Liquid fabric detergent is the most used type of liquid detergent, which is used for the washing and maintenance of various fabrics. These fabrics are generally cotton, cotton/chemical or chemical fibre products and are often stained with body dirt (leather), solid dirt (dust) and animal and vegetable oils and greases.
Detergent formulations for general clothing should have the following basic requirements:
① strong stain removal power.
② good adaptability to water quality, can be used for hard water.
③ foam appropriate. For machine washing, the foam should not be high, and should be easy to rinse.
④ Moderate alkalinity. Heavy-duty laundry detergent can have a certain alkalinity to improve the detergency, but the alkalinity should be in line with national standards.
Washing silk and wool products are generally neutral to prevent damage to the natural fibres of silk and wool.
Laundry detergent is generally composed of surfactants, synergists, pH adjusters, chelating agents, functional additives, pigments, preservatives, defoamers, inorganic salts, solvents and co-solvents.
Commonly used raw materials are as follows:
Surfactant: Surfactant is the main active ingredient of laundry detergent to remove dirt, often composed of anionic surfactant and non-ionic surfactant.
1-2 anionic surfactants are the main surfactants:
Sodium fatty alcohol polyoxyethylene ether sulfate (AES), sodium alkylbenzene sulfonate (LAS), sodium alkyl sulfonate (SAS), allyl sulfonate (AOS) and so on;
Nonionic surfactants such as fatty alcohol polyoxyethylene ether (AEO7,AEO9, etc.) as auxiliary synergistic active agents, can be added as a penetrating agent with a small EO number to increase the penetration rate.
Alkanolamides (6501) or amine oxides mainly play the role of thickening and synergising.
The total surfactant content of the industry recommended standards require not less than 15%, to ensure that the decontamination requirements in the normal use of the amount. Concentrated products reach more than 25%.
Synergist: It refers to the component that enhances the washing effect in liquid detergent, and its products include protease, lipase, cellulase and other enzyme preparations.
Anti-fouling redepositing agents: sodium polyacrylate, polyvinylpyrrolidone, etc.
pH adjusting agent: commonly used potassium hydroxide, sodium hydroxide, triethanolamine, citric acid, sodium citrate, sodium succinate, sodium carbonate, sodium bicarbonate, sodium metasilicate and so on.
Chelating and dispersing agent: sodium citrate, sodium polyacrylate, polyacrylic acid / maleic anhydride copolymer sodium salt
Inorganic salts: often sodium chloride-based, used to adjust the viscosity of laundry detergent; enzyme protection with sodium sulfate, calcium chloride and so on.
Functional additives: including anti-colour fading agents, active oxygen additives for colour bleaching, plant extracts for antibacterial effect, etc. Some add softeners with softening effect. Some of them have softening function by adding softener.
Solvent: ethanol, propylene glycol, isopropanol, etc.
Co-solvent: sodium methanesulfonate, sodium dimethyl sulfonate, urea, etc.
Anti-foaming agent: Anti-foaming agent is often used to control the number of bubbles in the laundry detergent, to play the role of easy rinsing, water saving. Commonly used defoamers are silicone, polyether and mineral oil. Among them, silicone antifoam agent has the best effect of elimination and foam suppression, but it is often used in the form of emulsion, adding a slightly larger amount will affect the transparency of the laundry detergent; polyether antifoam agent above the turbidity point of the defoaming effect, this type of antifoam agent is suitable for the preparation of transparent laundry detergent; mineral oil antifoam agent is relatively inexpensive and economical.
Preservatives: The preservatives commonly used in liquid detergents are Kasone, Brombol, etc.
Fragrance, colouring: to give a pleasant appearance to the laundry detergent, and the fabrics stay fragrant and long-lasting after use.
Laundry detergent will be concentrated, low-temperature water-saving, safe and environmentally friendly, green and natural for the development trend, more functional to meet individual needs, such as antibacterial, anti-color, anti-pilling, more bright and soft, more lasting fragrance.
Isomeric Alcohol Ether Nonionic Surfactants in the Laundry Industry
Alcohol Ether Nonionic Surfactants
Alcohol ether nonionic surfactants are usually surfactants produced by the addition of fatty alcohols to ethylene oxide or propylene oxide. They have the advantage of being compatible with any other surfactant, usually in the form of a 100% active product, are electrolyte-free, and are resistant to hard water, polyvalent metal cations, and high concentrations of electrolytes. Soluble in water and organic solvents, polyether-based nonionic surfactants are usually good dispersants.
According to the type of carbon chain of non-ionic can be divided into:
1) Straight chain alkyl polyether type nonionic surfactants
2)Branched alkyl polyether type nonionic surfactants
Isomeric alcohol ether surfactants
Isomeric alcohol polyoxyethylene ether (referred to as isomeric alcohol ether) is a new type of surfactant, which is a non-ionic surfactant generated by the reaction between isomeric alcohol and ethylene oxide or propylene oxide.
The lipophilic group of isomeric alcohol polyoxyethylene ether is a fatty alcohol with a branched chain, which has a low freezing point compared with straight-chain alcohols, and has a strong penetration force, a fast diffusion speed in water, and is not easy to form gels at high concentrations. Used in concentrated and ultra-concentrated liquid detergent formulations, it can greatly improve the low-temperature stability and decontamination performance of the product.
Application of isomeric alcohol ethers in detergents
Isomeric ethers are mainly used in laundry gels, dishwasher detergents and hard surface cleaners in China.
Especially in the laundry gel industry, since the appearance of laundry gel in the Chinese market in 2014, it has been in a high growth stage in recent years.
In the formulation of laundry gel beads, because the water content is usually not more than 15%, the traditional anionic surfactants and non-ionic surfactants, such as AEO7, AEO9, can not meet the needs of the formulation, which is mainly reflected in the easy appearance of the gel phase, especially in the storage of laundry gel beads, there will be the case of water volatilisation, it is necessary to take into account the impact of the actual storage environment of the product, and try to maintain the surface of the formulation. It is more necessary to consider the effect of the actual storage environment, trying to maintain the solubility of the surface active agent in the formulation.
Currently, the main isomeric ethers widely used in laundry gels are.
(1) Guerbet ethers, such as BASF’s XP, XL series, which are also produced by domestic companies such as Luen Hong.
(2) Isomeric tridecanol polyether, such as BASF’s TO series.
(3) Semi-branched chain alcohol ether, such as Sasol 23.
In the field of concentrated detergent mainly for laundry gel, the formula is still mainly fatty acid, LAS, AES, AEO, of which the anionic LAS and AES generally do not exceed 30% due to the solubility factor, while the non-ionic AEO is more soluble, but its dissolution speed is slow, and it is easy to form a gel at high concentration in the system of laundry gel with less water. Or at low temperatures, join the washing machine is easy to line into a gel in the dispersion process.
There are two ways to solve this problem:
One is to increase the amount of solvent or the use of aqueous solvents, such as sodium isopropylbenzene sulfonate, sodium xylene sulfonate and so on;
One is to choose the isomeric alcohol ether with small gelation area.
Gel bead system using solvent is too high, easy to lead to the soft collapse of the film, aqueous solvent and solvent cleaning power does not help much, not as good as this part of the cost is invested in the cost of surfactants.
In terms of the current industry situation, the main isomeric ethers used in laundry beads are guerbet C10 ethers and some mixed alcohols and semi-branched chain ethers.
Due to the price factor, the amount of isomeric tridecanol ether is small.
Another factor is that the SOE and FMEE developed by China Light Group can have cheaper price theoretically because the reaction steps are less than that of isomeric ethers. They have already started to be used in the bead industry, and they have certain advantages in biodegradability.
FMEE with mixed straight-chain methoxylate termination of natural origin also has good performance in washing performance and foam performance. It will become one of the competitive raw materials for the application of isomeric ethers.