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What is Aluminium paste used for

Aluminium paste is a type of pigment paste that contains aluminum flakes or powders suspended in a solvent. It is primarily used in various industries for its unique properties and applications. Here are some common uses of aluminium paste:

Paint and Coatings: globaltuocai Aluminium paste is added to paint and coating formulations to provide metallic effects and improve their visual appearance. The reflective properties of the aluminum flakes create a shiny or metallic finish on surfaces.

Automotive Industry: Aluminium paste is used in automotive paints and coatings to achieve metallic finishes on cars and other vehicles. It enhances the aesthetic appeal and gives a reflective appearance to various automotive parts.

Printing Inks: Aluminium paste is utilized in printing inks, especially those used for metallic or reflective printing effects. It imparts a metallic sheen to the printed materials such as packaging, labels, and graphics.

Reflective Films: Aluminium paste is incorporated into reflective films used in applications like mirror films, reflective insulation, solar panels, and emergency blankets. The reflective properties of the aluminum flakes help in reflecting heat, light, and radiation.

Construction Materials: Aluminium paste finds use in construction materials such as architectural coatings, metal finishes, and decorative paints. It adds a metallic luster to surfaces like metal roofs, building facades, and interior decorations.

Electronics and Appliances: Aluminium paste is employed in manufacturing electronic components, circuit boards, electrical connections, and appliance parts. It can help in enhancing the electrical conductivity, heat dissipation, and corrosion resistance of these materials.

It's worth noting that the specific applications of aluminium paste can vary depending on the formulation and the requirements of different industries. Additionally, the use of aluminium paste should follow applicable safety guidelines as aluminum can be a flammable material in certain forms.



 

Polyurethane Resin in Gravure lamination Ink Characteristics and Applications

2024-04-03
In the field of gravure compound ink, polyurethane resin plays a significant role with its unique properties and applications. This article aims to explore the application characteristics of polyurethane resin in gravure compound ink.

 

Firstly, polyurethane resin offers excellent adhesion properties, enabling it to bond effectively to various substrates. Whether it is paper, plastic, or other materials, the resin ensures a strong and durable connection, ensuring the ink remains intact throughout the printing process and after application.

 

Furthermore, the resin provides good flexibility, allowing the printed ink to withstand bending, folding, and other mechanical stresses without cracking or peeling. This flexibility is crucial in applications where the printed materials are subject to deformation.

 

In addition, polyurethane resin offers excellent resistance to chemicals, ensuring the ink's durability and stability even in the presence of various substances. It can withstand exposure to solvents, acids, and bases, making it suitable for a wide range of printing applications.

 

The resin also exhibits good abrasion resistance, ensuring that the printed images retain their quality and clarity even after prolonged use or exposure to external forces. This property is particularly important in applications where the printed materials come into contact with frequent handling or friction.

 

Another notable characteristic is its good gloss and finish. The resin contributes to the ink's ability to produce a smooth and shiny surface, enhancing the visual appeal of the printed matter.

 

Moreover, polyurethane resin allows for precise control over ink viscosity, enabling easy handling and application in the gravure printing process. This property ensures consistent printing quality and efficiency.

 

In conclusion, the application of polyurethane resin in gravure compound ink offers numerous benefits, including excellent adhesion, flexibility, chemical resistance, abrasion resistance, and gloss. These characteristics contribute to the high quality and durability of the printed materials, making it a preferred choice in the printing industry.

Select the suitable polyurethane resin for gravure laminationink

2024-04-03

To select the suitable polyurethane resin for gravure lamination ink, the following several key factors need to be considered:

 

 

Printing substrate: Determine the type of substrate on which the ink will be applied, such as paper, plastic film, etc. Different substrates may require polyurethane resin with specific properties. Adhesion: Ensure that the polyurethane resin can provide good adhesion on the substrate to prevent the ink from peeling off. Solvent resistance: Select the polyurethane resin with sufficient solvent resistance according to the type of solvent the ink comes into contact with. Elasticity and toughness: Consider the bending, folding, or stretching that the printed matter may undergo, and select the resin with appropriate elasticity and toughness. Drying speed: Select the polyurethane resin with a drying speed that meets the requirements according to the production efficiency requirements. Weather resistance: If the printed matter needs to be exposed in the outdoor environment, select the resin with good weather resistance. Chemical stability: Ensure that the polyurethane resin can tolerate the chemicals that may be encountered in the printing process. Viscosity and fluidity: Select the resin with suitable viscosity and fluidity according to the requirements of the printing equipment and process. Compatibility: Be compatible with other ink components and additives to avoid adverse reactions. Cost: Consider cost factors on the premise of meeting performance requirements. Supplier reputation: Select reliable suppliers to ensure product quality and technical support. Technical data and test reports: Refer to the technical data and related test reports provided by the supplier to understand the performance characteristics of the resin. Sample test: Conduct sample tests under actual printing conditions to assess whether the performance of the polyurethane resin meets the requirements.

How to choose binder of gravure printing ink for high-temperature retort-resistant bag?

2024-03-22

How to choose the formula of gravure printing ink for high-temperature retort-resistant bags? Specifically, the selection of ink connecting materials, the selection of toners and pigments, the selection of special wax powder for ink, etc.


01

Selection of retort bag ink binder(RESIN)

There are no more than two types of ink BINDER suitable for gravure on-machine printing: high-temperature-resistant polyurethane resin for gravure ink and ternary chlorine-acetic acid resin with high chlorine content and medium viscosity.

Gravure ink uses high-temperature resistant polyurethane resin, the chemical name is polyurethane plastic resin, and the English abbreviation code is PU. It is a liquid resin obtained by reacting polyurethane monomer resin liquid with polyether polyol or polyester polyol through a catalyst and other additives. According to the composition of these liquid resin raw materials, it is divided into polyether type and polyester type. species, and are divided into soft and hard.

When selecting the POLYURETHANE BINDER for ink, we require that the ink has excellent adhesion to the plastic film, the ink film has good heat resistance and water boiling resistance, good solvent release, low residual content, and moisturizing of the pigment. Good wettability and high gloss.

The main components of polyurethane resin liquids for inks currently on the market are polyurethane compounds, isopropyl alcohol, methyl ethyl ketone, toluene, etc. The appearance is colorless or light yellow transparent viscous liquid, and the solid content is generally 25 -35%, the amount added in the ink formula is usually 35-45%.

The high chlorine content chlorine-vinegar resin used in high-temperature resistant inks is actually a copolymer of vinyl chloride (VC) and vinyl acetate (VAC), which is essentially a dry paint base. When the ink is printed on the surface of the plastic film, after the volatile organic solvent contained in the ink system evaporates quickly, the high chlorine content ternary chlorine-acetic resin can be combined with compatible resins from other systems to form an ultra-thin ink film.

In the formula of gravure composite high-temperature retort-resistant bag ink, we generally choose inks that have high toughness after film formation, long-lasting flexibility, abrasion resistance, low water swelling, low air permeability, high-temperature retort resistance, etc. Chlorine vinegar resin.

02

Selection of high-temperature composite retort-resistant toners and pigments

The composite high-temperature retort-resistant bag ink for gravure printing has a series of special requirements for its toner and pigment: the color must be bright and the glossiness must be good, and the colorful world must be decorated with dazzling colors; the tinting strength must be high, which is a measure The conditions for the significance and economic value of the pigment; the transparency and hiding power should be good. According to the different uses of the ink, there are different requirements for the transparency and hiding power of the pigment; the amount of oil absorption should be small, so that the ink concentration can be easily increased and the ink properties can be improved. Easy to adjust; good wetting and dispersion. The dispersion ability of the pigment in the ink binder directly affects the success or failure of ink making.

Other physical and chemical properties, such as light resistance, heat resistance, solvent resistance, acid and alkali resistance, migration resistance, etc., are few and far between. Only suitable varieties can be selected according to the special requirements of the application.

The pigments used in the composite high-temperature retort-resistant bag ink for gravure printing must first be resistant to solvents, and secondly, they must be resistant to high-temperature retort and can withstand high temperatures above 120°C without decomposing and discoloring.

According to the standard of retort-resistant bag ink, all black pigments used in the ink should be channel carbon black; most white pigments use silica-modified rutile titanium dioxide, and some use alumina-modified ones, but they are resistant to temperature and turn yellow. The color ink has slightly poorer performance; color inks must be selected for ink testing conditionally, such as phthalocyanine blue and phthalocyanine green that have been resinized on the surface of the pigment particles, benzimidazolone azos, condensed azos, etc., according to the test They can withstand high temperatures above 180°C without discoloration.

03

Selection of wetting and dispersing agents for gravure ink systems

The wetting and dispersion of high-temperature resistant toners and pigments is an important part of the manufacturing technology of high-temperature retort-resistant gravure plastic composite inks. The ink developer and pigments are crushed into fine particles so that they can be evenly distributed in the mixed binder of the ink. , in order to obtain a stable suspension mixed medium viscosity system.

Wetting and dispersing agents are essentially special surfactants that have both wetting and dispersing functions for pigments. Its wetting and dispersing effect is to reduce the surface tension of the substance, so that the molecules of the surfactant are adsorbed on the surface of the pigment, thereby generating charge repulsion or steric hindrance, preventing harmful flocculation of the pigment, and keeping the dispersed system in a stable suspension state. .

The dispersant used in the composite high-temperature retort-resistant bag ink for gravure printing is generally an anionic surfactant. Its main component is carbonate or special metal aluminum chromium compound. It is a light yellow or yellow-brown liquid and is an oil-soluble dispersion. It is an agent that improves the dispersion of pigments in ink, prevents overflow and discoloration of pigments in ink, improves color concentration and color development, and enhances the adhesion and composite fastness of ink film and plastic film.

04

Selection of special wax powder for high-temperature retort-resistant bag ink

Some special high-temperature resistant wax powder is usually added to the ink formula of composite high-temperature retort-resistant bags for gravure printing. It can provide excellent anti-wear and scratch resistance for the high-temperature-resistant ink film of the printed product, prevent adhesion and increase the ink loading. Fluidity, improved printability and improved post-processing performance, etc.

When designing the formula of composite high-temperature retort-resistant bag inks for gravure printing, most of them use molecular linear synthetic polyethylene wax with high melting point and strong hardness. There are two methods of pre-adding and post-adding in the ink production process. The general addition amount is: 0.5-1.0% of the total weight of ink. Under normal circumstances, it is added before grinding the ink coarse material, which is beneficial to dispersion and improving fluidity; however, be careful not to make the grinding temperature too high to avoid deformation and agglomeration of these wax powder particles, which will affect its performance.

There are also ink system resins and organic solvents to make a paste - wax slurry, which is added during the viscosity and color matching stage of ink making; however, in doing so, it is necessary to prevent certain organic solvents with strong penetrating power from dissolving the wax powder particles. Recrystallization occurs and the wax becomes coarse, losing the proper performance of the special wax powder.

05

Selection of antistatic agents for high-speed printing

When gravure plastic ink is printed at high speed, the accumulation of static electricity will cause problems such as offset, blur, spots, whiskers, edge rejection, etc. In severe cases, fires, explosions and other vicious events may even occur. Therefore, the purpose of adding antistatic agents to ink is to reduce the surface resistance of the plastic film during the printing process and eliminate static electricity to solve the above problems that occur during printing.

Anionic antistatic agents are generally used in plastics and inks, including higher fatty acid salts, alkyl phosphate ester salts, alkyl sulfate ester salts, and sulfonate ester salts. This type of compound can be dissolved in water, ketones, alcohols, etc. Organic solvents such as benzene and benzene are sold as organic solvent aqueous solutions containing 30-60% of active substances. The composite high-temperature retort-resistant bag ink for gravure printing mainly uses an isopropyl alcohol solution of ethyl phosphate as an antistatic agent. The added amount accounts for 0.1-0.4% of the total ink, and has no adverse effects on the ink properties.

06

Selection of Adhesion Promoting Resins and Fumed Silica Powders

In the ink system of polyurethane and chlorine-vinegar resin in the composite high-temperature retort-resistant bag ink for gravure printing, due to the insufficient flexibility of the chlorine-acetyl resin itself, adhesion-promoting resin needs to be used to improve its flexibility; composite for gravure printing Some modified chlorinated polypropylene resin liquid must be added to the formula of high-temperature retort-resistant bag ink. Its solid content is generally about 15-25%, which can improve the adhesion of polyurethane ink on plastic films and enhance the dispersion effect and fluidity.

Fumed silica powder, also called matte powder, generally undergoes organic surface treatment and is easy to disperse. Its role in the composite high-temperature retort-resistant bag ink for gravure printing: A. Prevent pigment settlement and maintain the long-term rheological properties and fineness of the ink; B. Improve the sagging performance of the ink film when printing on the machine, preventing The generation of water marks; C. It can also be used like wax powder to facilitate the even coating of adhesive and improve the composite fastness.

07

Selection of organic solvents for gravure high temperature resistant retort bag ink system

Plastic gravure ink mainly relies on solvent evaporation to dry and form a film. When the ink is printed on the surface of the substrate, the thickness of the ink film decreases and shrinks due to the solvent evaporation. The film formation of ink solvent volatilization is mainly divided into two stages: the first is the "wet stage", which is controlled by the surface layer; the second is the "dry stage", where the solvent evaporation rate is controlled by the diffusion of the solvent in the overall ink film. When there is a true solvent, it ensures that the resin and other polymers can fully stretch and interact with each other, and the leveling properties are good.

If the true solvent evaporates too quickly and the remaining solvent is only a co-solvent, the polymer molecules tend to form tight curls or even precipitate. What is particularly important is that the volatilization of the solvent causes endothermic cooling and an increase in polymer concentration, which increases the surface tension of the ink film and causes the solution to flow from the low surface tension area to the high surface tension area. This is called peak flow, which easily produces "orange peel" and floating color phenomenon, so maintaining the necessary amount of true solvent is an important condition to ensure the leveling of the ink film.

For polyurethane and chlorine-vinyl resin ink systems, in addition to toluene, xylene, ethyl acetate, methyl ethyl ketone, and isopropyl alcohol, acetone, methyl isobutyl ketone, ethylene glycol monobutyl ether, Special organic solvents such as propylene glycol methyl ether. Among them, benzene and alcohol are only co-solvents for polyurethane and chlorine-vinyl resin. Although ketones and esters are true solvents, they evaporate too quickly.

Therefore, special solvents such as methyl isobutyl ketone, ethylene glycol monobutyl ether, and propylene glycol methyl ether must be used to adjust the volatilization rate and solubility, enhance the dispersion power of the mixed solvent, and improve the dissolution parameters so that the ink always presents a good fluid status to ensure the smooth progress of printing work.

 

 

Polyurethane resin is a versatile material that can be used in the preparation of gravure printing ink for film. Gravure printing is a method of printing that uses engraved cylinders to transfer ink onto a substrate, and it is commonly used for high-volume printing applications such as packaging and labeling.

as a binder to provide adhesion and durability to the ink. It can also be used to adjust the viscosity and flow properties of the ink, which is important for ensuring consistent print quality and optimal ink transfer to the substrate.

We could provide solvent based polyurethane resin, polyurethane emulsion, acrylic resin, waterborne polyurethane dispersion to meet diversified requirement.


 

 

How to Detect the Ionicity of Polyacrylamide

2024-03-15

To detect the ionicity of polyacrylamide, you can use the following method:

 

1. Conductivity measurement: indirectly determine the ionicity of the polyacrylamide solution by measuring its conductivity. Conductivity is related to changes in ion concentration in a solution. Highly ionic polyacrylamide solutions usually have higher conductivity.

 

2. Ion-selective electrode: Use ion-selective electrodes, such as pH electrodes or ion-selective electrodes (such as sodium ion electrodes, ammonium ion electrodes, etc.), to directly measure the concentration of specific ions in the solution. This can be used to determine the concentration of ions in a polyacrylamide solution and thus infer the ionicity.

 

3. Ion exchange chromatography: Use ion exchange chromatography to determine the ion concentration in the polyacrylamide solution. This method uses an ion exchange resin to adsorb ions from solution and determines the concentration of individual ions through varying elution conditions.

 

4. Thermogravimetric analysis (TGA): Thermogravimetric analysis can be used to measure the thermal decomposition behavior of polyacrylamide. Polyacrylamides with higher ionicity generally decompose faster at high temperatures, while polyacrylamides with lower ionicity have higher thermal stability.

 

These methods can help determine the ionicity of polyacrylamide. However, specific test methods may need to be appropriately adjusted and optimized based on actual needs and available equipment. In actual operation, it is best to refer to relevant standard methods or consult professional laboratory technicians.

Application of Polyacrylamide in Coal Washing

2024-03-15

Polyacrylamide (PAM) is a versatile polymer that finds applications in various industries, including coal washing. Coal washing is a process used to remove impurities from coal before it is burned for energy production. Polyacrylamide can be applied in coal washing for several purposes. Here are some common applications:

 

1. Solid-liquid separation: Polyacrylamide is used as a flocculant in the coal washing process to promote solid-liquid separation. It helps in agglomerating fine coal particles and settling them faster, resulting in improved solid-liquid separation efficiency. By forming larger and denser flocs, polyacrylamide aids in the sedimentation of coal particles, leading to cleaner coal and reduced water consumption.

 

2. Filtration aids: Polyacrylamide can act as a filtration aid in coal washing. It enhances the cake formation on filter media, improves filtration rates, and reduces moisture content in the final coal product. By facilitating the dewatering process, polyacrylamide helps in reducing the moisture content of coal, which improves its combustion efficiency.

 

3. Foam control: During the coal washing process, foaming can occur, which interferes with the separation and dewatering steps. Polyacrylamide can be used as an antifoaming agent to suppress foam formation and enhance the efficiency of the coal washing process.

 

4. Rheology modification: Polyacrylamide can modify the rheology (flow properties) of the coal washing slurry. By adjusting the viscosity and consistency of the slurry, it helps in controlling the flow rate, improving mixing efficiency, and reducing sedimentation and settling time.

 

It's worth noting that the specific application and dosage of polyacrylamide in coal washing may vary depending on the coal characteristics, washing process, and plant conditions. The selection of the appropriate molecular weight and charge characteristics of polyacrylamide is crucial to achieve desired results in coal washing operations. Additionally, it's important to handle and use polyacrylamide in accordance with safety guidelines and environmental regulations to minimize any potential risks associated with its use.

functions of polyurethane binder in printing ink

2024-03-15

The functions of polyurethane resin in inks are as follows:

1. Excellent yellowing resistance.
Polyurethane resin for ink is mainly synthesized from aliphatic polyester and aliphatic isocyanate as the main raw materials during the preparation process. Compared with aromatic polyurethane, it has excellent optical stability, and the film has excellent Yellowing resistance.
2. Excellent adhesion fastness to film substrates.
The molecular segments of the polyurethane binder for ink contain polar groups such as urethane, allophanate, ester bonds, and ether bonds, and are compatible with a variety of polar substrates, PET The polar groups on the surface of plastics such as PA and PA form hydrogen bonds, thereby forming joints with a certain connection strength. After the polyurethane resin is made into ink, it has good adhesion fastness when printed on the surface of polar plastic substrates.
3. Has good affinity and wettability with pigments
Polyurethane resin for ink is generally prepared from polyester or polyether polyol, alicyclic diisocyanate and diamine/diol chain extender. Due to the introduction of urea bonds in PU resin, polyurethane-urea resin (PUU) is formed, which makes it have good dispersion and wetting properties for pigments.

4. Good resin compatibility.
Polyurethane resin for ink has good compatibility with aldehyde-ketone resin, chlorine-vinegar resin, etc., and can be appropriately added to your own process formula according to actual conditions to improve the overall performance of the ink.
5.Excellent film-forming properties
The structure of ink polyurethane resin is different from the polyurethane resin used in other fields. Traditional polyurethane mainly reacts with polyester polyol/polyether polyol and isocyanic acid to form hydroxyl-terminated polyurethane resin. The polar group in the molecular structure is aminomethyl. Mainly acid ester, the molecular cohesion is not enough to meet the film-forming performance requirements of resin for ink. Therefore, polyurethane resin for ink introduces urea group on the basis of traditional polyurethane to greatly improve the cohesive strength and film-forming properties of the resin itself.
6. Good solvent release:

The dissolving effect of organic solvents on resin is to attract solute molecules through the polarity of solvent molecules, which is commonly known as like dissolves. Traditional polyurethane resins have a wide range of compatibility with organic solvents. However, in the process of making inks, in order to adjust the ink flow properties and viscosity, alcoholic organic solvents need to be added. This will greatly reduce the stability of the resin system for traditional polyurethane resins. properties, turbidity, flocculent precipitation and other incompatibility phenomena may occur. However, the polyurethane resin used in ink is miscible with alcohol due to the presence of urea groups, but it should be noted that alcohol solvents are still pseudo-solvents. In the microscopic state, alcohol solvents wrap the polyurethane resin molecules, rather than true solvents due to the polarity of the molecules. Penetrating through the molecule, the ink made of polyurethane resin has good fluidity.

 

Polyurethane resin is a versatile material that can be used in the preparation of gravure printing ink for film. Gravure printing is a method of printing that uses engraved cylinders to transfer ink onto a substrate, and it is commonly used for high-volume printing applications such as packaging and labeling.

as a binder to provide adhesion and durability to the ink. It can also be used to adjust the viscosity and flow properties of the ink, which is important for ensuring consistent print quality and optimal ink transfer to the substrate.

We could provide solvent based polyurethane resin, polyurethane emulsion, acrylic resin, waterborne polyurethane dispersion to meet diversified requirement.


 

Application of polyurethane binder in film printing ink

2024-03-15

The liquid part of the ink component is called the binder; the solid component is the color material (pigment or dye); and various additives.The connecting material is a colloidal fluid with a certain viscosity. Its function is first to serve as a carrier for pigments, mixing and connecting solid particles such as powdered pigments. The pigments are evenly dispersed in it, relying on its wetting effect. , it is easier to be ground finely on the grinding machine; secondly, it serves as a binder to enable the pigment to be finally fixed on the surface of the substrate to achieve the purpose of displaying text, images, marks, decoration, etc.It is also relying on its adhesion function that the ink can be transferred and delivered on the printing press.Finally, on the printed matter, the connecting material also plays the role of a protective film, presents the necessary gloss, and can even protect the substrate.

The quality of the connecting material directly affects the performance of the ink, because the connecting material determines the viscosity, stickiness, dryness, fluidity and other properties of the ink to a large extent.If you want to get high-quality ink, you must use high-quality connecting materials.The various properties of the ink binder determine the various adaptability of the printing ink. The resins used in plastic gravure printing inks generally include chlorinated polypropylene, polyamide, polyurethane, etc.For a long time, chlorinated polypropylene has occupied most of the resin market for gravure composite back printing inks due to its low price and excellent adhesion to OPP. However, its biggest shortcoming is that its main solvent is toluene, and environmentally friendly solvents such as ester are usually used. Alcohol-based solvents are ineffective. Solvent-based polyurethane binder for ink has the advantages of easy use, stable performance, strong adhesion, excellent gloss, and good heat resistance. It can meet the requirements of various printing methods, especially suitable for screen printing, plastic packaging, and composite films. aspect.Industrialization has been achieved in foreign countries in the 1970s, such as Toyo Corporation of Japan, Dainippon Ink Chemical Industries, and Takeda Pharmaceuticals. The polyurethane ink connecting materials used in China are generally polyurethane rubber particles imported from abroad, and then processed and used. The demand reaches 30,000 tons.In recent years, many domestic production and scientific research units have been engaged in the research of polyurethane ink connectors, and have achieved good results. For example, units that can withstand 121°C and 135°C cooking ink connectors have been put into production and are widely promoted and used in the market. , but there is a certain gap between the comprehensive performance of the product and imported products. Improving the comprehensive performance of the product and developing multi-functional products are the focus of domestic research on polyurethane ink connecting materials.

 

The polyurethane resin used in ink is generally formed by the reaction of polyester/polyether polyol and isocyanate, with a molecular force of about 20,000 to 40,000.The solvents are mainly benzene, ketone and ester solvents.During the research and development process, ketone ester solvents or alcohol ester solvents can be used to prepare corresponding benzene-free ink resins according to the environmental protection needs of ink factories and printing factories.

 

Characteristics of polyurethane resin for ink

1. Excellent yellowing resistance

Polyurethane resin for ink is mainly synthesized from aliphatic polyester and aliphatic isocyanate as the main raw materials during the preparation process. It has excellent optical stability compared to aromatic polyurethane, and the film has excellent yellowing resistance after film formation.

2. Excellent adhesion fastness to film substrates

The molecular segments of polyurethane resin for ink contain polar groups such as urethane, allophanate, ester bond, and ether bond, which form with the polar groups on the surface of various polar base materials such as PET and PA. Hydrogen bonds, thereby forming joints with a certain connection strength.After the polyurethane resin is made into ink, it has excellent adhesion fastness when printed on the surface of polar plastic substrates.

3. Good affinity and wettability with pigments/dyes

Polyurethane resin for ink is generally prepared from polyester or polyether polyol, alicyclic diisocyanate and diamine/diol chain extender, with a molecular weight of approximately tens of thousands.Due to the introduction of urea bonds in PU resin, polyurethane-urea resin (PUU) is formed, which has good dispersion and wetting properties for pigments.

4.Good resin compatibility

Polyurethane resin for ink has good compatibility with aldehyde-ketone resin, chlorine-vinegar resin, etc. Users can add it appropriately according to the actual situation and their own process formula to improve the overall performance of the ink.

5.Excellent film forming properties

Ink polyurethane resin is structurally different from polyurethane resins used in other fields. Traditional polyurethane mainly reacts with polyester polyol/polyether polyol and isocyanic acid to form hydroxyl-terminated polyurethane resin. The polar group in the molecular structure is carbamic acid. Mainly ester, the molecular cohesion is not enough to meet the film-forming performance requirements of resin for ink.Therefore, polyurethane resin for ink introduces urea group on the basis of traditional polyurethane, which greatly improves the cohesive strength and film-forming properties of the resin itself.

6. Wide compatibility with organic solvents and good solvent release

The dissolving effect of organic solvents on resin is to attract solute molecules through the polarity of solvent molecules, which is commonly known as like miscibility; traditional polyurethane resin has a wide range of compatibility with organic solvents, such as ketones, esters, benzene, etc. Non-alcoholic organic solvents are excellent solvents.However, in the process of making ink, in order to adjust the flow performance and viscosity of the ink, the addition of alcoholic organic solvents is essential. For traditional polyurethane resins, the addition of alcoholic solvents greatly reduces the stability of the resin system, often causing turbidity, Incompatibility phenomena such as flocculent precipitation.However, the presence of urea groups in polyurethane resin for ink makes its compatibility with alcohol a reality. However, it is worth pointing out that alcohol solvents are still pseudo-solvents. In the microscopic state, alcohol solvents wrap the polyurethane resin molecules instead of Like a true solvent, the ink made from polyurethane resin has good fluidity due to the molecular polarity running through the molecule.

 

Applications of polyurethane ink resin

①Selection of solvent

During the ink manufacturing process, considering the volatilization gradient of the overall solvent system of the ink, to improve the solvent release of the printing ink and reduce the organic solvent residue of the printed product solvent, the solvents used are often several mixed solvents with different volatilities.The main organic solvents used in the ink manufacturing process include toluene, methyl ethyl ketone, cyclohexanone, ethyl acetate, butyl acetate, n-propyl acetate, isopropyl alcohol, etc. Customers can adjust the volatility of the ink according to seasonal changes. adjust.

②Selection of pigments

Due to the large differences in pigment grades on the market today, the dispersion and ink stability of the same pigment from different manufacturers of the same resin often vary greatly in polyurethane inks. Therefore, it is recommended that users base their actual needs on their own. Customers need to choose pigments carefully.

③Selection of additives

Wax powder: The wax powder used in the production of polyurethane ink is often low molecular weight polyethylene wax, with a relative molecular weight of generally 1000 to 6000. It has good solubility in the organic solvents in the ink and has affinity with the polyurethane resin itself. Better and has good chemical stability.It mainly serves to increase the friction resistance of the ink film surface, and at the same time, it can appropriately alleviate the anti-stick resistance of the ink itself.

 

Dispersant: A type of surfactant, mainly used to moisten the surface of the pigment, shorten the ink manufacturing time, facilitate the dispersion of the pigment, and sometimes appropriately reduce the oil absorption of the pigment.When manufacturing high-concentration ink, it can reduce the yield value of the ink and prevent the aggregation and precipitation of pigment particles in the ink.

 

Adhesion promoter: The polyurethane resin used for ink contains a large number of polar groups. Even if the surface of non-polar substrates such as BOPP and PE is treated with surface corona, the surface tension is generally between 38 and 42 dynes. To improve the adhesion of polyurethane ink, The adhesion fastness on the surface of this type of substrate often requires the appropriate addition of titanate coupling agents or chlorinated polypropylene adhesion accelerators.

 

Ink binder resin is an extremely critical raw material in the production of ink. It not only serves as a bridge between the color material and the base material, but also gives the ink various excellent physical properties.In ink production, choosing the right resin connecting material directly affects the performance of the ink on various substrates and the process adaptability during the printing process.When selecting resin, the physical properties of the resin must be fully considered to match the performance that the ink needs to achieve.

 

Polyurethane resin is a versatile material that can be used in the preparation of gravure printing ink for film. Gravure printing is a method of printing that uses engraved cylinders to transfer ink onto a substrate, and it is commonly used for high-volume printing applications such as packaging and labeling.

as a binder to provide adhesion and durability to the ink. It can also be used to adjust the viscosity and flow properties of the ink, which is important for ensuring consistent print quality and optimal ink transfer to the substrate.

 

We could provide solvent based polyurethane resin, polyurethane emulsion, acrylic resin, waterborne polyurethane dispersion to meet diversified requirement.

 

What is GRS certification

2024-03-14

GRS (Global Recycled Standard) is a globally recognized certification and labeling system for products made from recycled materials. The purpose of GRS is to promote the use of recycled materials, reduce the environmental impact of production, and provide transparency and assurance to consumers. By using products certified under the Global Recycled Standard, consumers can make more informed choices, supporting sustainability and reducing waste by promoting the use of recycled materials.

 

To achieve GRS certification, companies must meet specific criteria related to the recycled content of their products. This includes ensuring that a minimum percentage of the product's materials come from recycled sources and maintaining traceability throughout the supply chain. GRS also takes into account issues such as environmental management, social responsibility, chemical use, and labeling.

TPU (Thermoplastic Polyurethane) resin can be produced using both virgin and recycled materials. Recycled TPU resin is made from post-industrial or post-consumer waste, which is collected and processed to create new TPU resin. The use of recycled TPU resin helps to reduce waste and conserves resources. Koslen TPU is on the process to obtain GRS (Global Recycled Standard) certification. We can provide GRS (Global Recycled Standard) certification to the industries that standard covered soon, including textiles, apparel, home furnishings, and personal care products.


 


 


 

The proportion of MDI influence the embrittlement performance of TPU at low temperatures

2024-03-14

MDI is one of the key components used in the production of TPUs. It serves as the isocyanate component, reacting with polyols to form the polyurethane segments of TPU.

 

The selection of MDI type and the ratio of MDI to polyols can affect the physical properties and performance characteristics of the TPU, including its low-temperature behavior. TPU formulated with a higher proportion of MDI generally have a higher density of hard segments, which can enhance the stiffness and rigidity of the material. This, in turn, can make the TPU more prone to embrittlement at low temperatures.


 

Therefore, the proportion of MDI in TPU formulations is an essential factor to consider when aiming for specific low-temperature performance requirements. It's crucial to optimize the MDI-to-polyol ratio to achieve the desired balance between hardness, flexibility, and resistance to embrittlement at low temperatures.

 

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