Rosin resin dispersions for the package printing industry

Rosin resin dispersions for the package printing industry Dr. M. Eva Ramos 1 Masami Aihara 1, Tony Dallavia 2, Wietze Bakker 3, John Hazen 3, Anton de Krom 1, David Bainbridge 2 1 Lawter BVBA, Kallo, Belgium - 2 Lawter Inc., Elgin, IL, USA - 3 Lawter BV, Maastricht, The Netherlands

A brief introduction to SnowPack

Introduction There has been a growing interest in bio-renewable raw materials due to depletion of fossil resources. Sustainability has become increasingly important to scientific institutions, industries and governments. Souce: U.S. Energy Information Agency With regard to polymer synthesis, the current challenge is to replace the most common monomers, while maintaining performance, on a reasonable time scale and in a cost effective way. 3

Renewable raw materials There is an increase in research focused on the development of new and alternative polymers based on bio-renewable resources due to the growing awareness of sustainability. Rosin is a non-edible readily available raw material extracted from pines trees which are relatively fast growing. Tall oil rosin Rosin derivatives are employed in resins for adhesives and inks along with a number of other applications. Wood rosin Gum rosin 4

INKS Paste Inks Non-Impact Printing Liquid Inks Letter Press Offset Screen Inks Toner Publication Packaging Coldset Heatset Sheetfed Jet Gravure Gravure Flexo No heat NEWS Colour Quickset Digital Toluene Based Waterborne Solventborne Waterborne Black Gloss Offset UV Solventborne UV 5

Water-based inks. State of the Art Waterborne inks are currently formulated with fossil-based polymers, acrylics Properties Acrylic Resins High AV Rosin Resins Rosin resin dispersion Gloss Moderate High Drying Fastest Slow Re-solubility Moderate Good Pigment wetting Moderate Good Wet rub resistance Good Poor Adhesion Good Moderate Alkali resistance Good Poor High Medium Moderate Good Good Good Good 6

SnowPack TM Process In the beginning of the 80 s, Lawter (Akzo Nobel) developed a tackifier dispersions for pressure sensitive adhesives, Snowtack TM. Lawter developed a unique production procedure (Robust TM ) for these products and a patented surfactant system for this technology. 7

SnowPack TM is What is SnowPack TM? A rosin resin dispersion designed for use in waterbased flexo inks and aqueous coatings/opv SnowPack TM dispersions can be used in combination with acrylics to increase the bio-renewable content (BRC) Developed as a green alternative to the pure acrylic systems for the benefit of the ink & overprint varnish formulator, printer and print buyer 8

Our core green technology combined! Combining our wide knowledge of rosin chemistry and our dispersion technology together with waterborne ink requirements we developed a product line, SnowPack TM, to partially or completely replace acrylics in flexo inks. 9

SnowPack TM Several SnowPack TM and OPV. dispersions were evaluated in ink The high performance rosin resin dispersions represent a green alternative to contribute to sustainability in the liquid ink market Due to the broad field of application we are developing this concept in alignment with customer requirements. 10

Materials and Methods Aqueous Dispersions Characterization Methods

Dispersions employed Materials & Methods Rosin resin dispersions PE dispersions XW2289 XW2312 XW 2328 Flexonic W378 E % solids 55 55 52 55 ph @ 25 C 8.5 7.8 8 NA Viscosity (mpa.s) 600 700 750 NA Avg particle size (µm) 0.17 0.21 0.19 6 Acrylic dispersions HR 810E Ac 1 Ac 2 Ac 3 % solids 40 45.5 46 48 ph @ 25 C 8.5 8.5 8.2 8.3 Viscosity (mpa.s) 270 550 500 500 Characteristic FF FF FF NFF FF = film forming. NFF = non-film forming 12

Materials & Methods Probes preparation: Substrate: Opacity chart, sheen 301-E, C1S stock ; different non-absorbing substrate Drying procedure: 1) few seconds @70 o C & 2-24 hrs @RT Test methods: Gloss: Gloss was measured with NOVO-GLOSS at an angle of 60 degrees. Drying: A cotton ball was pressed (with finger) on the printed substrate and removed. Drying was evaluated by judging the remaining degree of cotton fibers. Rub resistance: A sweeping paper was rubbed against the printed substrate 10 times. The transfer of color was compared to a reference ink. Block: Substrate was placed under spring loaded pressure of 40 psi for 24 hours face to face and face to back. Block was evaluated as amount of ink removed from substrate. Adhesion: A tape (3 5 cm) was pressed with the fingers on the printed substrate and pulled off quickly at an angle of 45 degree. Substrates: Polyethylene Polypropylene Polyester Polyvinyl chloride 13

Results and Discussion Evaluation results of initial development of SnowPack TM in liquid inks. Evaluation of initial development of SnowPack TM as OPV. Customer feedback. Evaluation of improved SnowPack TM

Evaluation of SnowPack TM in liquid inks Samples Preparation: SnowPack TM XW2289 - Ink Formulation A B C D E Reference Pure SP SP + HR C + wax Pure HR Reference ink (Blue process lagon 42507) 100 Commercial Ink base 35 35 35 35 SnowPack TM XW2289 65 SnowPack TM & Hydro-Rez TM 810 (75/25) 65 SnowPack TM & Hydro-Rez TM 810 & PE wax (74,7/24,9/0,4) 65 Hydro-Rez TM 810 65 Extra demineralized water 18 5 5 6 5 Drying All the samples presented a comparable drying level to the standard commercial ink after similar treatments (70 C for 20 s and RT for 2 or 24 hours). 16

Evaluation of SnowPack TM in inks. Gloss The rosin resin dispersion maintains the high gloss 17

Poor Ref. Excelent Better, cleaner chemistry Evaluation of SnowPack TM in inks. Adhesion Adhesion comparable to reference ink was achieved when using SnowPack TM dispersion solely or in combination with acrylic dispersion. 18

Poor Reference Better, cleaner chemistry Evaluation of SnowPack TM in inks. Rub resistance Rub resistance can be significantly improved by PE wax addition in the formulation. 19

Evaluation of SnowPack TM as OPV Samples Preparation: SnowPack TM XW2289. OPV Formulation F G H I J K L SP XW2289 SP + HR G + wax Pure HR Pure Ac1 SP + Ac1 K + wax SnowPack TM XW2289 100 75 74.7 75 74.7 Hydro-Rez TM 810 25 24.9 100 Acrylic 1 (Ac1) 100 25 24.9 Flexonic W378 0.4 0.4 Drying Pure SnowPack TM OPV samples presented slower drying than the pure acrylic systems. Used in combination with acrylics the product showed better drying. 21

Evaluation of SnowPack TM as OPV. Gloss The rosin resin dispersion maintains the high gloss. 22

Poor Excellent Better, cleaner chemistry Evaluation of SnowPack TM as OPV. Adhesion Using SnowPack TM as OPV improves the adhesion on PE and PP in comparison with both acrylic dispersions. 23

Evaluation of SnowPack TM Feedback from customers: Improvements were needed with SnowPack TM XW2289 Drying quality, tackiness Block resistance Based on those remarks : We developed improved versions of SnowPack TM We evaluated the modified SnowPack TM : XW2312 and XW2328 in ink and OPV 25

Results and Discussion Evaluation in inks of modified Snowpack TM as 100% replacement for acrylic emulsions Evaluation in inks as 50% replacement for acrylic emulsions, blended with NFF acrylic Evaluation of modified Snowpack TM as OPV

Evaluation of SnowPack TM in inks. Gloss Rosin resin dispersions have similar or better gloss than acrylic 29

Evaluation of SnowPack TM in inks. Drying time At 100% replacement, Snowpack TM dispersions are slower than acrylics in Leneta substrate. XW2328 is best of current rosin dispersions. 30

Poor Excellent Better, cleaner chemistry Evaluation of SnowPack TM in inks. Dry quality XW2328 is showing better drying than other rosin dispersions. 31

Poor Excellent Better, cleaner chemistry Evaluation of SnowPack TM in inks. Adhesion and Block XW2328 adhesion and block nearly identical to acrylic dispersion on C1S. 32

Evaluation of SnowPack TM in inks. Gloss Acrylic/Rosin resin dispersion blends have better gloss than pure acrylic 34

Evaluation of SnowPack TM in inks. Drying time Acrylic/Rosin resin dispersions blends are similar in dry time to straight acrylic inks. 35

Evaluation of SnowPack TM in inks. Gloss Again, gloss is equal to or slightly better than acrylic emulsions. 36

Poor Excellent Better, cleaner chemistry Evaluation of SnowPack TM in inks. Adhesion and Block XW2328/acrylic blend presented adhesion and block comparable to acrylic dispersion on C1S stock. 37

Evaluation of SnowPack TM as OPV. Gloss The modified SnowPack TM showed comparable high gloss compared to the initial development and pure acrylics. 39

Poor Excellent Better, cleaner chemistry Evaluation of SnowPack TM as OPV. Drying The modified SnowPack TM XW2328 presented significantly better drying compared to the initial development and close to pure acrylic system. 40

Poor Excellent Better, cleaner chemistry Evaluation of SnowPack TM as OPV. Adhesion All SnowPack TM samples showed better adhesion to PE and PP than pure acrylics and comparable adhesion to polyester and PVC 41

Conclusions

Conclusions Ink testing revealed that including SnowPack TM XW2289 in the formulation led to high gloss and comparable adhesion. Rub resistance of SnowPack TM based ink formulations was noticeably improved by the addition of PE wax. As a full or partial acrylic replacement in OPV, SnowPack TM XW2289 showed high gloss, and better adhesion to PE and PP substrates than acrylics, but slower drying. 43

Conclusions Modified SnowPack TM XW2328 presented improved drying and similar adhesion and block to acrylics, when tested in ink formulations as 100% replacement. As 50% replacement, properties are comparable to acrylics. Improved version of SnowPack TM also showed better drying in OPV study than the initial development and better adhesion to PE and PP than acrylics. SnowPack TM represents an attractive eco-friendly alternative to acrylics in order to increase bio-renewable content in liquid-ink formulations thus contributing to sustainability. 44

Snowpack TM concept The innovative concept of SnowPack TM was designed to increase BRC in waterbased inks and coatings The rosin resin can be tailored for different end applications We are studying how to improve compatibility with acrylics, polyamides and polyurethane systems 45

Snowpack TM concept We are currently working with partners to further develop this idea. We are seeking to expand the SnowPack TM concept in other markets to contribute to sustainability. 46

Briefly SnowPack TM offers... A green alternative to use in combination with acrylics. A more sustainable chemistry. High bio-renewable content. We will continue tailoring SnowPack TM according to customer requirements 47

Thank you! 48