PVF Resin Back Sheet Adhesion via Silane Coupling

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Solution Overview

Problem

Current back sheets for photovoltaic cells require high-energy drying processes, leading to increased manufacturing costs and potential thermal degradation, while also being poorly adhesive and lacking durability and weatherability.

Innovation Solution

A multilayered film comprising a substrate coated with a resin layer containing a fluorine-based polymer and an acrylic polymer with reactive functional groups, which improves adhesion and mechanical properties, and can be dried at low temperatures using solvents with low boiling points.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a PVF resin layer is used on a PET substrate, then good weatherability and durability are achieved, but adhesive strength deteriorates and complex manufacturing processes are required

Engineering Contradiction:
Improveweatherability and durabilityVSAvoidadhesive strength
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The patent introduces a silane coupling agent as an intermediary substance between the PVF resin layer and PET substrate. This coupling agent contains both organofunctional groups that bond with the substrate and inorganic functional groups that bond with the resin, creating a bridging layer that significantly improves adhesive strength while maintaining the good weatherability and durability of the PVF resin

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent creates a composite structure by combining PVF resin with silane coupling agents and other additives to form a resin composition. This composite material integrates the weatherability of PVF with the adhesion properties of silane-modified components, achieving both good durability and adhesive strength simultaneously

Inventive Principle:
Principle #40Composite materials

2Ease of manufacture

If a PVF resin solution is used, then coating process is simplified, but high drying temperature is required consuming large energy

Engineering Contradiction:
Improvecoating process simplicityVSAvoiddrying energy consumption
Core Design Contradiction:
Ease of manufactureVSUse of energy by moving object

Solution Approach 1:

The patent modifies the chemical composition parameters of the resin solution by incorporating solvents with appropriate boiling points and silane coupling agents that enable lower temperature drying. This parameter change allows the coating process to be simplified while reducing drying temperature from the conventional high temperature to a more energy-efficient range, thereby reducing energy consumption

Inventive Principle:
Principle #35Parameter changes

3Ease of manufacture

If high drying temperature of 200°C or higher is used, then resin suspension or solution can be dried, but manufacturing cost increases and thermal degradation occurs

Engineering Contradiction:
Improveresin coating feasibilityVSAvoidmanufacturing cost
Core Design Contradiction:
Ease of manufactureVSUse of energy by stationary object

Solution Approach 1:

The patent changes the chemical composition of the resin system to include components that can be processed at lower temperatures. By using silane coupling agents and appropriately formulated resin solutions, the drying temperature is reduced from 200°C or higher to a lower temperature range, which decreases energy consumption and manufacturing cost while preventing thermal degradation of the photovoltaic cell and other components

Inventive Principle:
Principle #35Parameter changes

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 solution enhances adhesive strength, durability, and weatherability of the back sheet, reducing manufacturing costs and preventing thermal degradation, while maintaining effective performance even after exposure to harsh outdoor conditions.

Implementation Method 1

an acrylic polymer containing a reactive functional group... An equivalent weight of the reactive functional group with respect to the entire polymer of the resin layer is 30,000 or less

Methodology Applied
Scientific EffectChemical bonding: Chemical Bonding

Implementation Method 2

can be dried at low temperatures using solvents with low boiling points

Methodology Applied
Scientific EffectEvaporation: Evaporation

Data Source

PatentEP2639060B1Multilayer film, and photovoltaic module comprising same
Publication Date: 2018.10.03 LG CHEM LTD
  • EP2639060B1 patent drawingFigure 1

AI summary

A multilayered film, a back sheet for a photovoltaic cell, methods of manufacturing the film and cell, and a photovoltaic module including the film and cell are provided. The multilayered film includes a resin layer formed on a substrate, and the resin layer contains a fluorine-based polymer and a reactive functional group having an equivalent weight of 30,000 or less. The resin layer containing the fluorine-based polymer has good durability and weatherability and is highly adhesive to the substrate at an interface between the resin layer and the substrate. Also, since a drying process may be performed at a low temperature during manufacture of the multilayered film, manufacturing costs may be reduced, productivity may be increased, and degradation in the quality of products due to thermal deformation or thermal shock may be prevented. The multilayered film may be effectively used as, for example, a back sheet for various photovoltaic modules.