Natural series resin

Rosin is one of the earliest natural materials used as a tackifier. It is derived from the natural resin secreted by pine trees. It can be divided into gum rosin, tall oil rosin and wood rosin according to the production source. Gum rosin is extracted from the oil secreted by pine trees, tall oil rosin is extracted from tall oil, a by-product of the paper industry, and wood rosin is extracted from pine wood. They are all monocarboxyl isomers with different positions of the double bond dominated by rosin acid. Rosin acid contains double bonds and carboxyl groups in its structure, has strong reactivity, is unstable under light, heat, and oxygen conditions, shows poor aging resistance, poor weather resistance, and is prone to discoloration and other phenomena. Therefore, on the basis of rosin, various derivatives such as hydrogenated rosin, disproportionated rosin, polymerized rosin, esterified rosin and maleated rosin are derived. These derivatives can not only improve the instability of rosin, but also endow rosin with more excellent properties, and are widely used in tackifying resins. Terpenes are limonene (dipentene) extracted from raw turpentine or pine root shavings, turpentine oil obtained by extraction and distillation of wood shavings, or orange peel. Among them, the polymers obtained by cationic polymerization of α-terpene, β-terpene and limonene are terpene resins, and there are also products that use phenol, styrene, etc. to modify terpene resins. Resins also need to be prepared by processes such as polymerization. Since the raw materials of these resins are all natural products, they are also natural.

Synthetic series resin

Synthetic series tackifying resins refer to resins produced from chemical raw materials. According to the polymerization method, they can be simply divided into coumarone-indene resins, C5, C9, C5/C9 petroleum resins, DCPD resins and other polymer resins, including alkyl phenolic resins. Condensed resins such as resins and xylene resins. One of the more special ones is Koresin resin from BASF Chemical Company in Germany, which is similar in structure to alkyl phenolic resin and is formed by addition polymerization of alkyl phenol and acetylene. For ease of discussion, it is also grouped under the class of alkylphenolic resins.

Gumarone-indene resin is a product obtained by distillation of coal tar obtained from dry distillation coal. After removing the pitch, the indene component is obtained, which is obtained by cationic polymerization. Due to the complex composition of coal tar, the obtained indene component contains various compounds such as styrene, indene, coumarone, etc., and more catalysts are often used during polymerization, resulting in a darker color of the resin. improve.

C5 resin is obtained by cationic polymerization of C5 fraction decomposed from naphtha, and its components include isobutene, 1,3-dipentene, methylbutene, pentene, cyclopentadiene, pentane, cyclopentane, etc. , some other monomers can also be added for copolymerization. C9 resin is the C9 fraction decomposed from naphtha, including indene, vinyltoluene, styrene, methylstyrene, DCPD and other components that are polymerized. The C5 and C9 components can also be adjusted and copolymerized as required, thereby obtaining a C5/C9 copolymer resin. DCPD resin can be obtained by rectifying and purifying the decomposed DCPD in naphtha, and then by thermal polymerization or cationic polymerization.

There are also two polymers commonly used as tackifying resins in synthetic resins, namely alkyl phenolic resins and xylene resins. Using alkyl phenols, commonly used tert-butyl, tert-octyl, nonyl phenol and aldehydes are polycondensed to obtain alkyl phenolic resins. Xylene resin is a polymer obtained by reacting xylene with formaldehyde under acidic conditions, among which m-xylene is the most reactive, and the structural formula is often exemplified by m-xylene. Xylene resin has a complex structure and is composed of complexes with various structures. Since alkylphenolic resins contain phenolic hydroxyl groups, while xylene resins contain more ether linkages, both resins have higher polarities.