Hot-Melt PSA Composition to Suppress Rapid Gelation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The rapid gelling of solvent-free hot-melt pressure-sensitive adhesive (PSA) compositions during heating for film formation leads to non-uniform thickness and poor appearance of the PSA layer, affecting adhesive performance.
Innovation Solution
A solvent-free hot-melt PSA composition comprising a base polymer, an isocyanate crosslinking agent, and a tackifier A with a specific formula, which suppresses rapid gelling during heating, ensuring uniform thickness and improved adhesive performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If conventional hot melt adhesives are used, then adhesion to porous substrates is achieved, but water resistance and bonding strength are insufficient
Solution Approach 1:
The patent uses a composite adhesive system combining polyolefin resin (provides water resistance) with rosin and rosinate (provide adhesion to porous substrates). This composite formulation achieves both water resistance and strong bonding to porous materials like paper and cardboard, resolving the contradiction between these two properties.
Solution Approach 2:
The patent modifies the chemical composition parameters of the adhesive by incorporating specific ratios of polyolefin resin (60-95 mass%), rosin (0.1-5 mass%), and rosinate (0.1-5 mass%). By adjusting these compositional parameters, the adhesive achieves optimal balance between water resistance and bonding strength to porous substrates.
2Reliability
If polyolefin resin is used as adhesive, then water resistance is improved, but adhesion to porous substrates deteriorates
Solution Approach 1:
The patent combines polyolefin resin with rosin and rosinate in specific proportions. The polyolefin resin provides water resistance while the rosin and rosinate components provide adhesion to porous substrates, creating a composite adhesive that achieves both properties simultaneously.
Solution Approach 2:
The patent assigns different functional roles to different components: polyolefin resin for water resistance, rosin for adhesion promotion, and rosinate for bonding strength. Each component contributes its specific property to the overall adhesive performance, allowing the adhesive to exhibit both water resistance and strong adhesion to porous substrates.
3Reliability
If resin composition is optimized for water resistance, then bonding strength at high temperature deteriorates
Solution Approach 1:
The patent optimizes the compositional parameters by incorporating rosinate (0.1-5 mass%) in addition to polyolefin resin and rosin. The rosinate component specifically enhances high-temperature bonding strength while the polyolefin resin maintains water resistance, achieving optimal performance across different temperature conditions.
Solution Approach 2:
The patent creates a multi-component composite adhesive system where polyolefin resin provides water resistance, rosin provides adhesion, and rosinate provides high-temperature bonding strength. This composite formulation resolves the contradiction between water resistance and high-temperature bonding performance.
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 composition enables the formation of a PSA layer with favorable adhesive strength, uniform thickness, and appearance, while reducing environmental impact.
Implementation Method 1
a hot melt adhesive composition comprising a polyolefin resin, rosin and rosinate
Implementation Method 2
water resistance and bonding strength
Data Source
Figure 1~2
AI summary
Provided is a hot-melt pressure-sensitive adhesive composition which enables to form a pressure-sensitive adhesive layer without allowing the progression of rapid gelation at the time of heating and melting. The pressure-sensitive adhesive composition provided by the present invention is a solvent-free hot-melt pressure-sensitive adhesive composition. The pressure-sensitive adhesive composition includes a base polymer, an isocyanate crosslinking agent, and a tackifier A represented by the following general formula (1): R-[(CH3)2C6H2-(CH2O)n-CH2]m-OH (1) (in the general formula (1), R is a hydrogen atom or a hydroxyl group, m is 9 to 16, and n is 0 to 3). A content of the tackifier A with respect to 100 parts by weight of the base polymer is 1 part by weight to 10 parts by weight.