Structural differences: saturated resins contain saturated double bonds, carbon-carbon bonds are saturated, single bond saturated resins
Saturated resin has excellent bonding performance hardness and toughness balance performance
Saturated resin 1) Poor heat resistance, heat distortion temperature is 50 ～ 60 ℃, some heat resistant resin can reach 120 ℃
(2) The mechanical properties of saturated polyester resin have high tensile, bending, compression and other strengths
(3) Good chemical and corrosion resistance, saturated polyester resin is more resistant to water, acid and alkali
Poor solvent performance
(4) Dielectric properties Saturated polyacid resin has good dielectric properties
1. Saturated polyester resin
Saturated polyester resin (oil-free alkyd resin) is mainly used in the production of coil coatings, depending on the resin properties and structure
The difference can be used for the top coat, primer, back coat of coil coatings, and also used for ink and hot film coils
Used saturated polyester resin.
Characteristics of saturated polyester resin:
Saturated polyester resin requires good decorativeness, protection, durability, workability and processing of the coating film
Type, the most used polyester topcoat, because saturated polyester resin has the following characteristics:
(1) Strong versatility and good weather resistance. Mainly suitable for steel plate coating in the construction industry.
(2) The hardness and toughness are outstanding, and it has stick resistance, and the use grade is high.
(3) Economical. It is suitable for the general requirements of coil coating.
Second, unsaturated polyester resin
Unsaturated polyester resin, generally composed of unsaturated dibasic acid diol or saturated dibasic acid unsaturated diol
Linear polymer compound with ester bond and unsaturated double bond formed by polycondensation. Generally, polyesterized polycondensation reaction
It should be carried out at 190 ～ 220 ℃ until it reaches the expected acid value (or viscosity), at the end of the polyester shrinkage reaction
Afterwards, add a certain amount of vinyl monomer while hot to make up a viscous liquid. Such a polymer solution is called
It is an unsaturated polyester resin.
Characteristics of unsaturated polyester resin:
(1) Heat resistance. The thermal deformation temperature of most unsaturated polyester resins is between 50 and 60 ° C. Some resistance
Good thermal resin can reach 120 ℃.
(2) Mechanical properties. Unsaturated polyester resin has high tensile, bending, and compression strength.
(3) Chemical resistance. Unsaturated polyester resin has good resistance to water, dilute acid and alkali, organic resistance
The performance of the solvent is poor, and at the same time, the chemical resistance of the resin varies with its chemical structure and geometric switch.
At the same time, there can be great differences.
(4) Dielectric performance. The dielectric properties of unsaturated polyacid resins are good.
(5) The unsaturated polyester resin changes from a soluble and fusible state to an insoluble and infusible state.
(6) It is still soluble in a suitable solvent and has good fluidity when heated.