Things about pre-treatment agents.
What are pre-treatment additives
Commonly used pretreatment additives include desizing agents, detergents, scouring agents, penetrants, oxygen bleaching stabilizers, chelating agents, etc. Most of these additives are surfactants and organic Compounds, inorganic salts and solvents, etc. The most commonly used surfactants are anionic surfactants and nonionic surfactants, and there are also a small amount of amphoteric surfactants. Among them, the most commonly used anionic surfactants are: sodium alkyl sulfonate, sodium alkyl benzene sulfonate, sodium butyl naphthalene sulfonate, sodium lauryl sulfate, sodium alkyl sulfate, sulfated castor oil, amber Acid alkyl ester sodium sulfonate, etc. The most commonly used nonionic surfactants are: fatty alcohol polyoxyethylene ethers, alkylphenol polyoxyethylene ethers, coconut oil polyoxyethylene ethers, sorbitol polyoxyethylene ethers, alkyl alcohol amides, and ethylene oxide Propylene oxide copolymer, etc.
Most of the pretreatment aids are a combination of nonionic surfactants and anionic surfactants. In the manufacture of these products, if the raw materials are improperly selected, not only will the product quality be problematic, but the product will also fail to meet environmental protection requirements or a certain indicator will not meet environmental protection indicators. For example, in the manufacture of scouring agents or detergents, nonylphenol polyoxyethylene ether (TX-10) and sodium dodecylbenzene sulfonate (LAS) are often added. Although the former can be treated biochemically, the decomposition products after biochemical treatment are still phenols, which are fish-toxic and can damage the human reproductive system. Furthermore, nonylphenol has been listed by the international market as one of the 70 environmentally friendly hormones with restricted use (also known as endocrine hormones). Disturbing chemical substances)”, some European countries have passed laws to ban the use. Therefore, when developing environmentally friendly products, nonylphenol polyoxyethylene ether should be used as little or as little as possible, and natural fatty alcohol polyoxyethylene ether or dehydration should be used Sorbitan esters and sorbitan ethoxylates.
Alkyl polyglycosides (APG), known as a new generation of surfactants, are nonionic surfactants formed by the reaction of glucose in natural starch and fatty alcohols or fatty acids. It is non-toxic to the human body, biodegrades quickly, and has a good synergistic effect with other surfactants. APG has the characteristics of both nonionic and anionic surfactants, and has good surface tension. C s—APG at 2o°C The surface tension of C2-APG is 28raN/m, and that of C2-APG is 2o. 4mN/m, Cl6~APG is 14raN/m, and there are multiple hydroxyl groups on the sugar ring, which can form hydrogen bonds with each other in water, so this surfactant has a cloud point. The emulsifying performance of APG is better than TX-10, Pingpingjia O, Tween-2o, and Span-6o. Ethylene oxide and propylene oxide copolymer (polyether) is a type of nonionic surfactant with excellent biodegradability and can be used for compounding. Polyether is a high molecular weight surfactant. The hydrophilic and hydrophobic groups can be lengthened or shortened as needed. The product is in the form of L (L). (Products are indicated by P), sheet form (products are indicated by F). Polyether is a type of product with low foam, odorless, low toxicity and easy biodegradation. For example, the molecular weight of 2000-3000 L type has good decontamination, and F type has good dispersion. Polyether is also an emulsifier and defoaming agent, but different polyether molecular structures have different effects on decontamination and defoaming. When the end of the structure is ethylene oxide, the detergency is good but the defoaming property is poor: When the end is propylene oxide, the detergency becomes worse and the defoaming property becomes better. Therefore, it can be reasonably selected according to different uses. If you choose L” or F and combine it with other detergents, you can make a high-efficiency low-foaming detergent.
Among the anionic surfactants, LAS has a lot of foam, is highly irritating, has certain teratogenicity, and has poor resistance to strong alkali. Although it has not been eliminated at present, according to relevant information, LAS has been gradually replaced by lauryl polyoxyethylene ether sulfate (AES), sodium secondary alkyl sulfonate (SAS60) and monoalkenyl sulfonate (AOS). Taking detergents as an example, LAS accounted for 52.4% of the total output of detergents in my country in 1990, and accounted for 31.4% of the total output in 1996. O%, while AES increased from 19.4% in the same period to 34.7%. AES is better biodegradable than LAS and complies with environmental regulations, while AOS and SAS60 are better than LAS in almost all properties.
AESThere are two products, one uses synthetic alcohol as raw material (2EOAES), and the other uses natural lauryl alcohol as raw material (3EO AES). Among them, 3EO AES is less irritating, has good biodegradability and has low toxicity. S. Both 4S60 and AOS have good biodegradability, excellent washing, decontamination, emulsification, and degreasing properties. They have good solubility, strong wetting power, resistance to electrolytes, strong alkali resistance, and high temperature resistance (does not decompose at 130°C), and have good Compatible, it is an ideal raw material for manufacturing green pre-treatment additives. The raw materials of tea saponin and polypeptide-based surfactants are derived from natural products. They have good biodegradability, can withstand hard water, and have excellent washing and emulsifying properties. Peptide-based surfactant is composed of coconut oil fatty acids and casein hydrolyzed with lauric acidThe products of the reaction include PmmoisEMCP and Promois EFLS I. The above two are new anionic surfactants, both of which have excellent washing and emulsifying properties. Tea saponin has a good cleaning effect when used for wool washing. It has a better effect when combined with AES and AS three-origin copolymers. It is an ideal environmentally friendly wool detergent.
Some factories also add detergent IS to the detergent. Although it can improve the washing effect, this product cannot be considered a green product. Because para-aminoanisole is used in the manufacture of detergent IS, para-aminoanisole contains carcinogenic o-anisole and is listed as a banned substance. Environmentally friendly anionic surfactants include fatty acid methyl ester sulfonates (MEs), ether carboxylates (AEC) and other products. The main raw material of MES, fatty acid methyl ester (ME), comes from oil. For example, ME made from palm oil has good washability, is easily biodegradable, and is non-toxic. Its washing ability in cold or hard water exceeds L~S, and the dosage is only LAs. 1/3. It is one of the preferred raw materials for making detergents. Alkyl alcohol ether carboxylates (AEC) and amide ether carboxylates (AMEO) have good biodegradability, are resistant to hard water, and have excellent emulsifying, dispersing, wetting, solubilizing and other properties. They are green pretreatment additives for manufacturing main raw materials. In particular, alcohol ether carboxylates have strong detergency, good compatibility, and strong calcium soap dispersion. They are praised by developed countries as “green” surfactants in the 21st century. AEC has a variety of functions. It can be used for cotton scouring, bleaching, mercerization, wool and cashmere washing, and as a leveling agent for vat dyeing. It can also be used as a fabric softener in combination with alkyl siloxane to improve the softening effect. Among the anti-wrinkle and non-yellowing pre-treatment additives for fabrics, some auxiliary factories have introduced a fabric degreasing agent in recent years. However, some of these products are compounded with solvents such as toluene, xylene and ethylene glycol butyl ether. During use, It will volatilize harmful gases and affect environmental protection. According to information, the use of fatty alcohol hydroxyethyl ester mixed with oily solvents that can biodegrade ships has excellent wetting and decontamination effects on oils, esters, resins, tar, manure, dirt and many other Dirt that is difficult to remove has excellent solubility. For example, Losin OCB⋯ developed by Fextilcomr AG in Switzerland and ECCOHR-CO and 930-cm developed by Eastern Company in the United States do not contain harmful substances such as chloride aromatic hydrocarbons and phenol manure. Biodegradable.
Among penetrants and scouring agents, alkyl phosphates are currently the ideal product,and are pollution-free. For example, octanol polyoxyethylene ether phosphate has good penetration effect, especially in alkaline solution, it can withstand NaOH 120 g/L and has penetration power <10s. In 2. There is no separation in ~0g/L NaOH solution. It is an important raw material for manufacturing pre-treatment agents that are resistant to concentrated alkali, high temperature, oxidants and hard water in the one-step deboiling and bleaching method. It can also be used as a mercerizing penetrant.
Among the oxygen bleaching stabilizers, there is a type of organic chelating agent, which is formulated with nitrilotriacetic acid (NTA), diethylene triamine pentaacetic acid, IYFPA, EDTA, etc. Although this type of stabilizer is effective, it has poor biodegradability and has long been banned abroad. Among them, if the carboxylic acid of DTPA is replaced with a phosphate group to form diethylene triamine pentamethylene phosphonic acid (DTPMP), it will be biodegradable. Degradability improves. It is an ideal chelating agent. At present, hydrogen peroxide stabilizers tend to be mixed types. The main raw materials can be polyacrylamide and phosphate ester salts. Most of the chelating type stabilizers are organic acid sequestering agents, such as hydroxycarboxylates, carboxylates, and phosphoric acid. Ester salts, among which carboxylates have strong alkali resistance, are suitable for pretreatment cold stack processes.
Among oxygen bleach stabilizers and detergents, tripolyphosphate is added to some products. Such phosphorus-containing products are prohibited for environmental protection. Although sodium tripolyphosphate is non-toxic and biodegradable, when discharged into rivers, it will cause eutrophication of the water system, reduce the dissolved oxygen in the water system, and cause the deterioration of water quality. Cause massive death of fish and other aquatic animals. Therefore, phosphorus-free detergents should be produced in detergents, and sodium tripolyphosphate can be replaced by 4A zeolite, sodium metasilicate, etc. Polyoxyethylene (PEO) can also be added to the builder to make the liquid detergent viscous, control the fluidity of the detergent, and improve the softness of the fabric after washing. PEO is a water-soluble resin with very low toxicity and is environmentally friendly. type product.
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