Classifications

• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
  • C08F292/00—Macromolecular compounds obtained by polymerising monomers on to inorganic materials
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G83/00—Macromolecular compounds not provided for in groups C08G2/00 - C08G81/00
  • C08G83/001—Macromolecular compounds containing organic and inorganic sequences, e.g. organic polymers grafted onto silica
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K9/00—Use of pretreated ingredients
  • C08K9/04—Ingredients treated with organic substances
  • C08K9/06—Ingredients treated with organic substances with silicon-containing compounds
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
  • C09D7/00—Features of coating compositions, not provided for in group C09D5/00; Processes for incorporating ingredients in coating compositions
  • C09D7/40—Additives
  • C09D7/60—Additives non-macromolecular
  • C09D7/61—Additives non-macromolecular inorganic
  • C09D7/62—Additives non-macromolecular inorganic modified by treatment with other compounds
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K3/00—Use of inorganic substances as compounding ingredients
  • C08K3/18—Oxygen-containing compounds, e.g. metal carbonyls
  • C08K3/20—Oxides; Hydroxides
  • C08K3/22—Oxides; Hydroxides of metals
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K3/00—Use of inorganic substances as compounding ingredients
  • C08K3/34—Silicon-containing compounds
  • C08K3/36—Silica
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K9/00—Use of pretreated ingredients
  • C08K9/08—Ingredients agglomerated by treatment with a binding agent
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/31504—Composite [nonstructural laminate]
  • Y10T428/31652—Of asbestos
  • Y10T428/31663—As siloxane, silicone or silane

Definitions

• the present invention relates to scratch-resistant surfaces and more particularly concerns a method for making a polymerizable composition to be applied on substrates so as to produce thereon translucent or transparent coatings resisting corrosion and abrasion.
• Said coatings are intended to protect substrates against shocks, bruises and other mechanical accidents as well as against wear resulting from normal use.
• Such compositions are very useful in all industrial fields where it is desirable to avoid, as much as possible, progressive damage to sensitive objects of any kind exposed to shock and wear. This is particularly important when dealing with transparent articles such as optical goods the surface of which must be protected by all means against scratches so as not to lose their desirable optical properties.
• Colloidal silicas which are essentially hydrophilic (as are also the other types of silica such as amorphous, crystalline, microcrystalline, precipitated and pyrogenic silicas) are compatible in general, only with hydrophilic polymers. Such silicas are much less or not miscible with typical hydrophobia resins such as polyolefins, which very strongly restricts their use as a filler in film forming thermosetting or photo-setting compositions.
• particles of alumina are coated with ⁇ -(glycidyloxy)-propyl-trimethoxysilane and a mixture containing about 25% by weight of such treated alumina and an epoxy resin is used for coating a polycarbonate article so as to obtain, after polymerization, an abrasion-resistant film.
• organic groups such as vinyl, methacryl, epoxy, glycidoxy to hydrophilic silica so as to impart thereto hydrophobic properties: L. P. ZIEMIANSKI et al. Rubber World 163, 1 (1970); M. W. RANEY et al. Meeting of the Div.
• SiO 2 e.g. to make it hydrophobic: 2,610,167; 2,818,385; 3,652,379; 4,001,128.
• Forming SiO 2 in situ e.g. hydrolyzing organic silicates: 2,404,357; 2,404,426; 3,971,872; 4,049,868; 4,120,992; 4,186,026. 3.
• USP 3,645,779 provides a vacuum vapor deposited coating of B 2 O 3 -SiO 2 on organic glass
• USP 4,051,297 discloses a sputtered film of chromium silicide on smooth surfaces
• USP 4,242,403 there is disclosed a polyethylene terephtalate sheet covered with an intermediate layer of ⁇ -(3,4-epoxycyclohexyl)-ethyltrimethoxysilane and an upper layer of silica reinforced organopolysiloxane resin.
• compositions depositing of transparent protective films on substrates, such films being sufficiently mechanically resistant to withstand normal wear or accidental abuses without impairment of the surface properties; providing protective transparent film coatings on optical goods, the optical properties of which are not significantly modified and which keep such properties for a significant period of time under adverse conditions; depositing of thin well-adhering films on substrates, such adhesion not being affected by weathering conditions even after a prolonged period of exposure; providing film forming coatings that will strongly adhere to organic glass substrates and which can be cured at room temperature, i.e. much below the softening temperatures of the substrate; providing transparent scratch-resistant coatings applied on substrates as one layer films, i.e. without the need of an intermediate bonding layer; providing compositions stable enough for accepting prolonged storage periods at room temperature without hardening and nonetheless reactive enough to be cured on the substrates in a matter of seconds without the use of elevated temperatures.
• the fulfillment of these objects by the reference disclosure provided industrial optical articles made of relatively soft and easy moldable organic glasses protected with a scratch resistant film withstanding prolonged use under severe weathering conditions without discoloration, crazing or significant adhesion losses.
• the mineral particles to be incorporated into the organic phase are rendered hydrophobic by reacting with trialkoxysilane compounds.
• the trialkoxysilane compounds are first dispersed into an aqueous medium (mainly a water phase) wherein they are converted to some extent by hydrolysis into corresponding hydroxysilane compounds.
• step 3 procured the following advantages: a) Improved the yield of the grafting operation, i.e. increased the amount of organic matter attached to the mineral particles. (This increased yield is believed attributable to either direct covalent grafting or further polycondensation of unreacted silanol groups or, possibly, adsorption of non-covalently bonded homopolymerized polysiloxane chains on the structure of the particles.) b) Prevented the formation of undesirable premature cross-links between the grafted substituents carrying reactive functions, thus preserving the full potentiality of such functions for the time when the films obtained from the composition are cured, and provided advantageous rheological properties (reduced viscosity) to the composition for the application of thin films. c) Drastically reduced the formation of aggregates to be broken down before bringing about step 4) of the present method.
• the groups defined by RO in formula I above can be lower alkoxy or cycloalkoxy groups such as methoxy, ethoxy, propoxy (n and iso), butoxy, pentoxy and the like.
• the groups defined by R 1 and R 2 can be extremely variable, the only requirements therefor being chemical availability, stability, reasonable cost and compatibility with the organic monomers and/or prepolymers involved in the composition.
• step 1) can be performed are not critical provided that enough water is used to effect hydrolysis.
• the alkoxysilane is added to water in concentration by weight of about 1 to 20 although higher concentrations, i.e. up to 50% by weight or lower concentrations are possible although less practical.
• the two reagents are stirred together for a variable period (for instance from 15 minutes to 15 hours) at temperatures from about 10°C to 50°C. Lower temperatures will unnecessarily prolong the reaction time while temperatures above 50°C may be undesirable or even detrimental as being prone to favor premature autocondensation (prepolymerization into siloxane chains).
• acetic acid is preferred.
• the pH is desirably adapted to meet the requirements of the functional groups, e.g. the aminopropyl derivative is preferably hydrolyzed under mildly alkaline conditions (pH 8-9) and the epoxy derivative under neutral conditions.
• the types of mineral particles to be used in step 2) include many varieties of SiO 2 and AI 2 O 3 .
• the size of the particles is important with respect to the optical properties to be given to the ultimately obtained abrasion-resisting coating.
• using relatively large particles i.e. with a diameter of several micrometers (um) may provide at the surface of the film microscopic prominences not visible with the eye but detrimental to the optical properties thereof (undesirable light reflection and diffraction effects). This may impart to the film a milky appearance.
• the film should have a flawless, smooth, mirror-like surface. Consequently, one will preferably use particles of a size about one order of magnitude less than the coating thickness.
• step 2 The conditions under which the grafting of step 2) can be carried out are not critical either.
• the properties of the ultimately obtained product however depend on the dispersing ability of the equipment with which this step is performed, particularly regarding its ability to overcome the tendency of the particles to agglomerate during grafting or to break down by attrition the aggregates already formed.
• Suitable dispersing apparatus for this step are for instance homogenizers of types "PRESTO-MILL” (O. Krieger, Muttenz, Switzerland) or “HOMOREX” (BROGLI, Alschwil, Switzerland) and ULTRA TURRAX (KINEMATICA, Lucerne, Switzerland).
• step 3) is carried out by subjecting the dispersion resulting from step 2) to spray-drying, i.e. the mixture is atomized in a current of hot air which results in the instantaneous removal of water and deposition of the graft charge as a low moisture content powered mass at the bottom of the spray-drying apparatus.
• the residual moisture of the spray-dried product is then sufficiently low not to impede the subsequent implementation of step 4), that is, the incorporation and dispersion of the grafted charge into the organic phase of the composition.
• the conditions prevailing in spray-drying may be considered relatively mild (despite the relatively high temperature of the air) as compared to previously used standard drying conditions.
• prepolymers are known in practice most often under generic commercial names such as UVITHANE (Thiokol Corp), EBECRYL (Union Chimique Beige), UCAR-X (Union Carbide), SETAROL (Kunstharfabrik Synthese NV, Holland), ACTILANE (S.N.P.E.), GALGARD (Gulf Corp), CHEMLINK (Arco Chem) .
• UVITHANE Thiokol Corp
• EBECRYL Union Chimique Beige
• UCAR-X Union Carbide
• SETAROL Kerunstharfabrik Synthese NV, Holland
• ACTILANE S.N.P.E.
• GALGARD Gaf Corp
• CHEMLINK Arco Chem
• step 4) of this invention polymerization catalysts and other additives for various purposes such as stabilizers, initiators, fungicides, anti-discoloring agents and the like can be added.
• Fig. 3 is a graph showing the relation between spray-enclosure temperature and spray-drying rate (in terms of time yield of dry product).
• the present installation comprises a first reactor 1 supplied with water, acid for adjusting the pH of the medium and the alkoxysilane reagent from lines 2, 3 and 4 respectively.
• a first reactor 1 supplied with water, acid for adjusting the pH of the medium and the alkoxysilane reagent from lines 2, 3 and 4 respectively.
• step 1) the solution or dispersion of the hydrolyzed alkoxysilane is transferred into a second reactor 5 of the installation from a line 6, this reactor being fed with the mineral charge to be organophilized from a measuring feed hopper 7 connected to a supply line 8.
• the mineral charge and the hydrolyzed reagent are then vigorously mixed and homogenized in reactor 5 (step 2) whereby the mixture is recirculated into a cooling device 9 for maintaining the temperature within the prescribed limits in case the heat of mixing would raise the temperature unacceptably.
• the hot humid air (from evaporation of the mixture) containing in suspension the powdered spray dried material is sent to the cyclone wherein, according to means known in the art, it is subjected to a turbulent action along the walls of the cyclone whereby separation of the powder from the humid air occurs.
• the grafted mineral powder then accumulates to the bottom of the cyclone wherefrom it can be removed through a valve 15 and sent to a first mixer 16 while the humid gases escape by line 17 into the aspirator.
• the mixer 16 serves to carry out a first part of step 4) by mixing the grafted charge issued from cyclone 15 with a suitable organic phase brought in through supply line 18. Then, the mixture of the mineral charge and the organic monomer (s) is sent to a second mixer 19 in which mixing with the additives arriving by line 20 is effected. If desired, mixer 19 can be omitted, the mixing with the additives being done in mixer 16.
• step 1) The present example was repeated twice using in step 1) solutions with a pH of 4.25 and 3.6, respectively.
• the hydrolysis periods under identical conditions were 3/4 hour and 1/4 hour, respectively; the end properties of the compositions obtained using the hydrolyzed reagent and then proceeding exactly as described above were not significantly different.
• Step 4 was carried out as previously described.
• the results of the tests and comparative experiments showed that approximately similar properties (in term of final composition viscosity) were obtained for the (a) and (bl) tests (at 83 - 86°C) with the proviso that in the comparative (a) tests, careful milling of the dry grafted charge was necessary before carrying out step 4.
• the data below concern the tests referred to as
• the temperature of both the drying air and the spraying room has an influence on the spray-drying rate and the residual moisture of the pulverized product.
• the drying rate is higher at 260°C than at 200°C.
• the residual moisture is however higher at 260°C than at 200°C since at the lower temperature, the material remains longer in the enclosure than at the higher temperature.
• the importance of the enclosure temperature is the following: the lower the temperature, the higher the drying rate and the residual moisture level.
• a charge of grafted silica (AEROSIL-380) was prepared according to the conditions of the previous examples.
• the pertinent data are as follows: Step 1: 4% by weight of ⁇ -MPS in water; 30 minutes hydrolysis at 25°C, pH 3.6.
• Step 2 40 g of silica for 500 ml of the aqueous hydrolyzed silane solution, 20 minutes grafting time in the PRESTO MILL apparatus at 20°C.
• Step 3 spray drying with the NIRO apparatus, drying air 260 - 270°C, enclosure 80 - 90°C, pump pressure 4 kg/cm 2 ; rate about 230 g/hr.
• the obtained charge was distributed in the proportion of 20% by weight in the aforementioned standard testing organic phase, the variables tested being the milling technique and the milling time.
• a planetary ball mill “PULVERISETTE”. This mill comprises symmetrically placed containers which simultaneously rotate in the vertical and in the horizontal plane. The containers also enclose balls of about 1 cm or more.

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• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Health & Medical Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Medicinal Chemistry (AREA)
• Polymers & Plastics (AREA)
• Inorganic Chemistry (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Life Sciences & Earth Sciences (AREA)
• Wood Science & Technology (AREA)
• Paints Or Removers (AREA)
• Compositions Of Macromolecular Compounds (AREA)
• Polymerisation Methods In General (AREA)
• Graft Or Block Polymers (AREA)
• Pigments, Carbon Blacks, Or Wood Stains (AREA)
• Silicon Polymers (AREA)

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• 1983
  • 1983-09-29 US US06/537,215 patent/US4482656A/en not_active Expired - Fee Related
• 1984
  • 1984-09-17 AU AU34327/84A patent/AU569119B2/en not_active Ceased
  • 1984-09-17 DE DE8484903586T patent/DE3471111D1/de not_active Expired
  • 1984-09-17 EP EP84903586A patent/EP0158660B1/en not_active Expired
  • 1984-09-17 WO PCT/US1984/001470 patent/WO1985001511A1/en not_active Ceased
  • 1984-09-17 JP JP59503557A patent/JPS61500022A/ja active Granted
  • 1984-09-19 CA CA000463554A patent/CA1273441A/en not_active Expired - Fee Related

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