UV Curable raw Materials

1)、Bisphenol A epoxy resin

UV resin is produced by the bisphenol A and excessive epichlorohydrin through alkali catalysis and reaction. It’s a polycondensation reaction,

The equation is as follows

The structural formulas is as follows：

The unit of bisphenol A epoxy resin give the resin function：

1、The epoxy group and hydroxyl give the resin reactivity 

2、The hydroxyl is a polar group, It helps to improve the wetting and adhesion

3、The ether bond and the c-c bond make the macromolecule with flexibility.；

4、The benzene ring gives the heat resistance and rigidity of polymer；

5、The -c-o - bond has a high bond energy, which increases alkalinity

The reaction and decomposition processes:

1, The ring opening reaction

    2, The condensation reaction

   3, The ring opening reaction

4, The condensation reaction

5, The macromolecule of the epoxy resin be formed through many times the ring opening reaction and the condensation reaction

Remark：

⑴ n＝0～2，Low molecular weight, it’s a liquid at room temperature

⑵ n＝2～5，Medium molecular weight, it’s a solid at room temperature, the softly point is 50℃～90℃

⑶ n＞5, High molecular weight, the epoxy value index is 0.48～0.54mol/100g, it’s a solid at room temperature,the softly point is＞100℃。

The processes:

Technical specifications of bisphenol A epoxy resin made in China：

2), Novolac Epoxy

The novolac epoxy was produced by polycondensation reaction of phenol and formaldehyde in acidic medium, and then polycondensation reaction with excessive epichlorohydrin in the presence of sodium hydroxide.

Compared with bisphenol A type epoxy resin, Novolac epoxy resin, there are two or more epoxy groups in the molecular structure.which has high crosslink density after curing, and the heat resistance, solvent resistance, chemical resistance and dimensional stability of product will be relatively improved.However, the brittleness of the product will increase and the adhesion to the copper foil will decrease. Currently the most commonly used Novolac epoxy resin F-51.

3)、O-methyl Novolac epoxy

The O-methyl novolac epoxy was produced by polycondensation reaction of o-methylphenol and formaldehyde in acidic medium, and then polycondensation reaction with excessive epichlorohydrin in the presence of sodium hydroxide.

     The structural formulas is as follows：

The o-methyl novolac epoxy resin is basically the same as the phenol novolac epoxy resin,except that there is a methyl group in the o-position of benzene ring, which is superior to the former in terms of water resistance and melt viscosity.

4),  Polyether polyol

Polyether polyol refers to an alcohol (initiator) containing more than 2 hydroxyl groups with PO/EO ring opening polymerization to     form the chemical compound with hundreds or thousands of molecular weight terminal hydroxyl groups. The functionality of polyether polyol depends on Initiator functionality.

Common types of initiators：

Reaction Processes：

5),  Polyester Diol

Synthetic material 1: Dibasic acid or anhydride, mainly include Phthalic anhydride(PA), m-phthalic acid(IPA),terephthalic acid(PTA), succinic acid,glutaric acid ,Hexanedioic acid (AA),heptandioic acid,Suberic acid.

Synthetic material 2: Diol glycol, 1, 2-propylene glycol,1, 3-propylene glycol,1, 4-butanediol,1, 2-butanediol, 1.3-butanediol, 2-methyl-1, 3-propylene glycol (MPD), neopentyl glycol (2, 2-dimethyl-1, 3-propylene glycol,NPG),1, 5-pentanediol,1, 6-hexanediol (1, 6-hdo)

At polyester resin formula , if it want a excellent performance of polyester, A variety of alcohols and acids should be used together, to achieve a balance of hardness, flexibility, adhesion, impact resistance and cost.

Polyurethane prepared from polycarbonate has excellent weather resistance, chemical resistance, hydrolysis resistance and wear resistance, Conventional methods: Transesterification,take dimethyl carbonate or diphenyl carbonate as raw materials with aliphatic diols for transesterification and condensation.

Reaction formula：