Abstract : This article gives a comprehensive introduction to the variety and performance of plasticizers. The main considerations and characteristics of choosing plasticizers are the entry point. The current emphasis on the use of ATBC plasticizers for environmental protection inks is highlighted.
Keywords: Plasticizers, Inks, DOP, ATBC, Selection, Applications Plasticizers are used in most ink formulations. As the name suggests, plasticizers are additives that increase the plasticity of inks. With the definition of the scientific point, any substance added to the polymer system that can lower the glass transition temperature of the polymer and increase the ease of processing can be referred to as a plasticizer.
Plasticizers are not much used in gravure inks, but their properties are irreplaceable. Many of our ink formulators are not very familiar with it. This article from another point of view for a comprehensive introduction of plasticizers, error, please also give more guidance.
For its history, dating back to 1868, HYATT first discovered that camphor can be used as a nitrocellulose plasticizer to make a soft Celluloid plastic. However, until 1933, SOMON discovered that adding high-boiling esters to hard PVC could give soft PVC plastics before major breakthroughs in the use of plasticizers could be achieved by the plasticizer industry. Rapid development. In recent years, due to the rapid development of plastic packaging, pharmaceutical industry, medical device industry, food packaging and ink industry, the performance requirements for plasticizers are also advancing with the times.
First, the performance requirements of inks on plasticizers First of all, can be developed as a certain industry, indicating that a wide range of plasticizers and bright prospects for development. There are many experts suggest that the use of plasticizers is best used in combination with two or more plasticizers to achieve the purpose of complementing each other. The most common plasticizers in the ink industry are DOP, DBP, and the popular ATBC in recent years.
The primary condition for compounds that can be used as plasticizers is compatibility with the resin. Highly compatible plasticizers are called main plasticizers. Because of their low compatibility, they cannot add a large amount of plasticizers called secondary plasticizers or extenders. In the process of use, the main factors that should be considered for plasticizers are:
1, compatibility. Compatibility is actually referred to as compatibility. It refers to the amount of plasticizer that the resin can absorb. After plasticizing, these plasticizers no longer seep out. Normally, 100 ml of plasticizer is absorbed by 100 g and no bleed is observed, indicating that the plasticizer has good compatibility with the resin. If the above ratio is not reached or the phenomenon of seepage after absorption occurs, the compatibility of the plasticizer is poor.
2, volatile. The soft PVC plastic product contains a large amount of plasticizer, and its volatility is related to the diffusion rate of the plasticizer from the inside of the product to the surface and the vapor pressure of the plasticizer. The plasticizer evaporates onto the glass and condenses, causing fogging of the glass. This is a problem encountered by PVC in the automotive industry. In order to reduce the amount of fog on automotive glass, large molecular weight, low volatility plasticizers are used. In general, esters obtained by blending straight-chain alcohols with phthalic acid and C8-C13 as plasticizers can reduce fogging. In the ink industry, this issue is equally important, otherwise it is difficult to completely overcome the fog phenomenon.
3, mobility. In fact, the issue of migration also belongs to the issue of compatibility. The amount of plasticizer migrated to the surface of the article increases as its concentration increases and the temperature increases. This is a taboo in the ink manufacturing industry, so the investigation of mobility is very important.
4, chemical extraction. Plasticizers in plastic products are also easily extracted by other media, which is chemical extraction, also known as oil extraction. In general, high molecular weight plasticizers have high extraction resistance. In general inks, this performance requirement is not particularly strong. Except for special-purpose ink products, chemical extraction may not be considered as a requirement.
5, temperature resistance. The heat resistance and cold resistance of the plasticizer itself are directly related to the possibility of using the plastic product at high and low temperatures. Plasticizers having a high boiling point and a low freezing point are plasticizers that are excellent in temperature resistance and enable plastic products to be used in a wide temperature range. In the ink manufacturing industry, 180 degrees Celsius is generally a threshold, and above this temperature, it can be our candidate product.
6, because plasticizers are mostly low molecular weight organic ester compounds, so after adding the resin will generally affect the electrical insulation, flame retardant and anti-fungal properties of plastic products, but the degree of influence varies with the species. In addition, the toxicity of plasticizers should also be taken seriously.
In short, it is hoped that plasticizers have high compatibility with resins, low volatility, small migration and oil-water extractability, and are resistant to high and low temperatures, are flammable, nontoxic, and inexpensive, but none have yet been plasticizers. Can fully meet the above requirements, so in front of a wide variety of species to be a reasonable choice or use.
II. Types and Performance of Plasticizers 1. Phthalates Either plastics manufacturing or ink manufacturing industries, phthalates are the most widely used main plasticizers at present, with many varieties and high yields. Light color, low toxicity, good electrical properties, low volatility, low odor, general low temperature resistance and other characteristics. At present, the consumption of phthalates is about 80-85% of the total consumption of plasticizers, and among them, dioctyl phthalate and diisooctyl phthalate are the two most commonly used.
In fact, there are many varieties of these phthalates. The following is a brief introduction. Dioctyl phthalate (abbreviated as DOP) is a colorless, oily liquid with a special odor. Diisooctyl phthalate (abbreviated as DIOP) is an almost colorless, viscous liquid, soluble in most organic solvents and hydrocarbons. Diisodecyl phthalate (DIDP), a viscous liquid, soluble in most organic solvents and hydrocarbons, insoluble or slightly soluble in glycerol, ethylene glycol and certain amines, it is more volatile than DOP Small, resistant to migration, is a low volatility plasticizer, anti-aging, good electrical properties, but poor compatibility. Diisodecyl phthalate (referred to as DINP) is a transparent oily liquid. Its greatest feature is that its volatility at high temperature is only half that of DOP. Dibutyl phthalate (abbreviated as DBP), colorless and transparent liquid, with aromatic odor, soluble in most organic solvents and hydrocarbons, previously used in the pigment color chip industry, the critical plasticizing temperature of DBP to PVC 90-95°C. Diisobutyl phthalate (abbreviated as DIBP) is a colorless, transparent liquid. When DIBP was used in PVC agricultural films, it was found that the rice was rotted due to its precipitation. Butyl benzyl phthalate (abbreviated as BBP) is a transparent, oily liquid that dissolves in organic solvents and hydrocarbons and is insoluble in water. The critical plasticizing temperature of BBP for PVC is 96-100°C. Dimethyl phthalate (abbreviated as DMP) is a colorless, oily liquid with microstrip aromatic odor. It is insoluble in water at room temperature and is miscible with aliphatic hydrocarbons. It has good compatibility with most resins. Diethyl phthalate (abbreviated as DEP) is a colorless oily liquid, non-toxic, microstrip aromatic odor, soluble in most organic solvents. Dicyclohexyl phthalate (DCHP), a white crystalline powder with aromatic odor, is soluble in most organic solvents and is completely soluble in hot gasoline and mineral oil, slightly soluble in glycols and certain Some amines. For dioctyl terephthalate (DOTP), the physical properties of DOTP and DOP are similar and the mechanical properties of the products are similar, but the DOTP volatiles are much smaller than the DOP.
2. Fatty acid esters Fatty acid esters have good low-temperature properties, but they have poor compatibility with polyvinyl chloride and can only be used as cold-resistant secondary plasticizers and phthalate esters. The most common varieties are dioctyl adipate and dioctyl sebacate.
Dioctyl adipate (DOA), colorless, odorless, non-toxic, soluble in most organic solvents, slightly soluble in glycols, insoluble in water, the critical plasticizing temperature of DOA to PVC is 12l. 125 °C. Diisodecyl adipate (referred to as DIDA) is a clear, free-flowing, oily liquid. Dioctyl sebacate (abbreviated as D0Z) is a nearly colorless transparent liquid. Sebacic acid dibutyrate (DBS for short) is almost a colorless liquid. Dioctyl sebacate (abbreviated as DOS) is also an almost colorless oily liquid that is insoluble in water and soluble in organic solvents such as alcohol, benzene, and ether. Diisooctyl sebacate (abbreviated as DIOS), a colorless, clear liquid, soluble in most organic solvents such as ketones, alcohols, esters, aromatic hydrocarbons, and aliphatic hydrocarbons, and slightly soluble in amines and polyols. Di(2-ethylbutyric acid) triethylene glycol ester (abbreviated as 3GH), which is the most widely used plasticizer in polyvinyl butyral films for safety glass, and it is also used for cellulose plastics and acrylates. Plastics and polyvinyl chloride are also good plasticizers.
3. Phosphate esters Phosphate and polyvinyl chloride resin have good compatibility, transparency is good, but toxic. They are both plasticizers and flame retardants. Aromatic phosphate vinegar has poor low-temperature properties, while aliphatic phosphate esters have better low-temperature properties, but have poorer thermal stability and are not as durable as aromatic phosphate esters. Its main varieties are tricresyl phosphate and triphenyl phosphate.
Trimethyl phosphonate (TCP). Triphenyl phosphate (abbreviated as TPP) is a white, needle-like crystalline microstrip aroma, slightly soluble in ethanol, ether, benzene, chloroform, and acetone. There is also diphenyl phosphate-octyl ester (abbreviated as DPOP), which is a light yellow transparent oily liquid. Toluene diphosphate (CDPP) is a clear, odorless, oily liquid.