阅读说明：本技术 一种制革用甲醛清除剂及其制备方法 (Formaldehyde scavenging agent for tanning and preparation method thereof ) 是由 梁永贤 姚庆达 申治伟 陈永榜 黄朝七 温会涛 但卫华 于 2020-12-08 设计创作，主要内容包括：本发明公开了一种制革用甲醛清除剂及其制备方法,包括以下重量份的各组分：多元醇1-10份、改性纳米二氧化钛0.1-2份、异氰酸酯0.2-5份、小分子扩链剂0.05-1份、亲水性扩链剂0.05-1份、中和剂0.05-1份、氧化石墨烯0.01-1份、多胺类化合物0.05-1份、水2-80份；本申请的甲醛清除剂主要用于制革水场工段,甲醛清除剂中的纳米二氧化钛、聚氨酯一起进入皮革内部,与皮革发生交联固定于皮革中,可长效清除皮革中的游离甲醛。(The invention discloses a formaldehyde scavenger for tanning and a preparation method thereof, wherein the formaldehyde scavenger comprises the following components in parts by weight: 1-10 parts of polyol, 0.1-2 parts of modified nano titanium dioxide, 0.2-5 parts of isocyanate, 0.05-1 part of micromolecular chain extender, 0.05-1 part of hydrophilic chain extender, 0.05-1 part of neutralizer, 0.01-1 part of graphene oxide, 0.05-1 part of polyamine compound and 2-80 parts of water; the formaldehyde scavenger is mainly used for a leather-making water field workshop section, and the nano titanium dioxide and polyurethane in the formaldehyde scavenger enter the leather together and are fixed in the leather in a cross-linking manner with the leather, so that free formaldehyde in the leather can be removed for a long time.)

1. The formaldehyde scavenger for tanning is characterized by comprising the following components in parts by weight:

2. the formaldehyde scavenger for tanning according to claim 1, wherein the modified nano titanium dioxide comprises the following components in parts by weight:

1-10 parts of nano titanium dioxide

0.01-1 part of amino silane coupling agent

0.01-1 part of epoxy silane coupling agent.

3. The formaldehyde scavenger for tanning as claimed in claim 2, wherein the nano titanium dioxide is anatase titanium dioxide, and the particle size of the nano titanium dioxide is 10-100 nm.

4. The formaldehyde scavenger for tanning according to claim 1, wherein the isocyanate is one or more of isophorone diisocyanate, hexamethylene diisocyanate, and toluene diisocyanate.

5. The formaldehyde scavenger for leather making according to claim 1, wherein the polyol is one or more of polypropylene glycol, polyethylene glycol, polytetrahydrofuran ether, polybutylene adipate diol, and polycaprolactone diol.

6. The formaldehyde scavenger for tanning according to claim 1, wherein the small molecule chain extender is one or more of ethylene glycol, propylene glycol, butylene glycol, diethylene glycol and triethylene glycol.

7. The formaldehyde scavenger for tanning according to claim 1, wherein the hydrophilic chain extender is one or more of dimethylolpropionic acid, dimethylolbutyric acid, tartaric acid, citric acid, 2, 4-diaminobenzene sulfonic acid, sodium ethylene diamine ethanesulfonate, carboxyl-containing half ester diol, N-methyldiethanolamine, and triethylamine.

8. The formaldehyde scavenger for leather making according to claim 1, wherein the polyamine compound is one or more of ethylenediamine, diethylenetriamine, triethylenetetramine and tetraethylenepentamine.

9. A preparation method of a formaldehyde scavenger for tanning is characterized by comprising the following steps:

(1) adding 1-10 parts of nano titanium dioxide into a reaction container, adding 0.01-1 part of aminosilane coupling agent, 0.01-1 part of epoxy silane coupling agent, 10-100 parts of water and 20-200 parts of ethanol, stirring and dispersing, adjusting the pH to 4-12, then performing ultrasonic dispersion for 3-30min, reacting at the temperature of 20-60 ℃ for 1-10h, filtering, washing and drying to obtain modified nano titanium dioxide;

(2) dehydrating 1-10 parts of polyol, adding the dehydrated polyol into a reactor, adding 0.2-5 parts of isocyanate, prepolymerizing at 70-100 ℃ for 0.5-4h, cooling to 60-70 ℃, adding 0-8 parts of acetone for dilution, and adding 0.05-1 part of micromolecular chain extender, and reacting for 2-6 h; adding 0.05-1 part of hydrophilic chain extender, reacting for 0.5-4h, cooling to 40-60 ℃, and adding 0.05-1 part of neutralizing agent for 10-100 min; controlling the temperature to be 25-45 ℃, adding 0.1-2 parts of modified nano titanium dioxide and 0.01-1 part of graphene oxide, and stirring at a high speed for reaction for 10-120 min; controlling the temperature to be 25-45 ℃, adding 2-80 parts of water while stirring at a high speed, and emulsifying and dispersing for 0.5-4 h; adding 0.01-1 part of polyamine compound, controlling the temperature at 25-45 ℃, stirring and reacting for 10-120min, and removing acetone in the emulsion to obtain the formaldehyde scavenger.

Technical Field

The invention relates to the technical field of leather production, in particular to a formaldehyde scavenger for leather making and a preparation method thereof.

Background

In the process of processing and manufacturing leather, chemicals such as modified aldehyde, oxazolidine, amino resin, organic phosphine, modified protein and the like are synthesized by taking formaldehyde as a precursor, the chemicals contain a certain amount of formaldehyde, and the formaldehyde is brought into finished leather through tanning, retanning, filling, finishing and the like and is slowly released in the process of long-term use. In recent years, green consumption is gradually becoming a consumption trend at home and abroad, strict limits are provided on formaldehyde control, European Union is clearly specified in European Union chemical registration, evaluation, authorization and restriction regulations, and the formaldehyde content of leather and products thereof is not higher than 150 mg/kg. The national mandatory standards also specify: the formaldehyde content in the infant product is not higher than 20mg/kg, the formaldehyde content in the infant product is not higher than 75mg/kg when the infant product is directly contacted, and the formaldehyde content in the infant product is not higher than 300mg/kg when the infant product is not directly contacted. Therefore, the control and elimination of formaldehyde in leather products are of great significance to the sustainable development of the tanning industry and to the health of consumers.

At present, leather chemicals at home and abroad have three main components of formaldehyde catching agents and formaldehyde scavenging agents, namely proteins, amino and photocatalytic materials. But the adsorption capacity of the protein formaldehyde is limited, when the consumption is excessive, the finished leather board is hard and is easy to nourish bacteria to mildew; the formaldehyde adsorption capacity of the amino chemicals is strong, but the amino substances are limited by the synthesis process, the materials carry a certain amount of formaldehyde, and the formaldehyde is easily released slowly in the subsequent use, so that the health of a user is influenced; the photocatalytic material has the advantages of strong formaldehyde removal capability, long duration and the like, but the nano photocatalytic material has extremely poor dispersibility in aqueous solution, can only be added in a small amount in a coating workshop section, cannot be applied to a tanning water field workshop section to add the nano photocatalytic material into leather, and is difficult to rapidly remove formaldehyde in the leather.

Disclosure of Invention

The embodiment of the application provides a formaldehyde scavenger for leather making and a preparation method thereof, solves the problems of poor adsorption force and poor dispersibility in water of the formaldehyde scavenger in the prior art, realizes the beneficial effect of adsorbing formaldehyde in leather, and is mainly used for a leather-making water field workshop section.

The embodiment of the application provides a formaldehyde scavenger for tanning, which comprises the following components in parts by weight:

further, the modified nano titanium dioxide comprises the following components in parts by weight:

1-10 parts of nano titanium dioxide

0.01-1 part of amino silane coupling agent

0.01-1 part of epoxy silane coupling agent.

Further, the nano titanium dioxide is anatase titanium dioxide, and the particle size of the nano titanium dioxide is 10-100 nm.

Further, the isocyanate is one or more of isophorone diisocyanate, hexamethylene diisocyanate and toluene diisocyanate.

Further, the polyol is one or more of polypropylene glycol, polyethylene glycol, polytetrahydrofuran ether, polybutylene adipate diol and polycaprolactone diol.

Further, the small-molecule chain extender is one or more of ethylene glycol, propylene glycol, butanediol, diethylene glycol and triethylene glycol.

Further, the hydrophilic chain extender is one or more of dimethylolpropionic acid, dimethylolbutyric acid, tartaric acid, citric acid, 2, 4-diaminobenzene sulfonic acid, ethylene diamine ethyl sodium sulfonate, carboxyl-containing half-ester dihydric alcohol, N-methyldiethanolamine and triethylamine.

Further, the polyamine compound is one or more of ethylenediamine, diethylenetriamine, triethylenetetramine and tetraethylenepentamine.

A preparation method of a formaldehyde scavenger for tanning comprises the following steps:

(1) adding 1-10 parts of nano titanium dioxide into a reaction container, adding 0.01-1 part of aminosilane coupling agent, 0.01-1 part of epoxy silane coupling agent, 10-100 parts of water and 20-200 parts of ethanol, stirring and dispersing, adjusting the pH to 4-12, then performing ultrasonic dispersion for 3-30min, reacting at the temperature of 20-60 ℃ for 1-10h, filtering, washing and drying to obtain modified nano titanium dioxide;

(2) dehydrating 1-10 parts of polyol, adding the dehydrated polyol into a reactor, adding 0.2-5 parts of isocyanate, prepolymerizing at 70-100 ℃ for 0.5-4h, cooling to 60-70 ℃, adding 0-8 parts of acetone for dilution, and adding 0.05-1 part of micromolecular chain extender, and reacting for 2-6 h; adding 0.05-1 part of hydrophilic chain extender, reacting for 0.5-4h, cooling to 40-60 ℃, and adding 0.05-1 part of neutralizing agent for 10-100 min; controlling the temperature to be 25-45 ℃, adding 0.1-2 parts of modified nano titanium dioxide and 0.01-1 part of graphene oxide, and stirring at a high speed for reaction for 10-120 min; controlling the temperature to be 25-45 ℃, adding 2-80 parts of water while stirring at a high speed, and emulsifying and dispersing for 0.5-4 h; adding 0.01-1 part of polyamine compound, controlling the temperature at 25-45 ℃, stirring and reacting for 10-120min, and removing acetone in the emulsion to obtain the formaldehyde scavenger.

One or more technical solutions provided in the embodiments of the present application have at least the following technical effects or advantages:

1. the formaldehyde scavenger polyamine compound and the graphene oxide can serve as a cross-linking agent and a formaldehyde catching agent in a system, so that formaldehyde in leather is caught, and the formaldehyde scavenging effect in the formaldehyde scavenger is enhanced.

2. The formaldehyde scavenger is mainly used for a leather-making water field workshop section, and the nano titanium dioxide and polyurethane in the formaldehyde scavenger enter the leather together and are fixed in the leather in a cross-linking manner with the leather, so that free formaldehyde in the leather can be removed for a long time.

3. The silane coupling agent in the formaldehyde scavenger modifies the surface of the nano titanium dioxide, so that the compatibility and the dispersibility of the nano titanium dioxide in polyurethane can be improved, the silane coupling agent can also react with active groups on skin collagen fibers in leather to fix the nano titanium dioxide on the skin fibers, and the water washing resistance of the formaldehyde scavenger is improved.

4. The acetone in the formaldehyde scavenger can adjust the viscosity in a system, prevents the viscosity of the system from being too high, does not participate in the reaction of the system, and is removed after the reaction of the system is finished.

5. The neutralizing agent can be used for adjusting the acidity of the system, and when the hydrophilic chain extender is acidic, such as dimethylolpropionic acid, organic alkali is needed for neutralization; when the hydrophilic chain extender is basic, it is necessary to neutralize it with an organic acid to maintain the pH of the system at neutral.

Detailed Description

In order to better understand the technical solutions, the technical solutions will be described in detail with reference to the description and the specific embodiments.

Example 1:

a preparation method of a formaldehyde scavenger for tanning comprises the following steps:

(1) adding 5 parts of anatase titanium dioxide into a reaction container, adding 0.4 part of aminosilane coupling agent, 0.1 part of epoxy silane coupling agent, 50 parts of water and 100 parts of ethanol, stirring and dispersing, adjusting the pH value to 10, and then ultrasonically dispersing for 5min (t is t)¹) At 30 ℃ (T)¹) At a temperature of 5h (t)²) Filtering, washing and drying to obtain the modified nano titanium dioxide.

(2) Taking 3 parts of polytetramethylene glycol, dehydrating, adding into a reactor, and adding0.8 part of isophorone diisocyanate, 80 ℃ (T)²) Prepolymerization for 2h (t)³). Cooling to 65 deg.C (T)³) Diluting with 0.4 part of acetone, adding 0.3 part of butanediol, and reacting for 4h (t)⁴). 0.1 part of dimethylolpropionic acid is added and the reaction is carried out for 2h (t)⁵). Cooling to 50 deg.C (T)⁴) Adding 0.1 part of triethylamine (neutralizing agent) to neutralize for 30min (t)⁶). Controlling the temperature to be 40 ℃ (T)⁵) Adding 0.2 part of modified nano titanium dioxide and 0.05 part of graphene oxide, and stirring at high speed for reaction for 60min (t)⁷). Controlling the temperature to be 40 ℃ (T)⁶) Adding 12 parts of water while stirring at high speed, emulsifying and dispersing for 1h (t)⁸). Adding 0.05 part of ethylenediamine, and controlling the temperature to be 30 ℃ (T)⁷) Stirring and reacting for 30min (t)⁹) And removing acetone in the emulsion to obtain the formaldehyde scavenger.

Example 2:

a preparation method of a formaldehyde scavenger for tanning is the same as that adopted in example 1, and the components and conditions are different, and are specifically shown in the following table 1:

TABLE 1

Example 3:

a preparation method of a formaldehyde scavenger for tanning, which is the same as the method adopted in the example 1, and has different components and conditions, and the preparation method is specifically shown in the following table 2:

TABLE 2

Example 4:

a method of making leather comprising the steps of:

taking conventional wet blue leather, wringing, shaving, weighing, softening, retanning, neutralizing according to a conventional process, and then filling, wherein the filling process is as follows:

50% of water was added to the drum, 10% of formaldehyde scavenger (from example 1) was added, the temperature was controlled at 30 ℃ and the drum was rotated for 40min, 3% of acrylic resin retanning agent TP340(ALPA leather chemical Co., Ltd.), 3% of acrylic resin retanning agent RE (BASF Co., Ltd.), and rotated for 30min, 3% of vegetable tanning agent ME (Jinfeng leather chemical Co., Ltd.), 1% of synthetic tanning agent T-M (BASF Co., Ltd.), 2% of synthetic tanning agent OS (Langsheng chemical Co., Ltd.), 3% of amino resin tanning agent HB (Toepler Co., Ltd.), 2% of amino resin tanning agent DCT (Staal leather chemical Co., Ltd.), 3% of vegetable tanning agent ME (Jinfeng leather chemical Co., Ltd.), 2% of dye and rotated for 120 min. Adding 150% water and 0.75% formic acid, controlling temperature at 50 deg.C, rotating for 20min, adding 0, 75% formic acid, rotating for 30min, and draining.

And (3) adding grease, color registering, drying and finishing according to a conventional process, and detecting the performance of the leather.

The formaldehyde scavengers obtained in example 1, example 2 and example 3 were tested to obtain the experimental data shown in table 3, and the leathers obtained in example 2 were tested to obtain the experimental data shown in table 4:

TABLE 3

TABLE 4

The above description is only an embodiment utilizing the technical content of the present disclosure, and any modification and variation made by those skilled in the art can be covered by the claims of the present disclosure, and not limited to the embodiments disclosed.