The best epoxy resin formula is here

Epoxy resins are generally used in the same time as addeds for application value. Adders can be selected according to different uses, commonly used adders are
curing agents, modifiers, fillers and thinners and other
.
the curing agent is an essential adder, whether it is for adhesives, coatings, pouring materials need to add curing agents, otherwise epoxy resin can not cure

. Due to the different performance requirements,
epoxy resins and curing agents, modifiers, fillers, thinners
and other additions also have different requirements.
1, epoxy resin selection
1, from the use of the choice of
as a adhesive is best to choose a medium epoxy value (0.25-0.45) resin, for pouring materials, it is best to choose a high epoxy value < (0.40) resin;
2, from the mechanical strength of the choice of
epoxy value is too high resin strength, but more brittle; Because the strength is related to the size of crosslinking, the crosslinking degree after high curing of epoxy value is also high, and the crosslink degree after low curing of epoxy value is also low, which causes the difference in strength.
3, from the operating requirements of the choice
do not need to withstand high temperature, the strength requirements are not large, hope epoxy resin can be quickly dry, not easy to lose, you can choose a resin with a lower epoxy value;
2, curing agent selection
1, curing agent type:
commonly used epoxy resin curing agent has fatamine, lipocycamine, aromatic amine, polyamide, acid, resin, uncleamine, in addition to the role of light trigger UV or light can also make epoxy resin curing. At room temperature or low temperature curing generally choose amine curing agent, warm curing is commonly used acid anhydride, aromatic curing agent.
2, curing agent dosage
(1) amine as cross-linking agent when pressed calculation:
amine dosage s mg/hn
type:
m s amine molecular weight
hn - Number of active hydrogen
g - epoxy value (epoxy equivalent per 100 g epoxy resin)
the range of change is not more than 10-20%, if cured with excessive amine, the resin will become brittle. Curing is not perfect if the amount is too low.
(2) Pressed calculation when using acid anhydride:
acid anhydride dosing : mg (0.6 to 1)/100
type:
m
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . (0.6 to 1) for the experimental coefficient
3, the principle of choosing a curing agent
(1) from the performance requirements to choose: some requirements resistant to high temperature, some requirements of good flexibility, some requirements of good corrosion resistance, according to different requirements to choose the appropriate curing agent.
(2) from the curing method to choose: some products can not be heated, then can not choose the curing agent of thermo cure.
(3) from the applicable period to choose: the so-called applicable period, that is, the epoxy resin added to the curing agent from the time to the time when it cannot be used. To be applied for a long period of time, acid anhydrides or latent curing agents are generally used.
(4) from the safety of the choice: generally requires less toxicity as well, easy to safe production.
(5) is selected from the cost.
3, the choice of modifier
the role of modifier is to improve epoxy resin tanning, shear resistance, anti-bending, anti-flushing, improve insulation performance. Commonly used modifiers and characteristics to make a brief introduction.
(1) polysulfur rubber: can improve impact strength and peeling performance;
(2) polyamide resin: can improve brittleness, improve bonding capacity;
(3) polyethylene alcohol statins: improve impact resistance;
(4) butyl rubber: improve impact resistance,
(5) phenolic resins: can improve temperature and corrosion resistance;
(6) polyester resin: improve impact resistance;
(7) Urinary melamine resin: increase chemical resistance and strength;
(8) acetaldehyde resin: improve static bending performance, improve acid resistance performance;
(9) ethylene resin: improve peeling resistance and flush strength;
(10) isocyanate: reduce moisture permeability and increase water resistance;
(11) silicone resin: improve heat resistance.
polysulfur rubber and other dosage can be between 50-300%, need to strengthen the chemical agent, polyamide resin, phenolic resin dosage is generally 50-100%, polyester resin dosage is generally 20-30%, can no longer be additional reinforcement agent, can also add some curing agent to promote faster reaction.
generally speaking, the more modifier dosage, the greater the flexibility, but the thermal deformation temperature of resin products will decrease accordingly. To improve the flexibility of the resin, tougheners such as phthalates or phthalates are also commonly used.
4, filler selection
the role of fillers is to improve some of the properties of the product, and improve the heat dissipation conditions when the resin curing, the use of fillers can also reduce the amount of epoxy resin, reduce costs. Different fillers are available depending on the use. Its size is preferably less than 100 eyes, the dosing depends on the use. Common fillers are as follows:
asbestos fiber, glass fiber
: increase toughness, impact resistance;
. Alumina, porcelain powder: increase the adhesion, increase mechanical strength;
. asbestos powder, silicone powder, high temperature cement: improve heat resistance;
asbestos powder, quartz powder, asbestos powder: reduce shrinkage;
aluminum powder, copper powder, iron powder and other metal powders: increase heat conductivity, conductivity;
graphite powder, talcum powder, quartz powder: improve anti-wearing performance and lubrication performance;
. gold sand and other abrasives: improve anti-wear performance;
mica powder, porcelain powder, quartz powder: increase insulation performance;
Various pigments, graphite: with color;
additional data show that the appropriate amount (27-35%) p, as, sb, bi, ge, sn, pb oxides added in the resin can be high heat, pressure to maintain adhesion.
5, thinner selection
the role of thinner is to reduce viscosity, improve the permeability of the resin. Diluents can be divided into two major categories of inertness and activity, the dosage generally does not exceed 30%. Commonly used thinners are: di-shrink glyceroid ether, multi-shrink glyceride ether, epoxy propane butyl ether, epoxy propane ether, diethylene propane ether, triethyl propane propyl ether, inert thinner, xylene, toluene, propone and so on.
Before adding curing agents, all materials such as resins, curing agents, fillers, modifiers, thinners must be inspected and the following requirements should be met:
(1) water-free: water-containing materials must first be dried, solvents containing small amounts of water should be used as little as possible.
(2) Purity: Impurities other than water are best contained at less than 1%, and if impurities are available at 525%, increase the percentage of the formula. The reagent level is better when used in small amounts.
(3) to see if the materials are in failure.