JP2010116488A - Antifouling leather and method of manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a new method of manufacturing leather fixed to the surface of the leather with a film of a material having hydrophilic interfacial activity to prevent stain from adhering onto the leather, or to remove the stain adhered. <P>SOLUTION: In the leather having a coated film of a synthetic resin binder formed on a leather surface, and a film of a copolymer of 2-methacryloyloxyethyl phosphorylcoline (MPC) and a methacrylic ester formed on the surface of the coated film, the leather on which film formation is to be done with the synthetic resin binder is prepared by tanning again a leather obtained through a leather tanning process, passing a dying process and a fat liquoring process, and thereafter being introduced into a finishing process. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an antifouling leather and a method for producing the same.

Leather for automobile seats is obtained by retanning the leather obtained through the tanning process of the leather, followed by dyeing and greasing processes, and after the coating process is formed on the surface with a synthetic resin binder in the finishing process. As a result, the automobile seat is assembled and completed as an automobile by the automobile production line.
It can be seen that the process up to the formation of the coating film is almost completed as a normal process, and further, development efforts for obtaining improved products in line with the current trend are being made in the automobile seat manufacturing department.
The finishing process is an important process to meet the needs of users.
Formation of coating film with synthetic resin binder in finishing process includes color tone, color image, glazing, improvement of smoothness and touch, imparting durability, protection from water and light, water repellency and antifouling property, etc. The purpose is to give a function, and an important function is given as a product of an automobile seat.

In order to use the automobile conveniently, how to solve the inconvenience caused by the use is a difficult problem, and it is difficult to fundamentally solve it.
When you get on and off, there will be a stronger friction than usual, so dyes for clothing (especially jeans dyes), dust and dirt floating in the air by opening and closing doors in the city, exhaust gas soot (carbon black) ) Etc. is difficult to solve. If these measures are taken at the time of manufacture of automobile seats, the product is pre-treated with a process that goes against or goes against the original properties based on the premise that the product is likely to get dirty. Therefore, if it is an automobile seat, it may be a process that counteracts the goodness of natural leather against natural leather. There is a demand for measures against dirt that does not impair the goodness of natural leather.
Measures against dirt, not limited to automobile seats, are necessary for leather products in general, and countermeasures against dirt are considered as leather forming a coating film containing automobile seats.

In order to remove the dirt of leather that has already been stained, it is common to wipe off the dirt using a dirt remover found in shoe cleaners and the like. As the cleaner, there is known a composition in which an oil component such as a sorbitan fatty acid ester, a paraffinic hydrocarbon and a coconut oil are mixed.
The soil removal agent achieves its purpose by removing the attached soil from the leather surface together with the soil removal agent. If this is used, the peculiarity of leather will be lost, the luster will be lost, and it will be necessary to completely wipe it off, and further processing will be required to return it to the original leather.
If it is applied before the dirt adheres, the result of the application itself will be the dirt. A stain remover adheres to a person's clothes, resulting in the clothes becoming dirty.

In order to prevent dirt from adhering, even if dirt adheres to the leather, it can be said that it is an effective means if the state where the dirt is bound to the leather is weakened. By performing wiping, etc., it can be wiped off with a simpler operation compared to the case where no measures are taken, and the influence on the leather can be reduced. It can be understood that wiping off adhering dirt with water or the like is to make the dirt hydrophilic, and it is effective to make the dirt hydrophilic.
From the above, before the dirt adheres to the leather, the dirt adhesion preventing agent capable of making the dirt hydrophilic can be applied to the leather in advance to prevent or adhere to the dirt. It is considered that if the hydrophilic soil is made to be easily wiped off with water, the soil can be prevented and easily wiped off, which can be an effective means. In this case, it cannot be solved how the hydrophilic antifouling agent can be kept on the leather surface, and it is not a fundamental solution.

  In the technical fields other than automobile seats, the surface cleaning treatment of the target substances has been actively promoted. For example, in order to prevent rainwater stains from adhering to the surface of a building material such as ceramic, a functional paint such as acrylic or polyurethane having water repellency is applied. . As the surface of the water-repellent coating film, when the rainwater containing dirt flows down the surface, only the rainwater repels and leaves the dirt. As a result, the oil component that is dirt remains on the surface of the coating film. Results in inadequate results. On the other hand, if the water-repellent coating is changed to a coating with a hydrophilic functional paint, the rainwater will flow down and become familiar with the coating, so the rainwater will wash away the dirty oil together. No stains due to oil components found on aqueous surfaces remain. From this, it is said that it is effective to use a hydrophilic coating on the surface when wiping with water (Non-patent Document 1: Haruo Kiryu et al., December 31, 1998, issued by CMC Co., Ltd.) 13).

  In the removal of dust and mud adhering to the fiber surface, solid particle dirt such as dust and mud in the air aggregates and adheres to the fiber surface. The population of fine particles is agglomerated in an aggregated state with a very large surface area. In order to remove the dirt, it is first necessary to disperse the lump-like fine particles in each fine particle. For this purpose, it is necessary to cause a sufficient repulsive force (repulsive force) between the fine particles in order to release the force acting in the state of being agglomerated. If the surfactant is present on the fiber surface, the fine particles can be separated, and dust and mud cannot be adhered from the fiber surface. In addition, by using a surfactant, it is possible to prevent dirt from re-adhering (Non-Patent Document 2 by Satoshi Ushida et al., Science of Clothing Life, March 20, 2006. (Issue 149-151).

  In the technology that the present inventors pursue to prevent dirt from adhering to the leather surface, it becomes possible to form a hydrophilic film on the surface, for example, when dirt adheres to the film surface. Even if it exists, it turns out that it is in the state which is easy to remove dirt.

It is well known to provide a water-repellent film when providing a conventional anti-stain film on the leather surface. There are many inventions in which a film containing a fluorine-containing compound or a silicon compound is provided to form a water-repellent film.
Water repellent antifouling fur / leather product having a coating film containing fluorine, an alkoxysilane compound containing fluorine, and a chemical adsorption film formed on at least the surface of the product through a siloxane bond (Patent Document 1 2004-203946) ), A coating composition for leather comprising a fluorine-containing resin and silicone oil (Patent Document 2, Patent No. 3778168),
Fluorine-containing resin-coated leather having a fluorine-containing resin coating film as a cured product of a curable fluorine-containing resin paint containing a curable resin having a curable reactive group and a curing agent (Patent Document 3 Patent No. 3948126) ), And a composition for forming a silicone coating film of leather, synthetic rubber, natural rubber, and textile products comprising the following (A) and (B).
(A) 100 parts by weight of a polyorganosiloxane represented by the general formula R ¹ _a SiO _{(4-a) / 2} and having a viscosity of 10 to 20 million cP at 25 ° C. (R ¹ is a monovalent having 1 to 20 carbon atoms) Organic group, 1.95 <a <2.20),
(B) 0.1 to 100 parts by weight of a composite silicone powder obtained by coating a silicone rubber spherical fine particle with a polyorganosilsesquioxane resin (Patent Document 4, Patent No. 3854670).
The shape-retaining agent contains at least one compound selected from the group consisting of a silicon-based polymer, a cationic surfactant, a natural greasing agent such as score run, and a natural lubricant as a softening agent. Item 1. The shape holding method according to Item 1 (Patent Document 5 Japanese Patent Application Laid-Open No. 2008-095250). A water / oil repellent for leather, which is obtained by emulsifying and dispersing a fluororesin blended composition in water with an acrylic acid / methacrylic acid copolymer (Patent Document 6, Patent No. 3028128). Natural leather products treated with a mixture of squalane, higher fatty acid ester and aminosilicon (Patent Document 7 Patent 2659772).
Films of fluorine-containing compounds and silicon-containing compounds are water repellent. These coatings use fluorine compounds that are hard or hydrophobic, so they are charged and attract dirt, or the surface slips. Problems such as remaining are often pointed out, and this is a problem.

The above has described the car seat. What kind of measures should be taken against dirt is necessary for leather in general. The leather finally becomes a final product by forming a coating film. It is considered as the relationship between the coating film and the dirt adhering to the surface of the coating film, and in order to prevent the dirt adhering to the leather, to make it difficult to remove or to easily remove the adhering dirt, a water-soluble interface is formed on the leather surface. There is a need to attach an active substance and immobilize it on the leather surface.
However, it has not been technically solved to attach a water-soluble surface active substance, and a technique for attaching and fixing an appropriate water-soluble surface active substance and a water-soluble surface active substance to the leather surface is strong. It has been demanded.
2004-203946 Japanese Patent No. 3778168 Japanese Patent No. 3948126 Patent No. 3854670 JP 2008-095250 A Patent No. 3028128 specification Japanese Patent No.2645972 Waterborne coating by Haruo Kiryu et al. December 31, 1998, issued by CMC Co., Ltd., page 13 Satoshi Ushida et al., Science of Clothing Life, pp. 149-151, March 20, 2006

  The problem to be solved by the present invention is that a film of a substance having a hydrophilic surface activity is adhered and fixed on the surface of the leather in order to prevent the dirt adhering to the leather, to make the dirt less difficult, or to remove the adhering dirt. By providing a novel leather, a novel treatment agent for forming a film on the surface of the leather, and a novel leather manufacturing method using this treatment agent, to which a film of a substance having a hydrophilic surface activity is adhered and fixed to the leather surface is there.

The inventors of the present invention have made extensive studies in order to solve the above problems.
(1) As described above, it is generally difficult to attach and fix a film of a hydrophilic surfactant substance to the surface of leather forming a coating film. Even if a hydrophilic surface active substance is adhered to the coating film, it is expected to flow off from the surface.
(2) In recent years, 2-methacryloyloxyethyl phosphorylcholine (hereinafter also referred to as MPC) (Japanese Patent Publication No. 60-21599), and 2-methacryloyloxyethyl phosphorylcholine (MPC) and a methacrylic acid ester copolymer (Japanese Patent Laid-Open No. 3-39309) And Japanese Patent Laid-Open No. 9-3132, Japanese Patent No. 2890316, Japanese Patent No. 2870727) are known. This substance is noted for its unique action.
(3) MPC is a substance in which a 2-methacryloyloxyethyl group and a phosphorylcholine group are bonded, and the 2-methacryloyloxyethyl phosphorylcholine group exhibits super hydrophilicity. As a whole, these two parts are combined. These strongly interact with phospholipid molecules derived from the living body, and stably form an oriented phospholipid adsorbing layer on the surface of the material similar to the biological membrane. And it shows excellent biocompatibility. Adsorption of biological components such as proteins and blood cells is small, and activation of platelets that induce thrombus formation can be suppressed. This property is known as a biocompatible substance. If protein and blood cells are dirt, dirt is not adsorbed by the action of 2-methacryloyloxyethyl phosphorylcholine group oriented on the leather surface, and the dirt is left on the leather surface in a loose state. .
(4) The present inventors prepared 2-methacryloyloxyethyl phosphorylcholine (MPC) and a methacrylic acid ester copolymer as a film-forming treatment agent comprising a thickener, a leveling agent, and water. When the treatment agent is sprayed on the leather surface as a paint film and sprayed, and then dried, 2-methacryloyloxyethyl phosphorylcholine (MPC) and a methacrylic acid ester copolymer are applied onto the paint film protecting the leather surface. Succeeded in fixing.
(5) 2-Methacryloyloxyethyl phosphorylcholine (MPC) and methacrylate ester copolymer fixed on the leather surface not only prevents the adhesion of dirt due to the use of automobiles, but also makes it difficult to adhere dirt. The present invention has been completed by newly finding that it can be removed by wiping off the soiled dirt.

ADVANTAGE OF THE INVENTION According to this invention, the leather which formed 2-methacryloyloxyethyl phosphorylcholine (MPC) and the methacrylate ester copolymer as a coating film on the surface of a synthetic resin binder can be obtained.
This coating film can prevent dirt from adhering to the leather surface, and even if it adheres, it can be easily removed. It opens up a new field as a countermeasure against dirt on leather used for automobile seats.
According to the present invention, a novel leather treatment agent containing 2-methacryloyloxyethyl phosphorylcholine (MPC) and a methacrylic acid ester copolymer, a thickener, a leveling agent and water can be obtained, and this is applied to the leather surface. When applied and dried, a film of 2-methacryloyloxyethyl phosphorylcholine (MPC) and a methacrylate ester copolymer can be formed.
Since the leather treatment agent can be used in the form of spray spray or the like, it can be used easily in use.
Regarding the production of leather for automobile seats, after finishing the tanning process, retanning, dyeing, greasing process and drying process, after forming a coating film with a synthetic resin binder in the finishing process, 2-methacryloyloxyethyl phosphorylcholine (MPC) on the leather surface ) And a methacrylic acid ester copolymer coating can prevent dirt from adhering to the leather surface, and even if it adheres, it can be easily removed. It shows a new direction for final finishing of car seat leather and instrument panel leather. When the performance has deteriorated over the years to be used, a coating film may be formed again, and it can be regenerated as leather for automobile seats.
As described above, the present invention has been described as an automobile seat that requires a countermeasure against dirt in particular from the point of use, but the leather / film-forming treatment agent / leather manufacturing method of the present invention is not limited to an automobile seat, It can also be suitably used for automobile interior parts such as instrument panels, door trims, knob skirts, and furniture.

The present invention is a leather in which a coating film is formed on a leather surface with a synthetic resin binder, and a coating film of 2-methacryloyloxyethyl phosphorylcholine (MPC) and a methacrylate ester copolymer is formed on the surface of the coating film. is there.
In the present invention, the leather on the leather surface is not limited to automobile seats, but also includes leather used for automobile interior parts such as instrument panels, door trims, knob skirts, or furniture. Covers a wide range of leather. These leathers are provided with a synthetic resin binder coating on the surface to prevent or remove the dirt, and on this surface, both 2-methacryloyloxyethyl phosphorylcholine (MPC) and methacrylate ester are used. A film made of a polymer can be formed.
A known synthetic resin binder is used for the synthetic resin binder. Specifically, casein, nitrocellulose, polyurethane, and polyacrylic acid ester are used. Further, it is possible to undercoat with an acrylic binder and apply the urethane binder to the topcoat.
Synthetic resins include polyvinyl acetate (Tg 30 ° C), polymethyl acrylate (Tg 3 ° C), polyethyl acrylate (Tg-22 ° C), polymethyl methacrylate (105 ° C), polystyrene (Tg 105 ° C), polyacrylonitrile. (Tg 105 ° C.) and polyvinyl chloride (Tg 82 ° C.) are used. All are general-purpose known substances, and can be arbitrarily selected and used. The case where polyurethane is used for an automobile seat will be described later. The same can be done for other cases.
A case where a film made of 2-methacryloyloxyethyl phosphorylcholine (MPC) and a methacrylic acid ester copolymer is formed on the surface of the coating film will be described later. The same can be done for other leathers.
Arbitrary methods, such as brush painting and spray painting, are employ | adopted for formation of the resin coating film.

The leather on the leather surface is obtained by re-tanning the leather obtained through the preparation process and the leather tanning process, followed by the dyeing and greasing process, and then the leather surface is formed with a synthetic resin binder in the finishing process. On the other hand, a film is formed.
The series of steps is a normal leather manufacturing process, and is a process generally used for leather manufacturing.

  The preparation process is a preparation process for performing tannery. The preparatory process is a trimming process from a raw skin water washing / water soaking process.

In the tanning process, the leather treated in the preparation process is reversibly converted into leather having various practical performances by chemical and physical operations. Gives the skin heat resistance, resistance to chemical reagents and microorganisms, and flexibility.
In the tanning step, the tanning agent is treated in the presence of water under acidic conditions. The tanning agent is an operation of causing the collagen material of the skin to be cross-linked, giving the skin heat resistance, resistance to microorganisms and chemical substances, and imparting flexibility.
Many tanning agents are known as tanning agents, such as chromium compounds using hexaacocrystalline sulfuric acid expressed as a trivalent chromium complex, for example, Cr ₂ (SO ₄ ) ₃ , aldehyde compounds such as glutaraldehyde, and the like. All of these are conventionally known, and a commercially available product may be purchased and used.

The retanning / dyeing / greasing and drying steps are as follows.
In the retanning step, the retanning agent is selected from among already known synthetic tanning agents, plant tanning agents, and the like. In some cases, the tanning agent such as chromium or glutaraldehyde may be added and used.
In retanning, it is confirmed in advance whether the leather to be treated has been neutralized.

The dyeing process is as follows.
The dyeing step is for dyeing the leather obtained through the retanning step using the dye. It is dyed with an acidic aqueous dye.
The composition containing the dye is on the relatively strong acid side (pH is 3 to 4), and based on the weight of the leather, the leveling agent comprises 250% water, 2.5 to 4% of the dye, and an anionic surfactant. It is supplied as a 5% water-soluble composition.
The processing temperature is about 50 ° C. Process in the drum for about an hour.
After completion of the dyeing process, the dye is fixed with 1% formic acid (% by weight based on leather).

The greasing process is as follows.
In the greasing step, treatment with a greasing agent is performed.
The greasing process is a process performed after the dyeing process after retanning. Much water intervenes between the fibrils in the internal structure of the wet leather that has been subjected to wet leather work such as tanning, which gives the leather flexibility. When the leather is dried and this water is removed, the fibrils adhere to each other and the tissue hardens. When a part of the water intervening in the wet leather is replaced with another substance and then dried, fibril adhesion can be prevented. Filling an oil agent between leather fibrils and attaching it to the surface is the center of the greasing process.
The fibrils can be waterproofed by covering the fibrils or their surfaces with a hydrophobic oil film by the action of the oil agent, and the water resistance can be improved by using an oil agent having a water repellent effect. In addition, the suppleness and swelling of leather are affected by the greasing agent.
The greasing agents include (1) anionic greasing agents, (ii) sulfated oil, (b) sulfonated oil,
(C) sulfitized oil, (d) fatty acid soap, (e) phosphorylated oil, (f) multipolar greasing agent, (g) other anionic greasing agents, (2) cationic greasing agents, ( 3) Amphoteric greasing agent, (4) Nonionic greasing agent, (5) Neutral oil, specifically (i) animal oil, (b) marine animal oil, (c) plant (d) synthetic oil, etc. Can be mentioned.
The composition containing a greasing agent is as follows.
Water is 110% to 130% with respect to leather weight, synthetic greasing agent is 2 to 5% with respect to leather weight, pH of the liquid is 3.5, and water temperature is about 50 ° C.
The above composition is supplied to the leather in the drum, and after the treatment, it is sufficiently washed with water to complete the operation.

The leather that has undergone the greasing process is in the form of a tanned and softened leather.
It moves to a setter process, it stretches on a flat plate with a setting machine, the water | moisture content of the dyed leather is squeezed, and water | moisture content is made into about 50 to 60%.
Garbage drying involves fixing one piece of leather and applying drying air at 35 to 50 ° C. in a suspended state with the other side as a free end to bring the moisture to about 10 to 5%. Dry the leather to completely absorb chemicals and dyes in the leather. The texture is created by drying the leather once.
In the taste-removal process, the silver surface is excessively dried by dry drying, and it is easy to crack, and it is dried while it is stretched too strongly. Moisture is given to the leather by seasoning, transferred to a taste-removing shower machine, and seasoned by applying a small amount of water to the leather in a dry state. This is ultimately related to the even stretch and swelling of the leather.
In the vibration process, the leather is transferred to a vibration machine to take the hardness of the toes and edges and increase the area.
In the blanking process, the leather is transferred to a blanking drum to loosen the leather fibers after drying.
In the net tension drying step, the leather is lightly pulled, fixed to the net with a toggle clip, and dried with hot air. Usually, leather is flattened by avoiding tissue hardening due to drying from a moisture state with relatively little moisture.
The buff uses a buffing machine to finish the leather beautifully by pressing the buffing paper coated with abrasives against the leather. Since the leather waste generated at this time adheres to the surface and the inner surface of the leather, they are also removed.
In the vibration process, the leather is transferred to a vibration machine to loosen the fibers and take the hardness around the toe edge.

In the finishing process for leather that has undergone the following steps, a base coat layer is formed by coating a natural leather substrate surface with an aqueous paint containing a pigment, and a color coat obtained by coating the base coat layer with an aqueous paint. A layer and a top coat layer are further formed on the coat layer.
(1) Base coat coating Base coat coating is performed by roll coating or spray coating using an aqueous coating agent containing a pigment. The film thickness of this base coat is usually 3 to 10 μm. After the coating, it is subjected to a drying treatment, but usually a treatment of about 10 minutes with an 80 ° C. hot air dryer is sufficient.

(2) Color coat coating Color coat coating is performed after the above base coat coating. In order to make the final product have sufficient color tone and various physical properties, this color coat coating is preferably performed by a two-time coating operation. As the binder, usually two to three kinds of binders are mixed and used. A polyurethane-based synthetic resin binder is used as a solution-type binder.
As for the drying treatment, a treatment for about 10 minutes with an 80 ° C. hot air drier is usually sufficient. The film thickness of the base coat is usually 7 to 30 μm as the total film thickness. After finishing the color coat, it is subjected to a drying process as described above.

(3) Top coat painting Next to the color coat painting, top coat painting is performed. Spray with two-component urethane resin paint. The film thickness of the top coat is usually about 10 μm. After the coating, it is subjected to a drying process, and this drying process is also the same as the drying process in each of the aforementioned coating processes.

  Polyurethane resins are known and resins are used. Development of leather using an aqueous resin composition is advanced, and an aqueous resin composition is used.

An example of the aqueous polyurethane resin composition is as follows.
A) a specific aqueous polyol component having a viscosity at 23 ° C. of 25 to 15,000 mPa · s;
B) 3 to 35% by weight of a polyisocyanate component having a viscosity at 23 ° C. of 50 to 10,000 mPa · s and comprising one or more organic polyisocyanates, and components A) and B) are components B) This is a two-component aqueous binder composition based on the isocyanate group of component A) and the hydroxyl group of the polyol component of component A) and having an NCO / OH equivalent ratio of 0.3: 1 to 2: 1 (Japanese Patent No. 3860623).

  The above A is carried out by a known polycondensation reaction using a conventional esterification catalyst as necessary. The obtained polyester A is made to react with component B and C at 60-160 degreeC as needed. This reaction can be carried out using a urethanization catalyst in the absence of a solvent or in the presence of an inert organic solvent.

The polyurethane dispersion has a weight average molecular weight (Mw) greater than 25,000; contains ammonia, triethylamine, N-methylmorpholine and / or dimethylisopropanolamine as neutralizing agents; 3-20 mg KOH / g dispersion Having a minimum film formation temperature of 10 ° C. or less.
The polyisocyanate component is 50 to 10,000, preferably 50 to 3,000 mPa.s at 23 ° C. based on organic polyisocyanates having isocyanate groups which have a viscosity of s and are liquid at room temperature and have aliphatic, alicyclic, araliphatic and / or aromatically bonded isocyanate groups ing.

For the production of the coating composition, the polyisocyanate component B) is mixed with the aqueous dispersion A), where the dissolved or dispersed component A) can act as an emulsifier for the polyisocyanate. it can.
This mixing is performed by simple stirring at room temperature. The amount of polyisocyanate component is based on the isocyanate group of component B) and the alcoholic hydroxyl group of component A) of 0.3: 1 to 2: 1, preferably 0.6: 1 to 1.5: 1. Selected to give an NCO / OH equivalent ratio. Prior to the addition of the polyisocyanate component B), known additives of lacquer technology can be incorporated into the dispersion or solution of polyol. These additives include defoamers, flow regulators, pigments and dispersion aids for pigment distribution.
In addition, commercially available two-component aqueous polyurethane resin compositions can be purchased and used.

The two-component aqueous polyurethane resin composition may be appropriately purchased and used, and the product names are as follows.
Finish PF BASF
Finish PFM BASF
Finish PUM BASF
Finish PUMN BASF
Matching HS BASF
Matching MA BASF
Promul 95A Clariant
Top D-2017 Clariant
51UD LANXESS
61UD LANXESS
85UD LANXESS
Hydrolac HW LANXESS
Hydrolol UD-2 LANXESS
RU-13045 Stahl
RU-22003 Stahl
RU-6125 Stahl
WT-13-486 Stahl
WT-13-492 Stahl
WT-2524 Stahl

  It is pointed out that the at least one hydroxyl group-containing polyester dispersion, an aqueous urethane substantially free of hydroxyl groups or amino groups, and an aqueous coating composition containing a polyisocyanate are not sufficient in abrasion resistance, The following aqueous resin compositions are also known. A large excess of polyisocyanate-based crosslinking agent and silicone-based compound are added to the water-based polyurethane resin, and further, an organic or inorganic filler is added to make it suitable for coating without substantially using an organic solvent. A surface finish for leather comprising an aqueous resin composition capable of imparting excellent and high wear resistance to leather is known (Japanese Patent Application Laid-Open No. 2007-314919). It is effective to use the new resin processed well.

  Formation of a film of 2-methacryloyloxyethyl phosphorylcholine (MPC) and a methacrylic acid ester copolymer on the surface of the leather surface with a synthetic resin binder is as follows.

〔式中、ａは０．０３〜０．７０、ｂは０．３０〜０．９７、ｎは２以上の整数、ＲはＨ、ＯＲ’（Ｒ’は脂肪族炭化水素基、芳香族炭化水素基）を示す〕
で示される繰り返し単位により構成されている。
平均重量分子量は５０００以上である。この共重合体は以下の単量体を共重合させることにより得ることができる。
この重合体は公知の重合体である（特許第２８７０７２７号明細書）。
また、日油株式会社製、商品名ポテンシャルSG（皮革保護剤、粘度６０００cPs（２５℃）、MPCとメタクリル酸エステル共重合体の含有量１０重量％）を購入して用いることができる。 2-Methacryloyloxyethyl phosphorylcholine (MPC) and a methacrylic acid ester copolymer are represented by the following general formula.

[Wherein, a is 0.03 to 0.70, b is 0.30 to 0.97, n is an integer of 2 or more, R is H, OR ′ (R ′ is an aliphatic hydrocarbon group, aromatic carbonization) Hydrogen group)
It is comprised by the repeating unit shown by these.
The average weight molecular weight is 5000 or more. This copolymer can be obtained by copolymerizing the following monomers.
This polymer is a known polymer (Japanese Patent No. 2870727).
Moreover, the product name potential SG made from NOF Corporation (leather protective agent, viscosity 6000 cPs (25 degreeC), content of 10 weight% of MPC and a methacrylate ester copolymer) can be purchased and used.

In the above copolymer, 2-methacryloyloxyethyl phosphorylcholine (MPC) is a monomer having the following chemical structural formula.
This compound is represented by the following structural formula.

  2-Methacryloyloxyethyl phosphorylcholine (MPC) is obtained by, for example, reacting 2-bromoethylphosphoryl dichloride with 2-hydroxyethyl methacrylate to obtain 2-methacryloyloxyethyl 2′-bromoethyl phosphate (MBP). It can be obtained by reacting in a methanol solution of trimethylamine.

〔ただし、ｎ：２以上の整数、ＲはＨ又はＯＲ’（Ｒ’：脂肪族炭化水素基、芳香族炭化水素基）を示す〕であり、脂肪族炭化水素基はアルキル基、アルケニル基等、芳香族基はフェニル基等である。
ｎが２未満の場合は、ＭＰＣとの共重合体とした際に疎水性及びガラス転移温度が低いためにＭＰＣの効果を発現させるためにＭＰＣの組成を高くすると、水に溶解するか、著しく膨潤し、強度が低下する。
メタクリル酸エステルの具体例としてはメタクリル酸エチル、メタクリル酸プロピル、メタクリル酸ブチル、メタクリル酸ペンチル、メタクリル酸ヘキシル、メタクリル酸ヘプチル、メタクリル酸オクチル、メタクリル酸トリデシル、メタクリル酸２−エトキシエチル、メタクリル酸２−エトキシプロピル、メタクリル酸２−フエノキシエチル、メタクリル酸２−ブトキシエチル等である。 The methacrylic acid ester which is a copolymerization component is represented by the following structural formula.

[Wherein n represents an integer of 2 or more, R represents H or OR ′ (R ′ represents an aliphatic hydrocarbon group or aromatic hydrocarbon group)], and the aliphatic hydrocarbon group includes an alkyl group, an alkenyl group, and the like. The aromatic group is a phenyl group or the like.
When n is less than 2, when the copolymer with MPC is used, the hydrophobicity and glass transition temperature are low, so if the MPC composition is increased in order to express the effect of MPC, Swells and decreases strength.
Specific examples of the methacrylic acid ester include ethyl methacrylate, propyl methacrylate, butyl methacrylate, pentyl methacrylate, hexyl methacrylate, heptyl methacrylate, octyl methacrylate, tridecyl methacrylate, 2-ethoxyethyl methacrylate, and methacrylic acid 2 -Ethoxypropyl, 2-phenoxyethyl methacrylate, 2-butoxyethyl methacrylate and the like.

When forming a film of 2-methacryloyloxyethyl phosphorylcholine (MPC) and methacrylic acid ester copolymer on the surface of the synthetic resin binder polyurethane resin on the leather surface, 2-methacryloyloxyethyl phosphorylcholine (MPC) and methacrylic acid are used. A leather film-forming treatment agent comprising an ester copolymer, a thickener, a leveling agent and water is used.
A coating can be formed by applying this by spraying and heating to dry. As a result, a film made of 2-methacryloyloxyethyl phosphorylcholine (MPC) and a methacrylate ester copolymer is formed.

The film-forming treatment agent and its composition are as follows.
The blending amount of 2-methacryloyloxyethyl phosphorylcholine (MPC) and methacrylic acid ester copolymer is 1.6 to 6.4% by weight of the total treating agent,
The blending amount of the thickener is 1.8 to 3.2% by weight of the whole treatment agent,
Leveling agent is 6 to 10% by weight of the total treatment agent,
Water is 82 to 88.2% by weight (over 100% by weight in total) of the entire treatment agent.

  The 2-methacryloyloxyethyl phosphorylcholine (MPC) and methacrylic acid ester copolymer are as described above.

The thickener is added to the treating agent in order to prevent pouring by 2-methacryloyloxyethyl phosphorylcholine (MPC) and a methacrylate ester copolymer.
In addition, pouring refers to a phenomenon in which 2-methacryloyloxyethyl phosphorylcholine (MPC) and a methacrylic acid ester copolymer flow into a grain groove portion provided in the leather, and as a result, the touch of the leather is deteriorated.
When the blending amount of the thickener is insufficient from the above range, the effect of preventing pouring is not sufficiently achieved. Moreover, when the above range is exceeded, odor is observed and 2-methacryloyloxyethyl phosphorylcholine (MPC) and methacrylic acid ester copolymer are precipitated in a granular form, resulting in irregularities on the surface of the leather film. The problem occurs. When coating is performed using a spray gun, it is an important factor in stably supplying the flow rate and the coating amount when performing stable operation. A nonionic polyether type surfactant is used as the thickener. Any nonionic polyether type surfactant can be used as appropriate, but a specific example is shown by the following structural formula. As a trade name, Adecanol UH420 (manufactured by ADEKA Corporation, nonionic surfactant content 30% by weight) can be mentioned.

  Isopropyl alcohol or butyl cellosolve can be used as the leveling agent. When the leveling agent is less than the above range, the adhesion of the coating film is weakened, resulting in poor adhesion to the resin coating layer. When the leveling agent is more than the above range, problems such as generation of an irritating odor occur.

Water that does not contain impurities is used.
2-Methacryloyloxyethyl phosphorylcholine (MPC) and a methacrylic acid ester copolymer have high viscosity. If the viscosity is low and the solution is in a uniform state, uniform coating cannot be performed. Water as a solvent plays an important role.

The basis for determining the blending amount of the thickener is based on the following experimental basis.
It is as follows when the relationship between the blending amount of the thickener and the trouble occurrence state of poor pouring and atomization is examined.

（増粘剤配合量は、非イオン型界面活性剤の重量％で示した）

(Thickener blending amount is shown in% by weight of nonionic surfactant)

As the result of Table 1 shows, the range where the pouring according to the blending amount of the thickener is good is 1.8% by weight or more.
A good range that does not cause poor atomization is 2.7% by weight or less.
As a result, the preferable blending amount of the thickener is 1.8 wt% or more and 2.7 wt% or less.

The basis for the leveling agent being 6 to 10% by weight of the total treatment agent is based on the following experimental results. The occurrence of no repellency is not less than 6% by weight, and the occurrence of no odor is not more than 10.0% by weight. The content of the two is 6 to 10% by weight.
Table 2 below summarizes the occurrence of defects of repellency and odor depending on the leveling agent blending amount.

The antifouling effect can be recognized depending on the blending amount of MPC and methacrylic acid ester copolymer, as shown in Table 3 below, 1.6% by weight or more, and the non-sticky range is 6.4%. % Or less.
When both are combined, it is 1.6% by weight or more and 6.4% by weight or less.

以上の結果を考慮して最適な割合は以下の通りである。

Considering the above results, the optimum ratio is as follows.

  2-Methacryloyloxyethyl phosphorylcholine (MPC) and a methacrylic acid ester copolymer are the main components of a film formed on the leather surface. Exceeding the above range results in a thick film when it becomes a film, and does not spread well throughout the leather because it does not form a thin film well, resulting in an adverse effect on the original function as a film. On the other hand, if the amount is less than the above range, the film becomes too thin to perform its function.

  When a 2-methacryloyloxyethyl phosphorylcholine (MPC) and methacrylic acid ester copolymer is purchased and used as a film forming treatment agent, an alcohol such as 1,2,3-propanetriol and 1,3-butylene glycol We purchase in state that kind was included. In producing the film-forming treatment agent of the present invention, the content of 2-methacryloyloxyethyl phosphorylcholine (MPC) and methacrylic acid ester copolymer contained therein is clearly indicated, and the weight is calculated and used. To do. In that case, the alcohols are not used after being removed. Therefore, alcohol is contained in the film forming treatment agent.

The film is formed by spraying the film-forming treatment agent on the surface of the leather having a polyurethane coating formed thereon.
The amount sprayed on the surface is 80 mg to 600 mg / m ² in terms of 2-methacryloyloxyethyl phosphorylcholine (MPC) and methacrylic acid ester copolymer.
When spraying, various means can be adopted, and for example, it can be applied by hand coating or spray gun. However, in the case of hand-coating, it may be necessary to carry out wiping and stretching by hand so that the coating film is uniformly and widely applied.
Thereafter, a film is formed by keeping the leather surface heated from 100 ° C. to 140 ° C. and evaporating moisture. The processing time is about 30 seconds to 2 minutes.
The film thickness ranges from 1 μm to 2 μm.

2-Methacryloyloxyethyl phosphorylcholine (MPC) and a methacrylate ester copolymer have a hydrophilic 2-methacryloyloxyethyl group on the surface, and the synthetic resin coating layer is interposed through the methacrylate copolymer portion. It is considered that the entire film-forming treatment agent is adhered and fixed to the surface.
Therefore, if it is simply applied as an aqueous solution containing 2-methacryloyloxyethyl phosphorylcholine (MPC) and a methacrylic ester copolymer, it will not spread uniformly on the surface and will be repelled and cannot be fixed.
In order to prevent repellency, it is effective to take measures to improve the adhesion between the resin coating layer and the coating layer containing 2-methacryloyloxyethyl phosphorylcholine (MPC) and a methacrylate ester copolymer. Become.
The inventors have introduced a leveling agent as a means for enhancing adhesion to a coating film containing 2-methacryloyloxyethyl phosphorylcholine (MPC) and a methacrylic acid ester copolymer, thereby interposing the adhesion between the coating films. The coating film can be forcibly brought into close contact regardless of the hydrophilicity / hydrophobicity of the surface.

The degree of antifouling property of the leather formed with the 2-methacryloyloxyethyl phosphorylcholine (MPC) and methacrylic acid ester copolymer film of the present invention is as follows. And (2) Measurement can be made by measuring the result of wiping with dirt attached.
For wiping, there are cases where the cloth is wiped off by a frictional force of the soft cloth, water is contained in the soft cloth, and dirt is transferred to the water. In the case of frictional force, it can be seen that the dirt is not removed and has no effect.
Wiping was found to be most effective and easy to wipe with water.
The types of stains were tested in the case where stains from a contaminated fabric that stains jeans dye were adhered to the leather, and the stains from the contaminated fabric that were contaminated by proteins, fats, and carbohydrates were adhered to the leather. .
As the detection method, each stain degree was determined by color difference.
An example of the result is as follows.

なお、色差は汚れを付着させた部分と汚れを付着させていない部分の差を測定したものである。

The color difference is measured by measuring the difference between the part where dirt is attached and the part where dirt is not attached.

Looking at the color difference after soiling from the above results, when 2-methacryloyloxyethyl phosphorylcholine (MPC) and a methacrylic acid ester copolymer are applied, there is little dirt adhesion in both jeans and soiled cloth. Recognize. In particular, in the case of a contaminated cloth, it can be seen that the amount of dirt attached is small.
It can also be seen that dirt can be removed by wiping with water. In particular, in the case of jeans, dirt can be remarkably reduced by wiping with water.
In general, the period during which dirt is attached is about 6 to 9 months, which corresponds to wiping after that. It can be seen that the effect is sustained over that period.

The dirt test method and the apparatus used will be described below.
FIG. 1 shows an outline of the test apparatus (using the Gakushin friction fastness tester).
The test procedure is as follows.
1. Preparation of test piece (1) Cut out a test piece of leather (the size of the test piece is 30 mm × 250 mm)
(2) A test piece is attached to a test apparatus.
2 Preparation of soiled cloth (jeans cloth / contaminated cloth) Cut out soiled cloth (jeans cloth / contaminated cloth) (size of cloth is 30 mm)
× 50mm)
3. Operating method of test apparatus (1) Attach the cut out soiled cloth to the loader (fixed with a clasp).
(2) Apply water to the soiled cloth so that no water drops. (Make it spread over the entire adhesive surface.)
(3) The base reciprocating speed is 30 cycles / minute, the moving speed is 100 mm, and the total weight of the overlap with the friction element is 50 cycles.
4 Evaluation method • Remove the test specimen from the base and measure the color difference between the part with dirt and the part without dirt.
・ Wipe off the dirt with a half-wet cloth and measure the color difference.
• Use a color difference meter that can measure * L, * a, and * b.
A D65 light source is preferred.

  The contents of the present invention will be described more specifically with reference to the following examples. The present invention is not limited thereby.

  After pre-treating the leather, the leather obtained from the Cr tanning process, re-tanning process using synthetic tanning material, dyeing and greasing process is finished with a water-based polyurethane resin, and the bottom coat, base coat and top coat are applied to the leather surface. A coating consisting of layers was formed.

A film-forming treatment agent comprising 2-methacryloyloxyethyl phosphorylcholine (MPC) and a methacrylic acid ester copolymer, a thickener, a leveling agent and water is produced.
Polyhydric alcohol solution of 2-methacryloyloxyethyl phosphorylcholine (MPC) and methacrylic acid ester copolymer (manufactured by NOF Corporation, trade name potential SG, 6000 cPs (25 ° C.), MPC and methacrylic acid ester copolymer content 10% by weight) 43% by weight, Adecanol UH420 7% by weight as a thickener, 7% by weight of isopropyl alcohol and 43% by weight of water as a leveling agent were produced.

A film-forming treatment agent comprising 2-methacryloyloxyethyl phosphorylcholine (MPC) and a methacrylic acid ester copolymer, a thickener, a leveling agent and water is sprayed and sprayed onto the leather surface) 5 g / m ² , 120 ° C. And dried.

About the influence with respect to stain | pollution | contamination, about the thing which has formed the membrane | film | coat of this invention, the result after the stain | pollution | contamination of jeans and a stain cloth and water wiping was investigated.
Examples 1 to 4 show that a film of 2-methacryloyloxyethyl phosphorylcholine (MPC) and a methacrylate ester copolymer can be formed on a leather film (Examples 1 to 3). Next, Example 4 shows the result of a test conducted to confirm the effect.
The test results are as shown in Table 6 below.

上記実施例4では汚れが付着しやすいとされるジーンズに対しても、水拭きによって十分に汚れを落とすことができることが判明した。又、汚染布にあってはジーンズに比較すると、付着しにくい汚れであっても、とにかく水拭きによって汚れを落とすことができることを示している。
なお、色差は汚れを付着させた部分と汚れを付着させていない部分の差を測定したものである。
比較例１

In Example 4 above, it was found that even with jeans that are likely to be contaminated with dirt, the dirt can be sufficiently removed by wiping with water. Further, it is shown that the soiled cloth can be cleaned by wiping with water, even if it is difficult to adhere to the jeans compared to jeans.
The color difference is measured by measuring the difference between the part where dirt is attached and the part where dirt is not attached.
Comparative Example 1

Forming a film of 2-methacryloyloxyethyl phosphorylcholine (MPC) and a methacrylic acid ester copolymer shown in the above-mentioned examples on a leather film is characterized by the improvement of a conventional antifouling agent. It is not a thing, but a new type of antifouling agent. Therefore, Comparative Example 1 to be compared with the above example is a leather that has existed conventionally, specifically, a resin coating film formed in a finishing process starting from a tanning process. The results of the investigation items of Comparative Example 1 are also shown in Table 6 above.
It shows that dirt adheres more easily to the jeans than in the examples.
Moreover, although it can be said that it can be removed by wiping with water, it shows that it is harder to remove than the results of the examples. Moreover, it turns out that dirt tends to adhere to a contaminated cloth. It can also be seen that there is not much effect of wiping with water.
From the above results, it can be seen that the film of the present invention is a stain preventing agent having a new performance and has a new directionality.

The evaluation is as follows.
Contamination of dirt Both the jeans and the contaminated cloth have less dirt in the present invention. In particular, there is a marked difference in the contaminated cloth. That is, it can be said that it is not soiled or difficult to stick.
Contamination of dirt In the present invention, it is understood that dirt is sufficiently removed by wiping with jeans.
In the present invention, the soiled fabric is originally less soiled and therefore less soiled.
However, it can be said that dirt adhering after wiping with water is sufficiently removed in the present invention. The effect of the present invention can be sufficiently confirmed.

In the present invention, the basis for determining the blending amount of the thickener can be determined for the first time based on experimental grounds, and specifically, it can be determined by the state of occurrence of defects such as poor casting and atomization. It was shown to. Similarly, the leveling agent can be determined for the first time in the experiment that no repellency is observed and no odor is generated (Table 2). Similarly, the amount of MPC is antifouling and non-sticky. (Table 3). It can be seen that these are all first attempted for 2-methacryloyloxyethyl phosphorylcholine (MPC) and a methacrylate ester copolymer.
Unlike the film-forming treatment agent of the present invention, when an aqueous solution in which 2-methacryloyloxyethyl phosphorylcholine (MPC) and a methacrylic acid ester copolymer are dissolved in water is used, 2 -Methacryloyloxyethyl phosphorylcholine (MPC) and methacrylic acid ester copolymer are not adhered and fixed.

  It has been stated that the present invention is particularly effective for automobile seats that require countermeasures against dirt from the viewpoint of usage. It can also be used effectively as an antifouling method when an automobile sheet is formed with an aniline finish, semi-aniline finish, pigment finish, etc. using a protein binder such as casein, which is different from the formation of a paint film with a synthetic resin binder. The leather / film forming treatment agent / leather production method of the present invention is not limited to automobile seats, but is used for automobile interior parts such as instrument panels, door trims, knob skirts, furniture for daily life, clothing and shoes, etc. Even in cases, it can be used effectively.

The outline of the test equipment (using the Gakushin friction fastness tester) is shown.

Claims (10)

  A leather film characterized in that a coating film is formed on the leather surface with a synthetic resin binder, and a film made of 2-methacryloyloxyethyl phosphorylcholine (MPC) and a methacrylate ester copolymer is formed on the surface of the coating film. .   The leather according to claim 1, wherein the leather on the surface of the leather is leather led by a finishing process after re-tanning the leather obtained through a leather tanning process, followed by a dyeing and greasing process.   The leather according to claim 1 or 2, wherein the synthetic resin binder is an aqueous polyurethane. The leather according to any one of claims 1 to 3, wherein the 2-methacryloyloxyethyl phosphorylcholine (MPC) and a methacrylic acid ester copolymer are polymers represented by the following general formula.

[Wherein, a is 0.03 to 0.70, b is 0.30 to 0.97, n is an integer of 2 or more, R is H, OR ′ (R ′ is an aliphatic hydrocarbon group, aromatic carbonization) A hydrogen group)].]. The weight average molecular weight is 5000 or more.   A treatment agent for film formation on the surface of a coating film, comprising 2-methacryloyloxyethyl phosphorylcholine (MPC) and a methacrylic acid ester copolymer, a thickener, a leveling agent and water. 6. The coating agent for forming a film on the surface of a coating film according to claim 5, wherein the 2-methacryloyloxyethyl phosphorylcholine (MPC) and the methacrylic acid ester copolymer are polymers represented by the following general formula: .

[Wherein, a is 0.03 to 0.70, b is 0.30 to 0.97, n is an integer of 2 or more, R is H, OR ′ (R ′ is an aliphatic hydrocarbon group, aromatic carbonization) A hydrogen group)].]. The weight average molecular weight is 5000 or more.   A film is formed on the leather surface with a synthetic resin binder, and a film-forming treatment agent consisting of 2-methacryloyloxyethyl phosphorylcholine (MPC), methacrylate copolymer, thickener, leveling agent and water is applied and heated. A method for producing leather, characterized in that a film is formed.   The leather according to claim 7, wherein the leather on the surface of the leather is leather led by a finishing process after re-tanning the leather obtained through a leather tanning process, and through a dyeing and greasing process. Production method.   The method for producing leather according to claim 7 or 8, wherein the synthetic resin binder is an aqueous polyurethane. The method for producing leather according to any one of claims 7 to 9, wherein the 2-methacryloyloxyethyl phosphorylcholine (MPC) and a methacrylic acid ester copolymer are polymers represented by the following general formula.

[Wherein, a is 0.03 to 0.70, b is 0.30 to 0.97, n is an integer of 2 or more, R is H, OR ′ (R ′ is an aliphatic hydrocarbon group, aromatic carbonization) A hydrogen group)].]. The weight average molecular weight is 5000 or more.

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