Antistatic surface layer resin for synthetic leather

Abstract

The invention discloses antistatic surface layer resin for synthetic leather, and relates to the technical field of resin for synthetic leather, and the antistatic surface layer resin comprises 25-35 parts by mass of aromatic isocyanate, 20-25 parts by mass of hydrophilic polyester polyol, 10-15 parts by mass of a micromolecule dihydric alcohol chain extender, 0.3-1 part by mass of a catalyst, 2-3 parts by mass of segmented hydroxyl silane and 1-3 parts by mass of a conductive auxiliary agent. According to the antistatic surface layer resin for the synthetic leather, the advantages of all the components are integrated through melt blending of polythiophene and polypyrrole, the conductivity and other properties of a material are improved, and the antistatic surface layer resin is higher in conductivity and better in stability. Meanwhile, the manufacturing cost is reduced, and the precision requirement for the preparation process is low. The fabric has excellent physical properties, is soft and thick in hand feeling, and still has excellent hand feeling and antistatic effect when being used as a garment material under a low-temperature condition; meanwhile, the polyether polyol is used, so that the garment material has waterproof and moisture permeable functions.

Description

Technical Field

[0001] The invention relates to the technical field of resins for synthetic leather, in particular to an antistatic surface layer resin for synthetic leather. Background Art

[0002] With the enhancement of human environmental awareness and the increasing environmental restrictions in various countries around the world, the environmental protection issues in the polyurethane synthetic leather industry are increasingly valued by all links in the industry chain. The use of traditional solvent-based petroleum-based polyurethanes is subject to more and more restrictions, so the demand for organic solvent removal and environmental protection in the polyurethane synthetic leather industry is imminent. Among them, solvent-free polyurethane synthetic leather has gradually entered the field of vision of polyurethane synthetic leather manufacturers in the past two years due to its superior environmental performance, low production energy consumption, excellent physical properties of finished leather, and high cost performance. After the development in recent years, it has achieved certain results.

[0003] At present, polyurethane synthetic leather has been widely used in many aspects of human life, providing many conveniences for human beings. The excellent performance of polyurethane is due to the countless soft and hard structural units arranged alternately in the molecular chain. The unique performance and comprehensive performance of the soft and hard structural units due to the different stiffness and crystallinity can give the polyurethane molecular chain good creep and force bearing capacity, making the polyurethane synthetic leather have unique toughness and resilience, good folding resistance and elasticity, and extremely soft feel. Polyurethane synthetic leather has been widely used in footwear, sofas, clothing, furniture, and interior walls, but these fields are also troubled by static electricity while enjoying the beauty and convenience of polyurethane synthetic leather. The static electricity on the surface of synthetic leather easily absorbs dust and forms a layer of dust film, which not only affects the appearance, but also brings great trouble to daily cleaning; in addition, in relatively dry areas, static electricity is generated between the skin and synthetic leather products and clothing due to friction and contact, and the instantaneous voltage is high, which can cause physical discomfort and even cause cardiovascular disease.

[0004] At present, the resin antistatic agent for synthetic leather adopts carbon nanotubes, carbon fibers, conductive carbon black and other materials, which have high cost and price. In addition, the antistatic agent is not evenly mixed during the resin synthesis process, which greatly reduces the antistatic ability of the resin and requires high precision of the synthesis process. Summary of the invention

[0005] In view of the deficiencies of the prior art, the present invention provides an antistatic surface layer resin for synthetic leather, which solves the above-mentioned problems.

[0006] To achieve the above objectives, the present invention is implemented through the following technical scheme: an antistatic surface resin for synthetic leather, comprising 25-35 parts by mass of aromatic isocyanate, 20-25 parts by mass of hydrophilic polyester polyol, 10-15 parts by mass of small molecule diol chain extender, 0.3-1 parts by mass of catalyst, 2-3 parts by mass of segmented hydroxy silane and 1-3 parts by mass of conductive additive.

[0007] Preferably, the hydrophilic polyester polyol is composed of aliphatic carboxylic acid, polyethylene glycol, dihydroxymethyl propionic acid and tetrabutyl titanate; the aliphatic carboxylic acid is any one of diacid and succinic acid.

[0008] A method for preparing an antistatic surface layer resin for synthetic leather comprises the following steps:

[0009] Prepolymerization reaction: Add the hydrophilic polyester polyol into the reaction container, set the temperature in the reaction container to 80°C, slowly add the aromatic isocyanate, and add a proper amount of catalyst to accelerate the reaction; during this process, the isocyanate group of the aromatic isocyanate reacts with the hydroxyl group of the hydrophilic polyester polyol to form a prepolymer; the prepolymerization reaction time is 3 hours, and the reaction container is continuously stirred; the molar ratio of isocyanate group to hydroxyl group is 1.8:1; to ensure that the prepolymer has sufficient unreacted isocyanate groups for the subsequent chain extension reaction.

[0010] Chain extension reaction: After the prepolymerization reaction is completed, a small molecule diol chain extender is added to the obtained prepolymer through the feed control system. The hydroxyl group of the small molecule diol chain extender continues to react with the unreacted isocyanate in the prepolymer, thereby increasing the molecular chain of the polymer and the molecular weight, thereby improving the performance of the resin.

[0011] Introducing terminal hydroxy silane: After the chain extension reaction is completed, the terminal hydroxy silane is added to the reaction vessel. The hydroxyl group of the terminal hydroxy silane can react with the prepolymer or the polymer after chain extension to introduce the silane structure into the resin molecule; this can improve the adhesion, water resistance and heat resistance of the resin.

[0012] Adding conductive additive: Add the conductive additive to the reaction container. After adding the conductive additive, continue stirring for a period of time so that the conductive additive is evenly dispersed in the resin system. The role of the conductive additive is to give the resin a certain conductivity so that it can be used in applications that require conductive properties.

[0013] Post-treatment: After the reaction is completed, unreacted raw material impurities are removed by reduced pressure distillation to improve the purity and performance of the resin.

[0014] Preferably, the preparation method of the hydrophilic polyester polyol consists of the following steps:

[0015] S1. Drying the aliphatic carboxylic acid;

[0016] S2, adding polyethylene glycol into the reaction kettle, starting stirring and slowly raising the temperature to 140° C. to fully melt it and remove the existing water;

[0017] S3. Add aliphatic carboxylic acid and dimethylol propionic acid in sequence under stirring; the addition process should be slow to ensure local heat stability and uniform reaction;

[0018] S4, continue to raise the temperature to the reaction temperature of 180°C, and introduce nitrogen at the same time to isolate the air in the reaction system and prevent the oxidation reaction;

[0019] S5. When the reaction system reaches a predetermined temperature of 180° C., tetrabutyl titanate catalyst is added, wherein the amount of the catalyst is 0.8% of the total mass of the raw materials.

[0020] S6. Continuously monitor the temperature, pressure and acid value changes of the reaction system; the esterification reaction will produce water, which will be condensed and discharged from the reaction system through a reflux condenser; the reaction time is 10 hours, until the acid value reaches the requirement, then stop heating, continue stirring and cool the reaction system to room temperature.

[0021] Preferably, the conductive aid comprises: polythiophene, polypyrrole, polystyrene-butadiene-styrene block copolymer, polyethylene wax and dioctyl phthalate;

[0022] The preparation method of the conductive additive comprises the following steps:

[0023] Pre-drying polythiophene and polypyrrole to remove moisture and volatile impurities in the materials;

[0024] Add the dried polythiophene and polypyrrole, polystyrene-butadiene-styrene block copolymer, polyethylene wax and dioctyl phthalate into an internal mixer, gradually increase the temperature to above the melting point of the two materials, and the materials are in a molten state; the temperature of the internal mixer is set at 220°C, and the blending time is 30 minutes;

[0025] During the blending process, the materials need to be fully mixed and stirred to ensure that polythiophene and polypyrrole can be evenly dispersed in the blend;

[0026] The blended material is taken out from the blending equipment and water-cooled to form particles after cooling.

[0027] Polypyrrole has high electrical conductivity and good stability in air; polythiophene has high electrical conductivity and good thermal and chemical stability. By melt blending polythiophene and polypyrrole, the advantages of each component are combined to improve the conductivity and other properties of the material, higher conductivity and better stability. At the same time, the manufacturing cost is reduced and the precision requirements for the preparation process are low.

[0028] Preferably, the steps of drying the aliphatic carboxylic acid are as follows:

[0029] Place aliphatic carboxylic acid in a glass container, and place the glass container in an oven;

[0030] Set the temperature to 70°C for heating. Pay attention to ventilation during the heating process. Stir the carboxylic acid every 30 minutes. The drying time is 12 hours.

[0031] Preferably, in the chain extension reaction, the temperature of the chain extension reaction is the same as the prepolymerization temperature, that is, 80° C., and the reaction time is 1.5 hours.

[0032] Preferably, the feed control system includes a feed hopper, an environment acquisition module and a data processing feedback module;

[0033] The feed hopper is used to hold the small molecule diol chain extender and quantitatively feed the small molecule diol chain extender into the reaction container according to the reaction speed;

[0034] The environment acquisition module includes a concentration sensor and a temperature sensor; the concentration sensor is used to collect the concentration of the solution in the reaction container during the chain extension reaction; the temperature sensor is used to collect the real-time temperature of the chain extension reaction after adding the small molecule diol chain extender;

[0035] The data processing feedback module sets the filler threshold according to the collected chain extension reaction concentration and real-time temperature value, and adjusts the amount of small molecule diol filler by comparing the chain extension reaction situation with the filler threshold. The sensor accurately and quantitatively distributes the amount of small molecule diol added to avoid excessive chain extension reaction that causes excessive system temperature or gelation, thereby increasing the reaction rate.

[0036] Preferably, the method for adjusting the amount of small molecule diol filler after comparing the chain extension reaction situation with the filler threshold value comprises the following steps:

[0037] Step 1: The final concentration value after the reaction is calculated as A according to the total filler ratio of the chain extension reaction, and the real-time data collected by the concentration sensor during the chain extension reaction is B;

[0038] Step 2: The real-time chain extension reaction temperature threshold temperature monitored by the temperature sensor is set to 82°C, and the real-time collection temperature of the temperature sensor is C;

[0039] Step 3: When the collected value B-concentration value A≤0, and the collected temperature C-82°C≤0, the collected information is fed back to the hopper to periodically add a quantitative small molecule diol chain extender, each time adding 1 part by mass of the small molecule diol chain extender.

[0040] The invention provides an antistatic surface layer resin for synthetic leather. It has the following beneficial effects: by adding dried polythiophene and polypyrrole, polystyrene-butadiene-styrene block copolymer, polyethylene wax and dioctyl phthalate into an internal mixer, gradually raising the temperature to above the melting point of the two, the materials are in a molten state; in the blending process, the materials need to be fully mixed and stirred to ensure that polythiophene and polypyrrole can be evenly dispersed in the blend; the blended materials are taken out of the blending equipment and water-cooled and formed; after cooling, they are made into a granular form. Polypyrrole has high electrical conductivity and good stability in the air; polythiophene has high electrical conductivity and good thermal stability and chemical stability. By melt blending polythiophene and polypyrrole, the advantages of each component are combined to improve the conductive properties and other properties of the material, higher conductivity and better stability. At the same time, the manufacturing cost is reduced, and the precision requirements for the preparation process are low. The fabric is given excellent hand feel, waterproof and breathable and antistatic effects. It has excellent physical properties, soft and thick feel. As a clothing fabric, it still has excellent feel and anti-static effect under low temperature conditions. At the same time, due to the use of polyether polyols, the clothing fabric has the function of waterproof and moisture permeability.

[0041] The sensor accurately and quantitatively distributes the amount of small molecule diols to be added, and the feed control system controls the addition of small molecule diols each time by accurately calculating the temperature difference and concentration difference, avoiding excessive chain extension reaction that causes the system temperature to be too high or produces gel, thereby improving the reaction efficiency. DETAILED DESCRIPTION

[0042] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0043] Embodiment 1

[0044] The present invention provides a technical solution: an antistatic surface layer resin for synthetic leather, comprising 25 parts by mass of aromatic isocyanate, 20 parts by mass of hydrophilic polyester polyol, 10 parts by mass of a small molecule diol chain extender, 0.3 parts by mass of a catalyst, 2 parts by mass of segmented hydroxy silane and 1 part by mass of a conductive additive.

[0045] Preferably, the hydrophilic polyester polyol is composed of aliphatic carboxylic acid, polyethylene glycol, dihydroxymethyl propionic acid and tetrabutyl titanate; the aliphatic carboxylic acid is any one of diacid and succinic acid.

[0046] A method for preparing an antistatic surface layer resin for synthetic leather comprises the following steps:

[0047] Prepolymerization reaction: Add the hydrophilic polyester polyol into a reaction container, set the temperature in the reaction container to 80°C, slowly add the aromatic isocyanate, and add a proper amount of catalyst to accelerate the reaction; during this process, the isocyanate group of the aromatic isocyanate reacts with the hydroxyl group of the hydrophilic polyester polyol to form a prepolymer; the prepolymerization reaction time is 3 hours, and the reaction container is continuously stirred; the molar ratio of isocyanate group to hydroxyl group is 1.8:1; to ensure that the prepolymer has sufficient unreacted isocyanate groups for the subsequent chain extension reaction.

[0048] Chain extension reaction: After the prepolymerization reaction is completed, a small molecule diol chain extender is added to the obtained prepolymer through the feed control system. The hydroxyl group of the small molecule diol chain extender continues to react with the unreacted isocyanate in the prepolymer, thereby increasing the molecular chain of the polymer and the molecular weight, thereby improving the performance of the resin.

[0049] Introducing terminal hydroxy silane: After the chain extension reaction is completed, the terminal hydroxy silane is added to the reaction vessel. The hydroxyl group of the terminal hydroxy silane can react with the prepolymer or the polymer after chain extension to introduce the silane structure into the resin molecule; this can improve the adhesion, water resistance and heat resistance of the resin.

[0050] Adding conductive additive: Add the conductive additive to the reaction container. After adding the conductive additive, continue stirring for a period of time so that the conductive additive is evenly dispersed in the resin system. The role of the conductive additive is to give the resin a certain conductivity so that it can be used in applications that require conductive properties.

[0051] Post-treatment: After the reaction is completed, unreacted raw material impurities are removed by reduced pressure distillation to improve the purity and performance of the resin.

[0052] The preparation method of the hydrophilic polyester polyol consists of the following steps:

[0053] S1. Drying the aliphatic carboxylic acid;

[0054] S2, adding polyethylene glycol into the reaction kettle, starting stirring and slowly raising the temperature to 140° C. to fully melt it and remove the existing water;

[0055] S3. Add aliphatic carboxylic acid and dimethylol propionic acid in sequence under stirring; the addition process should be slow to ensure local heat stability and uniform reaction;

[0056] S4, continue to raise the temperature to the reaction temperature of 180°C, and introduce nitrogen at the same time to isolate the air in the reaction system and prevent the oxidation reaction;

[0057] S5. When the reaction system reaches a predetermined temperature of 180° C., tetrabutyl titanate catalyst is added, wherein the amount of the catalyst is 0.8% of the total mass of the raw materials.

[0058] S6. Continuously monitor the temperature, pressure and acid value changes of the reaction system; the esterification reaction will produce water, which will be condensed and discharged from the reaction system through a reflux condenser; the reaction time is 10 hours, until the acid value reaches the requirement, then stop heating, continue stirring and cool the reaction system to room temperature.

[0059] The steps of drying the aliphatic carboxylic acid are as follows:

[0060] Place aliphatic carboxylic acid in a glass container, and place the glass container in an oven;

[0061] Set the temperature to 70°C for heating. Pay attention to ventilation during the heating process. Stir the carboxylic acid every 30 minutes. The drying time is 12 hours.

[0062] Embodiment 2

[0063] The present invention provides a technical solution: an antistatic surface layer resin for synthetic leather, comprising 35 parts by mass of aromatic isocyanate, 25 parts by mass of hydrophilic polyester polyol, 15 parts by mass of small molecule diol chain extender, 1 part by mass of catalyst, 3 parts by mass of segmented hydroxy silane and 3 parts by mass of conductive additive.

[0064] The hydrophilic polyester polyol is composed of aliphatic carboxylic acid, polyethylene glycol, dihydroxymethyl propionic acid and tetrabutyl titanate; the aliphatic carboxylic acid is any one of diacid and succinic acid.

[0065] A method for preparing an antistatic surface layer resin for synthetic leather comprises the following steps:

[0066] Prepolymerization reaction: Add the hydrophilic polyester polyol into the reaction container, set the temperature in the reaction container to 80°C, slowly add the aromatic isocyanate, and add a proper amount of catalyst to accelerate the reaction; during this process, the isocyanate group of the aromatic isocyanate reacts with the hydroxyl group of the hydrophilic polyester polyol to form a prepolymer; the prepolymerization reaction time is 3 hours, and the reaction container is continuously stirred; the molar ratio of isocyanate group to hydroxyl group is 1.8:1; to ensure that the prepolymer has sufficient unreacted isocyanate groups for the subsequent chain extension reaction.

[0067] Chain extension reaction: After the prepolymerization reaction is completed, a small molecule diol chain extender is added to the obtained prepolymer through the feed control system. The hydroxyl group of the small molecule diol chain extender continues to react with the unreacted isocyanate in the prepolymer, thereby increasing the molecular chain of the polymer and the molecular weight, thereby improving the performance of the resin.

[0068] Introducing terminal hydroxy silane: After the chain extension reaction is completed, the terminal hydroxy silane is added to the reaction vessel. The hydroxyl group of the terminal hydroxy silane can react with the prepolymer or the polymer after chain extension to introduce the silane structure into the resin molecule; this can improve the adhesion, water resistance and heat resistance of the resin.

[0069] Adding conductive additive: Add the conductive additive to the reaction container. After adding the conductive additive, continue stirring for a period of time so that the conductive additive is evenly dispersed in the resin system. The role of the conductive additive is to give the resin a certain conductivity so that it can be used in applications that require conductive properties.

[0070] Post-treatment: After the reaction is completed, unreacted raw material impurities are removed by reduced pressure distillation to improve the purity and performance of the resin.

[0071] The preparation method of the hydrophilic polyester polyol consists of the following steps:

[0072] S1. Drying the aliphatic carboxylic acid;

[0073] S2, adding polyethylene glycol into the reaction kettle, starting stirring and slowly raising the temperature to 140° C. to fully melt it and remove the existing water;

[0074] S3. Add aliphatic carboxylic acid and dimethylol propionic acid in sequence under stirring; the addition process should be slow to ensure local heat stability and uniform reaction;

[0075] S4, continue to raise the temperature to the reaction temperature of 180°C, and introduce nitrogen at the same time to isolate the air in the reaction system and prevent the oxidation reaction;

[0076] S5. When the reaction system reaches a predetermined temperature of 180° C., tetrabutyl titanate catalyst is added, wherein the amount of the catalyst is 0.8% of the total mass of the raw materials.

[0077] S6. Continuously monitor the temperature, pressure and acid value changes of the reaction system; the esterification reaction will produce water, which will be condensed and discharged from the reaction system through a reflux condenser; the reaction time is 10 hours, until the acid value reaches the requirement, then stop heating, continue stirring and cool the reaction system to room temperature.

[0078] The steps of drying the aliphatic carboxylic acid are as follows:

[0079] Place aliphatic carboxylic acid in a glass container, and place the glass container in an oven;

[0080] Set the temperature to 70°C for heating. Pay attention to ventilation during the heating process. Stir the carboxylic acid every 30 minutes. The drying time is 12 hours.

[0081] Embodiment 3

[0082] The present invention provides a technical solution: an antistatic surface layer resin for synthetic leather, comprising 25-35 parts by mass of aromatic isocyanate, 20-25 parts by mass of hydrophilic polyester polyol, 10-15 parts by mass of small molecule diol chain extender, 0.3-1 parts by mass of catalyst, 2-3 parts by mass of segmented hydroxy silane and 1-3 parts by mass of conductive additive.

[0083] Preferably, the hydrophilic polyester polyol is composed of aliphatic carboxylic acid, polyethylene glycol, dihydroxymethyl propionic acid and tetrabutyl titanate; the aliphatic carboxylic acid is any one of diacid and succinic acid.

[0084] A method for preparing an antistatic surface layer resin for synthetic leather comprises the following steps:

[0085] Prepolymerization reaction: Add the hydrophilic polyester polyol into the reaction container, set the temperature in the reaction container to 80°C, slowly add the aromatic isocyanate, and add a proper amount of catalyst to accelerate the reaction; during this process, the isocyanate group of the aromatic isocyanate reacts with the hydroxyl group of the hydrophilic polyester polyol to form a prepolymer; the prepolymerization reaction time is 3 hours, and the reaction container is continuously stirred; the molar ratio of isocyanate group to hydroxyl group is 1.8:1; to ensure that the prepolymer has sufficient unreacted isocyanate groups for the subsequent chain extension reaction.

[0086] Chain extension reaction: After the prepolymerization reaction is completed, a small molecule diol chain extender is added to the obtained prepolymer through the feed control system. The hydroxyl group of the small molecule diol chain extender continues to react with the unreacted isocyanate in the prepolymer, thereby increasing the molecular chain of the polymer and the molecular weight, thereby improving the performance of the resin.

[0087] Introducing terminal hydroxy silane: After the chain extension reaction is completed, the terminal hydroxy silane is added to the reaction vessel. The hydroxyl group of the terminal hydroxy silane can react with the prepolymer or the polymer after chain extension to introduce the silane structure into the resin molecule; this can improve the adhesion, water resistance and heat resistance of the resin.

[0088] Adding conductive additive: Add the conductive additive to the reaction container. After adding the conductive additive, continue stirring for a period of time so that the conductive additive is evenly dispersed in the resin system. The role of the conductive additive is to give the resin a certain conductivity so that it can be used in applications that require conductive properties.

[0089] Post-treatment: After the reaction is completed, unreacted raw material impurities are removed by reduced pressure distillation to improve the purity and performance of the resin.

[0090] The preparation method of the hydrophilic polyester polyol consists of the following steps:

[0091] S1. Drying the aliphatic carboxylic acid;

[0092] S2, adding polyethylene glycol into the reaction kettle, starting stirring and slowly raising the temperature to 140° C. to fully melt it and remove the existing water;

[0093] S3. Add aliphatic carboxylic acid and dimethylol propionic acid in sequence under stirring; the addition process should be slow to ensure local heat stability and uniform reaction;

[0094] S4, continue to raise the temperature to the reaction temperature of 180°C, and introduce nitrogen at the same time to isolate the air in the reaction system and prevent the oxidation reaction;

[0095] S5. When the reaction system reaches a predetermined temperature of 180° C., tetrabutyl titanate catalyst is added, wherein the amount of the catalyst is 0.8% of the total mass of the raw materials.

[0096] S6. Continuously monitor the temperature, pressure and acid value changes of the reaction system; the esterification reaction will produce water, which will be condensed and discharged from the reaction system through a reflux condenser; the reaction time is 10 hours, until the acid value reaches the requirement, then stop heating, continue stirring and cool the reaction system to room temperature.

[0097] The steps of drying the aliphatic carboxylic acid are as follows:

[0098] Place aliphatic carboxylic acid in a glass container, and place the glass container in an oven;

[0099] Set the temperature to 70°C for heating. Pay attention to ventilation during the heating process. Stir the carboxylic acid every 30 minutes. The drying time is 12 hours.

[0100] Embodiment 4:

[0101] The conductive additive includes: polythiophene, polypyrrole, polystyrene-butadiene-styrene block copolymer, polyethylene wax and dioctyl phthalate;

[0102] The preparation method of the conductive additive comprises the following steps:

[0103] Pre-drying polythiophene and polypyrrole to remove moisture and volatile impurities in the materials;

[0104] Add the dried polythiophene and polypyrrole, polystyrene-butadiene-styrene block copolymer, polyethylene wax and dioctyl phthalate into an internal mixer, gradually increase the temperature to above the melting point of the two materials, and the materials are in a molten state; the temperature of the internal mixer is set at 220°C, and the blending time is 30 minutes;

[0105] During the blending process, the materials need to be fully mixed and stirred to ensure that polythiophene and polypyrrole can be evenly dispersed in the blend;

[0106] The blended material is taken out from the blending equipment and water-cooled to form particles after cooling.

[0107] Polypyrrole has high electrical conductivity and good stability in air; polythiophene has high electrical conductivity and good thermal and chemical stability. By melt blending polythiophene and polypyrrole, the advantages of each component are combined to improve the conductivity and other properties of the material, higher conductivity and better stability. At the same time, the manufacturing cost is reduced and the precision requirements for the preparation process are low.

[0108] Embodiment 5

[0109] The present invention provides a technical solution: an antistatic surface layer resin for synthetic leather, wherein the feed control system comprises a feed hopper, an environment acquisition module and a data processing feedback module;

[0110] The feed hopper is used to hold the small molecule diol chain extender and quantitatively feed the small molecule diol chain extender into the reaction container according to the reaction speed;

[0111] The environment acquisition module includes a concentration sensor and a temperature sensor; the concentration sensor is used to collect the concentration of the solution in the reaction container during the chain extension reaction; the temperature sensor is used to collect the real-time temperature of the chain extension reaction after adding the small molecule diol chain extender;

[0112] The data processing feedback module sets the filler threshold according to the collected chain extension reaction concentration and real-time temperature value, and adjusts the amount of small molecule diol filler by comparing the chain extension reaction situation with the filler threshold. The sensor accurately and quantitatively distributes the amount of small molecule diol added to avoid excessive chain extension reaction that causes excessive system temperature or gelation, thereby increasing the reaction rate.

[0113] Preferably, the method for adjusting the amount of small molecule diol filler after comparing the chain extension reaction situation with the filler threshold value comprises the following steps:

[0114] Step 1: The final concentration value after the reaction is calculated as A according to the total filler ratio of the chain extension reaction, and the real-time data collected by the concentration sensor during the chain extension reaction is B;

[0115] Step 2: The real-time chain extension reaction temperature threshold temperature monitored by the temperature sensor is set to 82°C, and the real-time collection temperature of the temperature sensor is C;

[0116] Step 3: When the collected value B-concentration value A≤0, and the collected temperature C-82°C≤0, the collected information is fed back to the hopper to periodically add a quantitative small molecule diol chain extender, each time adding 1 part by mass of the small molecule diol chain extender.

[0117] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions. The sentence "includes an element defined by ... does not exclude the existence of other identical elements in the process, method, article or device including the element".

[0118] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An antistatic surface layer resin for synthetic leather, characterized in that: The invention comprises 25-35 parts by weight of aromatic isocyanate, 20-25 parts by weight of hydrophilic polyester polyol, 10-15 parts by weight of small molecule diol chain extender, 0.3-1 parts by weight of catalyst, 2-3 parts by weight of segmented hydroxy silane and 1-3 parts by weight of conductive additive.

2. The antistatic surface layer resin for synthetic leather according to claim 1, characterized in that: The hydrophilic polyester polyol is composed of aliphatic carboxylic acid, polyethylene glycol, dihydroxymethyl propionic acid and tetrabutyl titanate; the aliphatic carboxylic acid is any one of diacid and succinic acid.

3. A method for preparing an antistatic surface layer resin for synthetic leather, characterized in that: It consists of the following steps: Prepolymerization reaction: add the hydrophilic polyester polyol into a reaction container, set the temperature in the reaction container to 80°C, slowly add the aromatic isocyanate, and add a proper amount of catalyst to accelerate the reaction; during this process, the isocyanate group of the aromatic isocyanate reacts with the hydroxyl group of the hydrophilic polyester polyol to form a prepolymer; the prepolymerization reaction time is 3 hours, and the reaction container is continuously stirred; the molar ratio of isocyanate group to hydroxyl group is 1.8:1; Chain extension reaction: After the prepolymerization reaction is completed, a small molecule diol chain extender is added to the obtained prepolymer through a feed control system, and the hydroxyl group of the small molecule diol chain extender continues to react with the unreacted isocyanate in the prepolymer; Introduction of terminal hydroxyl silane: After the chain extension reaction is completed, terminal hydroxyl silane is added to the reaction vessel. The hydroxyl group of the terminal hydroxyl silane can react with the prepolymer or the polymer after chain extension to introduce the silane structure into the resin molecule; Adding conductive additive: Add the conductive additive into the reaction container. After adding the conductive additive, continue stirring for a period of time so that the conductive additive is evenly dispersed in the resin system. Post-treatment: After the reaction is completed, unreacted raw material impurities are removed by reduced pressure distillation.

4. The antistatic surface layer resin for synthetic leather according to claim 2, characterized in that: The preparation method of the hydrophilic polyester polyol consists of the following steps: S1. Drying the aliphatic carboxylic acid; S2, adding polyethylene glycol into the reaction kettle, starting stirring and slowly raising the temperature to 140° C. to fully melt it and remove the existing water; S3. Add aliphatic carboxylic acid and dimethylol propionic acid in sequence under stirring; the addition process should be slow to ensure local heat stability and uniform reaction; S4, continue to raise the temperature to the reaction temperature of 180°C, and introduce nitrogen at the same time to isolate the air in the reaction system and prevent the oxidation reaction; S5. When the reaction system reaches a predetermined temperature of 180° C., tetrabutyl titanate catalyst is added, wherein the amount of the catalyst is 0.8% of the total mass of the raw materials. S6. Continuously monitor the temperature, pressure and acid value changes of the reaction system; the esterification reaction will produce water, which will be condensed and discharged from the reaction system through a reflux condenser; the reaction time is 10 hours, until the acid value reaches the requirement, then stop heating, continue stirring and cool the reaction system to room temperature.

5. The antistatic surface layer resin for synthetic leather according to claim 1, characterized in that: The conductive additive includes: polythiophene, polypyrrole, polystyrene-butadiene-styrene block copolymer, polyethylene wax and dioctyl phthalate; The preparation method of the conductive additive comprises the following steps: Pre-drying polythiophene and polypyrrole to remove moisture and volatile impurities in the materials; Add the dried polythiophene and polypyrrole, polystyrene-butadiene-styrene block copolymer, polyethylene wax and dioctyl phthalate into an internal mixer, gradually increase the temperature to above the melting point of the two materials, and the materials are in a molten state; the temperature of the internal mixer is set at 220°C, and the blending time is 30 minutes; During the blending process, the materials need to be fully mixed and stirred to ensure that polythiophene and polypyrrole can be evenly dispersed in the blend; The blended material is taken out from the blending equipment and water-cooled to form particles after cooling.

6. The antistatic surface layer resin for synthetic leather according to claim 4, characterized in that: The steps of drying the aliphatic carboxylic acid are as follows: Place aliphatic carboxylic acid in a glass container, and place the glass container in an oven; Set the temperature to 70°C for heating. Pay attention to ventilation during the heating process. Stir the carboxylic acid every 30 minutes. The drying time is 12 hours.

7. The method for preparing an antistatic surface layer resin for synthetic leather according to claim 3, characterized in that: In the chain extension reaction, the temperature of the chain extension reaction is the same as the prepolymerization temperature, which is 80° C., and the reaction time is 1.5 hours.

8. The method for preparing an antistatic surface layer resin for synthetic leather according to claim 3, characterized in that: The feed control system includes a feed hopper, an environment acquisition module and a data processing feedback module; The feed hopper is used to hold the small molecule diol chain extender and quantitatively feed the small molecule diol chain extender into the reaction container according to the reaction speed; The environment acquisition module includes a concentration sensor and a temperature sensor; the concentration sensor is used to collect the concentration of the solution in the reaction container during the chain extension reaction; the temperature sensor is used to collect the real-time temperature of the chain extension reaction after adding the small molecule diol chain extender; The data processing feedback module sets a filler threshold value according to the collected chain extension reaction concentration and real-time temperature value, and adjusts the amount of small molecule diol filler after comparing the chain extension reaction situation with the filler threshold value.

9. The method for preparing an antistatic surface layer resin for synthetic leather according to claim 8, characterized in that: The method for adjusting the amount of small molecule diol filler after comparing the chain extension reaction situation with the filler threshold comprises the following steps: Step 1: The final concentration value after the reaction is calculated as A according to the total filler ratio of the chain extension reaction, and the real-time data collected by the concentration sensor during the chain extension reaction is B; Step 2: The real-time chain extension reaction temperature threshold temperature monitored by the temperature sensor is set to 82°C, and the real-time collection temperature of the temperature sensor is C; Step 3: When the collected value B-concentration value A≤0, and the collected temperature C-82°C≤0, the collected information is fed back to the hopper to periodically add a quantitative small molecule diol chain extender, each time adding 1 part by mass of the small molecule diol chain extender.