Classifications

• • 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
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L101/00—Compositions of unspecified macromolecular compounds
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L73/00—Compositions of macromolecular compounds obtained by reactions forming a linkage containing oxygen or oxygen and carbon in the main chain, not provided for in groups C08L59/00 - C08L71/00; Compositions of derivatives of such polymers
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L23/00—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers

Definitions

• the photodegradability and/or heat-seal range of polymeric matrix materials is controllably enhanced by incorporating therein Ti ⁇ 2 and ethylene copolymers which have pendent carbonyl groups along the copolymer chain.
• Photodegradation is the process whereby the ultraviolet radiation in sunlight attacks the chemical bonds in a chemical structure, such as plastics and polymers, thereby breaking the structure into smaller segments. This causes the structure to lose its physical strength, especially its ability to flex or stretch. The degradation process can continue the embrittlement and produce smaller and smaller pieces.
• the ethylene/carbon monoxide copolymers include those which have other copolymerizable monomers contained in the polymer, such as acrylic acid, methacrylic acid, vinyl alkylates, alkyl acrylates, and even minor amounts of lower olefins, such as propylene or butylene.
• Patents showing the preferred method of making CO-containing ethylene copolymers include U.S. Patent 4,600,614 and U.S. Patent 4,601,948.
• a European Patent Application published July 29, 1987 as European Patent No. 0230143 discloses that a photodegrading agent comprising a heavy metal dithiocarbamate or heavy metal dithiophosphate together with an ethylene/carbon monoxide polymer is useful for enhancing the photodegradation of an ethylene polymer, such as a linear low density polymer.
• copolymer which has carbonyl oxygen groups is one prepared by copolymerizing ethylene with an alkyl vinyl ketone, such as methyl vinyl ketone, ethyl vinyl ketone, propyl vinyl ketone, or an alkyl isopropenyl ketone and the like; these copolymers have the carbonyl groups pendent from one of the carbons of the vinyl group which is directly in the polymer "backbone" chain.
• alkyl vinyl ketone such as methyl vinyl ketone, ethyl vinyl ketone, propyl vinyl ketone, or an alkyl isopropenyl ketone and the like.
• n is a plural number
• R' is hydrogen or alkyl group
• the photodegradation properties of olefin polymers which contain carbonyl groups along the chain are disclosed in U.S. Patent 3*676,401 and U.S. Patent 3,860,538.
• HM88143 for a degradable polyethylene based white concentrate trademarked SPECTRATECHTM HM88143 by Quantum Chemical Corporation and described as 50 blend of polyethylene modified to be degradable and 50 of titanium dioxide (CAS RN: 13463-67-1); this Chemical Abstracts Service Registry Number is generic to Ti ⁇ 2-
• Ti ⁇ 2 will accelerate the photodegradation of polyethylene and polypropylene.
• the rutile form of Ti ⁇ 2 is relatively inactive with respect to the photodegradation of polymers to which it may be added, but it may be employed for other purposes, such as for pigmentation or thermal activity.
• the term "polymers or copolymers” refers herein to portions of the photodegradating agents, and which are also useful in enhancing the photodegradation of the matrix resins.
• a first aspect of the invention is a photodegrading agent comprising a blend of anatase Ti ⁇ 2 and at least one photodegrading polymer containing carbonyl CO groups along the polymer chain.
• a second aspect of the invention is a process of synergistically enhancing the photodegradation rate of photodegradation polymers containing carbonyl groups along the polymer chain; the said process comprising incorporating the anatase form of Ti ⁇ 2 therein.
• the heat- seal range of the matrix resin is beneficially broadened by the presence therein of the above Ti ⁇ 2/CO-containing polymer agents; in heat-sealing using radiant and or conduction heat it does not matter (vis-a-vis the heat seal range) whether the Ti0 2 is rutile or anatase, though it does matter if heating is being done using RF energy, especially MW energy, to cause heating of the material.
• the present invention involves the following listed related, identifiable aspects or embodiments:
• copolymer containing copolymerized carbon monoxide (CO) in the polymer chain backbone is the preferred type of CO-containing polymer.
• a photodegrading composition comprising anatase Ti ⁇ 2 and at least one CO-containing polymer.
• a process of providing a predetermined regulated rate of photodegradation to a matrix resin comprising blending the matrix resin with predetermined amounts of anatase Ti ⁇ 2, at least one CO- containing polymer and optionally rutile Ti ⁇ 2 > and/or a UV stabilizer.
• the photodegradation rate of CO-containing polymers is synergistically accelerated by the addition thereto of the anatase form of Ti ⁇ 2 and is not merely a numerically additive effect of the two ingredients. That, in itself, is beneficial in the preparation of articles which can be made directly from an anatase Ti ⁇ 2/polymer blend and relatively fast photodegradation is desirably obtained.
• the mixture of anatase Ti ⁇ 2/CO-containing polymer is also used as an agent to provide a faster photodegradation rate to articles such as resin films, filaments, fibers, sheets, slabs, containers or other configurations prepared from matrix resins.
• the agent may, as a "masterbatch" of Ti02/C0-containing polymer, be blended with the matrix resin in which the accelerated rate of photodegradation is desired.
• the carbonyl-containing polymer and the Ti ⁇ 2 can be added separately to the matrix resin, but are beneficially and preferably mixed together to form a photodegrading agent which is then added to the resin.
• additives and/or degradation accelerators and/or photostabilizers and/or photosensitizers may also be employed along with the agent of this invention either by way of having the photodegradation agent added to matrix resins which contain the said optional ingredients, or by way of adding the optional additives to matrix resins which contain the photodegradation agents, or by adding them to the matrix resin at substantially the same time.
• the matrix resins to which a photodegrading property are desired to be imparted or accelerated may be resins which are used in making packaging materials, especially those which are usually intended to be discarded after their first use.
• matrix resins are polyolefins, polyesters, polyurethanes, polyamides, polyepoxides, polyacrylates and plolycarbonates.
• Such articles as garbage bags, grocery bags, tampon-type applicators, wipe-cloths, hygiene products, disposable diapers, sanitary napkins, food-wrapping, food cartons, can holders, beverage overwraps, beverage containers, beer can "loop carriers", and the like, often comprise or include resins which can be caused to be more rapidly photodegraded by sunlight.
• Resins prepared from olefin monomers and/or vinyl monomers such as ethylene, propylene, butene, styrene, vinyl acetate, vinyl halide, and derivatives of these or other such monomers which are used in making plastics and which are often used as discardable packaging materials.
• Resins prepared from olefins and mixtures of olefins such as low density branched polyethylene (LDPE), linear low density polyethylene (LLDPE) and high density linear polyethylene (HDPE) as well as styrene polymers and copolymers are of particular interest as the matrix resins in this invention.
• LLDPE resins are of special interest considering, among other things, the strength and impact resistance they exhibit which makes them popular in the making of garbage bags and trash bags.
• Compositions comprising HDPE are particularly useful for preparing discardable molded articles.
• Compositions comprising LLDPE or LDPE are particularly useful for preparing discardable melt-extruded films.
• Compositions comprising styrenic polymers or copolymers are particularly useful for preparing discardable foams.
• the titanium oxide, Ti ⁇ 2 > which exhibits a synergistic effect when combined with CO-containing polymers is of the crystalline form known as anatase.
• the Ti ⁇ 2 is the anatase form
• Anatase Ti02 having a size range of between about 0.5 microns and about 3.5 microns is preferred, and the pigmentary grade of anatase Ti02 having a particle size of about 2 microns is especially -c preferred.
• the CO-containing polymer used as a photodegrading agent, in conjunction with the Ti ⁇ 2 » may be any thermoplastic polymer which has carbonyl groups Q along the polymer chain and which is either compatible with, or can be compatibilized with, the resin into which it is to be blended. Compatibilizing may be accomplished, e.g., by the addition of a compatibilizer or by special blending techniques while the 5 polymers/resins are in solution or are molten.
• the CO-containing polymer is an ethylene copolymer, especially a binary or ternary polymer, which is prepared using carbon monoxide as one of the monomers.
• the preparation of such ethylene/carbon 0 monoxide polymers is known in the art of making ethylene copolymers. Less preferred are those polymers wherein the carbonyl groups are supplied to the polymer chain by the presence of an alkyl vinyl ketone polymerized into the chain.
• the effect of the CO- containing polymer is not very likely to provide an appreciably significant effect on the photodegradation of the resin.
• the polymer which contains the CO groups may not exhibit the physical properties needed for attaining the initial strength or other properties desired in the resin article of which it is to be a part.
• a preferred range is 1 percent to 30 percent by weight, more preferably 2 percent to 20 percent by weight.
• the amount of the CO-containing polymer used in the matrix resin usually is an amount in the range of 0.05 percent to 50 percent of the total weight of the formulation.
• the amount of the anatase Ti ⁇ 2 used in the matrix resin usually is an amount in the range of 0.05 percent to 25 percent of the total weight of the formulation. Most often it is used in an amount in the range of 5 to 10 weight percent.
• the ratio of the CO-containing polymer to the anatase Ti ⁇ 2 usually is in the range of 99.9/0.1 to 0.3/99.7, preferably in the range of 99.8/0.2 to 0.5/99.5, most preferably in the range of 99.7/0.3 to 1/99.
• Irganox 1010 Tetrakis [methylene 2-(3' ,5'-di-tert- butyl-4'hydroxylphenol) propionate] methane,
• Tinuvin 770 hindered piperidines
• Tinuvin 328 a benzotriazole Tinuvin 328 a benzotriazole, and Cyasorb UV 5411 a benzotriazole.
• UV stabilizers are, e.g., as follows: Hindered amines light stabilizers, Substituted hindered amine light stabilizers, Hindered piperidines,
• Dithiolate metal complexes e.g. Ni, Co, Cu
• Phosphite esters e.g. Ni, Co, Cu
• Salicylaldehyde oximes e.g., Thiobisphenolates, Hydroxy-benzyl phosphonates, Substituted 2-hydroxybenzophenones,- 2-hydroxyphenyl benztriazoles, Metal dithiocarbamates, Metal acetyl acetonates, Hindered phenols, Metal dithiophosphate, Hindered aliphatic amine, Metal salicylaldehyde oximes, Peroxydienones,
• Dithiolate metal complexes e.g. Ni, Co, Cu
• Phosphite esters e.g. Ni, Co, Cu
• Salicylaldehyde oximes e.g., Thiobisphenolates, Hydroxy-benzyl phosphonates
• Substituted 2-hydroxybenzophenones e.g
• foaming agents to cause foaming of the matrix resin and produce lightweight articles, and/or add other polymers to the CO-containing polymer/Ti ⁇ 2 compositions, thus preparing an appreciable variety of final products having an enhanced tendency to degrade under the influence of actinic radiation, especially UV.
• LLDPE linear low density polyethylene which is actually an ethylene/1-alkene copolymer prepared by using a coordination catalyst, such as a Ziegler catalyst or the like.
• MFR melt flow rate
• MI melt index
• LLDPE linear low density polyethylene which is actually an ethylene/1-alkene copol ⁇ mer prepared by using a coordination catalyst, such as a Ziegler catalyst or the like.
• MFR melt flow rate
• MI melt index
• LLDPE-1 Ethylene/octene copolymer, density of 0.941 g/cc and MFR of 4 g/10 min.
• LLDPE-2 Ethylene/octene copolymer, density of 0.920 g/cc and MFR of 1 g/10 min.
• LDPE-1 Branched homopolymer of ethylene, 0.922 g/cc density, MFR of 2 g/10 min.
• Ti ⁇ 2 Titanium oxide indicated as the anatase crystal form or the rutile crystal form, or in some instances it can be either one. Unless indicated otherwise, the Ti ⁇ 2 used is pigment grade Ti ⁇ 2 (particularly that available as Mobay ® Type A-X).
• a composite blend is prepared by blending 9.9 parts of LLDPE-1 , 0.3 parts of LLDPE-2, 4.2 parts of EC0-1 and 0.6 parts of Concentrate #1.
• the components are tumble dry blended prior to being fabricated into cast film at 550°F (288°C) of 1.2 mil thickness. Strips of film, 1-inch by 8-inch (2.54cm by 20.32cm) are cut from the cast film and subjected to outside weathering in accordance with ASTM D-1435-85.
• ASTM D-1435-85 By analyses of the parameters of interest, average tensile, average yield and percent elongation at break are determined and analyzed in accordance with ASTM D-882.
• the brittle point is determined to be that point where the tensile at break and yield strength values were identical and the film samples demonstrated brittleness when handled.
• Example 2 In similar manner to Example 1, a composite blend is prepared consisting of 9.9 parts of LLDPE-1, 0.3 parts of LLDPE-2, 4.2 parts of ECO-2 and 0.6 parts
• Example 2 In similar manner to Example 1, a composite blend is prepared consisting of 9.9 parts of LLDPE-1, 4.5 parts of LDPE-1 and 0.6 parts of Concentrate #4. The composite is tested by outside weathering and the
• Example 2 In similar manner to Example 1 , a composite blend is prepared consisting of 9.9 parts of LLDPE-1, 0.3 parts of LLDPE-2, 4.2 parts of EC0-1 and 0.6 parts of Concentrate #5. The composite is tested by outside weathering and the data are shown in TABLE I.
• Example 2 In similar manner to Example 1, a composite blend is prepared consisting of 9.9 parts of LLDPE-1, 0.3 parts of LLDPE-2, 4.2 parts of ECO-2 and 0.6 parts of Concentrate #6. The composite is tested by outside weathering and the data are shown in TABLE I.
• the range of about 1/99 to about 99/1 is believed to be operable, preferably about 40/60 to about 90/10, most preferably about 50/50 to about 80/20.
• Hot tack tests are performed on a "Pack Forsk” instrument which is fully automated and is equipped with an Instron type seal strength testing device.
• the dwell time is set at 0.5 seconds.
• the delay time (between the formation of seal and the strength) is set at 0.2 seconds.
• the film samples are 1-inch (2.54 cm) wide strips of uniform thickness. Each data point is calculated from an average of at least 3 measurements.
• the tear resistance is measured by Elmendorf tear test type B, which is ASTM # D-1922. Each data point is an average of four measurements.
• Films from which testing samples are taken are prepared by dry blending the components for 1 hour and then extruding the well-mixed ingredients through a 1- inch 24/1 L/D MPM extruder and fabricated into cast film (film gauge of 2.5 to 2.7 mils, i.e. about 0.0635 to 0.06858 mm), under the following conditions:
• Zone 2 430°F/221°C Zone 3 450°F/232°C
• a typical prior art composite contains about 73% LLDPE, about 25% LDPE, and about 2% Ti0 2 .
• the heat seal temperature range and the tear strength of this currently used composite, when fabricated into a cast film without the Ti0 2 » are 225°F to 275°F and 200 grams, respectively.
• the heat seal temperature range and tear strength become reduced to 230°F to 265°F and 146 grams, respectively.
• Ti ⁇ 2 acidic surface
• ECO basic carbonyl
• Ti ⁇ 2 can be either anatase or rutile or any variety having an acid surface.
• Other particulate solid compounds having acid surfaces may be employed in place of, or along with, the Ti02 and the CO-containing olefin polymer.
• EC0/Ti0 2 in place of LDPE/Ti0 2 is found to result in widening the heat seal temperature range of a wide variety of polymers into which the ECO/Ti ⁇ 2 is incorporated, especially olefin polymers and copolymers such as LLDPE, HDPE, and LDPE and the like.
• olefin polymers and copolymers such as LLDPE, HDPE, and LDPE and the like.
• the benefits of the ECO/Ti ⁇ 2 additives are found in blown films as well as cast films. For the purposes of improving the heat seal range of the preferred LLDPE the following amounts are preferred:
• the ECO copolymer can contain 1 to 50 weight % CO.
• the LLDPE can contain any one or more alkene comonomers in the C3-C10 range.

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• 1990
  • 1990-06-21 WO PCT/US1990/003540 patent/WO1991018944A1/en not_active Application Discontinuation
  • 1990-06-21 AU AU61481/90A patent/AU6148190A/en not_active Abandoned
  • 1990-06-21 EP EP19900911424 patent/EP0486524A4/en not_active Withdrawn
  • 1990-06-21 JP JP51097790A patent/JPH04504734A/ja active Pending

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