CN119102125A

CN119102125A - A wet foaming material for resistant leather and resistant leather prepared by the same

Info

Publication number: CN119102125A
Application number: CN202411589322.4A
Authority: CN
Inventors: 姜秋颖; 邹子想; 邹子括
Original assignee: Wenzhou Tongying Technology Co ltd
Current assignee: Wenzhou Tongying Technology Co ltd
Priority date: 2024-11-08
Filing date: 2024-11-08
Publication date: 2024-12-10
Anticipated expiration: 2044-11-08
Also published as: CN119102125B

Abstract

The invention discloses a wet foaming material for leather resistance and the leather resistance prepared therefrom, comprising a solvent, a polyurethane resin, and a water-soluble bio-based powder; the water-soluble bio-based powder is one or more of modified starch, cyclodextrin, English gum, white dextrin, maltodextrin, and yellow dextrin. In the present invention, the foaming material is mainly used for the bass layer in synthetic leather, which is mainly a mixture of solvent, polyurethane resin, and soluble bio-based powder. The soluble bio-based powder can absorb water and dissolve. During the dissolution process, there will be a long swelling process, and then dissolve after swelling. When swelling, it will expand, thereby forming pores inside the polyurethane resin. When the swelling limit is reached, it will dissolve, thereby dissolving in the solvent, thereby leaving the pores inside the polyurethane. Therefore, when the soluble bio-based powder is used as the foaming material, it will not remain inside the polyurethane.

Description

Wet foaming material for skin-entangling resistance and skin-entangling resistance prepared from wet foaming material

Technical Field

The invention relates to the field of leather, in particular to a wet foaming material for skin-winding resistance.

Background

The dermis is animal skin which is denatured and not easy to rot after dehairing, tanning and chemical processing, and people are loved in the dermis products due to the scarcity of dermis resources and the comfort and fashion of the dermis. However, the dermis is a rare imitation leather, and the existing imitation leather is formed with regenerated leather, microfiber leather and polyurethane synthetic leather.

In recent years, a protein soft synthetic leather is also appeared on the market, which is prepared by stirring raw materials such as wood powder, polyurethane resin solvent liquid, dimethylformamide, a small amount of polyvinyl alcohol powder, a small amount of pregelatinized starch and the like to prepare a wet mixed material, wherein the wood powder swells when meeting solvents, the swelled wood powder, the polyvinyl alcohol powder and the pregelatinized starch are uniformly dispersed in the mixed material, the mixed material is coated on a base cloth, the polyvinyl alcohol powder and the pregelatinized starch in the coating swells when meeting water molecules, the swelling of the pregelatinized starch particles is 50-100 times of the original volume, the polyvinyl alcohol powder absorbs water with the weight of more than 7 times, and the swelled polyvinyl alcohol powder and the swelled pregelatinized starch are washed out in hot water. The foaming layer is shrunk in the drying process, the polyvinyl alcohol powder and the pregelatinized starch form large cells, the wood powder forms small cells, and the structure of the large cells is clamped among compact small cells. The polyvinyl alcohol is too viscous after being expanded and solidified when being used for water, the pregelatinized starch is more viscous after being expanded and solidified when being used for water, the water dissolving speed is very slow, the solvent and water exchange is realized by transferring moisture through wood powder in the solidification process of a solidification tank, the dissolving speed is increased by using hot water in the water washing process of a water washing tank, and a lot of wood powder is needed to transfer moisture to achieve the aim of cleaning. The polyvinyl alcohol washed out causes the blockage of a dimethylformamide recovery system, the blockage cleaning is quite troublesome, equipment such as a solvent recovery tower and the like is required to be changed, and only one manufacturer of the protein soft synthetic leather exists at present. The international cancer research organization of the world health organization lists the industrial grade polyvinyl alcohol in the 3 kinds of cancerogenic substance list, and the recovered industrial grade polyvinyl alcohol needs to be recovered by a professional environment-friendly qualification recovery unit, thus greatly increasing the manufacturing cost.

The production capacity of the protein-like soft synthetic leather is limited, and the market demand is far from being met. The softness is in direct proportion to the usage amount of wood powder, paper pulp powder, polyvinyl alcohol and pregelatinized starch, so that the softer the protein-like soft leather is, the shorter the firmness and the service life are, the advantages of the protein-like soft synthetic leather are mainly good in softening effect, but the hand feeling of a large-cell wet foaming layer is in loose, hollow and light floating feeling, the hand feeling and the sagging feeling of sheep dermis are not possessed, the loose and drum wrinkles of the leather are not attractive, and the softness and the attractiveness cannot be simultaneously considered. The sheep skin is soft and attractive, the skin lines are compact and attractive, the hand feeling is hard, and the skin lines are loose and the wrinkles are not attractive when the hand feeling is emphasized to be soft. And the softer the hand, the poorer the mechanical properties.

At present, the PU synthetic leather is produced by fully relying on wood powder, mold spoilage is easy to grow on the bass due to the existence of the wood powder, sanitation and quality are affected, and the sanitation and quality are seriously affected due to the fact that the leather is of a collagen tissue structure and mold spoilage is easier to grow on the leather.

Disclosure of Invention

Aiming at the defects existing in the prior art, the invention aims to provide the wet foaming material which has the advantages of softness and mechanical property and can not grow mould spoilage.

In order to achieve the above purpose, the present invention provides the following technical solutions:

a wet foaming material for skin-winding resistance,

Comprising

Solvent, polyurethane resin and water-soluble bio-based powder;

The water-soluble bio-based powder is one or more of modified starch, cyclodextrin, british gum, white dextrin, maltodextrin and yellow dextrin.

As a further improvement of the present invention,

The water-soluble bio-based powder absorbs 50% -200% of water by weight to swell and absorbs 100% -400% of water by weight to dissolve.

As a further improvement of the present invention,

The solvent is dimethylformamide.

As a further improvement of the present invention,

The wet mix also includes a wax emulsion.

As a further improvement of the present invention,

The wax emulsion is one or more of paraffin wax emulsion, palm wax emulsion and PE wax emulsion.

As a further improvement of the present invention,

The wet mix also includes an organosilicon.

As a further improvement of the present invention,

The organosilicon is long-chain amino polyether block silicone oil or long-chain amino polyether block silicone oil emulsion.

As a further improvement of the present invention,

The mass ratio of the polyurethane resin to the soluble bio-based powder is 20-40:30-150.

As a further improvement of the present invention,

And the grease emulsion is 2-15 parts.

As another object of the present invention, there is provided a skin-care product,

The wet foaming material comprises a grain surface layer and a wet foaming layer, and is characterized in that the wet foaming layer is prepared from the wet foaming material.

As a further improvement of the present invention,

The wet foaming layer is positioned on the base cloth layer, and the elastic stretching rate of the base cloth is less than 10%.

The invention has the beneficial effects that the foaming material of the bass layer in the synthetic leather is mainly prepared by mixing solvent, polyurethane resin and soluble bio-based powder, wherein the soluble bio-based powder can absorb water and dissolve, and has a longer swelling process in the dissolving process, after swelling, the swelling process is carried out, so that cells are formed in the polyurethane resin, and when the swelling limit is reached, the foaming material is dissolved in the solvent, and leaves the cells in the polyurethane, so that the soluble bio-based powder is used as the foaming material, and the residues in the polyurethane can not be remained.

Unlike wooden powder filler, the foaming agent is used for expanding and then is remained in the bass, and polyurethane is continuously rubbed in the continuous bending process, so that the mechanical property of the bass is reduced, the wooden powder is easy to mold and rot, and the weather resistance of the bass is reduced. The wooden powder remains in the bass, after the hand is grabbed or crumpled and pressed again, the wooden powder is hard to restore to original shape after being stressed and deformed, the trace of grabbing mark can be left to affect the beauty, and high-grade leather, especially leather with very fine dermatoglyph, cannot be produced. At present, sheep skin with very thin skin lines can also leave a trace of grabbing marks after being grabbed by hands or crumpled and pressed again to affect the beauty, so that the leather industry cannot produce very thin skin lines. The finer the grain, the more beautiful, the finer the higher the end, mainly the more difficult to produce.

The purpose is based on no longer using wood powder as foaming filler and reducing the use of wood parts as foaming filler, thereby improving the mechanical property, softness and weather resistance of the bass, improving the recovery capability of the bass after being deformed under stress and improving the possibility of leather production with fine dermatoglyph.

In the selection of the soluble bio-based powder, modified starch, cyclodextrin, british gum, white dextrin, maltodextrin and yellow dextrin are selected. The selected soluble bio-based powder can be uniformly dispersed in a mixture, the wet-process mixture is coated on a base cloth and then is soaked in a coagulating liquid, water molecules penetrate into each dextrin powder through DMF, swelling and pasting are rapidly carried out on the soluble bio-based powder after the soluble bio-based powder meets the water molecules, the soluble bio-based powder and adjacent parts of the soluble bio-based powder are in swelling communication with each other in the swelling process, the swelled soluble bio-based powder is irregularly connected in series with each other, polyurethane resin is slowly coagulated when the soluble bio-based powder swells, the soluble bio-based powder is continuously dissolved into a dextrin aqueous solution after being swelled and meeting penetrating water, the soluble bio-based powder aqueous solution and dimethylformamide are washed by water in a water washing process, and a foaming layer is obtained through drying, so that the special foaming layer with a towel gourd structure is obtained. No hot water washing is needed as in the prior art, and even other auxiliary substances are added for washing.

Compared with the prior art, the soluble bio-based powder used first has the capability of dissolving after swelling, can form uniform and compact cells, and the produced synthetic leather does not drift slightly, so that calcium powder is not needed for weight gain, but the synthetic leather has better mechanical property and weather resistance.

In the selection of the soluble bio-based powder, water with the performance of absorbing 50% -200% of the self weight is preferably selected to be swelled, and water with the performance of absorbing more than 100% -400% of the self weight is preferably selected to be dissolved. The cells thus formed are relatively dense.

As the preferable mode of the invention, a proper amount of wax emulsion is added, the lubrication and astringency of the wax slows down the rebound speed of the foaming layer, and the anti-skin is close to or exceeds the rebound hand feeling of the sheep skin.

In order to realize moist and oily, grease emulsion is added into the wet mixture, and the emulsion plays a role in strengthening uniform dispersion of powder particles in the wet mixture, and has the effects of reducing friction force, slowing rebound speed and absorbing moisture and increasing weight by wetting the inner wall of an oil sliding hole.

The long-chain amino polyether block silicone oil or the long-chain amino polyether block silicone oil emulsion is added into the wet mixture, the organic silicon plays a role of uniformly dispersing particles in the wet mixture, the characteristics of softness of a foaming layer produced by reducing friction force among molecules and in cells are reduced, and the long-chain amino polyether block silicone oil or the long-chain amino polyether block silicone oil emulsion is harder to be finely removed by water in a water washing process than the short-chain amino polyether block silicone oil or the short-chain amino polyether block silicone oil emulsion, so that the softening effect is better.

Drawings

FIG. 1 is an electron microscope image of a first embodiment of the present invention;

FIG. 2 is an electron microscope image of a second embodiment of the present invention;

FIG. 3 is an electron microscope image of comparative example one of the present invention;

FIG. 4 is an electron microscope image of a comparative example II of the present invention.

Detailed Description

The invention will be further described in detail with reference to examples of embodiments shown in the drawings.

Examples

Step one, preparing a wet foaming material

Taking the following components in parts by weight:

100 parts of polyurethane resin with 30% of solid content and 10kgf/cm2 of modulus

80 Parts of yellow dextrin powder

180 Parts of DMF;

and mixing a proper amount of DMF with polyurethane resin to ensure that the viscosity of the wet foaming material is at a proper coating viscosity of about 5000 cps.

Wherein, 1 part of yellow dextrin powder can absorb 1 part of water by weight in the swelling stage and 2 parts of water can be dissolved after the test.

Mixing the yellow dextrin powder and the residual DMF to prepare a yellow dextrin mixture;

and fully stirring and mixing the polyurethane resin mixture and the yellow dextrin powder mixture to obtain the wet foaming material.

Step two, pretreatment of base cloth

The base cloth with the thickness of 0.20 mm is immersed into 17% DMF water solution, the excessive water solution is pressed by a squeezing roller, and the base cloth is ironed by an ironing wheel, wherein the humidity is 40%.

Step three, coating and solidifying

Uniformly scraping the wet foaming material on the pretreated base cloth, wherein the scraping gap is 1.00 mm, and then immersing the base cloth in a DMF water solution with the concentration of 20% in a solidification tank for solidification, wherein the solidification time is 20min.

Step four:

After solidification, the excessive solidification liquid is extruded through extrusion rollers, then is washed by clean water through a washing tank, the first section of the washing tank is washed with five groups of extrusion rollers for extrusion, the second section is washed with six groups of extrusion rollers, and finally, the wet foaming layer is obtained through drying, expanding and shaping.

Examples

Step one, preparing a wet foaming material

Taking the following components in parts by weight:

Cyclodextrin 80 parts

180 Parts of DMF;

The DMF was taken in the appropriate parts by weight to bring the viscosity of the wet laid foam material to the appropriate coating viscosity of around 5000 cps.

Wherein the cyclodextrin powder is tested, 1 part of cyclodextrin can absorb 2 parts by weight of water and 3 parts of water can be dissolved in the swelling stage.

Mixing cyclodextrin and the residual DMF to prepare cyclodextrin mixture;

And fully stirring and mixing the polyurethane resin mixture and the cyclodextrin mixture to obtain the wet foaming material.

Step two, pretreatment of base cloth

Step three, coating and solidifying

Step four:

Examples

Step one, preparing a wet foaming material

Taking the following components in parts by weight:

80 Parts of yellow dextrin powder

PE wax emulsion 2 parts

10 Parts of long-chain amino polyether block silicone oil emulsion

180 Parts of DMF;

And fully stirring and mixing the polyurethane resin mixture, the yellow dextrin powder mixture and other auxiliary materials to obtain the wet foaming material.

Step two, pretreatment of base cloth

Step three, coating and solidifying

Step four:

Examples

Step one, preparing a wet foaming material

Taking the following components in parts by weight:

80 Parts of yellow dextrin powder

5 Parts of grease emulsion

180 Parts of DMF;

Step two, pretreatment of base cloth

Step three, coating and solidifying

Step four:

Example five preparation of vein-resist coating

Step 1, taking

40 Parts of a dry polyurethane resin having a solids content of 30% and a modulus of 50kgf/cm2

DMF 50 parts

Butanone 20 parts

Obtaining a dry mixed solution;

And 2, preparing a release paper coating, namely selecting the special release paper with the finest fine sheep veins for the release paper, carrying out dry-process mixing on a release paper film, coating a scraping gap of 0.20mm, and drying for 20min by an 80 ℃ oven to obtain the release paper coating.

Step 3, dry veneering:

Directly bonding the wet foaming layers obtained in the first embodiment, the second embodiment, the third embodiment, the fourth embodiment and the fifth embodiment on the release paper coating prepared in the step 2 by pressure, drying for 30min by a 120 ℃ oven, cooling by a cooling roller, and respectively rolling the release paper and the laminated wet bass to obtain the finished leather.

Comparative example one:

step one, preparing a wet foaming material

Taking the following components in parts by weight:

50 Parts of pregelatinized starch

20 Parts of wood powder

180 Parts of DMF;

Mixing pregelatinized starch and residual DMF to prepare a pregelatinized starch mixture;

And fully stirring and mixing the polyurethane resin mixture and the pregelatinized starch mixture to obtain the wet foaming material.

Step two, pretreatment of base cloth

Step three, coating and solidifying

Uniformly scraping the wet foaming material on the pretreated base cloth, wherein the scraping gap is 1.00 mm, and then immersing the base cloth in a DMF water solution with the concentration of 20% in a coagulation tank for coagulation, wherein the coagulation time is 15min.

Step four:

After solidification, the excessive solidification liquid is extruded through extrusion rollers, and then is washed by 80 ℃ hot water through a washing tank, the first section of the washing tank is washed with five groups of extrusion rollers for extrusion, the second section is washed with six groups of extrusion rollers, and finally, the wet foaming layer is obtained through drying, expanding and shaping.

Comparative example two:

step one, preparing a wet foaming material

Taking the following components in parts by weight:

5 Parts of polyvinyl alcohol

20 Parts of wood powder

180 Parts of DMF;

Mixing pregelatinized starch and the residual DMF to prepare a polyvinyl alcohol mixture;

and fully stirring and mixing the polyurethane resin mixture and the polyvinyl alcohol mixture to obtain the wet foaming material.

Step two, pretreatment of base cloth

The suede nap base fabric having a thickness of 0.20 mm was immersed in a 17% DMF aqueous solution, and the excess aqueous solution was pressed by a squeeze roller, and ironed by an ironing wheel to a humidity of 40%.

Step three, coating and solidifying

Step four:

Comparative example three (the most common clothing leather on the market):

step one, preparing a wet foaming material

Taking the following components in parts by weight:

100 parts of polyurethane resin with 30% of solid content and 50kgf/cm2 of modulus

30 Parts of wood powder

20 Parts of light calcium powder

180 Parts of DMF;

Mixing wood powder and the residual DMF to prepare a pregelatinized starch mixture;

and fully stirring and mixing the polyurethane resin mixture and the wood powder mixture to obtain the wet foaming material.

Step two, pretreatment of base cloth

Step three, coating and solidifying

Step four:

Raw material table:

The bass obtained in examples one to four and comparative examples one to three were faced with example five and sheep skin for clothing, and then subjected to the following tests.

And (3) testing:

1. Folding fastness test QB/T2714-2018;

2. Peel load test, GB/T2791-1995;

3. jungle experiments QB/T4671-2014, temperature 70 ℃ and relative humidity 95%;

4. softness test GB/T39371-2020.

5. Indentation test (50 kg of the leather was folded in half, pressed against a bottom 0.2mx0.2m iron block for 1 hour and then released, and the time taken for the indentation to disappear was visually observed).

6. Mildew test (the leather is placed in a mould incubator, and mould can be seen to grow by naked eyes at a temperature of 28 ℃ and a humidity of 70%)

As is apparent from the comparison of examples one to four, the examples one to four are all better in folding endurance than the comparative examples one to three, and the peel load is also better than that of the comparative examples, and in the softness test, it can be seen that the softness of the comparative examples one and two is somewhat better than that of the examples one and two because the pregelatinized starch and the polyvinyl alcohol used in the comparative examples one and two are foamed to a larger extent, so that the formed cells are also larger, and therefore the softness is better than that of the examples one and two, but the difference between the two is not great, but the mechanical properties such as folding endurance and peeling strength are poor due to the oversized cells, and the comparative example three is prepared from wood powder, which is not large compared with the pregelatinized starch and the polyvinyl alcohol, but the wood powder cannot be washed out, so that the dried wood powder is harder, and the polyurethane is rubbed continuously during the mechanical test, so that the mechanical properties are degraded. In jungle experiments, the service life of the embodiment is obviously superior to that of the comparative example, the service life of the embodiment is far longer than that of the comparative example, the service life of the embodiment is more than 12 years and almost exceeds that of sheep skin, and the third comparative example is worst, which shows that the service life of common synthetic clothing leather in the market is less than 2 years. From the indentation test, the indentations from the first to the third of the comparative examples never disappear, the indentation disappearance time of the sheep skin is longer to influence the wear leveling and aesthetic degree, and the indentation disappearance time from the first to the fifth of the comparative examples is faster to be beneficial to the wear leveling and aesthetic degree. In mildew experiments, sheep skin is most prone to mold growth, comparative examples one to three are also prone to mold growth, and examples one to four are not prone to mold growth, because collagen of dermis and wood powder of synthetic leather provide nutrition for mold.

In the third embodiment, wax and organic silicon are added on the basis of the first embodiment, so that the softness can be effectively improved, and the softness exceeds that of the first and second comparative examples with large pores.

In the fourth embodiment, the fat emulsion is added on the basis of the first embodiment, and the softness can be further improved by adding the fat emulsion.

By observing the first and second embodiments and the first and second comparative embodiments through a scanning electron microscope, fig. 1 is an electron microscope image of the first embodiment, dense and uniform cells can be seen, fig. 2 is an electron microscope image of the second embodiment, and also dense and uniform cells can be seen, but the cells are slightly larger than the first embodiment, which is why the mechanical properties of the second embodiment are slightly weaker than those of the first embodiment, fig. 3 is an electron microscope image of the first comparative embodiment, larger cells can be seen, and the formed cells are very uneven, and likewise fig. 4 is an electron microscope image of the second comparative embodiment, larger cells can be seen, and the formed cells are very uneven, which is why the mechanical properties of the first and second comparative embodiments are poor.

Unlike wooden powder filler, the foaming agent is used for expanding and then is remained in polyurethane, and the polyurethane is continuously rubbed in the continuous bending process, so that the mechanical property of the bass is reduced, the wooden powder is easy to mold and rot, and the weather resistance of the bass is reduced.

The long-chain amino polyether block silicone oil emulsion is added into the wet mixture, the organic silicon plays a role of uniformly dispersing particles in the wet mixture, the characteristics of softness of a foaming layer produced by reducing friction force among molecules and in cells are reduced, and the long-chain amino polyether block silicone oil emulsion is harder to be thinned out by water than the short-chain amino polyether block silicone oil emulsion in a water washing process, so that the softening effect is better.

The above description is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above examples, and all technical solutions belonging to the concept of the present invention belong to the protection scope of the present invention. It should be noted that modifications and adaptations to the present invention may occur to one skilled in the art without departing from the principles of the present invention and are intended to be within the scope of the present invention.

Claims

1. A wet foaming material for resistant skin, characterized in that:

include

Solvents, polyurethane resins, water-soluble bio-based powders;

The water-soluble bio-based powder is composed of one or more of modified starch, cyclodextrin, English gum, white dextrin, maltodextrin and yellow dextrin.

2. A wet foaming material for resistant leather according to claim 1, characterized in that:

The water-soluble bio-based powder absorbs 50% to 200% of its own weight of water to swell, and absorbs more than 100% to 400% of its own weight of water to dissolve.

3. A wet foaming material for resistant leather according to claim 1, characterized in that:

The solvent is dimethylformamide.

4. A wet foaming material for resistant leather according to claim 1, characterized in that:

The wet mixture also includes 1 to 3 parts of wax emulsion.

5. A wet foaming material for resistant leather according to claim 4, characterized in that:

6. The wet foaming material for resistant leather according to claim 1, characterized in that:

The wet mixture also includes 4 to 30 parts of silicone.

7. A wet foaming material for resistant leather according to claim 6, characterized in that:

The organic silicon is long-chain amino polyether block silicone oil or long-chain amino polyether block silicone oil emulsion.

8. The wet foaming material for resistant leather according to claim 1, characterized in that:

9. The wet foaming material for resistant leather according to claim 1, characterized in that:

It also includes 2 to 15 parts of oil emulsion.

10. The anti-foaming leather prepared from the wet foaming material according to any one of claims 1 to 9, characterized in that:

It comprises a textured pavement layer and a wet foaming layer, and is characterized in that the wet foaming layer is made of the wet foaming material.