Curable bonded assemblies capable of being dissociated

An adhesive and composition technology, which is applied in the direction of adhesive heating, non-polymer adhesive additives, adhesives, etc., can solve the problem of limited strength of adhesive joints and irregular distribution of heat-activatable substances , adhesive thermal decomposition and other problems, to save time and energy, avoid non-selective thermal decomposition

Inactive Publication Date: 2007-10-17
EVONIK DEGUSSA GMBH +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The use of chemical agents has the disadvantage that they can cause serious environmental pollution and that it takes a very long time for the chemicals to penetrate into the bondline of a long-term stable structurally bonded joint
These fillers have the following disadvantage: the size of the particles is several micrometers or even larger, which leads to non-uniform heating of the contact adhesive
However, the disadvantage of this method is that the entire adhesive must be heated, including where heating is not needed or desired, because the activatable nanofillers are also included in the adhesive or primer where heating is not required to separate the bonded joint
Additionally, high temperatures are required to separate high-strength bonded joints because chemical bonds must be broken to break up the composite
The described method also has the disadvantage of non-specific thermal decomposition of the adhesive and / or primer when separating high-strength bonded joints
However, conventional methods of making adhesive bonded joints have the disadvantage that the entire structure has to be heated in order to cure the adhesive
However, these methods have the disadvantage that the inductively activatable substance is not evenly distributed in the adhesive and thus leads to uneven heating of the adhesive
As a result, the strength of such bonded joints is limited
In addition, this method also has the following disadvantages: during the induction heating process, back mixing may occur in the adhesive, and the distribution of the heat-activatable substance in the adhesive becomes more irregular

Method used

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  • Curable bonded assemblies capable of being dissociated
  • Curable bonded assemblies capable of being dissociated
  • Curable bonded assemblies capable of being dissociated

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0068] Example 1: Curing and Separation of Adhesive Joints Containing Inductively Excitable Filler Particles Bonded to Crosslinkers

[0069] 1a) Nano-sized magnetite coated with silica

[0070] 43.3 g of iron (III) chloride hexahydrate was dissolved in 370 ml of water, and then dissolved oxygen was removed by blowing nitrogen gas through the solution. 15.9 g of iron(II) chloride tetrahydrate were added, followed by a solution of 25.6 g of sodium hydroxide in 100 ml of water dropwise in a stream of nitrogen over 2 hours while stirring with a precision glass stirrer. thus forming Fe 3 o 4 fine granular black precipitate. Add 22 g of Na dropwise over a period of 30 minutes 2 Si 3 o 7 (annealing loss 17% by weight) solution in 80 ml of hot water. The silicic acid was precipitated by the slow dropwise addition of hydrochloric acid (14 ml of 37% hydrochloric acid, made up to 50 ml with water) with further stirring. The precipitate was filtered and slurried with water 5 times...

Embodiment 2

[0077] Example 2: Adhesive joints separable by inductively excitable gas agents

[0078] 2a) Recipe consisting of magnetite powder and gas generator

[0079] 20 g of the material prepared according to 1 a) (40% residual water content in the filter cake) or nano-sized magnetite powder obtained from other sources was suspended in 100 ml of ethanol, and 20 g of oxy-bis( benzosulfonyl hydrazide) as an infuriating agent. The mixture was heated with stirring at 70°C for 4 hours and the solvent was removed on a rotary evaporator. The dry formulation was ground in a ball mill for 5 minutes and then sieved. The fraction with particle size nominally smaller than 63 μm was used in further experiments.

[0080] 2b) Incorporation of the mixture of example 2a) in the adhesive

[0081] Stir 8g of 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexane-formic acid ester, 2g of polytetrahydrofuran (M n =250), 0.1 g of (cresyl cumyl) iodonium tetrakis (pentafluorophenyl) borate and 0.04 g of ascorb...

Embodiment 3

[0087] Example 3: Separation of glass bonded bodies based on adhesives containing inductively excitable gassing agents

[0088] 3a) Formulation of composite particles and binders prepared by flame pyrolysis

[0089] 25 g of nano-sized composite particles prepared by flame pyrolysis and composed of silica and iron oxide (the properties of which are shown in Table 1) were suspended in 100 ml of ethanol, and then 20 g of oxy-bis(benzene and sulfonyl hydrazide) as an infuriating agent. The mixture was heated with stirring at 60°C for 5 hours and the solvent was removed on a rotary evaporator. The dry formulation was ground in a ball mill for 3 minutes and then sieved. The fraction with particle size nominally less than 63 μm was used in further experiments.

[0090] 3b) Incorporation of the formulation of Example 3a) in the adhesive and the adhesive experiment

[0091] 300 g of the hydraulic one-component polyurethane binder Dinitrol PUR 501 were used in a Planimax (Molteni) m...

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Abstract

The present invention relates to an adhesive composition for producing thermoset products, capable of being heated by means of an electric field, a magnetic field, an electromagnetic field or an alternating electromagnetic field, and containing filler particles which are metallic, ferromagnetic, ferrimagnetic, superparamagnetic or paramagnetic. Said adhesive composition can be hardened under the action of heat to form a high-resistance stable adhesive assembly, said resulting adhesive assemblies capable of being likewise dissociated under the action of heat.

Description

technical field [0001] The invention relates to an adhesive composition according to the preamble of the main claim, comprising inductively heatable filler particles, its use and a curing method. The invention also relates to an adhesive compound comprising a hardened layer of said adhesive composition, a method for thermally separating said hardened adhesive composition, and the use of this method. Background technique [0002] Adhesive bonds, such as in particular bonded joints, coatings, laminates or cast structures, should be designed to be able to be produced under mild conditions, to be as durable as possible and to have the highest possible strength. High strength means that, during repair or recycling, separation of the adhesively bonded body can only be achieved under extreme conditions, for example under the action of strong forces and high temperatures. Bonded joints based on reinforcing adhesives are often separable but not suitable for transferring the high str...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C09J11/04C08K9/04C08J9/10C09J5/06C09J9/00
CPCC09J9/00C08J2207/02C08K9/04C08J9/10C09J5/06C09J11/04C09J2205/302C09J2301/502
Inventor 让娜·科尔贝托马斯·科瓦利克马蒂亚斯·波普莫妮卡·泽巴尔德奥利弗·朔尔施斯特凡·黑贝雷尔马库斯·普里德尔吉多·齐默尔曼安德烈亚斯·哈特维希埃尔温·博恩
Owner EVONIK DEGUSSA GMBH
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