Propylene Hotmelt Adhesive Resolving Agglomeration and Heat Resistance
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Solution Overview
Problem
Current hotmelt adhesives for woodworking and related applications face issues such as agglomeration problems, high softening points requiring high application temperatures, low setting speed, and inadequate heat and cold resistance, which limit their effectiveness and versatility.
Innovation Solution
A hotmelt adhesive composition comprising 15-35% tackifying resin and 60-85% of a mixture of single-site catalyzed propylene homopolymer and propylene copolymer, with specific molecular weight and viscosity ranges, which eliminates residual tack and agglomeration, allows for lower application temperatures, and provides fast setting and improved heat and cold resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If APAO based polymers are used to achieve acceptable heat resistance and adhesion properties, then heat resistance and adhesion are improved, but residual tack creates agglomeration problems and softening points are high requiring high application temperatures
Solution Approach 1:
The patent changes the polymer parameters by using single-site catalyzed propylene homopolymer with specific molecular weight (40,000-140,000) and propylene copolymer with controlled ethylene content (5-15%), replacing traditional APAO polymers. This parameter change eliminates residual tack while maintaining heat resistance and adhesion properties.
Solution Approach 2:
The patent creates a composite adhesive system combining propylene homopolymer and propylene copolymer in specific ratios (weight ratio 1:1 to 5:1), along with tackifying resin (15-35 wt%). This composite material approach achieves the desired balance of heat resistance, adhesion, and freedom from agglomeration problems.
2Object-generated harmful factors
If metallocene technology based polymeric materials are used, then some problems are addressed, but viscosity levels are low, heat resistance is poor and setting characteristics are poor
Solution Approach 1:
The patent optimizes viscosity by selecting propylene homopolymer with weight average molecular weight of 40,000-140,000, which provides appropriate viscosity levels unlike metallocene materials. The controlled molecular weight parameter ensures good setting characteristics while maintaining heat resistance.
Solution Approach 2:
The patent formulates a composite system combining propylene homopolymer and propylene copolymer with tackifying resin, creating a material that achieves both high viscosity for good setting characteristics and adequate heat resistance, overcoming the limitations of metallocene-based single-component systems.
3Reliability
If high softening point materials are used to achieve heat resistance, then heat resistance is improved, but application temperatures must be high increasing energy consumption
Solution Approach 1:
The patent changes the softening point parameter by using propylene-based polymers with controlled molecular weight and composition, achieving adequate heat resistance at lower softening points compared to APAO polymers, thus reducing application temperature and energy consumption.
4Productivity
If fast setting adhesive is used to improve productivity, then setting speed is improved, but open time is reduced limiting working time
Solution Approach 1:
The patent optimizes the molecular weight parameter of propylene homopolymer (40,000-140,000) and ethylene content of propylene copolymer (5-15%) to achieve a balance between setting speed and open time, allowing adequate working time while maintaining fast setting characteristics.
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 adhesive composition offers stable adhesion over broad temperature ranges, long open-time, and reliable bonding of various materials, particularly suitable for woodworking and textile applications, with enhanced heat and cold resistance.
Implementation Method 1
hotmelt adhesive composition comprising at least one tackifying resin and a high amount of a mixture of at least one single-site catalyzed propylene homopolymer and at least one propylene copolymer
Implementation Method 2
adhesiveness is exhibited after the adhesive is melted by heating and coated onto an adherend
Implementation Method 3
followed by cooling to solidify the adhesive
Data Source
AI summary
The present invention relates to a hotmelt adhesive composition comprising 15 to 35% by weight of at least one tackifying resin, and 60 to 85% by weight of a mixture of at least one single-site catalyzed propylene homopolymer (A) and at least one propylene copolymer (B), wherein the propylene homopolymer (A) has a weight average molecular weight of 40,000 to 140,000, the propylene copolymer (B) has an ethylene comonomer content of 5 to 25% by weight, and the weight ratio of propylene homopolymer (A) to propylene copolymer (B) is 1:1 to 5:1.