(12) United States Patent (10) Patent No.: US 6,416,817 B1 Rangwalla Et Al
Total Page：16
File Type：pdf, Size：1020Kb
USOO6416817B1 (12) United States Patent (10) Patent No.: US 6,416,817 B1 Rangwalla et al. (45) Date of Patent: Jul. 9, 2002 (54) BARRIER COATINGS HAVING BIS-SILANES 5,576,068 A 11/1996 Caburet et al. ............. 427/452 5,663.215 A * 9/1997 Milligan ..................... 523/122 (75) Inventors: Imtiaz, J. Rangwalla, Andover, MA (US); John E. Wyman, Sanibel, FL FOREIGN PATENT DOCUMENTS (US); Patrick Jacques Jean Merlin, EP O 502 274 A2 9/1992 Belgium (BE); Shrenik Mahesh EP O 671 450 A1 9/1995 Nanavati, Midland, MI (US); Laurence WO WO 98/31539 7/1998 Gallez, Belgium (BE) WO WO 98/31719 7/1998 s WO WO 98/31720 7/1998 WO WO-99/55754 A1 * 11/1999 (73) ASSignees: RSA"..." (BE); E.G. WO WO-OO/64647 A1 * 11/2000 9 eles Wilmington, MA (US) * cited by examiner (*) Notice: Subject to any disclaimer, the term of this Primary Examiner-Erma Cameron patent is extended or adjusted under 35 (74) Attorney, Agent, or Firm-James L. De Cesare; Alan U.S.C. 154(b) by 0 days. Zombeck, Richard I. Gearhart 57 ABSTRACT (21) Appl. No.: 09/517,900 (57) A process of preparing an oxygen barrier coating using a (22) Filed Mar. 3, 2000 compound of the general formula (51) O - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - B05D3/02; B05D 3/10 R.X. Si-Z-SiX R (52) O - - - - - - - - - - - - - - - - - - - - 427/377; 427/387; 427/3884; As Sl A. SLA3R, 427/388.5; 427/391; 427/392; 427/393.5 wherein Z is R'NH(R'NH) R', each R is selected from the (58) Field of Search .............................. 427/385.5, 377, group consisting of a hydrogen atom and a hydrocarbon 427/387, 388.4, 388.5, 391,392,393.5 group, each X is Selected from the group consisting of an alkoxy group with 1 to 4 carbon atoms, a halogen atom, an (56) References Cited Oxime group or an acyloxy group, each R" is a divalent U.S. PATENT DOCUMENTS hydrocarbon group having 1 to 12 carbon atoms, a is from 0 to 3 and p is 0 or 1. The invention further comprises 2,832,754 A 4/1958 Kenmore et al. .......... 260/46.5 compositions incorporating the above compound. Coatings 2.920,095 A 1/1960 JeX et al. ................. 260/448.8 prepared may be used in packaging applications as a top 4,659,798 A * 4/1987 Pohl et al. .................... 828/33 coat, or a primer for further coatings 4,689,085 A 8/1987 Plueddemann .... ... 106/287 s 5,101,055 A 3/1992 Dinh et al. ....... ... 556/413 5,215,822 A 6/1993 Wyman et al. ............. 428/447 14 Claims, No Drawings US 6,416,817 B1 1 2 BARRIER COATINGS HAVING BS-SILANES ings as pretreatments for particulate fillers before compounding, and as additives to filled polymer Systems FIELD OF THE INVENTION during compounding as well as for treating glass cloth. This invention relates to the preparation of barrier coat Various proposals to employ organosilicon compounds in ings on films and particularly to oxygen, carbon dioxide, the treatment of plastics films to achieve gas barrier prop flavor and aroma barrier coatings on films for use in pack erties have been made. However, bis-Silanes have not pre aging. viously been utilized to control the gas barrier properties of BACKGROUND OF THE INVENTION a Substrate. Furthermore, it is to be noted that none of the The pharmaceutical and food industries have, over recent prior art discussed above Suggests the use of Such com years, increasingly provided products in a prepackaged pounds for coating materials to be cured on plastic, form. Fruit and vegetables for example, apples and cellulosic, glass or metal Substrates to achieve gas barrier tomatoes, meat and cheese are often prepackaged in a tray properties. and the tray and the fruit are covered with a transparent film. It is one of the various objects of the present invention to One of the most important requirements for films used for provide a proceSS for treating a Surface of a Substrate to packaging applications is that they should protect products 15 provide improved barrier properties. from aromas or odors in the vicinity in which the products The present inventors have now Surprisingly found that are Stored, i.e. they should act as barriers to Such aromas or Substrates having coatings of Selected moisture cured disi odors. Similarly the films are utilized as barriers to prevent lylated Secondary amines demonstrate excellent gas barrier Strong Smelling products contained in packages from taint properties at low to high relative humidity values. ing the Surrounding area with their aroma during Storage. Furthermore, these properties may be achieved without the Oxygen barrier coatings are utilized to prevent the ingreSS need for exposure of the coating to electron beam or other of oxygen into products with a view to extending the shelf forms of ionizing radiation. life of products and carbon dioxide barrier coatings are SUMMARY OF THE INVENTION typically utilized to prevent the release of carbon dioxide 25 from rigid plastic bottles holding carbonated drinkS. The present invention provides, in accordance with one of U.S. Pat. No. 5,215,822, describes a process of control its aspects, a proceSS for treating a Surface of a Substrate with ling the impermeability of a film to gases by mixing a vinyl a compound of the general formula benzylamine Silane with an ethylenically unsaturated car boxylic acid e.g. itaconic acid, in a Solvent, Solubilising, hydrolyzing and equilibrating the resultant Solution and wherein Z is R'NH(R'NH) R', each R is selected from the coating this Solution on a corona treated low density poly group consisting of a hydrogen atom and a hydrocarbon ethylene film and drying the resulting film. The coated film group, each X is selected from the group consisting of an is then Subjected to an electron beam radiation to graft the alkoxy group with 1 to 4 carbon atoms, a halogen atom, an coating to the film Surface and further improve the barrier 35 Oxime group or an acyloxy group, each R" is a divalent properties of the Silane coating. The Vinyl benzyl amine hydrocarbon group having 1 to 12 carbon atoms, a is from Silane was also co-polymerised with 3-(2-aminoethyl)- 0 to 3 and p is 0 or 1; which proceSS comprises applying the aminopropyl trimethoxy Silane or gamma aminopropyltri compound on to the Substrate to form a layer and exposing ethoxysilane prior to mixing with the acid. The resultant the layer to moisture. mixture was then used to coat the relevant Substrate. While 40 these coatings gave excellent gas barrier properties at low to DETAILED DESCRIPTION OF THE moderate relative humidity values, the gas permeability was INVENTION leSS Satisfactory at very high relative humidity values. In In a process according to the present invention there is addition, the use of electron beam radiation may lead to used a compound of the general formula cross-linking or chain Scission in underlying plastics 45 Substrates, with concomitant loss of tensile properties. The use of electronbeam radiation and Several other complicated wherein Z is R'NH(R'NH).R. and/or expensive procedures with respect to coatings of this In this formula each R is preferably a hydrogen atom or type containing mono-silyl constituents can make the use of a hydrocarbon group having 1 to 10 carbon atoms, for Such compounds for the manufacture of coated films for use 50 example a Saturated or unsaturated aliphatic or aromatic in the packaging industry unattractive. group, for example alkyl alkenyl or phenyl groups, preferred U.S. Pat. No. 4,689,085/U.S. Pat. No. Re. 34675 groups are methyl and ethyl, the most preferred of which are describes the preparation of disilylated hydrocarbons of the methyl groups. Each X is an alkoxy group with 1 to 4 carbon general structure (RO)SiR'Si(OR) where OR is a atoms, a halogen atom, an OXime group or an acyloxy group, hydrolysable group and R is a divalent organic radical. They 55 of these methoxy and ethoxy groups are preferred, the most further teach the combination of a Silane coupling agent for preferred being methoxy groups. R' may be a divalent example, 3-methacryloxypropyltrimethoxysilane with a hydrocarbon group having 1 to 12 carbon atoms, preferably disilyl cross-linking compound of the general formula Struc each R" has from 2 to 3 carbon atoms. Each a is from 0 to ture (RO)SiR'Si(OR) where OR is a hydrolysable group 3 but is most preferably 0, and p is 0 or 1. The best results and R' is a divalent organic radical for example, an alkylene 60 are obtained by use of compounds in which each X is a group or a Selection of branched, unsaturated or aryl Sub methoxy group, each R" is a propylene group, a is 0, and p Stituted groupS as an improved coupling agent and primer is 0, i.e. when the compound is bis-(gamma mixture demonstrating that the combination of the compo trimethoxysilylpropyl)amine. nents provided improved results compared with either com These materials, referred to as disilylated Secondary ponent when used alone. 65 amines may be prepared by processes known in the art for These compositions are Said to be useful as primer example, as disclosed in U.S. Pat. Nos. 2,832,754, 2,920, coatings between non-particulate Surfaces and polymer coat 095, and 5,101,055. US 6,416,817 B1 3 4 In a process according to the invention the Surface of a The condensation catalyst (iv) may be used with the Substrate is treated with a compound as aforesaid with or compound to catalyze the cure process.