阅读说明：本技术 一种低tvoc低气味环保生态汽车皮革工艺 (Low-TVOC low-odor environment-friendly ecological automobile leather process ) 是由 张志刚 杨热闹 于 2020-04-30 设计创作，主要内容包括：一种低TVOC低气味环保生态汽车皮革工艺,本发明属于汽车皮革制作领域。本发明依次按照皮坯分选、片皮、摔软、除尘、封里、底涂、挂晾通风、压花、混合层、挂晾通风、顶涂、挂晾通风的工艺对皮革进行加工,获得低TVOC低气味的汽车皮革。本发明配方中采用低TVOC的涂饰用水性材料避免了含有有机溶剂交联剂和含有有机溶剂树脂的使用；在涂饰工程中加入对皮革的通风挂晾,加快皮革内可挥发有机物的挥发,皮革TVOC的散发试验结果明显优于常规生产流程所生产的皮革并且气味得到明显的改善,可以满足汽车主机厂对汽车内饰皮革材料有机挥发物和气味的限值要求,从而改善乘车环境,减少对人体产生的危害。(The invention discloses a low-TVOC low-odor environment-friendly ecological automobile leather process, and belongs to the field of automobile leather manufacturing. The method comprises the steps of sorting leather blanks, splitting leather sheets, softening, dedusting, sealing, priming, airing and ventilating, embossing, mixing layers, airing and ventilating, top coating and airing and ventilating in sequence, so that the low-TVOC and low-odor automobile leather is obtained. The coating aqueous material with low TVOC in the formula avoids the use of organic solvent-containing crosslinking agent and organic solvent-containing resin; the leather is ventilated and hung in the coating engineering, so that the volatilization of volatile organic compounds in the leather is accelerated, the emission test result of the TVOC of the leather is obviously superior to that of the leather produced by the conventional production flow, the smell is obviously improved, the limit value requirements of an automobile host factory on the volatile organic compounds and the smell of the automobile interior leather material can be met, the riding environment is improved, and the harm to the human body is reduced.)

1. The low-TVOC low-odor environment-friendly ecological automobile leather process is characterized in that leather is processed according to the procedures of sorting leather blanks, splitting leather, softening, dedusting, sealing, priming, airing and ventilating, embossing, mixing layers, airing and ventilating, top coating and airing and ventilating in sequence to obtain the low-TVOC low-odor automobile leather;

the lining sealing process specifically comprises the following steps:

roll coating lining slurry on the back of leather by a pass-type roll coating machine, wherein the lining slurry comprises, by weight, 550 parts of water of 450-;

the priming process specifically comprises the following steps:

performing a bottom coating process on the lowest layer consisting of the coating layer on the surface of the leather, roll coating the water-based bottom coating slurry containing the pigment paste to the front side of the leather by a reverse roll coater to form a coating film, wherein the roll coating amount per square meter is 100-130g, and the coating film passes through a drying channel at the temperature of 110-130 ℃ after roll coating; the primer coating slurry comprises, by weight, 130-170 parts of water, 20-40 parts of polysiloxane A, 80-120 parts of acrylic resin, 150 parts of protein filler, 200-240 parts of aqueous acrylic resin B, 170-230 parts of aqueous acrylic resin A, 100-150 parts of pigment paste and 15-30 parts of isocyanate crosslinking agent A, wherein the total amount is 1000 parts;

the hanging and airing ventilation process specifically comprises the following steps:

after the leather is dried, hanging and drying the leather on a leather hanging and drying machine, and installing fans on two sides of the hanging and drying machine to blow air to the leather, so that the leather is in a good hanging and drying ventilation environment;

the mixed layer process specifically comprises the following steps:

the mixed layer is a middle layer positioned on the surface of the leather coating layer, the slurry of the mixed layer is uniformly attached to the embossed bottom coating layer of the leather by a high-grade roller coater or a spraying coater, and the mixed layer passes through a drying channel at the temperature of 110-130 ℃ after being roller-coated for 2-3 minutes, wherein the drying time is 32-38 g per square meter;

the mixed layer slurry consists of polyurethane resin, water, pigment paste, cross-linking agent and finishing assistant. The mixed layer slurry comprises, by weight, 30-80 parts of water, 350 parts of 200-350 parts of waterborne matt polyurethane resin A, 150 parts of 100-150 parts of waterborne acrylic resin C, 30-80 parts of polysiloxane A, 80-120 parts of waterborne matt polyurethane resin B, 200 parts of 100-200 parts of waterborne acrylic resin B, 150 parts of 100-100 parts of pigment paste and 60-80 parts of isocyanate crosslinking agent B, wherein the total amount is 1000 parts;

the top coating process specifically comprises the following steps:

spraying the top coating slurry on the mixed layer by a spraying machine on the uppermost layer of the leather surface coating layer to enable the top coating slurry to be adhered above the mixed layer, and then drying the mixture through a drying channel at the temperature of 110-130 ℃ to enable the top coating slurry to form a film, wherein the spraying amount of the top coating is 24-30 g per square meter;

the top coating slurry comprises, by weight, 100-200 parts of water, 100-300 parts of aqueous extinction polyurethane resin A, 100-150 parts of aqueous brightening polyurethane resin, 100-150 parts of aqueous extinction polyurethane resin C, 30-80 parts of polysiloxane A, 100-200 parts of aqueous extinction polyurethane resin B, 30-80 parts of polysiloxane B, 20-60 parts of pigment paste and 80-100 parts of isocyanate crosslinking agent B, wherein the total amount is 1000 parts.

2. The automotive leather process with low TVOC and low odor as claimed in claim 1, wherein the lining paste comprises the following components:

3. the low TVOC low odor environmental protection ecological automobile leather process as claimed in claim 1, wherein the primer slurry comprises the following components:

4. the low TVOC low-odor environmental protection ecological automobile leather process as claimed in claim 1, wherein the mixed layer slurry comprises the following components:

5. the low TVOC low odor environmental protection ecological automobile leather process as claimed in claim 1, wherein the top coating slurry comprises the following components:

6. the process for preparing ecological leather for car with low TVOC and low odor as claimed in claim 1, wherein the pattern is pressed on the front surface or surface of the leather by a passing-through type embossing machine under the conditions of temperature 100-.

7. The process of claim 1, wherein each hanging and ventilating operation lasts 2-4 hours.

Technical Field

The invention belongs to the field of automobile leather manufacturing, and particularly relates to a low-TVOC low-odor environment-friendly ecological automobile leather process.

Background

In the manufacturing process of automobile leather, a plurality of polymer materials, polyurethane for coating, a cross-linking agent and the like are used, a solvent and a coating material have volatile organic compounds, the polymer materials can be continuously decomposed and slowly emit organic compounds harmful to human bodies such as formaldehyde, acetaldehyde and the like and bad smell for a long time after the leather is manufactured, and all the volatile organic compounds-TVOC are gathered in a narrow and closed space in an automobile, so that the automobile leather becomes poor in riding environment in the automobile and can cause harm to the body of a passenger for a long time.

With the increasing importance of the automobile market on the environment in the automobile, the leather produced by the existing automobile leather processing technology can generate a large amount of volatile organic compounds, and can generate serious pungent odor in the automobile, and the technology for producing the automobile leather with low TVOC and low odor is urgently needed in the field.

Disclosure of Invention

In order to make up the defects of the prior art, the invention provides the production process of the low-TVOC low-odor automobile leather, and the leather produced by the process has the characteristics of low TVOC, low odor, environmental friendliness and ecology.

In order to realize the purpose of the invention, the overall technical concept of the invention is as follows: and sequentially processing the leather according to the processes of sorting leather blanks, splitting leather into sheets, softening, removing dust, sealing, priming, airing and ventilating, embossing, mixing layers, airing and ventilating, top coating and airing and ventilating to obtain the automobile leather with low TVOC and low odor.

The invention adopts the following specific scheme:

s1, sorting of leather blanks

And (4) screening the raw material leather blanks according to the leather surface damage standard, screening out the leather meeting the actual application requirement, and performing batch production.

S2. sheet skin

Splitting the screened blank into sheets, wherein the steps have the following functions: because the leather has certain thickness difference at different parts in the processing process and each piece of leather also has certain thickness difference, the splitting process ensures that the thickness of the whole leather blank reaches the range of practical application requirements, reduces the difference of different parts of the same leather blank and also ensures that the thicknesses of the same batch of leather blanks are unified, thereby being beneficial to the uniformity of roller coating amount when the leather passes through a roller coater in the subsequent leather processing process, reducing the texture and color difference of different parts of the final finished leather product, and further ensuring the stable quality of the product.

S3, softening

Because different varieties have different requirements on the softness of the leather, the leather fibers are loosened by the beating and softening rotary drum in the process, so that the leather blank achieves the required softness, and the leather has soft and comfortable touch.

S4, dust removal

The fine fibers adsorbed on the surface of the leather are removed by a passing leather dust removal device, so that the short fibers are prevented from falling to the genuine leather products of the leather in the subsequent processing process to form fiber adhesion and form appearance flaws.

S5. seal lining

The lining sizing agent is coated on the back of the leather in a roller way by a through type roller coater, so that the function of fixing leather fibers is achieved, and the leather fine fibers are prevented from being adhered to the front of the leather in the subsequent processing process. The sealing slurry comprises, by weight, 550 parts of water of 450-.

The micromolecular acrylic acid in the composition plays a role in forming a film and fixing fibers, the hydrazide organic matter is used as an aldehyde remover to remove aldehyde substances such as formaldehyde, acetaldehyde and the like emitted from the leather, and the formaldehyde and the acetaldehyde are main components in the TVOC of the leather, so that the emission of the TVOC of the leather is finally reduced. The phosphate is used as a deodorant to reduce the concentration of bad smell in the leather and optimize the final smell of the leather.

S6. first coat

And performing a bottom coating process on the lowest layer consisting of the leather surface coating layer, using natural leather as the surface of the substrate, and rolling the water-based bottom coating slurry containing pigment paste to the front surface of the leather by a passing reverse roll coater to form a coating film, so as to form the basis for the subsequent embossing and top coating of the mixed layer. The amount of the roll coating per square meter was 100-130 g. After roller coating, the leather passes through a drying channel at the temperature of 110-130 ℃, and under the condition, the moisture in the sizing agent is volatilized to enable the bottom coating sizing agent to form a film on the surface of the leather, thereby being beneficial to the formation of the leather coating. The primer coating slurry comprises, by weight, 130-170 parts of water, 20-40 parts of polysiloxane A, 80-120 parts of acrylic resin, 120-150 parts of protein filler, 200-240 parts of aqueous acrylic resin B, 170-230 parts of aqueous acrylic resin A, 100-150 parts of pigment paste and 15-30 parts of isocyanate crosslinking agent, and the total is 1000 parts.

The proper cross-linking agent is selected according to the reaction time of the cross-linking agent and the process requirement, the isocyanate cross-linking agent has the function of increasing the cross-linking of resin to enable a formed film to have better strength, the auxiliary agent has the function of adjusting the viscosity of the sizing agent, the leveling performance of the sizing agent and the like, and the physical property requirement of the leather is met by adding various waterborne acrylic resins.

S7. hanging and airing ventilation

After the leather is dried, the leather is hung and aired on a leather hanging and airing machine, fans are arranged on two sides of the hanging and airing machine to blow air to the leather, so that the leather is in a good hanging and airing ventilating environment, volatile organic matters and bad smell in the leather and a coating are volatilized as much as possible before the next process, the residue of organic volatile matters in the leather is reduced, the content of the volatile organic matters and the strength of the bad smell in a final product are reduced, and the hanging and airing ventilating time is generally 2-4 hours. Generally, need dry the operation in the workshop of scribbling paint, the workshop temperature is higher, and the volatile organic matter harmful gas of leather can persist in the workshop, is unfavorable for volatilizing of the organic matter that can volatilize in the leather, and consequently, the inventor is carrying out the workshop ceiling design and is having the skylight, makes volatile organic matter and hot-air strengthen flowing through the skylight for the interior volatilizable organic matter of leather gives off.

S8, embossing

Pressing special patterns on the front surface of the leather or forming various patterns on the surface of the leather by using a passing type embossing machine under the conditions of temperature of 100-120 ℃, pressure of 100-200bar and speed of 3-6 m/min. The temperature and pressure of the embossing can be adjusted according to different varieties, and then the compacted fiber is loosened through the vibration softening process, so that the leather becomes soft again.

S9. preparation of mixed layer

The mixed layer is an intermediate layer of a coating layer on the surface of leather, slurry of the mixed layer is uniformly attached to the embossed bottom coating of the leather through a high-grade roller coater or a spraying coater, and after roller coating, the mixed layer passes through a drying channel at the temperature of 110-130 ℃ for 2-3 minutes, so that moisture in the slurry is volatilized to enable the slurry of the mixed layer to form a film, and each square meter of the mixed layer is 32-38 g. The mixed layer slurry consists of polyurethane resin, water, pigment paste, cross-linking agent and finishing assistant. The mixed layer slurry comprises, by weight, 30-80 parts of water, 350 parts of 200-350 parts of waterborne matt polyurethane resin A, 150 parts of 100-150 parts of waterborne acrylic resin C, 30-80 parts of polysiloxane A, 80-120 parts of waterborne matt polyurethane resin B, 200 parts of 100-200 parts of waterborne acrylic resin B, 150 parts of 100-150 parts of pigment paste and 60-80 parts of isocyanate, wherein the total amount is 1000 parts. The isocyanate crosslinking agent has the function of increasing the crosslinking of resin to enable a formed film to have better strength, and the auxiliary agent has the function of adjusting the viscosity of the slurry, the leveling performance of the slurry and the like. After the mixed layer slurry is formed into a film, the color of the leather is as close as possible to the final color of the leather, and the leather is prepared for top coating and finishing. And after the mixing layer is finished, hanging and airing the leather again. The specific operation steps of hanging, airing and ventilating are the same as those of the step S7.

S10. top coating

Spraying the top coating slurry on the mixed layer by a spraying machine on the uppermost layer of the leather surface coating layer to enable the top coating slurry to be adhered above the mixed layer, then drying the top coating slurry through a drying channel at the temperature of 110-130 ℃ to enable the top coating slurry to form a film, wherein the spraying amount of the top coating slurry is 24-30 g per square meter, and after the top coating slurry is formed into the film, hanging and airing the film by a hanging and airing machine again to ventilate so as to further disperse volatile organic matters and smell. The sizing agent of the top coating consists of polyurethane resins, water, pigment paste, a cross-linking agent and a finishing auxiliary agent. The top coating slurry comprises, by weight, 100-200 parts of water, 100-300 parts of aqueous extinction polyurethane resin A, 100-150 parts of aqueous brightening polyurethane resin, 30-80 parts of aqueous extinction polyurethane resin C, 30-80 parts of polysiloxane A, 100-200 parts of aqueous extinction polyurethane resin B, 30-80 parts of polysiloxane B, 20-60 parts of pigment paste and 80-100 parts of isocyanate, and the total is 1000 parts. The top coating sizing agent enables leather to have required gloss color, touch feeling and physical and chemical properties, wherein polysiloxane substances can be used as a hand feeling agent to endow the leather with touch relative hand feeling, the final finished product gloss is adjusted through the proportion of the water-based brightening polyurethane resin and the water-based delustering polyurethane resin, so that the finished product gloss presents a bright surface or matte effect, and the pigment paste is used for determining the final color of the leather and improving the scratch resistance of the leather.

Further, the lining paste comprises the following components in percentage by weight:

chemical name	Model number	Manufacturer of the product
			Water (W)	WATER
Aqueous acrylic resin A	SB100	STAHL
			Organic hydrazide compound	CHEMCATCH	Big weed chemistry
Phosphates	511 deodorant	RASA

Further, the priming paint comprises the following components in percentage by weight:

further, the mixed layer slurry comprises the following components in percentage by weight:

chemical name	Model number	Manufacturer of the product
			Water (W)	WATER
Aqueous extinction polyurethane resin A	Matt 200	LANXESS
			Water-borne acrylic resin C	CL-1	LANXESS
Polysiloxane A	XF	LANXESS
			Water-based extinction polyurethane resin B	Matt 102	LANXESS
Water-borne acrylic resin B	PS	LANXESS
			Pigment paste	Pigment paste	STAHL
Isocyanate crosslinking agent B	XL 1010	LANXESS

Further, the top coating slurry comprises the following components in percentage by weight:

chemical name	Model number	Manufacturer of the product
			Water (W)	WATER
Aqueous extinction polyurethane resin A	Matt 200	LANXESS
			Aqueous brightening polyurethane resin	WT21433	STAHL
Water-based extinction polyurethane resin C	HS	STAHL
			Polysiloxane A	XF	LANXESS
Water-based extinction polyurethane resin B	Matt 102	LANXESS
			Polysiloxanes B	GF	LANXESS
Pigment paste	Pigment paste	STAHL
			Isocyanate crosslinking agent B	XL 1010	LANXESS

In addition, a plurality of hanging ventilation procedures are added in the production process of the invention, so that the leather is in a good hanging ventilation environment, more volatile organic compounds can be emitted in the production process, the volatile organic compounds can be reduced, the volatile organic compounds in the leather can be reduced in the volatile organic compound-free X L1010 of L AXESS can be effectively reduced, the content of the total volatile organic compounds can be effectively reduced, and the residual organic compounds in the leather layer and the residual odor of the leather layer before the volatile organic compound-free coating layer and the volatile organic compound-free coating layer can be reduced to the greatest extent.

According to the invention, a proper cross-linking agent is selected according to the reaction time of the cross-linking agent and the requirements of the process, the cross-linking agent with relatively fast reaction time is selected for the mixed layer and the top coating, and the cross-linking agent with relatively long reaction time is required for the bottom coating.

Compared with the prior art, the invention has the beneficial effects that: the invention takes the conventional leather blank of the automobile leather as a raw material, adopts the water-based material with low TVOC for coating, and obtains the automobile leather with low TVOC and low odor through a special coating processing technology. The coating aqueous material with low TVOC in the formula avoids the use of organic solvent-containing crosslinking agent and organic solvent-containing resin; the leather is ventilated and hung in the coating engineering, so that the volatilization of volatile organic compounds in the leather is accelerated, the emission test result of the TVOC of the leather is obviously superior to that of the leather produced by the conventional production flow, the smell is obviously improved, the limit value requirements of an automobile host factory on the volatile organic compounds and the smell of the automobile interior leather material can be met, the riding environment is improved, and the harm to the human body is reduced.

Detailed Description

The invention is described in more detail below with reference to specific examples, without limiting the scope of the invention. Unless otherwise specified, the experimental methods adopted by the invention are all conventional methods, and experimental equipment, materials, reagents and the like used in the method can be obtained commercially.