CN116536009A - Strong-viscosity heat-resistant transparent aqueous polyurethane dispersion and preparation method thereof - Google Patents

Abstract

The invention discloses a high-viscosity heat-resistant transparent aqueous polyurethane dispersion which is prepared from a prepolymer, an acrylic ester monomer, a coupling agent, ice deionized water, a polyamine chain extender and an initiator, wherein the use amount of the acrylic ester monomer is 10-15% of the total amount of the prepolymer; the dosage of the coupling agent is 0.1 to 0.3 percent of the total amount of the prepolymer; the deionized water consumption of the ice is 110% of the total prepolymer; the consumption of the polyamine chain extender is 0.3 to 0.5 percent of the total amount of the prepolymer; the initiator is 0.05% of the acrylate monomer; the prepolymer is prepared from the following components in total amount of 100wt percent: 55 to 70wt% of polyester polyol and/or polyether polyol; 20-30 wt% of diisocyanate; 6-12 wt% of hydroxy sulfonate; 0.8 to 3 weight percent of small molecular dihydric alcohol chain extender; 0.02 to 0.03 weight percent of catalyst. The dispersion has a high solids content of 50%, a high optical transparency of greater than 92%, a high viscosity heat resistance and excellent stability.

Description

A kind of strong viscous heat-resistant transparent aqueous polyurethane dispersion and preparation method thereof

technical field

The invention belongs to the technical field of water-based polyurethane dispersions, and in particular relates to a transparent water-based polyurethane dispersion with strong adhesive strength and high heat-resistant spring-off and a preparation method thereof.

Background technique

Adhesives are made of binders as the main agent and compounded with curing agents, plasticizers, fillers and other additives. They can closely combine similar or different materials. They are widely used in furniture, construction, automobiles, electronics, Packaging and consumer goods and other fields. With the requirements of environmental protection, the current adhesive industry is increasingly developing in the direction of environmental protection, water-based, high-performance and sustainable recycling. Water-based polyurethane uses water as the dispersion medium. It not only has the advantages of non-toxic, non-polluting, and non-flammable, but also has certain properties such as flexibility, mechanical strength, and wear resistance. It can also be compounded with various water-based resins to improve performance and reduce Cost is an important part of the sustainable development of adhesives in the future. As the main resin of waterborne polyurethane adhesive, waterborne polyurethane dispersion plays a decisive role in its own performance.

At present, in the actual preparation technology of water-based polyurethane, the acetone method is mostly used to prepare high-performance dispersions, and it is often applied in automobiles, leather, shoes, etc. in a milky white state, which limits the application space of water-based polyurethane to a certain extent. Transparent dispersions with excellent performance not only have good applications in the above industries, but also can be developed on the surface of materials. Wang Yi and others prepared highly transparent water-based polyurethane by reacting TDI/HDI with different polyols, and found that the type of polyol, R value and DMPA have a great influence on the transparency, mechanics and stability of the dispersion, but the research did not detail Describe the optical, mechanical and stability properties of water-based polyurethane products, there may be problems of incompatibility with excellent properties (see Wang Yi, Liu Wenli, Chen Bingcheng, etc. Preparation of highly transparent water-based polyurethane adhesives [J]. Guangdong Chemical Industry, 2008, No. .184(08):10-12.). At present, domestic and foreign technical requirements for water-based polyurethane dispersions with strong adhesion, heat-resistant elasticity, and high transparency are relatively high, and there are few related studies.

The existing transparent water-based polyurethane dispersions mainly have the following problems: (1) It is difficult to ensure that the dispersion has high optical transparency and excellent bonding strength at the same time; (2) Water-based polyurethanes generally have low solid content and cannot achieve fast bonding (3) The storage stability of the dispersion is relatively poor, and the validity period is short. Therefore, how to make the dispersion have good optical, mechanical and stable properties at the same time is of great research and practical significance.

In view of this, the present invention is proposed.

Contents of the invention

The object of the present invention is to provide a kind of transparent aqueous polyurethane dispersion of strong viscosity and heat resistance and preparation method thereof, have high solid content, high optical transparency, strong viscosity heat resistance and excellent stability, and then solve the problem existing in the prior art the above technical problems.

The purpose of the present invention is achieved by the following technical solutions:

A strong viscous heat-resistant transparent water-based polyurethane dispersion, the transparent water-based polyurethane dispersion is made of prepolymer, acrylate monomer, coupling agent, ice deionized water, polyamine chain extender and initiator; in,

The amount of acrylate monomer is 10-15% of the total amount of prepolymer;

The amount of coupling agent is 0.1-0.3% of the total amount of prepolymer;

The deionized water consumption of ice is 110% of the total amount of prepolymer;

The amount of polyamine chain extender is 0.3-0.5% of the total amount of prepolymer;

The initiator consumption is 0.05% of the acrylate monomer consumption;

The prepolymer is made of the following components, the total amount of each component is 100wt%, including:

Polyester polyol and/or polyether polyol 55-70wt%;

Diisocyanate 20～30wt%;

Hydroxysulfonate 6-12wt%;

Small molecular diol chain extender 0.8-3wt%;

Catalyst 0.02-0.03wt%.

Further, in the above dispersion, the polyester polyol or polyether polyol in the prepolymer is:

Polyethylene adipate-propylene glycol ester diol, polyethylene adipate-1,4-butylene glycol ester diol, polycaprolactone diol and polycastor oil adipate polyol, Polyethylene adipate Either or both of methyl ether glycol and polytetramethylene ether glycol.

Further, in the above dispersion, the average molecular weight of the polyester polyol or polyether polyol in the prepolymer is 1000-3000.

Further, in the above dispersion, the diisocyanate in the prepolymer is:

One or more of xylylene diisocyanate, isophorone diisocyanate, dicyclohexyl methylene diisocyanate and tetracresyl dimethylene diisocyanate.

Further, in the above dispersion, the hydroxysulfonate in the prepolymer is: sodium ethylenediaminoethanesulfonate, sodium 1,4-butanediol-2-sulfonate, sodium diaminobenzenesulfonate , one of sodium 1,2-dihydroxy-3 propanesulfonate;

The small molecule glycol chain extender in the prepolymer is: one or both of 1,4-butanediol, 1,6-hexanediol, ethyl butyl propylene glycol, and neopentyl glycol ;

The catalyst in the prepolymer is dibutyltin dilaurate.

Further, in the above dispersion, the acrylate monomer is one or two of hydroxyethyl acrylate, styrene, and methyl methacrylate.

Further, in the above dispersion, the coupling agent is one of vinylmethyldiethoxysilane, vinyltriacetoxysilane, and vinyltriisopropoxysilane;

The polyamine chain extender is: one of isophoronediamine, diethylenetriamine and triethylenetetramine;

The initiator is azobisisobutyronitrile.

Further, in the above-mentioned dispersion, prepare this transparent aqueous polyurethane dispersion in the following manner, comprising:

Preparation of prepolymer: Add polyester polyol or polyether polyol, diisocyanate, and hydroxysulfonate into the container, and react under vacuum at 100°C for 1 hour; after cooling to 60°C, add small molecule diols to extend the chain and Catalyst, heated up to 80°C for 3 hours to prepare a prepolymer with an NCO content of 1.6-2.0%;

Add acrylate monomer to the prepolymer in the container at a temperature of 65°C to dilute and reduce viscosity. After stirring for 20 minutes, add a coupling agent to react for 30 minutes at a temperature of 50°C, transfer to a high-speed stirrer, and quickly add ice Stir and emulsify with deionized water at a high speed, extend the chain with a polyamine chain extender for 20 minutes, and then slowly add an initiator to react for 1 hour to obtain a highly transparent water-based polyurethane dispersion with a solid content of 50%.

Further, in the above dispersion, the pH value of the system in the preparation of the prepolymer is controlled to be 7-8;

The NCO content of the prepolymer is 1.6-2.0%.

A kind of preparation method that is used to prepare the transparent aqueous polyurethane dispersion of strong viscosity heat resistance of the present invention, comprises the steps:

Get each component by transparent aqueous polyurethane dispersion formula of the present invention;

Preparation of prepolymer: Add polyester polyol or polyether polyol, diisocyanate, and hydroxysulfonate into the container, and react under vacuum at 100°C for 1 hour; after cooling to 60°C, add small molecule diols to extend the chain and Catalyst, heat up to 80°C and react for 3 hours to prepare a prepolymer with an NCO content of 1.6-2.0%, and control the pH value of the system to 7-8 during the reaction process;

Add acrylate monomer to the prepolymer in the container at a temperature of 65°C to dilute and reduce viscosity. After stirring for 20 minutes, add a coupling agent to react for 30 minutes at a temperature of 50°C, transfer to a high-speed stirrer, and quickly add ice Stir and emulsify with deionized water at a high speed, extend the chain with a polyamine chain extender for 20 minutes, and then slowly add an initiator to react for 1 hour to obtain a highly transparent water-based polyurethane dispersion with a solid content of 50%.

Compared with the prior art, the strong viscous heat-resistant transparent aqueous polyurethane dispersion provided by the present invention and preparation method thereof, its beneficial effect comprises:

The transparency of the transparent water-based polyurethane dispersion is directly related to the crystallinity of the soft segment in the molecular chain. If the prepolymer adopts polyester polyol, the mixing degree of the soft and hard segment is low, it is not easy to crystallize, and it can provide better transparency; If the prepolymer adopts polyether polyol, the polyester polyurethane with lower symmetry or difficult molecular chain movement is not easy to crystallize, and can also provide better transparency, and it is prepared by internal crosslinking method, so that the dispersion The volume light transmittance is above 92%, and the solid content is 50%. It also has high optical performance and solid content, and has excellent bonding performance and stability. Compared with the carboxylate, the sulfonate added to the prepolymer of the dispersion does not need to be neutralized by adding triethylamine, which avoids the problems of odor and instability caused by volatilization of triethylamine during storage. In addition, the sulfonate is a strong acid and strong alkali salt with high ionization strength, which can form strong electrostatic repulsion between latex particles and prevent latex particles from agglomerating, thereby obtaining high solid content and stable waterborne polyurethane. Using acrylic acid as a solvent not only avoids the danger of using acetone, but also participates in the reaction while diluting the viscosity, providing better water resistance, optical and adhesive properties for the system. The stability and performance degradation caused by neutralization of the carboxylic acid type polyurethane and the risk problems caused by using acetone as the solvent are avoided. The dispersion well overcomes the difficulties that the existing dispersions in the market are difficult to simultaneously have high solid content, high optical transparency, strong adhesion and heat resistance, and excellent stability. In terms of application, it has long-term development potential, and at the same time broadens the application of water-based polyurethane on the surface of materials.

Detailed ways

The technical solutions in the embodiments of the present invention are clearly and completely described below in conjunction with the specific content of the present invention; obviously, the described embodiments are only some of the embodiments of the present invention, rather than all of them, and this does not constitute a limitation on the present invention. Invention Limitations. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

First, the terms that may be used in this article are explained as follows:

The term "and/or" means that either or both can be realized at the same time, for example, X and/or Y means that both "X" or "Y" and "X and Y" are included .

The terms "comprising", "comprising", "containing", "having" or other descriptions with similar meanings shall be construed as non-exclusive inclusions. For example: including certain technical feature elements (such as raw materials, components, ingredients, carriers, dosage forms, materials, dimensions, parts, components, mechanisms, devices, steps, procedures, methods, reaction conditions, processing conditions, parameters, algorithms, signals, data, products or products, etc.), should be interpreted as including not only a certain technical feature element explicitly listed, but also other technical feature elements not explicitly listed in the art.

The term "consisting of" means excluding any technical characteristic elements not explicitly listed. If this term is used in a claim, the term will make the claim closed so that it does not contain technical characteristic elements other than those expressly listed, except for conventional impurities related to them. If the term only appears in a certain clause of a claim, it only limits the elements explicitly listed in the clause, and the elements stated in other clauses are not excluded from the entire claim.

The term "parts by mass" refers to the mass ratio relationship between multiple components, for example: if it is described that X component is x mass parts and Y component is y mass parts, then it means the mass of X component and Y component The ratio is x:y; 1 part by mass can represent any mass, for example: 1 part by mass can be expressed as 1 kg or 3.1415926 kg, etc. The sum of the parts by mass of all components is not necessarily 100 parts, but may be greater than 100 parts, less than 100 parts or equal to 100 parts. Unless otherwise specified, parts, ratios and percentages described herein are by mass.

When concentration, temperature, pressure, size or other parameters are expressed in the form of numerical ranges, the numerical ranges should be understood as specifically disclosing all ranges formed by any pairing of upper limit, lower limit and preferred value within the numerical range , regardless of whether the range is explicitly stated; for example, if the numerical range "2-8" is stated, then the numerical range should be interpreted as including "2-7", "2-6", "5-7" , "3~4 and 6~7", "3~5 and 7", "2 and 5~7" and other ranges. Unless otherwise indicated, numerical ranges recited herein include their endpoints and all integers and fractions subsumed within the numerical range.

The strong viscous heat-resistant transparent water-based polyurethane dispersion provided by the present invention and its preparation method are described in detail below. The content not described in detail in the embodiments of the present invention belongs to the prior art known to those skilled in the art. In the embodiment of the present invention, if no specific conditions are indicated, it is carried out according to the conventional conditions in the art or the conditions suggested by the manufacturer. The reagents or instruments used in the examples of the present invention, whose manufacturers are not indicated, are all conventional products that can be purchased from the market.

Embodiments of the present invention provide a strong viscous heat-resistant transparent water-based polyurethane dispersion, which is composed of prepolymer, acrylate monomer, coupling agent, deionized water of ice, polyamine chain extender and initiator, the light transmittance of the transparent water-based polyurethane dispersion is greater than 92%, and the solid content is 50%; wherein,

The amount of acrylate monomer is 10-15% of the total amount of prepolymer;

The amount of coupling agent is 0.1-0.3% of the total amount of prepolymer;

The deionized water consumption of ice is 110% of the total amount of prepolymer;

The amount of amine chain extender is 0.3-0.5% of the total amount of prepolymer;

The initiator consumption is 0.05% of the acrylate monomer consumption;

The prepolymer is made of the following components, the total amount of each component is 100wt%, including:

Polyester polyol and/or polyether polyol 55-70wt%;

Diisocyanate 20～30wt%;

Hydroxysulfonate 6-12wt%;

Small molecular diol chain extender 0.8-3wt%;

Catalyst 0.02-0.03wt%.

Further, in the above dispersion, the polyester polyol or polyether polyol in the prepolymer is:

Polyethylene adipate-propylene glycol ester diol, polyethylene adipate-1,4-butylene glycol ester diol, polycaprolactone diol and polycastor oil adipate polyol, Polyethylene adipate Either or both of methyl ether glycol and polytetramethylene ether glycol.

Further, in the above dispersion, the average molecular weight of the polyester polyol or polyether polyol in the prepolymer is 1000-3000.

Further, in the above dispersion, the diisocyanate in the prepolymer is:

One or more of xylylene diisocyanate, isophorone diisocyanate, dicyclohexyl methylene diisocyanate and tetracresyl dimethylene diisocyanate.

Further, in the above dispersion, the hydroxysulfonate in the prepolymer is: sodium ethylenediaminoethanesulfonate, sodium 1,4-butanediol-2-sulfonate, sodium diaminobenzenesulfonate , one of sodium 1,2-dihydroxy-3 propanesulfonate;

The small molecule glycol chain extender in the prepolymer is: one or both of 1,4-butanediol, 1,6-hexanediol, ethyl butyl propylene glycol, and neopentyl glycol ;

The catalyst in the prepolymer is dibutyltin dilaurate.

Further, in the above dispersion, the acrylate monomer in the prepolymer is: one or two of hydroxyethyl acrylate, styrene, and methyl methacrylate.

Further, in the above dispersion, the coupling agent is one of vinylmethyldiethoxysilane, vinyltriacetoxysilane, and vinyltriisopropoxysilane;

The polyamine chain extender is: one of isophoronediamine, diethylenetriamine and triethylenetetramine;

The initiator is azobisisobutyronitrile.

Further, in the above-mentioned dispersion, prepare this transparent aqueous polyurethane dispersion in the following manner, comprising:

Preparation of prepolymer: Add polyester polyol or polyether polyol, diisocyanate, and hydroxysulfonate into the container, and react under vacuum at 100°C for 1 hour; after cooling to 60°C, add small molecule diols to extend the chain and Catalyst, heat up to 80°C and react for 3 hours to prepare a prepolymer with an NCO content of 1.6-2.0%, and control the pH value of the system to 7-8 during the reaction process;

Add acrylate monomer to the prepolymer in the container at a temperature of 65°C to dilute and reduce viscosity. After stirring for 20 minutes, add a coupling agent to react for 30 minutes at 50°C, and transfer to a high-speed stirrer with a rotation speed of 1500r/min. , add iced deionized water within 5 seconds, stir and emulsify at high speed, and use polyamine chain extender for 20 minutes, then add initiator to react for 1 hour, and then obtain a highly transparent water-based polyurethane dispersion with a solid content of 50%.

Further, in the above dispersion, the pH value of the system in the preparation of the prepolymer is controlled to be 7-8;

The NCO content of the prepolymer is 1.6-2.0%.

The embodiment of the present invention also provides a preparation method for preparing the above-mentioned strong viscous heat-resistant transparent water-based polyurethane dispersion, comprising the following steps:

Get each component by above-mentioned transparent aqueous polyurethane dispersion formula;

Preparation of prepolymer: Add polyester polyol or polyether polyol, diisocyanate, and hydroxysulfonate into the container, and react under vacuum at 100°C for 1 hour; after cooling to 60°C, add small molecule diols to extend the chain and Catalyst, heat up to 80°C and react for 3 hours to prepare a prepolymer with an NCO content of 1.6-2.0%, and control the pH value of the system to 7-8 during the reaction process;

Add acrylate monomer to the prepolymer in the container at a temperature of 65°C to dilute and reduce the viscosity. After stirring for 20 minutes, add a coupling agent to react for 30 minutes at a temperature of 50°C, and transfer to a high-speed stirring machine with a rotation speed of 1500r/min. Add ice deionized water within 5 seconds, stir and emulsify at high speed, and use polyamine chain extender to extend the chain for 20 minutes, and then add initiator to react for 1 hour to obtain a highly transparent water-based polyurethane dispersion with a solid content of 50%.

In summary, the dispersion of the embodiment of the present invention has a light transmittance of over 92%, a solid content of 50%, high optical performance and solid content, and excellent adhesive performance and stability. The stability and performance degradation caused by neutralization of the carboxylic acid type polyurethane and the risk problems caused by using acetone as the solvent are avoided. The dispersion well overcomes the difficulties that the existing dispersions in the market are difficult to simultaneously have high solid content, high optical transparency, strong adhesion and heat resistance, and excellent stability.

In order to more clearly demonstrate the technical solutions provided by the present invention and the resulting technical effects, the strong-adhesive and heat-resistant transparent water-based polyurethane dispersion provided by the embodiments of the present invention and its preparation method are described in detail below with specific examples.

Example 1

The present embodiment provides a transparent water-based polyurethane dispersion with strong adhesive strength and high heat-resistant bounce, and its preparation comprises the following steps:

(1) Preparation of prepolymer: Weigh polyester polyol, polyether polyol, isocyanate, sulfonate into the container, vacuumize at 100°C for 1 hour; cool to 60°C and add small molecule binary Alcohol chain extender and catalyst, heated up to 80°C for 3 hours to obtain a prepolymer;

(2) Add acrylate monomer to the prepolymer to dilute and reduce viscosity, and stir at 65°C for 20min;

(3) Add a coupling agent at 50°C to react and crosslink for 30 minutes;

(4) Emulsification: add deionized water for high-speed stirring emulsification;

(5) Post-chain extension: add polyamine chain extender for chain extension;

(6) Add an initiator and react for 1 hour to obtain a highly transparent water-based polyurethane dispersion.

The transparent aqueous polyurethane dispersion that present embodiment makes, advantage is as follows:

(1) The transparency of polyurethane is directly related to the crystallinity of the soft segment in the molecular chain. The degree of mixing of soft and hard segments of polyether polyurethane is low, and it is not easy to crystallize; polyester polyurethane with low symmetry or difficult molecular chain activities is also not easy. Crystalline, so it can provide better transparency.

(2) Compared with carboxylate, sulfonate does not need to add triethylamine for neutralization, which avoids the problem of odor and instability caused by volatilization of triethylamine during storage. In addition, the sulfonate is a strong acid and strong alkali salt with high ionization strength, which can form strong electrostatic repulsion between latex particles and prevent latex particles from agglomerating, thereby obtaining high solid content and stable waterborne polyurethane.

(3) Using acrylate as a solvent not only eliminates the danger of using acetone, but also participates in the reaction while diluting the viscosity, providing the system with better water resistance, optical and adhesive properties.

Example 2

The present embodiment provides a transparent water-based polyurethane dispersion with strong adhesive strength and high heat-resistant bounce, and its preparation comprises the following steps:

Weigh respectively 30wt% polyethylene adipate-1,4-butylene glycol ester diol (Mn=2000), 40wt% polytetramethylene ether glycol (Mn=2000), 25wt% isophor Add ketone diisocyanate and 6wt% sodium ethylenediaminoethanesulfonate into a four-necked flask, and react under vacuum at 100°C for 1h; after cooling to 60°C, add 1.0wt% trimethylolpropane, 0.02wt% catalyst dilaurel Dibutyltin acid was heated to 80°C for 3 hours to obtain a prepolymer (the total amount is M). Add 15%M hydroxyethyl acrylate and styrene to the prepolymer to dilute and reduce the viscosity, and stir at 65°C for 20min. After cooling down to 50° C., 0.2% M vinylmethyldiethoxysilane was added to react for 30 minutes. Transfer the prepolymer with a pH of 7 to a high-speed stirrer, add iced deionized water, stir and emulsify at a high speed, then add 0.4% M isophorone diamine to extend the chain for 20 minutes, and add an initiator to react for 1 hour to obtain a high transparency aqueous polyurethane dispersions.

The dispersion was formed into a film, the test tensile strength was 32.86 MPa, and the light transmittance was 95.62%. According to the national standard GB/T2791-1995, the maximum peel strength of T is 213.33N/mm, and the substrate is completely peeled off. The heat-resistant bounce is 1.2/1.8cm. The stable storage period is more than 6 months.

Example 3

The present embodiment provides a transparent water-based polyurethane dispersion with strong adhesive strength and high heat-resistant bounce, and its preparation comprises the following steps:

Weigh respectively 25wt% polyadipate-1,4-butylene glycol ester diol (Mn=1500), 35wt% polytetramethylene ether glycol (Mn=2000), 20wt% isophorone diisocyanate Add dicyclohexylmethane diisocyanate, 6wt% 1,4-butanediol-2 propanesulfonate sodium into a four-necked flask, and react under vacuum at 100°C for 1h; after cooling to 60°C, add 1.2wt% trimethylol propane, 0.02wt% catalyst dibutyltin dilaurate, heated to 80 ° C for 3 hours to obtain a prepolymer (the total amount is M). Add 12.8% M methyl methacrylate and styrene to the prepolymer to dilute and reduce the viscosity, and stir at 65°C for 20min. After cooling down to 50° C., 0.2% M vinyltriacetoxysilane was added to react for 30 minutes. Transfer the prepolymer with a pH of 7 to a high-speed stirrer, add ice deionized water, stir and emulsify at a high speed, then add 0.4% M diethylenetriamine to extend the chain for 20 minutes, and add an initiator to react for 1 hour to obtain a highly transparent water-based Polyurethane dispersion.

The dispersion was formed into a film, the test tensile strength was 40.26MPa, and the light transmittance was 93.46%. According to the national standard GB/T2791-1995, the maximum peel strength of T is 252.74N/mm, and the substrate is completely peeled off. The heat-resistant bounce is 1.0/1.4cm. The stable storage period is more than 6 months.

Example 4

The present embodiment provides a transparent water-based polyurethane dispersion with strong adhesive strength and high heat-resistant bounce, and its preparation comprises the following steps:

Weigh respectively 25wt% polyadipate-1,4-butylene glycol ester diol (Mn=3000), 36wt% polytetramethylene ether glycol (Mn=1500), 20wt% isophorone diisocyanate Add dicyclohexylmethane diisocyanate and 6wt% sodium diaminopropanesulfonate into a four-necked flask, and react under vacuum at 100°C for 1h; after cooling to 60°C, add 1.0wt% trimethylolpropane, and 0.025wt% The catalyst is dibutyltin dilaurate, and the temperature is raised to 80°C for 3 hours to obtain a prepolymer (the total amount is M). Add 12% M styrene to the prepolymer to dilute and reduce the viscosity, and stir at 65°C for 20min. After cooling down to 50° C., 0.3% M vinyltriisopropoxysilane was added to react for 30 minutes. Transfer the prepolymer with a pH of 7 to a high-speed stirrer, add iced deionized water, stir and emulsify at a high speed, then add 0.3% M diethylenetriamine to extend the chain for 20 minutes, and add an initiator to react for 1 hour to obtain a highly transparent water-based Polyurethane dispersion.

The dispersion was formed into a film, the test tensile strength was 46.88 MPa, and the light transmittance was 92.21%. According to the national standard GB/T2791-1995, the maximum peel strength of T is 271.45N/mm, and the substrate is completely peeled off. The heat-resistant bounce is 1.0/1.4cm. The stable storage period is more than 6 months.

Example 5

The present embodiment provides a transparent water-based polyurethane dispersion with strong adhesive strength and high heat-resistant bounce, and its preparation comprises the following steps:

Weigh respectively 30wt% polyethylene adipate-propylene glycol ester diol (Mn=2000), 25wt% polytrimethylene ether glycol (Mn=2000), 25wt% isophorone diisocyanate and dicyclohexyl Add methane diisocyanate and 7wt% sodium 1,2-dihydroxy-3-propanesulfonate into a four-necked flask, and react under vacuum at 100°C for 1 hour; after cooling to 60°C, add 1.0wt% trimethylolpropane, 0.02 The wt% catalyst is dibutyltin dilaurate, and the temperature is raised to 80° C. for 3 hours to obtain a prepolymer (the total amount is M). Add 12% M hydroxyethyl acrylate to the prepolymer to dilute and reduce the viscosity, and stir at 65°C for 20min. After cooling down to 50° C., 0.2% M vinylmethyldiethoxysilane was added to react for 30 minutes. Transfer the prepolymer with a pH of 7.5 to a high-speed stirrer, add ice deionized water to stir and emulsify at a high speed, then add 0.3% M triethylenetetramine to extend the chain for 20 minutes, add an initiator to react for 1 hour, and obtain a highly transparent water-based polyurethane Dispersions.

The dispersion was formed into a film, the test tensile strength was 29.68 MPa, and the light transmittance was 97.22%. According to the national standard GB/T2791-1995, the maximum peel strength of T is 202.86N/mm, and the substrate is completely peeled off. The heat-resistant bounce is 1.3/1.9cm. The stable storage period is more than 6 months.

Example 6

The present embodiment provides a transparent water-based polyurethane dispersion with strong adhesive strength and high heat-resistant bounce, and its preparation comprises the following steps:

Weigh respectively 30wt% polycastor oil adipate polyol (Mn=2000), 30wt% polytetramethylene ether glycol (Mn=3000), 20wt% dicyclohexyl diisocyanate, 6wt% ethylenediamine Sodium ethyl sulfonate was added to a four-necked flask, and the vacuum reaction was carried out at 100°C for 1 hour; after cooling to 60°C, 1.0wt% trimethylolpropane and 0.02wt% catalyst dibutyltin dilaurate were added, and the temperature was raised to 80°C for reaction After 3h, a prepolymer (the total amount is M) was obtained. Add 13%M styrene to the prepolymer to dilute and reduce the viscosity, and stir at 65°C for 20min. After cooling down to 50° C., 0.2% M vinyltriisopropoxysilane was added to react for 30 minutes. Transfer the prepolymer with a pH of 7 to a high-speed stirrer, add iced deionized water, stir and emulsify at a high speed, then add 0.3% M diethylenetriamine to extend the chain for 20 minutes, and add an initiator to react for 1 hour to obtain a highly transparent water-based Polyurethane dispersion.

The dispersion was formed into a film, the test tensile strength was 33.42 MPa, and the light transmittance was 96.57%. According to the national standard GB/T2791-1995, the maximum peel strength of T is 223.66N/mm, and the substrate is completely peeled off. The heat-resistant bounce is 1.1/1.7cm. The stable storage period is more than 6 months.

Comparative example 1

This comparative example does not belong to the prior art. It is only to determine the impact of changes in certain components and dosages on the performance of the product of the present invention. On the basis of the scheme of the present invention, some components and dosages are adjusted. include:

Weigh respectively 20wt% polyethylene adipate-1,4-butylene glycol ester diol (Mn=2000), 35wt% polytetramethylene ether glycol (Mn=2000), 40wt% isophor Add ketone diisocyanate and 6wt% sodium 1,2-dihydroxy-3 propane sulfonate into a four-necked flask, and react under vacuum at 100°C for 1h; after cooling to 60°C, add 1.0wt% trimethylolpropane, 0.02wt% % Dibutyltin dilaurate as a catalyst, heated up to 80°C for 3h to obtain a prepolymer (the total amount is M), and its NCO content is greater than 2.0%;

Add 15%M hydroxyethyl acrylate and styrene to the prepolymer to dilute and reduce the viscosity, and stir at 65°C for 20min. After cooling down to 50°C, add 0.2% M vinylmethyldiethoxysilane to react for 30min. Transfer the prepolymer with a pH of 7 to a high-speed stirrer, add iced deionized water, stir and emulsify at a high speed, then add 0.4% M isophorone diamine to extend the chain for 20 minutes, and add an initiator to react for 1 hour to obtain waterborne polyurethane Dispersions.

Compared with Example 1, increasing the hard segment of isocyanate in the system increases the NCO content of the prepolymer, reduces the shearing effect, and increases the particle size. The tensile strength tested after film formation was 12.65MPa, and the light transmittance was 82.95%. According to the national standard GB/T2791-1995, the maximum peel strength of T is 163.21N/mm, and the substrate cannot be completely peeled off. The heat-resistant bounce is 2.3/4.7cm. The stable storage period is more than 6 months.

Comparative example 2

This comparative example does not belong to the prior art. It is only to determine the impact of changes in certain components and dosages on the performance of the product of the present invention. On the basis of the scheme of the present invention, some components and dosages are adjusted. include:

Weigh respectively 30wt% polyethylene adipate-1,4-butylene glycol ester diol (Mn=2000), 35wt% polytetramethylene ether glycol (Mn=2000), 40wt% isophor Add ketone diisocyanate and 6wt% sodium ethylenediaminoethanesulfonate into a four-necked flask, and react under vacuum at 100°C for 1h; after cooling to 60°C, add 1.0wt% trimethylolpropane, 0.02wt% catalyst dilaurel Dibutyltin acid was heated to 80°C for 3 hours to obtain a prepolymer (the total amount is M). Add 5% M hydroxyethyl acrylate and styrene to the prepolymer to dilute and reduce the viscosity, and stir at 65°C for 20min. After cooling down to 50° C., 0.2% M vinyltriisopropoxysilane was added to react for 30 minutes. Transfer the prepolymer with a pH of 7 to a high-speed stirrer, add iced deionized water, stir and emulsify at a high speed, then add 0.4% M isophorone diamine to extend the chain for 20 minutes, and add an initiator to react for 1 hour to obtain waterborne polyurethane Dispersions.

Compared with Example 1, the solvent content is lower than 10% of the solid content of the prepolymer, and it is difficult to dilute the prepolymer well. In turn, it affects the subsequent neutralization, emulsification, and post-chain extension effects. The tensile strength tested after film formation was 10.66MPa, and the light transmittance was 82.36%. According to the national standard GB/T2791-1995, the maximum peel strength of T is 158.65N/mm, and the substrate cannot be completely peeled off. The heat-resistant bounce is 2.3/4.9cm. The stable storage period is more than 6 months.

Comparative example 3

This comparative example does not belong to the prior art. It is only to determine the impact of changes in certain components and dosages on the performance of the product of the present invention. On the basis of the scheme of the present invention, some components and dosages are adjusted. include:

Weigh respectively 30wt% polyethylene adipate-1,4-butylene glycol ester diol (Mn=2000), 40wt% polytetramethylene ether glycol (Mn=2000), 25wt% isophor Add ketone diisocyanate and 6wt% sodium 1,4-butanediol-2propanesulfonate into a four-necked flask, and react under vacuum at 100°C for 1h; after cooling to 60°C, add 1.0wt% trimethylolpropane, 0.02 The wt% catalyst is dibutyltin dilaurate, and the temperature is raised to 80° C. for 3 hours to obtain a prepolymer (the total amount is M). Add 15%M hydroxyethyl acrylate and styrene to the prepolymer to dilute and reduce the viscosity, and stir at 65°C for 20min. After cooling down to 50° C., 0.2% M vinyltriisopropoxysilane was added to react for 30 minutes. Transfer the prepolymer with a pH of 7 to a high-speed stirrer, add iced deionized water to stir and emulsify at a high speed, then add 0.8% M isophorone diamine to extend the chain for 20 minutes, add an initiator to react for 1 hour, and obtain a water-based polyurethane dispersion body.

Compared with Example 1, the amount of post-extended amine increases, the molecular chain entanglement density is too large, the molecular weight increases rapidly, and the viscosity of the system increases greatly, which affects the use of subsequent tests. The stable storage period is less than 6 months.

Comparative example 4

This Comparative Example 4 is a high-transparency anionic waterborne polyurethane dispersion similar to the present invention disclosed in Chinese patent application 202011498704.8 and its preparation method. The steps of the preparation method are as follows:

Put 60g of adipic acid-based polyester diol 2000 into the reaction bottle for dehydration for 90 minutes; after the dehydration of the system is completed, cool down to 90°C, add 32g of isophorone diisocyanate, and react at 85°C for 2.5h; after the NCO test is qualified, add 4.5 g small molecule chain extender 2,2-dimethylolpropionic acid, and dropwise add 2 drops of dibutyltin dilaurate catalyst, react at 80°C for 5h until the NCO test is qualified; after cooling down to 55°C, slowly add 130g of acetone, to be dispersed Finally, slowly add 1.5g of ethylenediamine and 5g of water-miscible aqueous solution dropwise under stirring, and at the same time, pay attention to temperature control not to exceed 45°C. After the addition is completed, add 3.4g of triethylamine dropwise at 40°C for neutralization, and stir for 8 minutes , to obtain the reaction product. Slowly add 30g of 5% N-(n-butyl)-3-aminopropyltrimethoxysilane aqueous solution to the reaction product under the condition of 25°C and 600r/min, then immediately add 190g of water for emulsification, complete in about 10min, add After the defoaming agent is defoamed, acetone is distilled under reduced pressure to obtain a silicone-modified high-transparency water-based polyurethane finishing agent, that is, a high-transparency anionic water-based polyurethane dispersion.

In this comparative example, organosilicon modification is adopted, and the light transmittance of the obtained product is above 92%, the film-forming mechanical properties are good, the tensile strength is above 18 MPa, and the elongation ratio is greater than 500. Compared with the present invention, the tensile strength is slightly weaker. In addition, in the present invention, acetone is not used for viscosity reduction, which is safer and more environmentally friendly.

The above is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person familiar with the technical field can easily conceive of changes or changes within the technical scope disclosed in the present invention. Replacement should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be determined by the protection scope of the claims. The information disclosed in this Background section is only intended to enhance the understanding of the general background of the present invention, and should not be considered as an acknowledgment or any form of suggestion that the information constitutes the prior art that is already known to those skilled in the art.

Claims (10)

1. The transparent aqueous polyurethane dispersion with strong viscosity and heat resistance is characterized by being prepared from a prepolymer, an acrylic ester monomer, a coupling agent, ice deionized water, a polyamine chain extender and an initiator, wherein the light transmittance of the transparent aqueous polyurethane dispersion is more than 92%, and the solid content is 50%; wherein,,

the dosage of the acrylic ester monomer is 10-15% of the total amount of the prepolymer;

the dosage of the coupling agent is 0.1 to 0.3 percent of the total amount of the prepolymer;

the deionized water consumption of the ice is 110% of the total prepolymer;

the dosage of the amine chain extender is 0.3 to 0.5 percent of the total amount of the prepolymer;

the initiator amount is 0.05% of the acrylate monomer amount;

the prepolymer is prepared from the following components, wherein the total amount of the components is 100wt percent, and the prepolymer comprises the following components:

55 to 70wt% of polyester polyol and/or polyether polyol;

20-30 wt% of diisocyanate;

6-12 wt% of hydroxy sulfonate;

0.8 to 3 weight percent of small molecular dihydric alcohol chain extender;

0.02 to 0.03 weight percent of catalyst.

2. The highly viscous heat-resistant transparent aqueous polyurethane dispersion according to claim 1, wherein the polyester polyol or polyether polyol in the prepolymer is:

any one or two of polyethylene glycol-propylene glycol adipate glycol, polyethylene glycol-1, 4-butanediol adipate glycol, polycaprolactone glycol and poly (castor oil adipate) polyol, polytrimethylene ether glycol and polytetramethylene ether glycol.

3. The highly viscous heat-resistant transparent aqueous polyurethane dispersion according to claim 1 or 2, characterized in that the polyester polyol or polyether polyol has an average molecular weight of 1000 to 3000.

4. The highly viscous heat-resistant transparent aqueous polyurethane dispersion according to claim 1 or 2, characterized in that the diisocyanate in the prepolymer is:

one or more of xylylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, and tetramethylxylylene diisocyanate.

5. The highly viscous heat-resistant transparent aqueous polyurethane dispersion according to claim 1 or 2, characterized in that the hydroxysulfonate in the prepolymer is: one of sodium ethylenediamine-ethanesulfonate, sodium 1, 4-butanediol-2-sulfonate, sodium diaminobenzenesulfonate and sodium 1, 2-dihydroxy-3-propanesulfonate;

the micromolecular dihydric alcohol chain extender in the prepolymer is as follows: one or two of 1, 4-butanediol, 1, 6-hexanediol, ethyl butyl propylene glycol and neopentyl glycol;

the catalyst in the prepolymer is dibutyl tin dilaurate.

6. The highly viscous heat-resistant transparent aqueous polyurethane dispersion according to claim 1 or 2, characterized in that the acrylate monomers are: one or two of hydroxyethyl acrylate, styrene and methyl methacrylate.

7. The highly viscous heat-resistant transparent aqueous polyurethane dispersion according to claim 1 or 2, characterized in that the coupling agent is one of vinylmethyldiethoxysilane, vinyltriacetoxysilane, vinyltriisopropoxysilane;

the polyamine chain extender is: one of isophorone diamine, diethylene triamine and triethylene tetramine;

the initiator adopts azodiisobutyronitrile.

8. The highly viscous heat-resistant transparent aqueous polyurethane dispersion according to claim 1 or 2, characterized in that it is prepared in the following manner, comprising:

preparation of a prepolymer: adding polyester polyol or polyether polyol, diisocyanate and hydroxysulfonate into a container, and vacuumizing at 100 ℃ for reaction for 1h; cooling to 60 ℃, adding micromolecular dihydric alcohol for chain extension and a catalyst, heating to 80 ℃ for reaction for 3 hours to obtain a prepolymer with NCO content of 1.6-2.0%, and controlling the pH value of the system to be 7-8 in the reaction process;

adding acrylate monomer into the prepolymer in a container at 65 ℃ for dilution and viscosity reduction, stirring for 20min, adding coupling agent for reaction for 30min at 50 ℃, transferring to a high-speed stirrer with the rotating speed of 1500r/min, adding ice deionized water for high-speed stirring and emulsifying within 5 seconds, adding polyamine chain extender for 20min, and then adding initiator for reaction for 1h to obtain the high-transparency aqueous polyurethane dispersion with the solid content of 50%.

9. The transparent, highly viscous and heat-resistant aqueous polyurethane dispersion according to claim 8, wherein the pH of the system in the preparation of the prepolymer is controlled to 7 to 8;

the NCO content of the prepolymer is 1.6-2.0%.

10. A process for preparing the highly viscous heat-resistant transparent aqueous polyurethane dispersion according to any one of claims 1 to 7, characterized by comprising the steps of:

taking the components according to the transparent aqueous polyurethane dispersion formula of claims 1-7;

preparation of a prepolymer: adding polyester polyol or polyether polyol, diisocyanate and hydroxysulfonate into a container, and vacuumizing at 100 ℃ for reaction for 1h; cooling to 60 ℃, adding micromolecular dihydric alcohol for chain extension and a catalyst, heating to 80 ℃ for reaction for 3 hours to obtain a prepolymer with NCO content of 1.6-2.0%, and controlling the pH value of the system to be 7-8 in the reaction process;

adding acrylate monomer into the prepolymer in a container at 65 ℃ for dilution and viscosity reduction, stirring for 20min, adding coupling agent at 50 ℃ for reaction for 30min, transferring to a high-speed stirrer with the rotating speed of 1500r/min, and adding in 5 seconds

Adding ice deionized water, stirring at high speed for emulsification, extending chain for 20min by using a polyamine chain extender, adding an initiator for reaction for 1h,

thus, an aqueous polyurethane dispersion having high transparency and a solid content of 50% was obtained.