New product concept
Looking for a Solution for Improving Bonding of Silicone Coatings to Paper
ClosedInquiries no longer accepted
Type of Solution sought
- A manufacturing process
- A material
- A technology
Description of Desired Solution
A SpecialChem client, a global paper company, is looking for a solution improving bonding between coated paper and silicone coating (system described in illustration 1 below). In the usual systems, the adhesion between paper coating and silicone is based on chemical hydrogen bonds.
The company is looking for a solution:
- providing a stronger bonding between the paper coating and the silicone coating layer on top of it,
- while maintaining perfect silicone coverage on the paper surface and maintaining or improving the silicone processing conditions (for example: wider acceptable processing conditions, faster crosslinking or catalyst cost reduction).
Background
Illustration 1: self-adhesive label laminate structure
Typical base paper composition: cellulose
Typical base paper coating composition: PVOH (polyvinyl alcohol), CMC (carboxy methyl cellulose), clay, starch
Typical silicone coating composition: PDMS (polydimethylsiloxane), crosslinker, catalyst (Pt), release control additive
Silicone system: solventless (100%), thermally cross-linked (cured) silicone
This part describes the processes and materials used in the paper and label industry and the business potential of this request.
Current base paper production process on a paper machine:
- producing a continuous web of paper,
- applying the coating on-line to paper surface,
- drying the coating,
- increasing the moisture of the paper and coating by rewetting with water,
- calendering the paper with high temperature and high pressure to create a smooth surface which reduces the silicone penetration into the paper.
In the next step self-adhesive labels are manufactured by laminating the label material on the base paper which is first silicone coated with roll application method followed by thermal curing and adhesive coating. Silicone coating produces the releasing layer from which the label with adhesive can be peeled off and then stick to the end-product. The structure of such self-adhesive laminate construction is visible in Illustration 1.
Illustrations 2. and 3. below displays the peeling of a label from siliconized surface and sticking it to the consumer product.
In the industry, one of the big challenges is to have a good anchorage between the silicone and the paper so that when peeling off the label the adhesive surface remains fully sticky. To maintain the label functionality it is essential to avoid any situations where some silicone remains on the surface of the adhesive, which would mean that the label will not stick properly to the surface of the packaging/package it should be applied on.
Illustration 2: peeling off the label from the silicone coated paper
Illustration 3: sticking the label to the product or package
The applications for this type of labels are numerous: for example, labels for all kind of consumer products (bottles, boxes, containers, packaging as well as final consumer products like electronics) or for logistics (labelling of packages).
The objective is to develop a solution where the silicone anchoring to the paper surface outperforms the usual hydrogen bonding which is reversible and sensitive to the processing conditions. This kind of paper solution will enable the SpecialChem’s client to use it in a vast majority of its current products.
A short-term market potential of 900 mm2 of coated paper per year is expected with the potential up to 1800 mm2 per year mid-term if significantly improved performance is proven.
Detailed Solution Description
|
Feature |
Target |
|
Silicone anchorage to paper surface |
|
|
Silicone coverage on the paper surface |
Complete at the normal range of silicone application between 1.0 – 1.3 g/m2: Coverage evaluation
|
|
The silicone cross-linking reaction (curing) |
|
|
Silicone penetration into the base paper |
Low; meaning that silicone consumption remains in normal range of 1,0-1,3 g/m2. Preferably the silicone consumption is even reduced |
|
Surface of the paper and surface of the silicone layer |
Homogenous |
|
Platinum catalyst consumption of silicone |
At the normal level due to cost reasons. Preferably it is decreased from normal level of 50-60 ppm without negative effects on other key requirements |
|
Silicone system |
So called solventless (100%) thermal curing (cross-linking) silicone |
The following benefits on the silicone processing side would be valued by the company’s customers:
- More robust to the processing conditions
- Faster processing time = faster cross-linking (curing) of the silicone
- Lower consumption of silicone material (= better coverage)
- Lower use of Pt catalyst
- Lower cross-linking temperature (current 100-150°C) or lower energy consumption
Additionally, the proposed solution should enable a one-year shelf life of the base paper and the self-adhesive laminate is the standard requested in the industry.
The solutions could be among the following (but not limited to):
- change the paper coating formulation,
- physical treatment,
- additional coating layer.
Another option is to change the silicone coating formulation (at the silicone coating step). Although, this is not currently preferred by the SpecialChem’s client, this might be an option if the performances are overall much better: good release of the adhesive layer, good anchorage to base paper, lower cost of the silicone layer (less silicone or less catalyst needed), easier silicone processing conditions like less sensitivity to humidity, lower temperature, faster processing, no change in the release force compared to usual systems.
Possible Routes To Investigate
- Additives or processing creating covalent bonds between the silicone layer and the paper coating (existing or a modified paper coating)
- A new* way of modifying the paper coating raw materials in order to add vinylic functions to the paper coating and enable covalent bonds with silicone
- An alternative chemical or physical way to improve the bonding or
*There are existing patented solutions (for example publication number: WO2011/104427) to add vinylic groups to paper surface by modifying PVOH chemically before using it for the paper coating and enabling covalent bonds. These types of solutions remain of interest as long as they are not already covered by the existing patents.
Solution that are not of interest
- Hazardous chemicals (in working environment)
- Moisture sensitive compounds (as after the coating curing, the paper and coating are submitted to a high moisture environment)
- Compounds inhibiting the silicone curing process
- Solutions limiting the further process steps of making self-adhesive laminate
Anticipated Next Steps with Respondents
The ideal target is to have the solution ready to use by the end of 2020.
Other Comments / Important Considerations
Fully engaged towards innovation and high value collaborations to accelerate its progress towards achieving its business and sustainability goals. Developing ever more sustainable paper-based solutions is a key target for the company.
The additional cost related to this solution is preferred not to exceed the level of 1 €/1000 m2 (for a market potential from 900 Mm2/year and up to 1800 Mm2/year) However, also higher cost solutions can be interesting as the total cost of solution will be in any case evaluated.
Type of Outcome expected
The SpecialChem Client is open to a wide spectrum of proposals’ maturity.
- From a Proof of concept of Technology Readiness Level (TRL) 3 on the NASA TRL scale (Active R&D is initiated.This includes analytical studies and laboratory studies to physically validate the analytical predictions of separate elements of the technology. Examples include components that are not yet integrated or representative)
To
- An Actual System Proven through Successful Usage of TRL 9 (Actual application of the technology in its final form and conditions. Technology is commercially available)
And
- A solution Validated in a relevant environment of TRL 5 (The basic technological components are integrated with reasonably realistic supporting elements so they can be tested in a simulated environment) as a minimum would be preferred to have a faster go-to-market.
In case you would like to submit a proposal, please indicate the TRL of your solution:
|
TRL# |
Technology Readiness Level |
Description |
|
1 |
Basic principles |
Lowest level of technology readiness. Scientific research begins to be translated into applied research and development (R&D). Examples might include paper studies of a technology’s basic properties. |
|
2 |
Technology concept |
Basic principles are observed. Applications are speculative, and there may be no proof or detailed analysis to support the assumptions. Examples are limited to analytic studies. |
|
3 |
Proof of concept |
Active R&D is initiated. This includes analytical studies and laboratory studies to physically validate the analytical predictions of separate elements of the technology. Examples include components that are not yet integrated or representative. |
|
4 |
Validation in laboratory environment |
Basic technological components are integrated to establish that they will work together. Examples include integration of “ad hoc” hardware in the laboratory. |
|
5 |
Validation in relevant environment |
The basic technological components are integrated with reasonably realistic supporting elements so they can be tested in a simulated environment. Examples include laboratory integration of components. |
|
6 |
Prototype demonstration in a relevant environment |
Representative model or prototype system, which is well beyond that of TRL 5, is tested in a relevant environment. Represents a major step up in a technology’s demonstrated readiness. Examples include testing a prototype in a laboratory environment or in a simulated operational environment. |
|
7 |
System prototype demonstration in an operational environment |
Prototype near or at planned operational system. Represents a major step up from TRL 6 by requiring demonstration of an actual system prototype in an operational environment. |
|
8 |
Actual system completed and qualified through test and demonstration |
Technology has been proven to work in its final form and under expected conditions. In almost all cases, this TRL represents the end of true system development. Examples include developmental test and evaluation (DT&E) of the system in its intended system to determine if it meets design specifications. |
|
9 |
Actual system proven through successful usage |
Actual application of the technology in its final form and conditions. Technology is commercially available. |
Company Demographics
- Industry our client is in: Paper and packaging industry
- Annual Revenue: >EUR 1 billion
- Years in Business: >100 Years
- Headquarters Area: Europe
Business considered
- Licensing
- Contractual partnership
- Joint venture
- Buying
- Funding