Adhesives are substances that bond adjiacent surfaces of a material together. Adhesives can be subdivided into adhesives, binders, adhesive bonding agents, adhesion promoters, tackifiers and impregnating adhesives, etc., according to different bonding mechanisms and operating processes.
Tackifier: refers to substances that can increase the viscosity of unvulcanized adhesives, such as petroleum resin, coumarone resin, styrene indene resin, non-thermally reactive p-alkylphenol formaldehyde resin and pine tar. Adhesion refers to the force or work required to peel off two homogeneous films after a small load and a short time lamination, that is, self-adhesion. The tackifier only increases the surface viscosity of the rubber material during the processing of multi-layer rubber products, which facilitates the bonding process between the rubber layers. It mainly improves the bonding effect by increasing the physical adsorption, and belongs to the category of processing aids.
Impregnation adhesive: also known as indirect adhesive, refers to the impregnation liquid containing viscous components covering the surface of the fiber fabric or penetrating into the inner gap of the fabric through the impregnation process. The fabric is chemically bonded, and this impregnating liquid is called an impregnating adhesive, such as a three-component NaOH emulsion bonding system of resorcinol, formaldehyde and latex, or RFL system, which is to improve the bonding effect of rubber and fiber. one of the main methods. For different fibers, the composition of the impregnating liquid is different. For example, the latex (L component) can be NRL or butyl pyridine latex, and the amount of resorcinol and formaldehyde can also be changed. For fibers that are difficult to bond such as polyester, aramid and glass fiber, in addition to the RFL composition, other ingredients that are conducive to bonding should be added, such as isocyanate, silane coupling agent, etc.
Bonding agent: Also known as direct adhesive, it is mixed into the compound during mixing, and during vulcanization, chemical bonding or strong substance adsorption occurs between the surfaces to be adhered to form a firmly bonded substance, such as a typical interlayer. Hydroquinone donor-methylene donor-silica bonding system (m-methyl white system, HRH system), triazine bonding system. In this type of adhesive, there is no intermediate layer based on the adhesive on the surfaces of the two materials where the bond is produced. This adhesive is mostly used to form a strong and durable bond between rubber and skeleton materials.
Binder (adhesive): refers to the substance that adheres discontinuous powder or fibrous materials together to form a continuous whole, such as paper pulp binder, non-woven binder, asbestos binder, powder The binders used in wet granulation are mostly liquid or semi-fluid substances, and the binder and the powder are uniformly mixed by high-speed stirring and other methods, and the binder provides cohesive force for bonding.
Adhesivepromotingagen: refers to a chemical substance that directly produces physical adsorption or chemical bonding between materials, but can promote the occurrence of adhesion, such as in the adhesion of rubber and brass-plated metal. The organic cobalt salt used in the process is an adhesion promoter. This adhesion promoter is also directly added to the compound as a compounding agent and plays a role in the high temperature vulcanization process.
Adhesive (adhesive): refers to a class of substances that connect two or more parts (or materials) together, mostly in the form of glue or adhesive tape, and achieve adhesion through spraying, coating and sticking processes. Purpose. This bonding method is to form an intermediate bonding layer with adhesive as the main component between the surfaces of the two materials, such as bonding between vulcanized rubber, bonding between vulcanized rubber and skin, wood and metal. Adhesive Its own properties and performance, and the bonding process determine the bonding effect.
Among the above-mentioned adhesives, the adhesive with wide application, large dosage and simple operation process is the adhesive. There are many varieties of adhesives, and their performances are different. Selecting the appropriate variety can obtain higher bonding strength. Therefore, the adhesives have developed rapidly and have become the most commonly used substances in the bonding process.
At present, the most commonly used adhesives are isocyanate adhesives, halogen-containing adhesives and phenolic resin adhesives. Its isocyanate adhesive is a good adhesive for rubber and various metals. It is characterized by high bonding strength, excellent shock resistance, simple process, oil resistance, solvent resistance, liquid fuel resistance, acid and alkali resistance and other properties, but the temperature resistance is slightly poor. . Hydrochlorinated rubber is a product obtained by the reaction of natural rubber and hydrogen chloride, which has good chemical stability and does not burn. Chlorinated rubber adhesives with good adhesion can be obtained by dissolving chlorinated rubber in an appropriate agent. Chlorinated rubber adhesives are mainly used for polar rubber (neoprene rubber and nitrile rubber, etc.) and metals (steel, aluminum, It can also be used as a surface protective coating due to its excellent water resistance and seawater resistance.
Post time: May-06-2022