JPH0559400A - Collagen-containing impregnant composition and coating composition - Google Patents

Abstract

PURPOSE:To obtain an impregnant composition having improved ARABI in eather processing, providing the same appearance and handle as hose of leather, blended with an aqueous solution containing collagen. CONSTITUTION:(A) An aqueous solution containing a collagen preferably obtained by mixing a dispersion of insoluble collagen with an aqueous solution of solubilized collagen is optionally mixed with (B) an impregnant such as alcohol- or glycol-based impregnant and (C) a binder resin component such as acrylic resin, urethane resin or butadiene resin to give the objective composition.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an impregnating composition and a coating composition which give a leather-like texture.

[0002]

2. Description of the Related Art A tanned leather generally used for manufacturing leather products has a structure composed of a nipple layer and a net layer. The papillary layer has a fine constituent fiber and a dense structure, and is called a silver surface. The silver surface is soft even after tanning and has an extremely elegant appearance and touch. The value of leather depends largely on the sensory evaluation of the luster and feel of the silver surface. When the leather is put to practical use, the entire dermis provided with the papillary layer and the net-like layer is not used, but peeled to an appropriate thickness according to the intended use. This upper surface (the side with the teat layer on the surface) is generally referred to as "silvered leather" and the lower surface is "leather" with only a mesh layer.

[0003] In the leather-related industry, a leather which does not have a sufficient silver surface on the surface, called "heavy buff base", is used by shaving more than half of the silver surface from this floor leather and the lower grade raw leather with scratches and insect worms. Is used for product processing after being painted. However, these coated finished products, for example, in the process of stretching leather such as shoes, a phenomenon called so-called “arabi”, in which a concavo-convex pattern of a net-like layer of leather appears on the coated surface, and therefore, a product with high added value is required. I won't. As a countermeasure against this "arabi", a method of impregnating a binder and a method of filling with a paint containing casein and a binder are generally considered.
As a countermeasure, it had almost no effect, and in particular, it had no effect on soft leather.

On the other hand, the hygroscopicity of collagen in the coating film,
For the purpose of imparting moisturizing properties, air permeability, and a leather-like texture, powdery collagen is compounded with an oil-based paint, a synthetic resin or the like and applied (JP-A-62-25797).
3 and JP-A-62-257974). However, the product obtained by the method using such an oil-based paint is unsatisfactory in that it has a rubber texture and a plastic texture in the finish, and has a texture similar to that of genuine leather.

[0005]

As described above, a surface treatment agent for lower-grade raw leather and floor leather, which suppresses the "arabi" phenomenon and obtains a texture similar to that of genuine leather, has not been completed yet.

The present invention solves the above-mentioned problems and provides an impregnating agent and a coating agent capable of providing inexpensive leather such as floor leather with a quality not different from that of silver-coated leather and obtaining high added value. It is intended to be provided.

[0007]

[Means and Actions for Solving the Problems] In order to achieve the above object, the present inventors have conducted extensive studies and as a result, when leather is treated with an impregnating agent and a paint using an aqueous solution containing collagen. It was found that a leather similar in appearance and texture could be obtained, and the present invention was completed.

The impregnating composition of the present invention contains an aqueous liquid containing collagen.

Further, the coating composition of the present invention comprises collagen,
It is composed of water and a coating film forming component.

The present invention will be described in more detail below.

Collagen is a substance in which three polypeptide chains form a helix, and is usually insoluble in water, dilute acid, dilute alkali, organic solvent and the like. A special solubilized collagen aqueous solution can be obtained by performing special treatment / extraction with or enzyme. Further, when treated with a citrate buffer or the like, a viscous soluble collagen aqueous solution can be obtained. It is considered that these collagens are solubilized by eliminating the constraint between peptide chains due to intermolecular or intramolecular cross-linking in the telopeptide at the end of the polypeptide chain of insoluble collagen or cleavage of the telopeptide itself. .. In the following description, "solubilized collagen" in the present invention means soluble collagen or solubilized collagen present in a solution obtained by dissolving the above-mentioned collagen in an aqueous liquid, a method of adjustment, a molecular weight, and crosslinking. It is not strictly regulated by the degree of, but may include those having different molecular weights or degrees of cross-linking, or may be added, that is, those which are substantially in a solution state And

The solubilized collagen used in the present invention is a method using a proteolytic enzyme (Japanese Patent Publication No. 44-
1175), a method of treating with an aqueous solution in which a caustic alkali and sodium sulfate and the like coexist with a small amount of amines or the like (Japanese Patent Publication No. 46-1503).
No. 3, etc.) and the like, and can be prepared from insoluble collagen. The insoluble collagen powder can be obtained by mechanically crushing the insoluble collagen, but a method by enzymatic decomposition in a partially denatured state (Japanese Patent Laid-Open No. Hei 3)
The fine powder obtained in JP-A-128983) has high quality and good dispersibility and is suitable for use in the present invention.

The leather treating agent containing collagen and water according to the present invention comprises an impregnating agent and a coating agent.

First, the composition of the impregnating agent and its usage will be described. The impregnating agent is used by impregnating the leather surface, and when impregnating the leather without the silver surface, the coarse fibers of the net-like layer of the surface layer are densely filled with the impregnating agent collagen,
The surface of the leather has a similar appearance to the silver surface of genuine leather, so to speak, an artificial silver surface is created. This artificial silver surface provides the same appearance and feel as genuine leather having a natural silver layer. Therefore, by using the impregnating composition of the present invention, it is possible to produce high value-added leather from inexpensive leather. There are three modes of this impregnating agent: one containing solubilized collagen, one containing insoluble collagen powder, and one using both as a mixture. When the insoluble collagen powder is used by dispersing it in an aqueous liquid, the appearance and texture of the obtained impregnated leather are good, and the collagen content per unit volume of the impregnating agent can be increased, but the permeability to the leather is improved. Is inferior to solubilized collagen. If an aqueous solution of solubilized collagen is used, the permeability is good, but if the collagen concentration is too high, the viscosity becomes very high, and rather the permeability is impeded. Therefore, it is preferable to mix the insoluble collagen dispersion and the solubilized collagen aqueous solution at an arbitrary ratio, if necessary.

When the solubilized collagen aqueous solution is used as the impregnating agent, the concentration of the solubilized collagen is about 0.01-.
Although it can be set to about 10 wt%, it is preferable not to increase the concentration due to viscosity and the like, and preferably 2 wt%.
Before and after. 1 per 100 g of solubilized collagen aqueous solution
When the penetrant such as alcohol or glycol is added at a ratio of about 3 g, the penetrability of the impregnant is improved. to this,
Further, when 50 to 200 g of a binder resin component such as acrylic, urethane or butadiene is added, the permeability of the impregnating agent is further improved.

When insoluble collagen is used as the impregnating agent, insoluble collagen powder is added to water or a mixed solvent of water and a solvent miscible with water, and dispersed with a homogenizer. When insoluble collagen is used, it is preferable to further add and disperse a binder resin component and an alcohol or glycol type penetrant in order to improve the permeability of the impregnating agent. Collagen powder is preferably 80% pure
About 5 to 200 g of the above-mentioned aqueous solvent is used for 5 g of collagen powder. Examples of usable solvents include alcohols such as methanol, ethanol, propanol, isopropanol and butanol, polyhydric alcohols such as ethylene glycol and glycerin, oxyethers such as methylcellosolve and ethylcellosolve, dioxane and acetone. , DMF, DMSO
Etc. As the binder resin, a polyester resin, a phenol resin, an amino resin, a polyurethane resin, a condensation polymerization resin such as an epoxy resin, an acrylic resin, an addition polymerization resin such as a vinyl resin, further, a natural resin, alone, Alternatively, they can be used in any combination.

When the insoluble collagen and the solubilized collagen are mixed and used, the insoluble collagen may be dispersed in the solubilized collagen aqueous solution. However, the above-mentioned insoluble collagen dispersion and the solubilized collagen aqueous solution are mixed at an arbitrary ratio. It is easy to use. In this case, the medium used for the dispersion liquid of insoluble collagen may be only a solvent miscible with water.

The above-mentioned impregnating agent containing the solubilized collagen aqueous solution or the insoluble collagen powder is applied to a floor buff or a lower buff with a heavy buffed base using a roll coater, a brush or the like, and more preferably for about 2 minutes or more. If it is left under a reduced pressure of about 10 to 30 mmHg for about 4 minutes, it penetrates into the leather preferably. Alternatively, instead of directly applying to the leather, the impregnating agent may be applied onto a plate such as acrylic or glass with a roll coater or the like, and the leather may be overlaid on the plate under a reduced pressure. Therefore, there is no problem whether the application surface is facing up or down. About 2
By permeating for about 4 minutes under a reduced pressure of 0 mmHg,
The impregnating agent penetrates into the leather at a depth of about 0.3 to 0.7 mm. The impregnation condition of the impregnating agent changes depending on the quality and condition of the leather.

When the leather impregnated with the impregnating agent is subjected to a cross-linking treatment to cause cross-linking between the collagen of the impregnating agent and the collagen of the leather, the adhesion and heat resistance can be improved. Therefore, especially for leather used for things in which the leather is heated during the processing process, such as shoes,
Crosslinking is better. The cross-linking treatment is preferably carried out after the impregnating agent has penetrated into the leather and before the impregnating agent has dried. Examples of the cross-linking agent include inorganic cross-linking agents containing chromium and aluminum, organic cross-linking agents such as aldehydes, tannins, carbamic acid derivatives, phenol resins, and imides. It may be used, and a suitable one can be used depending on the application. These can be applied uniformly by spraying.

The crosslinked leather is dried at a temperature at which collagen does not denature. Although leather and insoluble collagen have heat resistance up to about 110 to 120 ° C, the impregnating agent that is not crosslinked is more easily denatured than the one that is crosslinked, so it should be dried at a temperature of about 40 ° C or less. Is preferred.

The dried leather is impregnated with collagen and has an artificial silver surface similar to that of the real leather. As a result, the arabic phenomenon is improved and the bending resistance is also significantly improved. After polishing this leather with polishing paper etc. as needed,
When a pattern is made by pressing (about 80 ° C, about 450t x 2 seconds) with a silver surface-like drawing template such as calf grain, the artificial silver surface has not only the texture, touch and functional characteristics, but also the appearance. It will be very similar to natural leather.

Next, a coating agent which is another leather treating agent will be described. The coating agent according to the present invention is a mixture of an aqueous liquid containing collagen and a coating film forming component. As collagen, it is preferable to use solubilized collagen from the viewpoint of the appearance of the obtained coating film. In this case, a state in which a small amount of insoluble collagen remains without being solubilized and causes turbidity and the like substantially has the effect as the solubilized collagen in the present invention. The solubilized collagen is preferably blended as an aqueous solution from the viewpoint of operability and the like. The concentration of the collagen aqueous solution can be arbitrarily changed as necessary, but it is from 1 to 10
wt%, more preferably around 5 wt% is used.
The coating film forming component in the present invention means a substance substantially required for forming a coating film, that is, a coating film forming substance such as a binder resin to which a curing agent, a catalyst, a plasticizer and the like are added if necessary. To do. In the coating composition of the present invention, various film-forming components can be blended, but considering the ease of uniform mixing into the collagen aqueous solution, a water-based coating, that is, a water-soluble coating,
A coating film-forming component of a paint using water as a main solvent, such as a water-dispersible paint, is preferable. Although it is possible to use a commercially available adjusted water-based paint, or only the film-forming component thereof for the preparation of the coating composition of the present invention, when the water-based paint is blended with the above-mentioned collagen aqueous solution, the operation is performed. Good sex. As water-based paints, for example, those in which a polymer introduced with a group for enhancing solubility and dispersibility in water is used as a binder resin are known, but from the viewpoint of strength and finish of the coating film, touch and the like. A urethane emulsion resin coating is particularly preferable. As the composition of the water-based paint, a commercially available composition generally used can be used, but 20 to 50 wt%,
More preferably, a coating material containing a resin component of about 40 wt% is used. In the case of urethane emulsion resin paint,
A hardener of about 1 to 2 wt% is included. Regarding the mixing ratio of the collagen aqueous solution and the paint, the above water-based paint 1
A mixing ratio of 30 to 300 g of the collagen aqueous solution, more preferably about 70 g, is preferable to 00 g.

When the above coating agent is applied to leather with a roll coater, a brush or the like at 200 to 600 g / m ² and dried, a film having good hygroscopicity and breathability and having the texture and feel of natural leather is obtained. Be done. In particular, when this coating material is applied onto the leather treated with the above-mentioned impregnating agent, the properties of the leather surface in terms of function and appearance are synergistically improved. Therefore, by treating an inexpensive and functionally inferior leather such as a floor leather and a lower grade raw leather with the impregnating agent and the coating agent of the present invention, the leather becomes excellent inferior to the genuine leather. Also, when the coating agent of the present invention is applied to leather having a silver surface, the aesthetic appearance of the surface is further improved, and since it is water-based, it gives the texture and feel of the leather, so that it is used for the final finishing over leather in general. It is extremely effective as a top coat agent. Furthermore, since these paints and impregnants can be artificially subjected to leather-like surface finishing and processing, they are not limited to leather surface treatments, and leather-like finishing can be applied to fibrous substrates. It can be applied to apply.

[0024]

EXAMPLES The physical properties of leather treated with the impregnating agent and the coating agent of the present invention will be described below in more detail with reference to Examples and Comparative Examples.

Example 1 To 100 g of a solubilized collagen aqueous solution having a concentration of 2 wt%, 100 g of an acrylic resin binder and 2 g of a penetrant (a mixture of isopropyl alcohol and butyl cellosolve) were added and dispersed in a mixer to obtain a solubilized collagen impregnating agent. ..

95 g of water was added to 5 g of insoluble collagen powder (purity of 80% or more) and dispersed with a homogenizer.
100 g of acrylic resin binder in 100 g of this dispersion
And 2 g of a penetrant (mixture of isopropyl alcohol and butyl cellosolve) were added and further dispersed by a homogenizer to obtain an insoluble collagen impregnating agent.

100 g of the solubilized collagen impregnating agent and 4 g of the insoluble collagen impregnating agent were mixed to prepare an impregnating agent for permeating the leather.

On the other hand, 500 g of a 6 wt% solubilized collagen aqueous solution was added to 100 g of a urethane emulsion coating obtained by mixing 450 g of a urethane resin, 20 g of an isocyanate curing agent and 430 g of water and well dispersed to obtain a coating agent.

A floor leather having a thickness of 2 mm was coated with the above-mentioned impregnating agent using a roll coater, and the coated surface was placed on a glass plate in a decompression device with the coated surface facing downward, and impregnated under a reduced pressure of 20 mmHg for 4 minutes. The agent penetrated the leather. This floor leather was taken out from the decompressor, and a 2% formalin solution was sprayed at a rate of 150 g / m ² by a spray to crosslink collagen.
After that, the leather is dried at 40 ° C., the surface thereof is polished with # 400 polishing paper, and 450 ° C. for 2 seconds at 80 ° C. using a diaphragm template.
The appearance was finished by applying a pressure of t and pressing. The above-mentioned coating agent was applied to this leather and dried.

The obtained leather was subjected to an arabic evaluation, a flex resistance test, a moisture permeability test and a moisture absorption test. The results are shown in Table 1.

Example 2 In the same manner as in Example 1, an impregnating agent was infiltrated into the floor skin to carry out a crosslinking treatment, and after drying, a press treatment was carried out. The paint was applied and dried. The same physical properties test as in Example 1 was performed on the obtained leather. The results are shown in Table 1.

Example 3 Using only the solubilized collagen impregnating agent prepared in Example 1 as an impregnating agent for impregnating leather, as in Example 1, the floor leather was subjected to impregnating agent application, reduced pressure infiltration, and crosslinking treatment. went.
The vacuum infiltration was performed twice in order to infiltrate the impregnating agent to an appropriate depth. After this, dry, surface polish, appearance finish,
The same procedure as in Example 1 was performed. The same physical properties test as in Example 1 was performed on the obtained leather. The results are shown in Table 1.

Example 4 Using only the insoluble collagen impregnating agent prepared in Example 1 as an impregnating agent for impregnating leather, as in Example 1, application of impregnating agent to floor leather, permeation under reduced pressure, crosslinking treatment, and drying. Surface polishing and appearance finishing were performed in the same manner as in Example 1. The same physical properties test as in Example 1 was performed on the obtained leather. The results are shown in Table 1.

Comparative Example 1 Untreated floor leather similar to that used in Example 1 was subjected to a press treatment, and a conventional collagen paint (the same as that used in Example 2) in which collagen was mixed with an oil-based paint was applied. Dried. The same physical properties test as in Example 1 was performed on the obtained leather. The results are shown in Table 1.

[0035]

[Table 1]

As is clear from Table 1, when the impregnating agent according to the present invention is used, the arabic evaluation is improved from the first to second grades to the fourth to fifth grades, and cracks do not occur even in the flex resistance test.
The performance of leather is significantly improved. Further, as shown by the results of the moisture permeability test and the moisture absorption test, the product coated with the coating agent of the present invention had good breathability and hygroscopicity, and was further imparted with the feel and texture of natural leather.

[0037]

As is apparent from the above description, by using the impregnating agent and the coating agent containing collagen and water of the present invention, arabic is improved and a leather excellent in both appearance and function is obtained. It is possible and its industrial value is extremely high.

Claims (10)

[Claims] 1. An impregnating composition comprising an aqueous liquid containing collagen. 2. The impregnating composition according to claim 1, further comprising a penetrant component. 3. The method according to claim 2, further comprising a binder component.
The impregnating composition described. 4. The impregnating composition according to claim 1, which contains insoluble collagen and solubilized collagen as the collagen. 5. The impregnating agent composition according to claim 4, comprising the steps of dispersing an insoluble collagen powder in an aqueous liquid to obtain a collagen dispersion, and mixing the collagen dispersion with a solubilized collagen aqueous solution. Production method. 6. A step of disposing the impregnating agent composition according to claim 1 on a leather surface, a step of impregnating the leather with the impregnating agent composition under reduced pressure, and a step of impregnating the leather with the impregnating agent composition. A method for impregnating an impregnating composition, comprising a step of cross-linking collagen and a step of drying impregnated leather. 7. Leather impregnated with the impregnating composition of claim 1. 8. A coating composition comprising collagen, water, and a film-forming component. 9. The coating composition according to claim 8, wherein the collagen is solubilized collagen. 10. A leather coated with the coating composition according to claim 8.