Water-based suede leather in suede style and method for preparing the same

Abstract

The application provides a water-based suede with a suede style and a preparation method thereof, and the preparation method comprises the following steps: preparing a water-based PU slurry, wherein the water-based PU slurry comprises deionized water, water-based polyurethane, sodium alginate, metal carbonate and an auxiliary agent; passing a base cloth through an impregnation tank at a certain speed, so that the water-based PU slurry in the impregnation tank fully infiltrates the base cloth; passing the base cloth after the impregnation treatment through an acid aqueous solution coagulation bath; and performing water washing, padding treatment, drying treatment and post-processing treatment on the base cloth after the coagulation bath treatment, so as to obtain the water-based suede with the suede style. The PU content of the water-based suede with the suede style is 10-30%, and a large number of cavities are distributed in the suede.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of artificial leather, and particularly relates to a water-based suede with a chamois style and a preparation method thereof. BACKGROUND

[0002] With the increasingly strict environmental protection policies of various countries, the production and export of oily leather are greatly limited. As an environmentally friendly leather product, water-based leather has good economic and environmental value. Moreover, with the rapid development of science and technology and the improvement of people's living standards, consumers' fashion concepts tend to return to nature, and simplicity and naturalness have become the mainstream aesthetic. Chamois suede with a simulation leather effect is favored by more and more consumers due to its simple and elegant texture, and has great market development potential. Most of the chamois suede on the market has general quality, exposed bottom and poor simulation of pile, and cannot meet the high use requirements of consumers for chamois suede. SUMMARY

[0003] To solve the above technical problems, the purpose of the present application is to provide a water-based suede with a chamois style and a preparation method thereof. The preparation method has the advantages of simple and stable process, low water-based PU resin consumption, low production cost and low carbon environmental protection. The suede obtained by the preparation method has the advantages of rich and delicate surface pile, soft and compact hand feeling, strong thickness and drape, and can meet the high requirements of water-based environmentally friendly synthetic leather fabric in hand feeling and style.

[0004] To achieve the above technical purposes and effects, the present application realizes the following technical solutions:

[0005] A preparation method of a water-based suede with a chamois style, comprising the following steps:

[0006] (1) preparing water-based PU slurry

[0007] The water-based PU slurry comprises the following components in mass percentage: deionized water 75% to 85%, water-based polyurethane 8% to 15%, sodium alginate 0.5% to 1.5%, metal carbonate 1% to 5%, and auxiliary agent 1% to 5%. After stirring and mixing the raw materials, the water-based PU slurry is obtained;

[0008] (2) impregnation treatment

[0009] The base cloth passes through the impregnation tank containing two pressing shafts at a certain speed, and the water-based PU slurry in the impregnation tank fully infiltrates the base cloth;

[0010] (3) coagulation bath treatment

[0011] The base fabric treated by step (3) is passed through an acid aqueous solution coagulation bath to coagulate the polyurethane on the surface of the base fabric and the polyurethane inside, and to decompose the metal carbonate to produce CO2 by using the acid, so that the PU is filled with pores, and the metal salt formed by the decomposition of the metal carbonate is crosslinked with sodium alginate and polyurethane respectively;

[0012] (4) water washing and padding treatment

[0013] The base fabric treated by the coagulation bath is subjected to water washing treatment, and then is passed through a pair of padding rollers to squeeze out the excess water;

[0014] (5) drying treatment

[0015] The base fabric treated by the water washing and padding treatment is subjected to drying treatment;

[0016] (6) post-processing treatment

[0017] The semi-finished product treated by step (5) is subjected to post-processing treatment to obtain a water-based suede with a suede style.

[0018] Further, the base fabric is a non-woven fabric, a woven raised fabric or a woven non-fiberized sea-island fabric.

[0019] Further, the metal carbonate is a mixture of calcium carbonate and sodium carbonate or a mixture of calcium carbonate and sodium bicarbonate.

[0020] Further, the acid in the acid aqueous solution coagulation bath is one of tartaric acid and oxalic acid.

[0021] Further, in step (4), the distance between the two padding rollers is 0.5-0.7 times the thickness of the base fabric.

[0022] Further, the drying time in step (5) is 25-35 min, and the drying temperature is 80-130℃.

[0023] Further, the viscosity of the water-based PU slurry is 2000-3000 mpa.s.

[0024] Further, if the base fabric is a non-woven fabric or a woven non-fiberized sea-island fabric, the post-processing treatment includes fiberization, high-temperature setting, dyeing, sanding, washing and drying treatment; if the base fabric is a woven raised fabric, the post-processing treatment includes high-temperature setting, dyeing, sanding, washing and drying treatment.

[0025] The application further provides a water-based suede with a suede style, which is obtained by the above preparation method; the PU content of the water-based suede with a suede style is 10-30%; and a large number of pores are distributed in the suede.

[0026] Compared with the prior art, the present application has the following advantages:

[0027] (1) The aqueous PU slurry in the present application contains sodium alginate and metal carbonate. After the base cloth containing the aqueous PU slurry is subjected to an acid aqueous solution coagulation bath, the metal carbonate reacts with the acid to produce metal ions (calcium ions and sodium ions). The calcium ions can crosslink with PU and sodium alginate, respectively, to form PU and sodium alginate gels. The gel formed by the crosslinking reaction of calcium ions and sodium alginate can provide a skeleton structure during the drying process of PU, improve the mechanical properties of the PU film, and prevent the coagulated PU from undergoing severe shrinkage during the drying process. The skeleton structure can be removed in subsequent post-processing, thereby forming a pore structure and improving the thickness and hand feeling of the suede. The gel reaction of calcium ions and PU can sharply increase the viscosity of the slurry in the base cloth, fix the PU inside the base cloth, and reduce the amount of PU resin on the surface of the base cloth, making it easier to grind fine bristles in subsequent buffing, and thus making the suede product have a full and soft hand feeling.

[0028] (2) The sodium ions produced by the metal carbonate can reduce the solubility of sodium alginate in water, causing it to precipitate. The precipitated sodium alginate is removed in subsequent processing to form pores in the suede product, thereby improving the thickness and hand feeling of the suede product.

[0029] (3) Sodium alginate can also thicken the aqueous PU slurry. Since it can be removed later, it does not affect the water resistance of PU.

[0030] (4) The acid in the acid aqueous solution coagulation bath can decompose the metal carbonate to produce CO2, causing the PU to be filled with pores, thereby forming pores in the suede product and further improving the hand feeling of the suede product. The acid used can be extracted from plants and is a bio-based material.

[0031] (5) The method of the present application can fix PU resin inside the base cloth through gel reaction, reduce PU migration, and reduce the amount of aqueous polyurethane used, thereby significantly reducing energy and resource consumption. Since the polyurethane concentration is low, the processing is simple and waste is unlikely to occur.

[0032] Overall, the preparation method of the present application has the advantages of simple and stable process, low amount of aqueous PU resin, low production cost, and low carbon environmental protection. The suede obtained by the preparation method has the advantages of rich and delicate surface bristles, soft and compact hand feeling, strong thickness and drape, and can meet the high requirements of water-based environmentally friendly synthetic leather fabrics in terms of hand feeling and style. DETAILED DESCRIPTION

[0033] The technical solutions in the present application will be clearly and completely described below in conjunction with specific embodiments. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of the present application.

[0034] The present application provides a preparation method of water-based suede with suede style, comprising the following steps:

[0035] (1) preparing water-based PU slurry

[0036] The water-based PU slurry comprises the following components in percentage by mass: deionized water 75-85%, water-based polyurethane 8-15%, sodium alginate 0.5-1.5%, metal carbonate 1-5%, and auxiliary agent 1-5%. The raw materials are stirred and mixed to obtain the water-based PU slurry. The metal carbonate is a mixture of calcium carbonate and sodium carbonate or a mixture of calcium carbonate and sodium bicarbonate. The percentage by mass of calcium carbonate in the metal carbonate mixture is 70-85%. The auxiliary agent is at least one of leveling agent, crosslinking agent, and defoaming agent. The viscosity of the water-based PU slurry is 2000-3000 mpa.s.

[0037] (2) impregnation treatment

[0038] The base fabric passes through the impregnation tank containing two pressing shafts at a certain speed, and the water-based PU slurry in the impregnation tank fully infiltrates the base fabric. The base fabric is non-woven fabric, woven fabric, or island-in-sea fabric without opening.

[0039] (3) coagulation bath treatment

[0040] The base fabric treated in step (2) passes through the acid aqueous coagulation bath, so that the polyurethane on the surface of the base fabric and the polyurethane inside the base fabric are coagulated. The coagulation mechanism is as follows: the water-based polyurethane is weakly basic anion type, and the alkaline substance is used for neutralization and dispersion during the preparation of the water-based polyurethane. The H ion in the acid aqueous solution reacts with the basic salt-forming substance, so that the water-based polyurethane is not salted, and the water solubility of the water-based polyurethane is poor. In addition, the H ion is a cation that can destroy the double electron layer of the water-based polyurethane, so that the water-based polyurethane is broken and coagulated.

[0041] The coagulation bath treatment step can also use acid to decompose the metal carbonate to produce CO2, so that the PU is filled with pores, and the metal salt formed by the decomposition of the metal carbonate crosslinks with the sodium alginate and the polyurethane, respectively. The acid in the acid aqueous coagulation bath is one of tartaric acid and oxalic acid.

[0042] (4) washing and padding treatment

[0043] The base cloth treated by the coagulation bath is subjected to water washing treatment, and then is extruded by a pair of squeezing rollers to squeeze out the excess water; the interval between the two squeezing rollers is 0.5-0.7 times the thickness of the base cloth;

[0044] (5) drying treatment

[0045] The base cloth treated by the water washing and the squeezing treatment is subjected to drying treatment; the drying time is 25-35 min, and the drying temperature is 80-130 DEG C;

[0046] (6) post-processing treatment

[0047] The semi-finished product treated by the step (5) is subjected to post-processing treatment to obtain the water-based suede with the imitation suede style.

[0048] In the step (6), if the base cloth is non-woven fabric or island-in-the-sea fabric without opening, the post-processing treatment includes opening, high-temperature setting, dyeing, sanding, washing and drying treatment; if the base cloth is spun fabric, the post-processing treatment includes high-temperature setting, dyeing, sanding, washing and drying treatment.

[0049] The application further provides a water-based suede with an imitation suede style, which is obtained by the above preparation method; the PU content of the water-based suede with the imitation suede style is 10-30%; and a large number of cavities are distributed in the suede.

[0050] Example 1

[0051] A preparation method of a water-based suede with an imitation suede style, comprising the following steps:

[0052] (1) preparing water-based PU slurry

[0053] The water-based PU slurry comprises the following components in percentage by mass: deionized water 80%, water-based polyurethane 10%, sodium alginate 1%, metal carbonate 5%, leveling agent 2% and crosslinking agent 2%; the raw materials are stirred and mixed to obtain the water-based PU slurry; the metal carbonate is a mixture of calcium carbonate and sodium carbonate; the mass percentage of calcium carbonate in the metal carbonate mixture is 80%;

[0054] (2) impregnation treatment

[0055] The base cloth passes through the impregnation tank containing two pressing rollers at a certain speed, and the water-based PU slurry in the impregnation tank fully impregnates the base cloth; the base cloth is non-woven fabric;

[0056] (3) coagulation bath treatment

[0057] The base fabric treated by step (3) is passed through an acid aqueous solution coagulation bath to coagulate the polyurethane on the surface of the base fabric and the polyurethane inside, and to make the metal carbonate decompose to generate CO2 by using the acid, so that the PU is filled with pores, and the metal salt formed by the decomposition of the metal carbonate is crosslinked with sodium alginate and polyurethane, respectively; wherein the acid in the acid aqueous solution coagulation bath is tartaric acid;

[0058] (4) water washing and padding treatment

[0059] The base fabric treated by the coagulation bath is subjected to water washing treatment, and then passed through a pair of padding rollers to squeeze out excess water; the distance between the two padding rollers is 0.6 times the thickness of the base fabric;

[0060] (5) drying treatment

[0061] The base fabric treated by the water washing and padding treatment is subjected to drying treatment; the drying time is 30 min, and the drying temperature is 100 DEG C;

[0062] (6) post-processing treatment

[0063] The semi-finished product treated by step (5) is subjected to post-processing treatment to obtain a water-based suede with a suede style. The post-processing treatment includes fiber opening, high-temperature setting, dyeing, napping, washing and drying treatment.

[0064] The application further provides a water-based suede with a suede style, which is obtained by the preparation method.

[0065] Example 2

[0066] A preparation method of a water-based suede with a suede style, comprising the following steps:

[0067] (1) preparing a water-based PU slurry

[0068] The water-based PU slurry comprises the following components in percentage by mass: deionized water 75%, water-based polyurethane 15%, sodium alginate 1.5%, metal carbonate 4%, leveling agent 2.5%, and crosslinking agent 2%. After the raw materials are stirred and mixed, the water-based PU slurry is obtained; the metal carbonate is a mixture of calcium carbonate and sodium carbonate; the mass percentage of calcium carbonate in the metal carbonate mixture is 85%;

[0069] (2) impregnation treatment

[0070] The base fabric passes through an impregnation tank containing two pressing rollers at a certain speed, and the water-based PU slurry in the impregnation tank fully impregnates the base fabric; wherein the base fabric is a spun island-in-sea fabric without fiber opening;

[0071] (3) coagulation bath treatment

[0072] The base fabric treated by step (2) is passed through an acid aqueous coagulation bath to coagulate the polyurethane on the surface of the base fabric and the polyurethane inside, and the metal carbonate is decomposed by the acid to generate CO2, so that the PU is filled with pores, and the metal salt formed by the decomposition of the metal carbonate is crosslinked with sodium alginate and polyurethane, respectively; wherein the acid in the acid aqueous coagulation bath is tartaric acid;

[0073] (4) water washing and padding treatment

[0074] The base fabric treated by the coagulation bath is subjected to water washing treatment, and then passed through a pair of padding rollers to squeeze out excess water; the distance between the two padding rollers is 0.6 times the thickness of the base fabric;

[0075] (5) drying treatment

[0076] The base fabric treated by water washing and padding is subjected to drying treatment; the drying time is 30 min, and the drying temperature is 100 DEG C;

[0077] (6) post-processing treatment

[0078] The semi-finished product treated by step (5) is subjected to post-processing treatment to obtain a water-based suede with a suede style. The post-processing treatment includes fiber opening, high-temperature setting, dyeing, sanding, washing and drying treatment.

[0079] The application further provides a water-based suede with a suede style, which is obtained by the above preparation method; the PU content of the water-based suede with a suede style is 25%; a large number of cavities are distributed in the suede.

[0080] Example 3

[0081] A preparation method of a water-based suede with a suede style, comprising the following steps:

[0082] (1) preparation of water-based PU slurry

[0083] The water-based PU slurry comprises the following components in mass percentage: deionized water 85%, water-based polyurethane 8%, sodium alginate 1.5%, metal carbonate 3.5%, leveling agent 1%, and defoaming agent 1%; the raw materials are stirred and mixed to obtain the water-based PU slurry; the metal carbonate is a mixture of calcium carbonate and sodium carbonate; the mass percentage of calcium carbonate in the metal carbonate mixture is 85%;

[0084] (2) impregnation treatment

[0085] The base fabric passes through an impregnation tank containing two pressing rollers at a certain speed, and the water-based PU slurry in the impregnation tank fully infiltrates the base fabric; wherein the base fabric is a spun non-opened island fabric;

[0086] (3) coagulation bath treatment

[0087] The base fabric treated in step (2) is passed through an acid aqueous coagulation bath to coagulate the polyurethane on the surface of the base fabric and the polyurethane inside, and to decompose the metal carbonate by using the acid to generate CO2, so that the PU is filled with pores, and the metal salt formed by the decomposition of the metal carbonate is crosslinked with sodium alginate and polyurethane, respectively; wherein the acid in the acid aqueous coagulation bath is oxalic acid;

[0088] (4) washing and padding treatment

[0089] The base fabric treated in the coagulation bath is washed, and then passed through a pair of padding rollers to squeeze out excess water; the distance between the two padding rollers is 0.6 times the thickness of the base fabric;

[0090] (5) drying treatment

[0091] The base fabric treated by washing and padding is dried; the drying time is 30 min, and the drying temperature is 100℃;

[0092] (6) post-processing treatment

[0093] The semi-finished product treated in step (5) is further processed to obtain a water-based suede with a suede style. The post-processing treatment includes fiber opening, high-temperature setting, dyeing, sanding, washing, and drying treatment.

[0094] The application further provides a water-based suede with a suede style, which is obtained by the above preparation method; the PU content of the water-based suede with a suede style is 18%; and a large number of cavities are distributed in the suede.

[0095] The above description is only an embodiment of the application, and does not limit the patent scope of the application, and any modification or equivalent transformation made by using the content of the specification, or direct or indirect application in other related technical fields, is also included in the patent protection scope of the application.

Claims

1. A method for preparing a water-based suede in the style of suede nubuck, characterized by, It comprises the following steps: (1) preparing water-based PU slurry The water-based PU slurry comprises the following components in percentage by mass: deionized water 75%-85%, water-based polyurethane 8%-15%, sodium alginate 0.5%-1.5%, metal carbonate 1%-5%, and auxiliary agent 1%-5%; the raw materials are mixed by stirring to obtain the water-based PU slurry; the metal carbonate is a mixture of calcium carbonate and sodium carbonate or a mixture of calcium carbonate and sodium bicarbonate; the auxiliary agent is at least one of leveling agent, crosslinking agent, and defoaming agent; (2) impregnation treatment The base fabric passes through the impregnation tank containing two press shafts at a certain speed, and the water-based PU slurry in the impregnation tank fully infiltrates the base fabric; (3) coagulation bath treatment The base fabric treated in step (2) passes through an acidic aqueous coagulation bath, so that the polyurethane on the surface of the base fabric and the polyurethane inside the base fabric are coagulated, and the metal carbonate is decomposed by the acid to produce CO2, so that the PU is filled with pores, and the metal salt formed by the decomposition of the metal carbonate respectively crosslinks with the sodium alginate and the polyurethane; (4) washing and padding treatment The base fabric treated by the coagulation bath is washed, and then passes through a pair of padding shafts to squeeze out excess water; (5) drying treatment The base fabric treated by the washing and padding treatment is dried; (6) post-processing treatment The semi-finished product treated in step (5) is subjected to post-processing treatment to obtain water-based suede with imitation suede style.

2. The method of preparing a water-based suede of suede-like grain according to claim 1, characterized in that, The base fabric is non-woven fabric, woven raised fabric, or island-in-the-sea fabric without opening.

3. The method for preparing a water-based suede-like leather with a suede-like finish according to claim 1, characterized in that, The acid in the acidic aqueous coagulation bath is one of tartaric acid and oxalic acid.

4. The method of claim 1, wherein the water-based suede leather having a suede grain style is characterized by, In step (4), the distance between the two padding shafts is 0.5-0.7 times the thickness of the base fabric.

5. The method for preparing a water-based suede-like leather with a suede-like finish according to claim 1, characterized in that, The drying time in step (5) is 25-35 min, and the drying temperature is 80-130℃.

6. The method of claim 1, wherein the water-based suede leather having a suede grain style is characterized by, The viscosity of the water-based PU slurry is 2000-3000 mpa.s.

7. The method for preparing a water-based suede-like leather with a suede-like finish according to claim 1, characterized in that, If the base fabric is non-woven fabric or island-in-the-sea fabric without opening, the post-processing treatment includes opening, high-temperature setting, dyeing, sanding, washing, and drying; if the base fabric is woven raised fabric, the post-processing treatment includes high-temperature setting, dyeing, sanding, washing, and drying.

8. An aqueous nubuck style suede characterized by, It is obtained by the preparation method of any one of claims 1-7; the PU content of the water-based suede with imitation suede style is 10-30%; and the suede contains a large number of cavities.