JP6707795B2 - Synthetic leather manufacturing process paper - Google Patents

Description

The present invention relates to a process paper used when manufacturing synthetic leather.

Conventionally, synthetic leather uses a process paper having a release agent layer composed of a release agent resin composition on a substrate, and a synthetic resin such as urethane resin, vinyl chloride resin, polyamide resin or the like is used as a main component on the release agent layer. It is manufactured by applying the coating liquid described above and drying it, and if necessary, further laminating a base fabric with an adhesive, and finally peeling the synthetic leather from the process paper.
In such a synthetic leather manufacturing method, since the surface state of the release agent layer of the process paper is transferred to the surface of the synthetic leather, the process paper provided for the production has a gloss or gloss depending on the use of the synthetic leather. Erasing or patterning is performed, and in particular, process paper for producing enamel type synthetic leather is required to have a high glossiness on the surface of the release agent layer.
Further, from the viewpoint of improving productivity, there is a demand for improvement in repeatability that can produce synthetic leather having a good surface condition when the process paper is repeatedly used in a series of synthetic leather production steps.

For example, Patent Document 1 discloses an alkyd resin and an amino resin for the purpose of providing a release agent composition and a release material which are useful in the production of a release material having excellent release properties, gloss, surface condition, reusability and the like. , A release agent for producing synthetic leather, which is obtained by applying a release agent composition containing a silicone resin having a functional group reactive with these resins and a cationic surfactant on the surface of a base material.
Patent Document 2 discloses a resin composition for process release paper, which has good gloss and releasability and is excellent in durability when repeatedly used, and is modified with a specific organopolysiloxane. There is described a resin composition for process release paper, which comprises a silicone-modified alkyd resin, an alkanol-modified amino resin, and an acidic catalyst.
Patent Document 3 discloses a release agent composition on a support for the purpose of providing a process release paper for synthetic leather, which has excellent release properties, initial release properties do not change with time, and stable release properties. In a synthetic leather process release paper obtained by applying a substance, a synthetic leather process release paper in which the release agent composition contains a specific amount of an amino resin and an alkyd resin with respect to a silicone-modified alkyd resin is described. There is.

Japanese Patent No. 4827282 Japanese Patent No. 3258589 Japanese Patent Publication No. 61-36117

However, in the techniques of Patent Documents 1 to 3, since the hardness of the release agent layer is insufficient, the surface of the release agent layer is easily scratched, and the glossiness and scratch resistance are insufficient.
Further, the technique of Patent Document 2 has an adequate peel force when the process paper is repeatedly used, but the repeatability is insufficient.
In the technique of Patent Document 3, although the change in the peeling force with time is described, there is no description about the repeatability when the process paper is repeatedly used, and further improvement of the repeatability is required.
Therefore, the present invention has been made in view of the above circumstances, and an object of the present invention is to provide a synthetic leather manufacturing process paper having a high glossiness, an excellent scratch resistance, and a high repeatability. To do.

As a result of intensive studies, the present inventors have made a cured product of a release agent composition containing a melamine resin and a silicone-modified alkyd resin, and the content of the silicone-modified alkyd resin in the release agent composition is relative to the melamine resin. The inventors have found that the above problems can be solved by adjusting the amount to a specific amount to complete the present invention. The present invention provides the following process paper for producing synthetic leather.
[1] A base material and a release agent layer on the base material,
The release agent layer comprises a cured product of a release agent composition containing a melamine resin (A) and a silicone-modified alkyd resin (B),
Process paper for producing synthetic leather, wherein the content of the silicone-modified alkyd resin (B) in the release agent composition is 5 to 80 parts by mass with respect to 100 parts by mass of the melamine resin (A).
[2] The synthetic leather manufacturing process paper according to the above [1], wherein a critical peeling load value for peeling the release agent layer from the base material is 20 mN or more, as measured by a scratch test.
[3] The process paper for producing synthetic leather according to the above [1] or [2], wherein the melamine resin (A) is a methylated melamine resin.
[4] The process paper for producing synthetic leather according to any one of [1] to [3] above, wherein the silicone-modified alkyd resin (B) has a silicone modification rate of 1 to 30% by mass.
[5] The process paper for producing synthetic leather according to any one of the above [1] to [4], wherein the content of the melamine resin (A) in the release agent composition is 50% by mass or more in terms of solid content. ..

According to the present invention, it is possible to provide a synthetic leather manufacturing process paper having high gloss, excellent scratch resistance, and high repeatability.

Hereinafter, embodiments of the present invention will be described in detail.
The synthetic leather production process paper of the present invention (hereinafter, also simply referred to as “process paper”) has a base material and a release agent layer on the base material, and the release agent layer is a melamine resin (A) ( Hereinafter, it comprises a cured product of a release agent composition containing a "(A) component") and a silicone-modified alkyd resin (B) (hereinafter also referred to as "(B) component"). The content of the modified alkyd resin (B) is 5 to 80 parts by mass with respect to 100 parts by mass of the melamine resin (A).
In the present invention, since the release agent composition contains the melamine resin (A) in a specific amount with respect to the silicone-modified alkyd resin (B), the hardness of the release agent layer made of a cured product of the release agent composition increases, A high glossiness is exhibited and scratch resistance is improved. As a result, when the process paper is repeatedly used, the surface condition of the release agent layer can be kept good, and an excellent effect of high repeatability is exhibited.

Next, each member of the process paper of the present invention will be described.
[Base material]
The substrate of the process paper of the present invention can be appropriately selected as long as it can support the release agent layer described later, and examples thereof include a paper substrate and a resin film.
Examples of the paper base include paper bases such as high-quality paper, medium-quality paper, glassine paper, art paper, coated paper, and cast-coated paper, and thermoplastic resin such as polyethylene is added to these paper bases. Laminated laminated paper is also included.
Examples of the resin film include a film made of polyester such as polyethylene terephthalate, polyethylene naphthalate and polybutylene terephthalate, and a film made of polyolefin such as polyethylene, polypropylene and polymethylpentene.
Further, these may be a single layer or a multilayer of two or more layers of the same kind or different kinds.
The thickness of the base material is not particularly limited, but is preferably 5 to 300 μm, and more preferably 10 to 200 μm.
Among these base materials, a paper base material is preferable, and cast coated paper is more preferable, from the viewpoint of strength and easy availability.
Examples of cast coated paper (high gloss paper) include those manufactured by the direct method, the rewet method, and the coagulation method. Commercially available products include Esprit series manufactured by Nippon Paper Industries Co., Ltd. and Oji Paper Co., Ltd. ) Manufactured by Mirror Coat series.

[Release agent layer]
The release agent layer of the process paper of the present invention comprises a cured product of a release agent composition containing a melamine resin (A) and a silicone-modified alkyd resin (B). Content is 5-80 mass parts with respect to 100 mass parts of melamine resin (A).
Hereinafter, the release agent composition will be described.

<Release material composition>
(Melamine resin (A))
The melamine resin (A) used in the present invention is obtained by addition reaction of melamine and formaldehyde in the presence of a basic catalyst. At this time, the number of primary or secondary amino groups per triazine nucleus can be controlled by adjusting the amount ratio of melamine and formaldehyde. Examples of the melamine resin (A) include a methylolated melamine resin, an iminomethylolated melamine resin, an iminated melamine resin, and an alkylated melamine resin.
Among these, alkylated melamine resins are preferable from the viewpoint of improving the compatibility with other components in the release agent composition. From the viewpoint of improving the glossiness of the release agent layer, methylol melamine resin and imino methylol melamine resin are preferable.
The alkylated melamine resin is one in which some or all of the methylol groups in the methylolated melamine resin are alkyl etherified with an alkyl monoalcohol. The type and etherification rate of the alkyl monoalcohol are not particularly limited, and are compatible with the silicone-modified alkyd resin (B), solubility in a solvent, curability of the resulting release agent composition, and adhesion to a substrate. It can be appropriately selected in consideration of the above. Specific examples thereof include a methylated melamine resin, a normal butylated melamine resin, an isobutylated melamine resin, and a normal octylated melamine resin.
Among these, an alkylated melamine resin having an alkyl group having 3 or less carbon atoms is preferable, and a methylated melamine resin is more preferable, from the viewpoint of compatibility with the silicone-modified alkyd resin (B). These may be used alone or in combination of two or more.
Examples of commercially available methylolated melamine resins include Nicalac MS-11 and MW-12LF (all of which are products of Sanwa Chemical Co., Ltd., trade names).
Examples of commercially available iminomethylolated melamine resins include Nicalac MS-001, MX-750, MX-706, and MX-035 (all of which are manufactured by Sanwa Chemical Co., Ltd., trade names). ..
Examples of commercially available iminated melamine resins include Nikalac MZ-351 and MX-730 (all of which are manufactured by Sanwa Chemical Co., Ltd., trade names).
Commercially available methylated melamine resins include Cymel 303, 325, 327, 350, and 370 (all manufactured by Nippon Cytec Industries Co., Ltd., trade name), Tesfine 200 (Hitachi Chemical Polymer Co., Ltd.). ), product name) and the like.
In addition, as a commercially available product of the silicone-modified alkyd resin (B) described later, there is a commercially available product in which a melamine resin has been blended as a curing agent for curing the silicone-modified alkyd resin (B). When a commercial product is used, the melamine resin (A) of the present invention also includes a melamine resin blended with the commercial product.

(Silicone modified alkyd resin (B))
The silicone-modified alkyd resin (B) used in the present invention is obtained by modifying an alkyd resin, which is a condensation product of a polyhydric alcohol and a polybasic acid, with a silicone modifier.
Examples of the polyhydric alcohol include dihydric alcohols such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, trimethylene glycol, tetramethylene glycol and neopentyl glycol, trihydric alcohols such as glycerin, trimethylolethane and trimethylolpropane. , Diglycerin, triglycerin, pentaerythritol, dipentaerythritol, mannitol, sorbit, and the like. These may be used alone or in combination of two or more.

Examples of the polybasic acid include aromatic polybasic acids such as phthalic anhydride, terephthalic acid, isophthalic acid, and trimetic anhydride, saturated saturated polybasic acids such as succinic acid, adipic acid, and sebacic acid, maleic acid, and maleic anhydride. Diels-Alder such as aliphatic unsaturated polybasic acid such as acid, fumaric acid, itaconic acid and citraconic anhydride, cyclopentadiene-maleic anhydride adduct, terpene-maleic anhydride adduct, rosin-maleic anhydride adduct Examples include polybasic acids produced by the reaction. These may be used alone or in combination of two or more.

A compound having an alkoxysilyl group or a silanol group can be used as the silicone modifier. Specific examples thereof include organopolysiloxane having an organic group such as dimethylpolysiloxane, and a part of the organic group is a phenyl group, an ethyl group, an isopropyl group, a hexyl group, a cyclohexyl group, a hydroxyl group, a vinyl group, or the like. Good. These may be used alone or in combination of two or more.
The silicone modification rate of the silicone-modified alkyd resin (B) is preferably in the range of 1 to 30% by mass, more preferably in the range of 1 to 10% by mass, and more preferably 2 to 5% by mass based on the solid content of the silicone-modified alkyd resin (B). The range of% is more preferable.
When the silicone modification rate is equal to or higher than the lower limit values, the peeling force becomes small, and when the modification rate is equal to or lower than the upper limit value, the peeling force can be prevented from becoming excessively low.
As a method of modifying an alkyd resin with a silicone modifier, a diol polysiloxane may be reacted as an alcohol component when a polyhydric alcohol and a polybasic acid are reacted, or an alkyd resin may be reacted with an organopolysiloxane. Good.
Examples of commercially available products of the silicone-modified alkyd resin include Tessfine 309, Tessfine 319, and TA31-209E (all of which are manufactured by Hitachi Chemical Co., Ltd., trade names).
In addition, as a commercially available product of these silicone-modified alkyd resins (B), there is a product in which a melamine resin is previously mixed as a curing agent for curing the alkyd resin (B). In the present invention, the melamine resin blended as such a curing agent is treated as the component (A), and the net content of the remaining silicone-modified alkyd resin is treated as the component (B).

In the release agent composition, the content of the silicone-modified alkyd resin (B) is 5 to 80 parts by mass, preferably 10 to 70 parts by mass, and 15 to 60 parts by mass with respect to 100 parts by mass of the melamine resin (A). A mass part is more preferable, and 20-50 mass parts is still more preferable.
When the content of the silicone-modified alkyd resin (B) is less than or equal to these lower limit values, the peeling force becomes unnecessarily large. Further, if it is more than these upper limit values, the glossiness of the process paper is lowered, and the hardness of the obtained release agent layer is lowered, so that the critical peeling load value described later is lowered, and excellent scratch resistance and repeatability are obtained. I can't get sex.
In the release agent composition, the content of the melamine resin (A) is preferably 50 mass% or more, more preferably 50 to 95 mass%, still more preferably 55 to 90 mass%, and 60 to 85 mass% in terms of solid content. % Is even more preferable. When the content of the melamine resin (A) is not less than these lower limit values, the hardness of the obtained release agent layer is increased and the glossiness is increased. Moreover, by making these upper limit values or less, it is possible to prevent the peeling force of the release agent layer from increasing more than necessary.
Further, the melamine resin (A) and the silicone-modified alkyd resin (B) may be prepared separately, so that the contents of the melamine resin (A) and the silicone-modified alkyd resin (B) are within the above ranges. It is also possible to use the one prepared by previously mixing the melamine resin (A) and the silicone-modified alkyd resin (B).

(Curing catalyst)
A curing catalyst can be used in the release agent composition used in the present invention. An acidic catalyst is preferable as the curing catalyst. Examples of the acidic catalyst include inorganic acids such as hydrochloric acid, sulfuric acid, phosphoric acid and boric acid, carboxylic acids such as acetic acid, monochloroacetic acid, dichloroacetic acid and butyric acid, benzenesulfonic acid, p-toluenesulfonic acid, xylenesulfonic acid, p- Examples thereof include organic acids selected from organic sulfonic acids such as phenol sulfonic acid, methane sulfonic acid and ethane sulfonic acid. These acidic catalysts may be used alone or in combination of two or more. Further, the content of the acidic catalyst is preferably 0.1 to 15 parts by mass, and more preferably 0.5 to 10 parts by mass, relative to 100 parts by mass of the component (A).

The release agent composition used in the present invention is a component other than the above-mentioned components (A), (B) and the curing catalyst, such as an antistatic agent, a surfactant, and a gloss, as long as the object of the present invention is not impaired. It may contain additives such as an eraser, a viscosity modifier, and a leveling agent.
When the above-mentioned other additive is contained in the release agent composition, the content of the additive other than the above-mentioned component (A), component (B) and curing catalyst is (A) component and (B). It is preferably 30 parts by mass or less, and more preferably 0.1 to 15 parts by mass, based on 100 parts by mass of the total amount of the components.

(Process for producing synthetic leather Paper manufacturing method)
The process paper of the present invention has a base material and a release agent layer on the base material. The method for producing the step paper is not particularly limited, but for example, a release agent composition can be applied onto a substrate and the coating film can be cured to form a release agent layer on the substrate.
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 and a gravure coating method.
The coating film formed on the base material may be cured by heating. When the component (A) or the component (B) has a functional group that reacts with active energy rays, it is cured by irradiation with active energy rays. Alternatively, heating and irradiation with active energy rays may be used in combination to cure. Examples of active energy rays include ultraviolet rays and electron rays.

From the viewpoint of convenience in use and the like, it is preferable to use the release agent composition usually in the form of a solution containing an organic solvent. The organic solvent can be appropriately selected and used from known solvents that have good solubility in the components (A) and (B) and are inert to them.
Examples of such a solvent include toluene, xylene, hexane, heptane, methanol, ethanol, isopropanol, isobutanol, n-butanol, acetone, methyl ethyl ketone, tetrahydrofuran and the like. These may be used alone or in combination of two or more.
Component (A), component (B), an acidic catalyst and various additives optionally used are added to these organic solvents at a predetermined ratio, respectively, and the viscosity is adjusted by the above organic solvent so that peeling can be achieved. A release agent composition solution for forming the agent layer is obtained. 5-60 mass% is preferable, as for the solid content density|concentration of a stripping agent composition solution, 10-50 mass% is more preferable, 20-40 mass% is still more preferable.
When the above release agent composition solution is used, it is preferable that the solution is applied onto a substrate to form a coating film, and the coating film is heated and dried.
The heating temperature is preferably 80 to 250° C., more preferably 100 to 230° 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 may be cured by heating during drying, or may be cured by means other than heating, for example, irradiation with active energy rays.

In the process paper of the present invention, the thickness of the release agent layer after curing is not particularly limited, but is preferably 3 to 15 μm, more preferably 3 to 8 μm. When the thickness of the release agent layer is 3 μm or more, a release agent layer having good smoothness can be formed and high glossiness can be obtained. Further, when the thickness of the release agent layer is equal to or less than these upper limit values, it is possible to suppress the generation of cracks when the process paper is curved and deformed, and it is possible to prevent transfer of crack traces to the synthetic leather. Further, it is possible to suppress the penetration of the solvent from the crack portion generated when the synthetic resin coating liquid is applied, and to suppress the peeling of the release agent layer from the base material.

In the process paper of the present invention, the critical peeling load value for peeling the release agent layer from the base material, measured by a scratch test, is preferably 20 mN or more, more preferably 23 mN or more, and 26 mN or more. More preferably,
When the critical peeling load value is equal to or more than these lower limit values, scratch resistance is improved, the release agent layer surface can be maintained in a good surface state even when the process paper is repeatedly used, and high repeatability is exhibited. be able to.
The scratch test is performed by slightly vibrating the indenter needle in a horizontal direction orthogonal to the scratch direction, pressing the indenter needle against the surface of the release agent layer and scratching the surface, and increasing the load pressing the indenter needle to remove the release agent. The load value applied to the indenter needle when the layer peeled off was calculated as the critical peeling load value. Specifically, for example, using a scratch tester “CSR-2000” (manufactured by Rhesca), scratch speed: 25 μm/s, indenter needle stylus diameter: 5 μm, indenter needle spring constant: 100 g/mm, excitation amplitude : It can be performed under the measurement condition of 100 μm.
The scratch test can evaluate the adhesion of the release agent layer formed on the surface of the base material to the base material, and the critical peel load value is an index for evaluating the scratch resistance.

(How to use synthetic paper for manufacturing synthetic leather)
The process paper of the present invention is used in the manufacturing process of synthetic leather.
As a method for producing synthetic leather using the process paper of the present invention, a coating solution containing a synthetic resin such as urethane resin, vinyl chloride resin, polyamide resin or the like as a main component is applied onto the release agent layer of the process paper and dried. After forming the resin layer, a base cloth may be further laminated thereon with an adhesive if necessary, and finally the synthetic leather may be peeled off from the process paper.
As the synthetic resin used in the method for producing the synthetic leather, a urethane resin is preferable from the viewpoint of the texture and durability of the synthetic leather.
Specifically, after applying a urethane resin on the release agent layer of the process paper of the present invention and appropriately drying to form a urethane resin layer, the base cloth is further bonded via an adhesive and then aged, Finally, the urethane resin layer together with the base fabric can be peeled off from the process paper to produce synthetic leather.
In the process paper of the present invention, the peeling force of the synthetic leather from the resin layer is preferably 30 to 3000 mN/20 mm, more preferably 50 to 2000 mN/20 mm, and further preferably 60 to 1000 mN/20 mm. It is more preferably 70 to 500 mN/20 mm, still more preferably 90 to 200 mN/20 mm. When the peeling force is less than or equal to these upper limit values, stable peeling performance from the synthetic leather is obtained even after the process paper is repeatedly used, and synthetic leather having high glossiness can be produced. When it is at least the value, it is possible to prevent the resin layer from being abruptly peeled from the release agent layer.

Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited to these examples.

The measurement method and evaluation method in the present invention are as follows. The results are shown in Table 1.
[Measurement of critical peel load value]
Using a scratch tester “CSR-2000” (manufactured by Rhesca Co., Ltd.), the indenter needle is slightly vibrated in the horizontal direction orthogonal to the scratch direction, and the indenter needle is pressed against the release agent layer surface of the synthetic leather manufacturing process paper. While scratching the surface, the load for pressing the indenter needle was increased to perform a scratch test. The load value applied to the indenter needle when the release agent layer peeled off was calculated as the critical peeling load value. The measurement conditions are shown below.
(Measurement condition)
Scratch speed: 25 μm/s
Indenter stylus diameter: 5 μm
Indenter needle spring constant: 100 g/mm
Excitation amplitude: 100 μm

[Measurement of gloss]
The glossiness at an angle of 20° was measured using a gloss meter “VG7000” (Nippon Denshoku Industries Co., Ltd.).

[Measurement of peeling force]
A one-pack type polyurethane resin solution (trade name: Chris Bonn 5516S, manufactured by DIC Corporation) was used as a coating solution for the synthetic leather resin layer, and this solution was applied to the release agent layer surface of the synthetic leather manufacturing process paper, After drying at 140° C. for 2 minutes, a polyurethane resin layer having a thickness of 25 μm was formed.
Then, a polyester adhesive tape (manufactured by Nitto Denko Corp., product number No. 31B) was attached to the surface of the formed polyurethane resin layer, left for 30 minutes in a thermostatic chamber at 23° C. and 50% relative humidity, and then width 20 mm, long It was cut to a size of 150 mm. Using a tensile tester (device name: Tensilon, manufactured by A&D Co., Ltd.), the polyurethane resin layer laminated with the adhesive tape was pulled in a direction of 180° at a speed of 1000 mm/min and peeled off. The peel force was measured.

[Evaluation of repeatability]
The coating solution used in the measurement of the peeling force is applied to the surface of the release agent layer of the synthetic leather manufacturing process paper, and dried at 140° C. for 2 minutes to form a resin layer, which is peeled from the process paper. A polyurethane resin layer was obtained. Subsequently, the surface of the release agent layer of the peeled process paper was rubbed with a cotton cloth (attached white cloth for dyeing fastness test defined in JIS L0803) 10 times to make a reciprocating movement. Further subsequently, the coating liquid was applied to the surface of the release agent layer of the rubbed process paper in the same manner as above, and dried at 140° C. for 2 minutes to release the polyurethane resin layer. This series of operations was performed 5 times, 1 time, and the surface state of the side of the polyurethane resin layer made without rubbing with the cotton cloth for the first time and the release agent layer of the polyurethane resin layer made at the 5th time And the repeatability was evaluated according to the following evaluation criteria.
〔Evaluation criteria〕
A: The surface change of the polyurethane resin layer at the fifth time was small compared to the surface of the polyurethane resin layer formed without rubbing with a cotton cloth at the first time, and it can be used as synthetic leather.
B: The surface of the polyurethane resin layer at the 5th time was scratched on the process paper, resulting in a projection mark, which cannot be used as synthetic leather.

(Manufacturing process paper for manufacturing synthetic leather)
[Example 1]
Methylated melamine resin solution (solid content concentration 80% by mass) (trade name: Tesfine 200, manufactured by Hitachi Chemical Polymer Co., Ltd.) 100 parts by mass, silicone-modified alkyd resin solution containing melamine resin (solid content concentration 50% by mass) %, mass ratio of melamine resin and silicone-modified alkyd resin [melamine resin/silicone-modified alkyd resin]=35/65, silicone modification rate 3% (trade name: TESFINE 309, manufactured by Hitachi Chemical Co., Ltd.) A release agent prepared by adding 17.8 parts by mass and 4.6 parts by mass of a p-toluenesulfonic acid methanol solution (solid content concentration 50% by mass) as a curing catalyst, and diluting it with a toluene solvent to a solid content concentration of 30% by mass. A composition solution was prepared.
Next, a coat layer of cast coated paper (trade name: Espricoat E(UT)165SW, manufactured by Nippon Paper Industries Co., Ltd., basis weight 150 g/m ² ) was formed using the release agent composition solution as a paper substrate. It was applied on the surface, dried and cured at 210° C. for 60 seconds to obtain a synthetic leather manufacturing process paper having a release agent layer having a thickness after curing of about 5.0 μm.

[Example 2]
A processed paper for leather production was obtained in the same manner as in Example 1 except that the addition amount of the silicone-modified alkyd resin solution (solid content concentration 50% by mass) was changed to 68.6 parts by mass.

[Example 3]
A process paper for producing synthetic leather was obtained in the same manner as in Example 1 except that the amount of the silicone-modified alkyd resin solution (solid content concentration 50% by mass) added was 274 parts by mass.

[Comparative Example 1]
A process paper for producing synthetic leather was obtained in the same manner as in Example 1 except that the silicone-modified alkyd resin solution (solid content concentration 50% by mass) was not added.

[Comparative example 2]
A process paper for producing synthetic leather was obtained in the same manner as in Example 1, except that the amount of the silicone-modified alkyd resin solution (solid content concentration 50% by mass) added was 560 parts by mass.

[Comparative Example 3]
For producing synthetic leather in the same manner as in Example 1 except that the melamine resin solution was not added and the addition amount of the silicone-modified alkyd resin solution (solid content concentration 50% by mass) was 100 parts by mass. The process paper was obtained.

＊１：剥離剤組成物における（Ａ）成分の含有量を固形分比率（質量％）で示す。
＊２：剥離剤組成物における（Ｂ）成分の含有量を（Ａ）成分１００質量部に対する質量部で示す。
＊３：ポリウレタン樹脂層が剥離しなかったため、リピート性評価を行わなかった。

*1: The content of the component (A) in the release agent composition is shown by the solid content ratio (mass %).
*2: The content of the component (B) in the release agent composition is shown in parts by mass relative to 100 parts by mass of the component (A).
*3: Since the polyurethane resin layer did not peel off, the repeatability was not evaluated.

In Examples 1 to 3, it had a high glossiness and an appropriate peeling force, and since the critical peeling load value was 20 mN or more, it was excellent in scratch resistance and had high repeatability. Particularly, in Example 2, the balance of the critical peeling load value, glossiness and peeling force was excellent. This is because the release agent layer is composed of a cured product of the release agent composition containing a specific amount of the melamine resin (A) and the silicone-modified alkyd resin (B), and the hardness of the release agent layer is increased. It is considered that this is because the surface state of the agent layer could be kept good.
On the other hand, in Comparative Example 1, since the silicone-modified alkyd resin (B) was not contained, the release agent layer could not be peeled from the base material, and the glossiness was also lowered. Further, in Comparative Examples 2 and 3, the content of the silicone-modified alkyd resin (B) was the same or excessive with respect to the melamine resin (A), so that although the peeling force was obtained, the glossiness was lowered and the repeatability was increased. The sex was also reduced.

Claims (1)

A base material and a release agent layer on the base material,
The release agent layer comprises a cured product of a release agent composition containing a melamine resin (A) and a silicone-modified alkyd resin (B),
The content of the silicone-modified alkyd resin (B) in the release agent composition is 5 to 80 parts by mass with respect to 100 parts by mass of the melamine resin (A) ,
The critical peel load value for peeling the release agent layer from the base material measured by a scratch test is 20 mN or more,
The melamine resin (A) is a methylated melamine resin,
The silicone-modified alkyd resin (B) has a silicone modification rate of 1 to 30% by mass,
Process paper for producing synthetic leather , wherein the content of the melamine resin (A) in the release agent composition is 50% by mass or more in terms of solid content .