FRAGRANCED LACQUER COAT AND PROCESS FOR PREPARATION THEREOF TO BE SCREEN PRINTED

Abstract: Fragranced lacquer coating composition polymerised by UV radiation, comprising of a/ 70 to 90 part by weight unsaturated polyester, b/ 5 to 20 part by weight vinylether monomer, c/ 3 to 10 part by weight initiator, d/ 1 to 10 part by weight fragrance and e/ 0,01 to 0,1 part by weight additive having fluidifying properties and no own smell.

Description: Fragranced lacquer coat and process for preparation thereof to be screen printed The present invention relates to a fragranced lacquer coat based on a polyester pre- polymer in a mixture of polymerizable vinylether monomer, UV photoinitiator, and process for preparation thereof. It is known some processes of fragrance coating by offset procedure of microencapsulated fragrances but that method is limited to a layer thickness of maximum 3 μm, and so fragrance content is less than 8%(w/w) of coating composition. This lacquer contains fragrance in relatively low concentration. Another inconvenience of this method is the fact that generally used binding material has own smell sometimes disguising the original fragrance. It is known another process of fragrance coating, fragrance dispersion into acryl dispersed phase. The disadvantage of this process is a high water content (from 50 to 60 % by weight) of the mixture enables printing on particular thick paper of more than 100 g/m 2 . This flexo-procedure allows limited coating amount comprising of low fragrance content due to danger of spontaneous coagulation. We found a process based on a liquid, unsaturated polyester being in pre- polymerisation state. Coating in the art and polimerised lacquer allows a slow, retarded elimination of fragrance, by membrane diffusion. The real advantage of the named process is unlimited concentration and type of fragrance (being synthetic and/or natural). The object of the present invention is a fragranced lacquer coat polymerised by UV (UV-A, from 315 to 380 nm ) radiation comprising of a/ 70 to 90 part by weight unsaturated polyester, b/ 5 to 22 part by weight vinylether monomer, c/ 3 to 10 part by weight initiator, d/ 1 to 10 part by weight fragrance and e/ 0,01 to 0,1 part by weight additive having fluidifying properties and no own smell. The sum of the amounts a+b+c being 100, d+e are premixed and then added so much to get a properly fragranced lacquer to be coated by UV radiation at temperatures from 20 to 30°C. As polyester base (a) can be utilized unsaturated , for instance aminmodified polyester acrylates, preferable polyester having an aliphatic chain, where carbon number is less than 20. For polymerization and crosslinking as monomer vinylether (b) can be utilized, having no own smell, for instance divinylether or others. Preferable triethylene glykol divinylether, diethylene glykol divinylether. As UV photoinitiator can be utilized benzophenone derivatives, preferable such one which does not produce any smelling by-product . Fragrances are variable, the invention enables utilizing both synthetic and natural origin. Their slight influence on polimerization process must be taken into consideration therefore concentrations of each component may vary and trial polymerization is recommended. As additive is adding to improve the coating aesthetic aspect, for instance colloidical silica, reactive double unsaturated polyester, fluoroaliphatic polymeric esters. The process according to the present invention can be carried out by dissolving of the vinylether monomer in the liquid unsaturated polyester, then initiator and the premixed additive and fragrance are added at room temperature ( from 20 to 30°C), homogenisation with continuous mixing and avoiding UV light. The homogen, viscous liquid is coated in a layer from 4 to 20 μm, radiated from 1 to 10 seconds. In order to avoid overheating due to the infrared component of the UV radiation emitted from mercury vapour UV lamps commonly used for polymerizing one can utilize UV lamps having a reduced infrared emission or placing a filter eliminating most of infrared radiations avoiding overheating of printed material more than to 40 °C. This invention discloses a new type of fragranced lacquer coat, specially useful in screen printing . The fragrance in this composition can be varied in concentration, printed easily. The printed materials have a decorative lacquer and smells. Example 1 A paper (without own smell) of 100 g/ m 2 was coated by spreading with a layer of 10 μm of a mixture containing 80 part by weight polyester-acrylate, 11 part by weight triethylene glykol divinylether, 9 part by weight UV photoinitiator, a benzophenone derivative , then 4 part by weight of rose oil and 0,02 part by weight fluidifying additive. The formulation was polymerized with one 80 W/cm UV lamp (utilizing a cold water flow) at a feeding rate 10 m/min. Example 2 A paper (without own smell) of 100 g/ m 2 was coated by spreading with a layer of 10 μm of a mixture containing 85 part by weight polyester-acrylate, 10 part by weight diethylene glykol divinylether, 5 part by weight UV initiator, a benzophenone derivative, then 6 part by weight synthetic lilly fragrance and 0,01 part by weight fluidifying additive. The formulation was polymerized with one 80 W/cm UV lamp (utilizing a cold water flow) at a feeding rate 10 m/min. The crosslinked coating layer showed an optimal lacquer with given fragrance.

Claims: CLAIMS 1. Fragranced lacquer coating composition polymerised by UV (UV-A, from 315 to 380 nm ) radiation comprising of a/ 70 to 90 part by weight unsaturated polyester, b/ 5 to 20 part by weight vinylether monomer, c/ 3 to 10 part by weight initiator, αV 1 to 10 part by weight fragrance and e/ 0,01 to 0,1 part by weight additive having fluidifying properties and no own smell. 2. Fragranced lacquer coating composition according to claim 1 , which comprises a/ 80 to 90 part by weight polyester-acrylate, b/ 9 to 15 part by weight vinylether monomer, c/ 4 to 10 part by weight UV photoinitiator, d/ 1 to 6 part by weight natural and/or synthetic fragrance el 0,01 to 1 part by weight additive having fluidifying properties. 3. Process for preparation the fragranced lacquer according to claim 1 , characterised that coating is carried out by dissolving of the vinylether monomer in the liquid unsaturated polyester, then initiator and the premixed additive and fragrance are added at room temperature (from 20 to 30°C), homogenisation with continuous mixing and avoiding UV light, the obtained homogen, viscous liquid is coated in a layer from 4 to 20 μm, radiated from 1 to 10 seconds. 4. Process according to claim 1 , wherein unsaturated polyester is aminmodified polyester-acrylate. 5. Process according to claim 1 , wherein UV photoinitiator is benzophenone derivative or another compound having polymerization-initiative properties and no smelling by-products at polymerization and crosslinking. 6. Process according to claim 1 , wherein it is utilized mercury vapour lamps as UV radiation source having power of from 80 to 100 W/cm and a reduced infrared emission or placing a filter eliminating most of infrared radiations or flow water cooling avoiding overheating of printed material more than to 40 °C.

Inventors: JERMAKOV TAMAS, PALFINE LEDNICZKY MARIA, JERMAKOV, TAMAS, PALFINE LEDNICZKY, MARIA
Applicants: JERMAKOV TAMAS, PALFINE LEDNICZKY MARIA, JERMAKOV, TAMAS, PALFINE LEDNICZKY, MARIA
Application year: 1998
Main classification: C09D167
IPC codes: C08F283, C09D167