agent layer 3 after curing is not particularly limited, but is preferably 3.0 m or more and 12 m or less, more preferably 3 m or more and 8 m or less.

The process paper 1 for synthetic leather may be produced by the following production method instead of the above method. First, the release agent composition 31 is applied or melt-extruded on the base material 2 by using a thermoplastic resin as a polymer material used for a peelable subject to form a release agent layer 3. The surface of the release agent layer 3 of the layered product in which the release agent layer 3 is formed on the base material 2 is pressed by an emboss roll to form a release agent layer 3 3 by transferring a predetermined concavo-convex shape to the surface of the base material.

In the process of the production method of the synthetic leather of the present invention, the composition and processing conditions of the stripper composition (31) are adjusted so that the mirror surface of the stripper layer (3) conforming to JIS Z 8741 The degree of gloss is 30% or less at a 20 ° gloss value, 70% or less at a 60 ° gloss value, and 100% or less at an 85 ° gloss value.

The arithmetic mean roughness Ra of the surface of the release agent layer 3 is in the range of 0.05 탆 or more and 0.30 탆 or less and the maximum height Rz is 3.0 탆 or less. However, even when the arithmetic average roughness Ra or the maximum height Rz of the surface of the release agent layer 3 is within this range, the mirror surface gloss of the release agent layer 3 must be 30% or less at 20 ° gloss value and 70% , The balance of the gloss value of 85 ° is not 100% or less. Therefore, it is not suitable as an index for generating " calm glossiness ".

[4] Use of the process paper for synthetic leather (1)

The process paper for synthetic leather (1) is used in a process for producing synthetic leather.

As a method for producing synthetic leather using the process paper 1 for synthetic leather, a synthetic resin such as urethane resin, vinyl chloride resin or polyamide resin is coated on the release agent layer 3 of the synthetic leather process paper 1 The synthetic leather is peeled off from the process paper for synthetic leather (1) after drying, and then a coating layer composed of a main component is applied and dried to form a resin layer, .

As the synthetic resin used in the method for producing the synthetic leather, a urethane resin is preferable from the viewpoints of the texture and durability as synthetic leather.

Specifically, a urethane resin is applied on the release agent layer 3 of the process step 1 for synthetic leather of the present invention and appropriately dried to form a urethane resin layer, and thereafter the bubbles are further adhered via an adhesive agent And finally the urethane resin layer together with the air bubbles is peeled off from the process paper for synthetic leather 1 to produce a synthetic leather.

The peel strength of the synthetic leather to the resin layer is preferably 30 to 3000 mN / 30 mm, more preferably 50 to 2000 mN / 30 mm, and more preferably 60 to 1000 mN / More preferably from 70 to 500 mN / 30 mm, even more preferably from 90 to 200 mN / 30 mm. If the peeling force is below these upper limit values, a stable peeling performance from synthetic leather can be obtained even after using the process paper 1 for synthetic leather, and synthetic leather having high gloss can be produced. If these lower limit values are exceeded, it is possible to prevent the resin layer from being suddenly peeled off from the release agent layer 3.

Example

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

[1] Embodiment

[Example 1]

100 parts by weight of a solution (trade name: TESFINE 309, Hitachi Kasei Polymer Co., Ltd., peelable base: curing agent = 65:35, solid content concentration 50%) obtained by mixing a silicon-modified alkyd resin as a peelable subject and a melamine resin as a curing agent 3.5 parts by mass of pseudomorphic silica particles (trade name: Silysia 420, manufactured by Fuji Silysia Chemical Co., Ltd.) was added to a mixed solution of 109.2 parts by mass of toluene and 46.9 parts by mass of ethyl acetate, And dispersed at 3,000 rpm for 30 minutes. To the solution was added 2.5 parts by mass of a methanol solution of p-toluenesulfonic acid (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 releasing agent composition.

This solution was coated on a surface of a coat base coat (trade name: Esprit Coat E (UT) 165SW, manufactured by Nippon Paper Industries Co., Ltd., basis weight 150 g / m 2) as a paper substrate and dried at 210 캜 for 60 seconds And cured to obtain a process paper for synthetic leather production having a release agent layer having a thickness of about 8.0 mu m after curing.

[Example 2]

The same releasing agent composition solution as in Example 1 was prepared except that the amorphous silica particles (trade name: Silysia 310P, manufactured by Fuji Silysia Chemical Co., Ltd.) were changed, and a step paper for synthetic leather production was obtained in the same manner as in Example 1 .

[Example 3]

The same releasing agent composition solution as in Example 1 was prepared except that amorphous silica particles (trade name: Silysia 430, manufactured by Fuji Silysia Chemical Co., Ltd.) were changed, and the same process as in Example 1 was used to obtain a process paper for synthetic leather production .

[Example 4]

The same releasing agent composition solution as in Example 1 was prepared, except that the amount of the amorphous silica particles was changed to 1.3 parts by mass, and a process paper for synthetic leather production was obtained in the same manner as in Example 1.

[Example 5]

The same release agent composition solution as in Example 1 was prepared except that the amount of the amorphous silica particles was changed to 5.4 parts by mass, and a process paper for synthetic leather production was obtained in the same manner as in Example 1.

[Example 6]

A process paper for synthetic leather production was obtained in the same manner as in Example 1 except that the same release agent composition solution as in Example 1 was used and the thickness of the release agent layer after curing was changed to about 4.0 占 퐉.

[Example 7]

(Trade name: TESFINE 303, manufactured by Hitachi Kasei Polymer Co., Ltd .; exfoliating base: curing agent = 80:20, solid content of a stearyl-modified alkyd resin with a long chain alkyl group as a peelable property and a melamine resin as a curing agent Concentration: 48%), a release agent composition solution similar to that of Example 1 was prepared, and a process paper for synthetic leather production was obtained in the same manner as in Example 1.

[2] Comparative Example

[Comparative Example 1]

The same releasing agent composition solution as in Example 1 was prepared except that no amorphous silica particles were added, and a process paper for synthetic leather production was obtained in the same manner as in Example 1.

[Comparative Example 2]

The same release agent composition solution as in Example 1 was prepared, except that spherical silica particles (trade name: Sihosta KE-P250 manufactured by Nippon Catalysts Co., Ltd.) were used, and a step paper for synthetic leather production was obtained in the same manner as in Example 1 .

[Comparative Example 3]

The same release agent composition solution as in Example 1 was prepared, except that the amount of the amorphous silica particles was changed to 9.0 parts by mass, and a process paper for synthetic leather production was obtained in the same manner as in Example 1.

[Comparative Example 4]

Except that a filler having a different particle diameter was blended by the use of two kinds of spherical silica particles (trade name: Sihosta KE-P250 manufactured by Nippon Catalysts Co., Ltd. and Sihosta KE-P100 manufactured by Nippon Catalysts Co., Ltd.) The same release agent composition solution as in Example 1 was prepared and the same procedure as in Example 1 was used to obtain a process paper for synthetic leather production.

Table 1 shows the blend of Examples and Comparative Examples.

[3] Testing 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 apparatus manufactured by Veeco.

[3-2] Mirror gloss

Glossiness at 20 deg., 60 deg. And 85 deg. Were measured using a gloss meter "VG7000" (Nippon Seimei Kogyo Co., Ltd.).

[3-3] Shiny feeling

The evaluation of glossiness was evaluated as A with glossy and without flashing, with a little gloss and without flashing with B, and the other cases were evaluated as C.

[3-4] Peeling force

(Trade name: Chrisborn 5516S, manufactured by DIC Corporation) was used as a coating liquid for the resin layer of the synthetic leather, this solution was applied to the surface of the release agent layer of the step paper for synthetic leather production, And dried for 2 minutes to form a polyurethane resin layer having a thickness of 25 탆.

Subsequently, a polyester adhesive tape (product number No.31B, manufactured by Nitto Denko KK) was attached to the surface of the formed polyurethane resin layer and allowed to stand in a thermostatic chamber at 23 캜 and a relative humidity of 50% for 30 minutes, Mm and a length of 150 mm. The polyurethane resin layer in which the adhesive tape was laminated was stretched in the direction of 180 占 at a speed of 1000 mm / min using a tensile tester (apparatus name: manufactured by Tencilon Co., Ltd., A & D) Was measured.

The results are shown in Tables 2 and 3. The theoretical calculated value of the specific surface area in the sieve base was calculated as 6 / (density × grain diameter) (m 2 / g). The silica density was 2.2 g / cm 3 and the grain size was D50.

In Comparative Example 1, since the silica particles were not contained in the release agent layer, the produced synthetic leather had an excessively high gloss value, so that the " calm glossiness " could not be obtained.

In Comparative Example 2 using the spherical silica particles, a slight glare feeling could be obtained, but the gloss value of the synthetic leather was likewise high, and it did not reach the "calm glossiness".

Further, in Comparative Example 3, since the amount of the amorphous silica particles added is too large, the gloss value of the process paper exceeds the range of the present invention, the gloss value of the produced synthetic leather becomes too low, and the synthetic leather becomes a matte- Calm and shiny ". It was also confirmed that the peeling force of the synthetic leather was also 510 mN / 30 mm, which made it difficult to peel off.

In Comparative Example 4, two kinds of spherical silica particles having different diameters were contained in the release agent layer. However, the gloss value of the synthetic leather produced was excessively high, so that " calm glossiness " could not be obtained.

On the other hand, in Examples 1 to 7, by setting the gloss value of the release agent layer 3 of the process step 1 for synthetic leather to the range of the present invention, the gloss value of the produced synthetic leather was evaluated as " I could do it in the range that I felt.

It was also confirmed that the peeling force of the synthetic leather can also be set in the range of 110 mN / 30 mm to 150 mN / 30 mm, thereby preventing the productivity in the peeling process of the synthetic leather from being hindered.

Claims (8)

A process for producing synthetic leather comprising a substrate and a release agent layer formed on the substrate,
Wherein the surface gloss of the release agent layer according to JIS Z 8741 is 30% or less at 20 ° gloss, 70% or less at 60 ° gloss, and 100% or less at 85 ° gloss. Fair ground. The method according to claim 1,
Wherein the release agent layer is formed of a release agent composition containing a filler comprising 0% by mass or more and less than 15% by mass of amorphous particles. 3. The method of claim 2,
Wherein the film thickness of the release agent layer is 3.0 占 퐉 or more and 12 占 퐉 or less. 3. The method of claim 2,
Wherein the average particle size D50 of the amorphous particles is 0.5 占 퐉 or more and 5.0 占 퐉 or less. 5. The method of claim 4,
Wherein the particle diameter distribution of the amorphous particles is 0.8 times or less the average particle diameter D50 of the cumulative distribution and the particle diameter D90 is 1.2 times or more of the average particle diameter D50. 3. The method of claim 2,
Wherein the amorphous particles are amorphous silica particles. The method according to claim 1,
Wherein the release agent layer comprises a silicone-modified alkyd resin. A process for producing a synthetic leather composition comprising the steps of applying a coating liquid containing a synthetic resin onto a release agent layer of a process paper for synthetic leather according to any one of claims 1 to 7,
Drying the applied coating liquid to form a synthetic leather,
And then peeling the synthetic leather sheet from the synthetic leather after drying.

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