Package assembly adhesives must maintain bond strength across temperatures from -40°C to 85°C while managing chemical migration concerns. Current two-component polyurethane systems show residual isocyanate monomer levels of 0.1-1.0%, which poses challenges for food-contact applications. Additionally, these adhesives must achieve complete cure within 24-48 hours under varying humidity conditions.

The fundamental challenge lies in developing adhesive systems that combine rapid cure rates and strong bonds while eliminating chemical migration and maintaining processability in high-speed assembly lines.

This page brings together solutions from recent research—including low-monomer polyisocyanate formulations, dual-property adhesive configurations, and biodegradable compositions with controlled melt viscosity. These and other approaches focus on practical implementation in modern packaging operations while addressing both performance and safety requirements.

1. Polyisocyanate Composition with Xylene Diisocyanate and Diol Reaction Product Exhibiting Reduced Monomer Content

DIC CORP, 2025

A polyisocyanate composition for two-component curing applications like adhesives and coatings. The composition contains a specific type of polyisocyanate made by reacting xylene diisocyanate and a diol with a molecular weight of 65-300. This polyisocyanate has lower diisocyanate monomer content compared to conventional polyisocyanates. It provides improved safety and reduced migration concerns in applications like food packaging adhesives. The lower diisocyanate monomer content reduces the risk of unreacted diisocyanate remaining in the final product.

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2. Packaging Box Adhesive Structure with Dual-Property Adhesive Configuration and Integrated Adhesive Holes

YOUNGJIN PACKAGING CO LTD, 2024

Adhesive structure for packaging boxes that improves adhesion strength between side plates by using different adhesives with complementary properties. The structure involves two adhesive types, like hot melt and water-based emulsion, applied side by side on the side plate folding surfaces. An adhesive hole is formed between the adhesive sections. The holes are filled with either adhesive type to increase adhesion area. This leverages the advantages of each adhesive type, like heat resistance vs water resistance, while mitigating their weaknesses.

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3. Laminated Film with Solventless Adhesive Applied via Roll Coating Device for Reduced Air Bubble Formation

TOYO SEIKAN CO LTD, 2024

Reducing air bubble formation in laminated films used for packaging containers like pouches and lids. The method involves coating one film with a solventless adhesive using a specialized roll coating device. The coated film is then laminated with the other film while sandwiched between them. The coating device has a configuration with rolls and transfer rolls to precisely apply the adhesive. The adhesive has specific viscosity and components like a polyester resin and aliphatic isocyanate curing agent. This allows controlled adhesive layering and bonding to reduce air trapped between films and prevent orange peel appearance in the laminated film.

4. Two-Component Curing Adhesive Composition with Acid Anhydride Oil/Fat and Acid-Modified Polyol-Amine Curing Agent

DIC CORP, 2024

Two-component curing adhesive composition and laminate made using it that combines recyclability and biodegradability. The adhesive composition contains an oil/fat with an acid anhydride group and a curing agent containing an acid-modified polyol and an amine compound. The oil/fat provides the adhesive strength when cured. The modified polyol and amine compound catalyze the reaction between the acid anhydride group and hydroxyl groups to form a crosslinked network. This allows a recyclable and biodegradable adhesive for laminating films.

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5. Automated Pouch Packaging Machine with Integrated Dunnage Conversion and Sealing Mechanism

RANPAK CORP, 2024

Automated machine for making pouch packages with cushioning. The machine converts sheets into a strip of expanded dunnage and then folds it into a pouch. The conversion step involves layering an upper cover sheet, lower cover sheet, and expanded slit sheet with adhesive between them. Pressure is applied to bond the cover sheets together. The folded pouch is formed by creasing the strip, applying adhesive to the edges, and compressing them to seal.

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6. Two-Component Adhesive Comprising Polyisocyanate and Polyol with Specified Viscosity Range

DIC CORP, 2024

Two-component room temperature curing adhesive with improved adhesion to a wide range of base materials. The adhesive consists of a polyisocyanate composition (X) with a viscosity of 20-180 mPa s at 50°C, and a polyol composition (Y) with a viscosity of 20-180 mPa s at 50°C. This allows the adhesive to cure at room temperature with good adhesion to various substrates.

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7. Two-Liquid Curable Adhesive with Low-Molecular-Weight Isocyanate and Polyol-Amines Blend

DAINIPPON INK & CHEMICALS, 2024

Two-liquid curable adhesive for laminating materials like packaging films that has reduced isocyanate residue compared to traditional adhesives. The adhesive contains a polyisocyanate composition with a specific blend of isocyanate monomers and a polyol composition. The isocyanate composition has a low-molecular-weight isocyanate monomer with 140-280 molecular weight blended at 0.001-0.1% by mass. This reduces the residual isocyanate in the cured adhesive. The polyol composition contains polyols and amines. The specific blend of low-molecular-weight isocyanates allows faster curing of the adhesive while minimizing residual isocyanates.

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8. Gas Barrier Film with Carboxyl Group-Containing Polymer and Dehydration-Condensation Heteroatom Compound

DAINIPPON INK & CHEMICALS, 2024

Gas barrier film for packaging that improves adhesion to other layers when laminated. The film contains a resin with a carboxyl group-containing polymer and a dehydration-condensation heteroatom compound. It optionally has adjacent layers with a polyvalent metal compound and/or an oxide, hydroxide, or nitride compound. The film provides high gas barrier properties and enhanced adhesion to laminated layers compared to conventional gas barrier films.

9. Packaging Laminate with Eco-Friendly Polyurethane Outer Adhesive Derived from Recycled Polyester or Biomass

NAN YA PLASTICS CORP, 2024

Packaging laminate material, outer layer adhesive, and a method for producing the same that uses environmentally friendly materials. The packaging laminate has an inner layer film, outer layer film, aluminum foil, inner adhesive, and outer adhesive. The outer adhesive is a polyurethane made from an eco-friendly polyester polyol derived from recycled polyester or biomass raw materials. The polyol has a weight average molecular weight of 25,000 to 75,000, number average molecular weight of 18,000 to 55,000, and glass transition temperature of -30°C to 60°C. The isocyanate component is an adduct of toluene diisocyanate and a C4-C15 polyol.

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10. Solventless Two-Component Adhesive with Polyisocyanate and Polyol Compositions for Metal Foil Bonding

DAINIPPON INK & CHEMICALS, 2024

A solventless two-component adhesive for packaging materials that provides excellent adhesion to metal foils and metal deposition layers. The adhesive contains a polyisocyanate composition with a specific polyisocyanate compound and a polyol composition containing a polyol and a compound like dimethylolpropionic acid or dimethylolbutanoic acid. The adhesive can be used to laminate base materials without volatile organic solvents, reducing environmental impact and improving worker safety compared to traditional solvent-based adhesives. The adhesive cures when the two components are mixed and applied to the base materials before bonding.

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11. Hot Melt Self-Adhesive Composition with Specific Tackifying Resin and Styrenic Block Copolymer Ratios

BOSTIK SA, 2024

Hot melt self-adhesive composition for resealable packaging with improved adhesive properties and quality of rupture. The composition contains specific ratios of tackifying resins and styrenic block copolymers. The tackifying resin is a non-hydrogenated tackifier derived from aliphatic hydrocarbons like C9 aromatic hydrocarbons. The composition also has a C2/C4 copolymer with >80% C2 content and a C2/C3/C4 copolymer. The composition is used in multilayer films for resealable packaging with improved adhesion, sealing, and rupture characteristics.

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12. Gas Barrier Film with Stretched Polyethylene Base and Inorganic Oxide Layer for Enhanced Layer Adhesion

TOPPAN INC, 2024

Gas barrier film for packaging applications that provides a mono-material packaging solution while maintaining strong adhesion between layers. The film has a base material made of stretched polyethylene with a low probe descent temperature (around 170°C) to enhance adhesion to the heat seal layer. An inorganic oxide layer or oxygen barrier membrane is formed on the base material surface. The film can be used in a laminate structure with another polyethylene layer joined by adhesive. The low probe descent temperature base material enables strong adhesion between the layers without delamination.

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13. Integrated Machine for Combined Printing, Drying, Folding, Joining, and Adhesive Application in Packaging Materials

KIM SE YOUNG, 2024

Integrated device for packaging printing and adhesive application that automates the production of self-adhesive packaging materials like self-sealing plastic wrap. The device combines all the necessary steps from printing and drying the packaging material to folding, joining, and applying adhesive in a single integrated machine. This eliminates the need for separate machines and manual transfer steps between them, improving efficiency and productivity.

14. Laminate Structure with Solvent-Free Adhesive and Reduced Air Bubble Formation

TOPPAN HOLDINGS INC, 2024

Laminate with excellent strength and physical properties, especially when made using a solvent-free adhesive to bond films like gas barrier films. The key is suppressing air bubble formation in the adhesive layer. The laminate has an area ratio of air bubbles in the adhesive layer of 4% or less when observed from the lamination direction. This is achieved by techniques like increasing roll temperature, pressure, and curing time during adhesive application to smooth out the adhesive surface and prevent bubbles.

15. Two-Component Solvent-Free Adhesive Comprising Polyisocyanate and Polyol Compositions with Polyoxyalkylene Chains and Polyamine Compound

DIC CORP, 2024

Two-component solvent-free adhesive for laminates that can be dried with excellent initial cohesive strength. The adhesive contains a polyisocyanate composition with a polyisocyanate compound, a polyol composition with polyester polyol, a compound with polyoxyalkylene chains and hydroxy groups, and a polyamine compound. This adhesive provides initial cohesive strength that is higher than freshly made and reduces over time compared to solvent-based adhesives. The adhesive is useful in laminate manufacturing as it allows air bubbles to be minimized and reduces defects.

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16. Layered Packaging Structure with Epoxy-Based Adhesive for Oxygen Barrier Retention After Heat Sealing and Retort Sterilization

TOYO SEIKAN GROUP HOLDINGS LTD, 2024

Layered packaging structure for oxygen barrier bags that maintains barrier properties after heat sealing and retort sterilization. The structure has a barrier film with an inorganic coating on a thermoplastic base, an adhesive layer, and a heat-sealing layer. The key is using an epoxy-based adhesive in the adhesive layer. This adhesive has a high storage modulus at 120°C, which helps prevent shrinkage and defects during heat treatments. This epoxy adhesive layer allows the packaging to retain oxygen barrier properties after heat sealing and retort sterilization.

17. Aluminum-Plastic Film Adhesive with Low Melting Point Polyolefin and Bisphenol A Epoxy Resin Components

GUANGDONG BTREE NEW ENERGY MATERIALS CO LTD, 2024

Improved aluminum-plastic film adhesive for lithium battery packaging that provides better electrolyte resistance and heat sealing strength compared to existing adhesives. The adhesive formulation contains components A and B. Component A includes low melting point polyolefin, acid anhydride monomer, initiator, auxiliary agent, and solvent. Component B has bisphenol A epoxy resin, modified bisphenol A epoxy resin, and solvent. The auxiliary agent contains a triazine ring compound. This composition improves adhesion, electrolyte resistance, and heat sealing compared to conventional adhesives.

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18. Packaging Device with Adjustable Angle Adhesive Application Module and Width-Responsive Sensor System

KRONES AG, 2023

Packaging device and method for producing packaging units with improved adhesive bonding between the packaging material and the items. The device has an adjustable adhesive application module that can change its angle of dispensing. This allows optimizing the distance between adjacent adhesive dots or strips based on the width of the packaging material. By adjusting the angle, the spacing between dots can be set to prevent gaps or weak connections. Sensors detect the packaging width and calculate the optimal angle. This eliminates the need to deactivate dispensers for narrow areas.

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19. Automated Packaging Container Manufacturing System with Embedded Leaflet Placement and Adhesion Verification

TANNA TEJAS, 2023

An automated system for manufacturing packaging containers with embedded leaflets that ensures proper placement and adhesion of the leaflets. The system uses a feeding mechanism for the blank containers, an adhesive applicator, a folder-gluer for the leaflets, and detection modules to check for presence of adhesive and leaflets during assembly. The containers, leaflets, and adhesive are transferred together on a conveyor. The first detection module checks for adhesive drops on the container. The second detection module checks for proper leaflet placement. Rejects are generated if either check fails.

20. Solvent-Based Polyurethane Adhesive with Water-Responsive Debonding Capability for Flexible Packaging

HENKEL AG & CO KGAA, 2023

Solvent-based polyurethane adhesive for bonding flexible packaging materials that can be debonded by water treatment. The adhesive composition contains a polyurethane polymer made by reacting polyether polyol and polyisocyanate. It also has organic solvents like ethyl acetate and ethanol. The adhesive cures to bond flexible packaging layers like polyolefins or polyesters. Treating the bonded packaging with water debonds the layers for recycling.

21. Two-Component Curable Adhesive with Specific Viscosity Polyol and Polyisocyanate for Laminates

DIC CORP, 2023

Two-component curable adhesive for bonding base materials in laminates like packaging films. The adhesive has a polyisocyanate composition and a polyol composition with specific viscosity ranges. The polyol composition's viscosity at 50°C is 20-180 mPa·s. This allows aging the adhesive at room temperature without precure steps. The adhesive has good adhesion to various base materials and can be used to make laminates like metalized films with improved bonding properties compared to solvent-free adhesives.

22. Reactive Isocyanate-Polyol Adhesive for Polyolefin Film Lamination with Low-Temperature Cure

DAINIPPON INK & CHEMICALS, 2023

Reactive adhesive for laminated films made from polyolefin resins like polyethylene. The adhesive allows bonding the polyolefin films without degrading their properties when recycled. The adhesive is a reactive isocyanate-polyol system that cures at low temperature. The adhesive has specific properties like particle size and cure characteristics to maintain strength and elongation of recycled plastics. This allows making recyclable laminated films by using a single polyolefin resin in the films and adhesive.

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23. Multilayer Film with Solventless Adhesive Comprising Polyester Resin and Aliphatic Isocyanate with Specific Viscosity Parameters

TOYO SEIKAN CO LTD, 2023

Multilayer film for packaging applications that uses a solventless adhesive to join the layers. The adhesive contains a polyester resin called a "main agent" and an aliphatic isocyanate curing agent. The viscosity of the solventless adhesive is 600-1400 mPa·s at 80°C. This reduces air bubbles in the adhesive layer during lamination and prevents winding misalignment. The main agent has a viscosity of 2000-4500 mPa·s at 80°C. Using this adhesive composition and viscosity range allows successful continuous lamination of multilayer films with improved appearance and strength.

24. Two-Component Curing Adhesive with Polyester Polyol and Isocyanuric Ring Incorporating Drying Aid for Solvent Evaporation

DAINIPPON INK & CHEMICALS, 2023

Two-component curing adhesive with reduced residual solvent for laminates and packaging applications. The adhesive contains a polyester polyol, isocyanate, solvent, and drying aid. The polyester polyol has aromatic carboxylic acid groups and an isocyanuric ring. The drying aid helps evaporate the solvent during cure. This adhesive formulation allows using polyester polyols with aromatic carboxylic acids that have better barrier properties, while minimizing solvent residue in the cured adhesive.

25. Two-Component Adhesive with Polyisocyanate and Polyol Components Exhibiting Controlled Viscosity for Packaging Materials

DAINIPPON INK & CHEMICALS, 2023

Two-component curable adhesive for packaging materials like laminated films that can be aged at room temperature and still provide favorable adhesion to various base materials. The adhesive composition includes a polyisocyanate component and a polyol component with a viscosity of 20-180 mPa/s at 50°C. This viscosity range allows the adhesive to be spread well over base materials at room temperature without excessive thickening. The aged adhesive provides good adhesion to base materials like plastics, metals, and aluminum deposition layers used in packaging films.

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26. Packaging Material with Layered Structure and Specific Molecular Weight Distribution for Enhanced Lamination and Tear Resistance

TOYO INK SC HOLDINGS CO LTD, 2023

A packaging material with improved lamination strength, tear resistance, and low residual solvent levels. The packaging has layers in order: substrate, printed layer, adhesive layer, sealant. The printed layer is a polyester-urethane with Mw/Mn of 4-12. The adhesive layer is cured using a urethane polyol (Mw/Mn 2-17) and isocyanate (Mw/Mn 5.5-18.5). This specific molecular weight distribution range for the isocyanate improves adhesion and tear resistance. The low Mw/Mn polyester-urethane and cured adhesive have better lamination strength and lower residual solvent compared to conventional materials.

27. Water-Based Laminating Adhesive Composition with Nanocellulose-Enhanced Acrylic Emulsion

DOW GLOBAL TECHNOLOGIES LLC, 2023

Water-based laminating adhesive composition for flexible packaging that has improved barrier properties compared to conventional water-based adhesives. The adhesive composition contains an acrylic emulsion, nanocellulose fibers/crystals, and optionally a crosslinker. The nanocellulose additive increases oxygen barrier performance of the laminate when made using this adhesive compared to a standard adhesive without nanocellulose. This allows using water-based adhesives with better barrier properties for flexible packaging applications.

28. Adhesive Composition with Polyisocyanate and Polyol Including Dimethylol Compounds for Laminate Bonding

DAINIPPON INK & CHEMICALS, 2023

Adhesive, laminate, method for producing laminate, and packaging material with improved appearance and strength. The adhesive uses a specific combination of isocyanate and polyol components. The isocyanate component contains a polyisocyanate compound. The polyol component contains a polyol and a compound selected from dimethylolpropionic acid and dimethylolbutanoic acid. This composition suppresses air bubble formation during curing, reducing defects like surface pitting and improving laminate strength. The adhesive is used to bond base materials for laminates like packaging materials.

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29. Two-Component Adhesive with Polyol and Polyisocyanate Compositions Featuring Specific Glycol Content

DIC CORP, 2023

Two-component curable adhesive for laminates that provides excellent boiling resistance and re-dissolution resistance of printed layers even with low molecular weight components. The adhesive consists of a polyol composition (X) and a polyisocyanate composition (Y). The polyol composition (X) contains a polyhydric alcohol (a) and a polyhydric carboxylic acid (b). The polyisocyanate composition (Y) contains a polyester polyol (A) made from reacting a polyhydric alcohol (c) and a polycarboxylic acid (d). The adhesive has a total amount of a specific glycol (c1) in the polyol and polyisocyanate compositions that is 5% to 20% by mass. This glycol (c1) has only one alkyl side chain.

30. Manufacturing Process for Plastic Roll Packs with Enhanced Adhesive Heat Treatment

AINSGRATECH CO LTD, 2023

An improved process for manufacturing plastic roll packs for packaging that provides better adhesion between the packs. The process involves upgrading the adhesive part by subjecting it to a more detailed heat treatment. The roll packs are made by connecting multiple plastic packs with a perforated line. After connecting the packs, the adhesive area is heated to improve adhesion between the packs. This enhanced heat treatment of the adhesive area ensures better bonding between the packs to prevent separation during handling and transportation.

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31. Solvent-Based Two-Component Polyurethane Adhesive with Crystalline Polyester-Polycarbonate and Acrylic Polymer

ROHM AND HAAS CO, 2022

Solvent-based laminating adhesive composition for flexible packaging applications that provides improved oxygen barrier properties compared to standard adhesives. The adhesive composition is a two-component polyurethane made by reacting a crystalline polyester-polycarbonate compound, an acrylic polymer compound, and a solvent. The composition is used to bond layers in flexible packaging structures, like food packaging, to improve oxygen barrier performance of the laminated product.

32. Packaging Film with Solvent-Free Polyisocyanate-Based Adhesive Incorporating Graphene Oxide and Functional Additives

ILJIN GRATEC CO LTD, 2022

Eco-friendly packaging film made using a solvent-free adhesive for lamination that avoids harmful organic solvents. The adhesive composition is a mixture of a main agent containing a polyisocyanate and a curing agent with additives like graphene oxide, titanium dioxide, aluminum nitride, fluorinated ether compound, amine chain extender, and isocyanate group-containing silane. The adhesive is applied to a printed base film, laminated, aged, divided, shaped, and packaged without solvents. The resulting film has improved mechanical properties, durability, and prevents peeling from repeated deformation compared to solvent-based adhesives.

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33. Two-Component Adhesive with Polyisocyanate and Polyol Compositions Featuring Controlled Viscosity

DIC CORP, 2022

Dryable two-component adhesive with improved storage stability and adhesive properties. The adhesive consists of a polyisocyanate composition and a polyol composition. The viscosity of the polyol composition at 50°C is 20-180 mPa·s. This range allows the adhesive to spread well on base materials without excessive thickening during storage. The adhesive provides favorable adhesion to a variety of substrates like films and papers when dried after mixing the components.

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34. Adhesives for Laminate Packaging with Polyester Polyol from Tetrameric Acid and Polyisocyanate Compound

DIC CORP, 2022

Adhesives for laminate packaging with improved retort resistance and fill resistance. The adhesives contain a polyol composition made from a polyester polyol derived from a reaction of polycarboxylic acid and polyhydric alcohol, where the polycarboxylic acid contains tetrameric acids. The isocyanate composition contains a polyisocyanate compound. This adhesive formulation provides better retort resistance and fill resistance compared to conventional adhesives.

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35. Adhesive Composition with Urethane Polymer and Acrylate Compound for Bonding Metal Foil in Battery Packaging Material

DONGWOO FINE-CHEM CO LTD, 2022

Adhesive composition and battery packaging material with improved adhesion and mechanical stability for bonding metal foil to an exterior substrate in battery packs. The adhesive composition contains a urethane polymer and an acrylate-based compound with a non-polar alkyl group. This provides balance between adhesion to metal foil and moldability. The battery packaging material uses the adhesive composition to bond the metal foil and exterior substrate.

36. Chlorinated Polyolefin Resin with Solvent-Free Chlorination and Controlled Molecular Weight Distribution

NIPPON PAPER INDUSTRIES CO LTD, 2022

Chlorinated polyolefin resin for adhesives and coatings that has improved adhesion and no detectable chlorinated low-molecular-weight compounds. The resin is made by chlorinating a mixture of polyolefins with fluidity at 40°C or less and melting points above 40°C. This avoids using organic solvents. The resin has chlorine content of 1-45 wt%. It provides good adhesion to nonpolar resins and compatibility with other coating components.

37. Laminated Structure with Inorganic, Protective, and Resin Layers Featuring Energy-Activated Covalent Bond Formation

TORAY ADVANCED FILM CO LTD, 2022

Laminated structure for packaging materials with improved adhesion between layers for better performance. The laminate has an inorganic layer, a protective layer, and a resin layer. The protective layer contains functional groups that react when irradiated with energy rays. This allows the protective layer and adjacent resin layer to form strong covalent bonds instead of weak intermolecular forces. This improves adhesion between the layers, preventing peeling and delamination during processing and use. The functional groups in the protective layer react with similar groups in the resin layer when exposed to energy rays like UV or electron beams.

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38. Reactive Adhesive for Laminates with Branched Hydrocarbon Polyol Containing Ether and Ester Bonds

DIC CORP, 2021

Reactive adhesive for laminates that provides both good adhesion and appearance in laminated products like packaging materials. The adhesive has a unique polyol component with a branched hydrocarbon group, ether bonds, and ester bonds. The reactive adhesive is made by reacting this polyol with isocyanate. This adhesive provides improved laminated appearance and heat seal strength compared to adhesives with just ester or ether structures. The laminate can be made by bonding films or papers using the reactive adhesive. The laminate can further have printed layers. The laminate can be molded into a bag shape to create a package.

39. Polyolefin-Based Film with Meltable Adhesive Layer for High-Speed Weldable Packaging

PROFOL GMBH, 2021

A film for forming packaging that enables pure and recyclable packaging by using a film with a meltable adhesive layer. The film has an outer cover layer made of a first polyolefin-based plastic and an inner adhesive layer made of a second polyolefin-based plastic. The adhesive layer is designed to be meltable. This allows the film to be welded together at high speeds during packaging processes without adding additional adhesives. The meltable adhesive layer connects to target surfaces when welded, providing a pure and recyclable packaging. The film can be used to create packaging like bags and containers that can be formed, filled, and sealed in a continuous process.

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