Processes for producing viscous epoxy syrups and epoxy syrups obtainable thereby

Patent metadata

Field	Value
Publication number	US-2016355634-A1
Application number	US-201615171037-A
Country	US
Kind code	A1
Filing date	Jun 2, 2016
Priority date	Jun 4, 2015
Publication date	Dec 8, 2016
Grant date	—

Abstract

A process for producing a viscous epoxy syrup from at least one liquid multifunctional epoxy, comprising the steps of:
adding an initiator selected from the group consisting of electron-poor monoisocyanate, photoinitiator and thermal initiator to at least one liquid multifunctional epoxy; mixing the components; polymerizing the multifunctional epoxy such that the viscosity of the resulting epoxy syrup is at least twice as high, preferably at least four times as high and in particular at least ten times as high as the viscosity of the employed epoxy in the unreacted state

makes it possible to produce epoxy adhesives having pressure-sensitive properties.

First claim

1 . Process for producing a viscous epoxy syrup from at least one liquid multifunctional epoxy, comprising the steps of:
adding an initiator selected from the group consisting of electron-poor monoisocyanate, photoinitiator and thermal initiator to at least one liquid multifunctional epoxy; mixing the components; polymerizing the multifunctional epoxy such that the viscosity of the resulting epoxy syrup is at least twice as high, as the viscosity of the employed epoxy in the unreacted state.

2 . Process according to claim 1 , wherein in the resulting epoxy syrup at least 65% of the original epoxy groups are still present.

3 . Process according to claim 1 , wherein the resulting epoxy syrup comprises high molecular weight uncrosslinked polyepoxies.

4 . Process according to claim 1 , wherein the at least one multifunctional epoxy is a bisepoxy.

5 . Process according to claim 1 , wherein the at least one multifunctional epoxy is a bisepoxycyclohexyl derivative or a bisepoxy based on bisphenol A, bisphenol S or bisphenol F.

6 . Process according to claim 1 , wherein the at least one multifunctional epoxy is 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexane carboxylate.

7 . Process according to claim 1 , wherein the initiator is selected from the group consisting of photoinitiator and thermal initiator and is employed in an amount of not more than 0.1 wt %.

8 . Process according to claim 1 , wherein the initiator is an electron-poor monoisocyanate and is employed in an amount of not more than 10 wt %.

9 . Process according to claim 8 , wherein the initiator is selected from the group consisting of p-tolyl isocyanate, o-tolyl isocyanate and sulphonyl isocyanates.

10 . Process according to claim 8 carried out at a temperature between 20° C. and 120° C.

11 . Process according to claim 1 , wherein the polymerization is stopped by addition of an initiator scavenger upon reaching a desired viscosity.

12 . Process according to claim 11 , wherein a mixture of water and acetone, solutions of alkali metal/alkaline earth metal hydroxides or solutions of alkali metal/alkaline earth metal alkoxides are used as the initiator scavenger.

13 . Process according to claim 1 , wherein the polymerization of the multifunctional epoxy is effected such that the resulting epoxy syrup has a polydispersity D of at least 3.

14 . Viscous epoxy syrup obtained by the process of claim 1 .

15 . Viscous epoxy syrup comprising multifunctional epoxy monomers and high molecular weight uncrosslinked multifunctional polyepoxies prepared therefrom, wherein the viscosity of the epoxy syrup is at least twice as high as the viscosity of the employed epoxy in the unreacted state.

16 . Viscous epoxy syrup according to claim 15 , wherein the molecular weight distribution of the polyepoxies present in the epoxy syrup encompasses at least the range from 2000 g/mol to 300 000 g/mol.

17 . Viscous epoxy syrup according to claim 14 , wherein the viscosity increase during storage at 25° C. is less than 5 Pa s per day.

18 . Viscous epoxy syrup according to claim 14 , wherein the epoxy monomer is 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexane carboxylate and the viscosity is at least 1 Pa s (1000 mPs).

19 . Adhesive having water vapor barrier properties, comprising
an adhesive base composed of
at least one epoxy syrup according to claim 14
at least one elastomer
optionally a solvent, wherein
the adhesive base has a water vapor permeation rate after activation of the reactive resin component of less than 100 g/m 2 d.

20 . Adhesive tape comprising a viscous epoxy syrup according to claim 14 .

21 . A method for encapsulation of assemblies in the field of organic electronics, wherein said assemblies are encapsulated with the adhesive of claim 19 .

22 . Adhesive tape comprising an adhesive having water vapor barrier properties according to claim 19 .

Assignees

• Tesa Se

Inventors

• Schuh Christian
• KEITE-TELGENBüSCHER KLAUS
• Shu Yao

Classifications

• C08K5/16

  Nitrogen-containing compounds {(C08K5/0091 takes precedence)} · CPC title

• C09J163/00 Primary

  Adhesives based on epoxy resins; Adhesives based on derivatives of epoxy resins · CPC title

• C08G59/245

  aromatic · CPC title

• C08G59/32

  Epoxy compounds containing three or more epoxy groups · CPC title

• C08G59/02

  Polycondensates containing more than one epoxy group per molecule · CPC title