Aluminum Alkoxide Crosslinking Agent for Aqueous Resins
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Solution Overview
Problem
Existing crosslinking agents for aqueous resins, such as polycarbodiimides and polyoxazolines, face challenges in achieving high crosslinking reactivity due to hydrolysis issues and reactions with amine compounds, leading to decreased crosslinking groups and incomplete curing.
Innovation Solution
The use of metal alkoxides, specifically titanium, zirconium, or aluminum alkoxides with substituents derived from polyalkylene glycol monohydrocarbyl ethers, which enhance hydrolysis resistance and improve crosslinking reactivity when combined with polycarbodiimides and polyoxazolines.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If alkali metal or alkaline earth metal alkoxides are used to promote carbodiimide crosslinking reaction, then crosslinking reactivity is improved, but hydrolysis resistance deteriorates and handling safety worsens
Solution Approach 1:
The patent changes the metal parameter from alkali/alkaline earth metals to aluminum, fundamentally altering the chemical properties of the crosslinking system. Aluminum alkoxide provides both the desired crosslinking promotion capability and superior hydrolysis resistance, resolving the contradiction between reactivity and stability.
Solution Approach 2:
The patent replaces expensive and hazardous alkali metal/alkaline earth metal alkoxides with aluminum alkoxide, which is more stable and less prone to hydrolysis. This substitution maintains crosslinking effectiveness while eliminating the handling safety issues and hydrolysis problems associated with the previous metals.
2Productivity
If amine compounds are added to aqueous titanium composition, then crosslinking reaction is promoted, but crosslinking groups decrease due to reaction between amine and carbodiimide group
Solution Approach 1:
The patent extracts the amine compound from the crosslinking system, eliminating the harmful side reaction between amine and carbodiimide group. By removing this interfering component, the patent preserves the crosslinking groups for their intended function while still achieving effective crosslinking through aluminum alkoxide promotion.
Solution Approach 2:
The patent introduces aluminum alkoxide as an intermediary substance that facilitates crosslinking without consuming crosslinking groups. Aluminum alkoxide acts as a catalyst or promoter that enables crosslinking reaction to proceed efficiently without the side reactions that occur with amine compounds.
3Adaptability or versatility
If polycarbodiimide and polyoxazoline are used as crosslinking agents, then crosslinking capability is provided, but crosslinking reactivity is low relative to alcoholic hydroxy group
Solution Approach 1:
The patent introduces aluminum alkoxide as an intermediary that mediates between the crosslinking agents (polycarbodiimide/polyoxazoline) and the alcoholic hydroxy groups. This intermediary substance enhances the reactivity of the crosslinking agents, enabling them to react more effectively with the hydroxy groups in the aqueous resin.
Solution Approach 2:
The patent changes the chemical parameter of the crosslinking system by introducing aluminum alkoxide, which modifies the reactivity parameters of the crosslinking agents. This parameter change enables the crosslinking reaction to proceed at higher rates while maintaining the desired crosslinking capability.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The metal alkoxides significantly improve the crosslinking reactivity of polycarbodiimides and polyoxazolines, leading to aqueous resin compositions with higher crosslinking degrees and enhanced water resistance and durability.
Implementation Method 1
a crosslinking agent composition for aqueous resin and an aqueous resin composition each using the same... by allowing a polycarbodiimide to react with a compound having a hydroxy group or a mercapto group in the presence of an alcoholate (alkoxide) of an alkali metal or alkaline earth metal, a crosslinking reaction by a carbodiimide group is promoted
Implementation Method 2
the alkali metal or alkaline earth metal is used as the metal of the metal alkoxide, such is easily hydrolyzed... the present inventors have found a metal alkoxide which is excellent in hydrolysis resistance
Data Source
AI summary
The present invention provides a novel metal alkoxide having excellent hydrolysis resistance, and a crosslinking agent composition for aqueous resin and an aqueous resin composition each using the same. A metal alkoxide represented by the following formula (1-1), (1-2), or (1-3) and having a mass average molecular weight of 800 to 8,500 is used: Ti(OA)4 (1-1) Zr(OA)4 (1-2) Al(OA)3 (1-3) wherein A's are each independently a residue resulting from removal of a hydroxy group from a polyalkylene glycol monohydrocarbyl ether represented by the following general formula (1a): R11(OCHR12CH2)nOH (1a) wherein R11 is an alkyl group having 1 to 4 carbon atoms or a phenyl group; R12 is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms; and n is an integer of 4 to 45.