WTECH DS POLYMERS
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Wolan Technologies produces low viscosity difunctional polymers for coatings, adhesives, and sealants. The polymers are based on shorter molecular weight diol and triol polyethers capped with amino silanes for easy processing and adhesion. Coatings and adhesives made with these polymers require high tensile strength, good adhesion, and fast room temperature curing. Example formulations are provided for industrial adhesives and tough membranes or coatings based on 12,000 MW and 10,000 MW polymers, along with manufacturing guidelines.
WTECH DS POLYMERS
- 1. WOLAN TECHNOLOGIES LOW VISCOSITY DIFUNCTIONAL POLYMERS FOR COATINGS, ADHESIVES , SEALANT APPLICATIONS. DS POLYMER.
- 2. 2 Polymers for high strength applications are based on shorter MW diol and triol polyether’s which are capped with amino dimethoxy silanes and triethoxy silanes for ease of processing and adhesion advantages. Coatings can contain some solvents for spreadibility or spraying, but otherwise their formulations are similar to adhesive formulations and are adjusted for toughness and UV resistance as needed. The Formulations used in these CASE products have much higher tensile strength requirements , usually starting at about 3.0 Mpa tensile at break and can go up to 6.0 Mpas . The formulations need good adhesion to the surfaces bonded , and usually are required to have a fast cure at room temperature from 10 minutes to 20 minutes . The coatings or adhesives need to have high tensile strengths and surface hardness with some elongation and good tear strength, which these Polymers accommodate. For the Adhesive manufacturer, the adhesives need different Polymers compared to Construction markets, as the adhesives contain lower plasticizer content and the reinforcing additives such as precipitated calcium carbonate and carbon black are processed with higher levels of catalyst and adhesion silanes. The adhesion properties of single or dual end capped polymers has been shown to be better, and the curing mechanism releases small amounts of methanol and ethanol with no bubbles like fast polyurethane adhesives. These polymers are very easily processed with Precipitated calcium carbonates and carbon black powders, and produce very tough adhesives and coatings or membranes. The content of some urethane and urea groups , introduces the Same hydrogen bonding as found in PU polymers, resulting in less creep and good plasticizer retention . Two part high strength coatings, membranes and adhesives can also be made combining epoxy resins with silane terminated polymers , where the addition of epoxy silane adhesion promoter allows the crosslinking of these two part systems. The low viscosity Difunctional methoxy and Triethoxy capped Polymers use the more environmentally friendly tin diketonate catalyst and secondary amino silane as the curing mechanism . They also reduce the amount of methanol released. Below we show some starting formulations and typical applications of these Wolan Technologies Polymers for Coatings and adhesives in Industry. COATINGS AND INDUSTRIAL ADHESIVES
- 3. 3 The polymers are based on the new generation diol and triol polyether polyols ,that are the same as used for PU adhesives and capped with reactive silanes that are the same as used by silicone sealants, and this is where the hybrid name comes from. The polyether chain is about twice the strength of the polysiloxane chain used in silicone adhesives and lets the adhesive have better recovery from shear movement and is also more compatible when mixed with plasticizing additives that do not come out of the sealant. The crosslinking of the sealant to form the one part curing sealant uses the dimethoxy and triethoxy silane chemistry as used by some silicone sealants. The adhesion is excellent and in most cases with metals like aluminium there is no need for primers. The other big advantage over polyurethane adhesive is that there is no solvent , there are no bubbles formed when the adhesive or coating cures and the vapour released at low levels is methanol and ethanol. These polymers can be made in several ways with the use of different silane molecules and the use of various polymer structures. Where the Polymers are used with no Plasticizer , there is needed low viscosity polymers to disperse the PCC and Carbon black powders. Adhesive Company formulators can mix resin systems to control crosslinking and movement capacity of adhesives 12000 MW DIOL and 10000 MW TRIOL POLYMERS Dimethoxy and triethoxy silane capped polymers for high tensile and tough formulations . Easy processing with PCC and Carbon Black that has some moisture. Enable bubble free curing at normal temperature & humidity levels.No solvents in the adhesive. Polymers can be of low viscosity (15000 Mpas) with patented hydrogen bonding reduction Technology . Excellent adhesion to aluminium with no primers and a wash with green dimethyl carbonate solvent Polymers cure with reduced methanol vapour which is safer for use in confined factory applications . Formulators can use the standard PPC fillers and carbon black for high tensile strengths Adhesives are solvent free and isocyanate free and safer for Processing in Factories Adhesives can be made in the factory with maximum mixer temperatures of 60 degree C and low energy use The dimethoxy and triethoxy polymer is catalysed with more environmentally friendly tin acetoacetate catalyst . No hazard warning labels on the sealant product when displayed in the factory . Vinyl silane is used as moisture scavenger. Formulations can be thickened with carbon black, polyamide wax or cheaper urea thickeners Design of Difunctional low viscosity Wolan Technologies Polymers
- 4. 4 Starting Formulation 12000 MW diol based Industrial adhesive BLACK Test Results MANUFACTURING GUIDELINES. PCC precipitated filler is of very small particle size and very hard to dry when wet , so in Humid environments some predrying at 120 degree is recommended. The 12000MW polymer and the PCC and other powders are loaded into the mixer and dispersed under high shear and vacuum to disperse the PCC in the resin and remove most moisture with high vacuum .Get the mixture to 50 degree C and keep there for 1 hour and check moisture with carl fischer equipment. At 50 degree the vacuum is reduced and the vinyl silane is added under nitrogen to chemically remove remaining moisture. The dry paste is now ready for addition of silanes and catalyst to finish the process. Very high tensile strengths are obtained by addition of carbon black at levels from 5 to 10 percent in the adhesive formulation , and an option is to disperse the carbon black in the same polymer in a separate process with some vinyl silane added to remove moisture in the Carbon black.. When the thickener system like carbon black paste is added and the mixture smooth , the formulation can be finished with final additions under nitrogen blanket and some vacuum . Material Parts by Weight 1. Polymer(15000 Mpas viscosity) 12000MW diol difunctional polymer 1800 2. Reinforcing filler Precipitated calcium carbonate 1800 3. Pigment Carbon black 120 4. Chemical drier Vinyl silane 30 5. Antioxidant Tinuivin 1076 15 6. Thixotropic Agent Polyamide wax or urea thickener 10 7.Stabilizer and UV inhibitor Tinuivin 765 and Irganox 1076 30 8. Adhesion Promoter Secondary amino silane KBM603 20 9. Catalyst dibutyl tin diacetylacetonate,KRA-1 20 10. Moisture scavenger Vinyl silane ,A171 20 As needed. Standard Tack free time 10 minutes Shore A penetration 55 ISO 868 Tensile strength at break 3.4 Mpa ISO 37 Elongation at break 250 percent ISO 37
- 5. 4 Starting Formulation 10000 MW triol polymer in a tough membrane or coating formulation Test Results MANUFACTURING GUIDELINES. PCC precipitated filler is of very small particle size and very hard to dry when wet , so in Humid environments some predrying at 120 degree is recommended .This is the same for Tio2 Polymer and the PCC,TIO2 and DIDP are loaded into the mixer and dispersed under high shear and vacuum to disperse the PCC,TIO2 in the resin and remove most moisture with high vacuum . Get the mixture to 50 degree C and keep there for 1 hour and check moisture with carl fischer equipment. At 50 degree the vacuum is reduced and the vinyl silane is added under nitrogen to chemically remove remaining moisture. When Dry under nitrogen the remaining chemicals and catalyst are added under Nitrogen ,and the final addition of vinyl silane acts as the moisture scavenger in the Cartridge and can affect open time or tack free time. In the final step vacuum the mixture for short time to remove all bubbles. The process above is very simple and a practical way to make one part moisture curing sealants and adhesives in a humid environment as is common across the Asian continent. Material Parts by Weight 1. Polymer 10000MW triol polymer 1200 2. Reinforcing filler PCC and GC calcium carbonate 1500 3. Plasticizer DIDP 400 4. Chemical drier Vinyl silane 30 5. Thickener Aerosil R972 50 6. Tio2 white pigment Paint grade 120 7.Stabilizer and UV inhibitor Tinuivin 765 and Irganox 1076 30 8. Adhesion Promoter Secondary amino silane KBM603 10 9. Catalyst Dibutyl tin diacetylacetonate ,KRA-1 15 10. Moisture scavenger Vinyl silane 15 Standard Tack free time 30 minutes Shore A penetration 40 ISO 868 Tensile strength at break 2.3 Mpa ISO 37 Elongation at break 400 percent ISO 37
- 6. Please contact WOLAN TECHNOLOGIES on vladimyr@wolantech.com for information on formulations and licence availability.