Classifications

• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J5/00—Manufacture of articles or shaped materials containing macromolecular substances
  • C08J5/18—Manufacture of films or sheets
• • 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
  • C08F8/00—Chemical modification by after-treatment
  • C08F8/44—Preparation of metal salts or ammonium salts
• • 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
  • C08L23/02—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers not modified by chemical after-treatment
  • C08L23/04—Homopolymers or copolymers of ethene
  • C08L23/08—Copolymers of ethene
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J2323/00—Characterised by the use of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Derivatives of such polymers
  • C08J2323/02—Characterised by the use of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Derivatives of such polymers not modified by chemical after treatment
  • C08J2323/04—Homopolymers or copolymers of ethene
  • C08J2323/08—Copolymers of ethene
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L2205/00—Polymer mixtures characterised by other features
  • C08L2205/02—Polymer mixtures characterised by other features containing two or more polymers of the same C08L -group
• • 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
  • C08L23/02—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers not modified by chemical after-treatment
  • C08L23/04—Homopolymers or copolymers of ethene
  • C08L23/08—Copolymers of ethene
  • C08L23/0846—Copolymers of ethene with unsaturated hydrocarbons containing other atoms than carbon or hydrogen atoms
  • C08L23/0869—Acids or derivatives thereof
  • C08L23/0876—Neutralised polymers, i.e. ionomers

Definitions

• the present invention relates to ethylene copolymer compositions that are useful for fabricating films, sheets and molded articles of scratch/abrasion resistant material.
• the ethylene copolymer compositions of the present invention can be used as protective coatings or layers on wear and scratch- exposed objects for example as wear layers on floor tiles or as protective layers for skis or other wear and scratch exposed objects such as seal layers in packaging structures that contain hard, abrasive objects such as dry soup mixes or the like.
• Ionomers are thermoplastic resins that contain metal ions in addition to organic-chain molecules. Ionomers have solid-state properties characteristic of cross-linked polymers and melt-fabricability properties characteristic of uncrosslinked thermoplastic polymers : see for example US Patent 3,262,272. Major applications of ionomers are in the areas of packaging and for sporting goods.
• US 3,264,269 teaches a process for crosslinking polymers containing carboxyl groups which comprises imbibing a shaped article of the polymer in a diisocyanate.
• the disadvantages of this process are its 2-step nature (processing plus imbibing) combined with the toxic nature of diisocyanates.
• An object of the present invention is to overcome the above-indicated disadvantages by providing property enhancements to ionomers comparable to those achieved with the previous crosslinking routes (such as higher scratch resistance) while still allowing thermoplastic processability, non toxicity and by using a one step process.
• the present invention provides a thermoplastic composition for producing a film or sheet or molded articles of abrasion and scratch-resistant transparent material, in particular for application as a protective transparent coating or layer on abrasion and scratch-exposed objects, comprising a copolymer of ethylene and 10-30% by weight of an ⁇ , ⁇ -unsaturated C3 -C8 carboxylic acid, particularly acrylic acid or methacrylic acid, that is neutralized with more than one metal ion.
• the copolymer may further contain an acrylate, and may be processed by e.g. extruding or casting a sheet or blowing a film, or injection molding a molded article.
• the ionomer compounds are well known to those familiar with the art but contain a combination of two different metal ions in a given ratio, instead of only one metal ion as those polymers that are commercially available.
• a combination of compounds of at least two ions (ion, and ion 2 ) selected from the group consisting of Na, Zn, Li, Mg and Ca is used, each ion type providing at least 5% of the neutralization of the acid functionality in the copolymer.
• the two ions must be present in a ratio, called the equivalent ratio, at a value close to one and in any event in the range from 0.3 to 2.5, preferably between 0.6 and 1.5.
• the "equivalent ratio" ion, to ion 2 is defined as: wt% ion, x ( " valence ion,) x Mw 2
• the ethylene copolymer composition of the present invention overcomes the aforementioned problems of scratching by providing a means of superior crosslink surprisingly obtained by different metal ion combinations without the addition of external crosslinking agents, and yields sheets and molded articles having a superior abrasion and scratch resistance from the very beginning. Additionally and surprisingly it was discovered that these ionomers containing two ions such as Zn and Mg show an unexpected clarity and an improved penetration resistance to stiff objects such as needles etc.
• thermoplastic copolymers used in the present invention are known. They are copolymers of ethylene and an ⁇ , ⁇ -unsaturated C3 -Cs carboxylic acid. Acrylic and methacrylic acids are preferred acid comonomers.
• the copolymer can be from about 10 to 99.9% neutralized with more than one metal ion type selected from sodium, zinc, lithium, magnesium, and calcium.
• neutralized ethylene acid copolymers are known in the art as 'ionomers'.
• neutralization will be from 10-70%.
• the copolymer has from about 35 to about 70% of the carboxylic acid groups ionized by neutralization with more than one metal ion selected from sodium, zinc, lithium, magnesium, and calcium, advantageously zinc/magnesium in the specified amounts providing an equivalent ratio close to 1 , or in any event in the range from 0.3 to 2.5.
• Fig. 1 graphically illustrates the measured scratch resistance for Examples according to the invention and comparative Examples.
• the acid copolymers used in the master batches CS1 and CS2 are based on 10wt% MAA for CS1 and 5wt% MAA for CS2 and have a melt-flow index MFI (190°C/2.16kg) of 500.
• CS 1 Ethylene methacrylic acid copolymer masterbatch 45% ZnO CS2
• Ionomers II and 16 are control ionomers available commercially under the Trademark SURLYN from E. I. du Pont de Nemours and Company.
• Ionomer 12 is a specially prepared Zn-neutralized control ionomer with low melt flow index.
• Ionomers 13, 14 and 15 are Zn-Mg neutralized ionomers according to the invention. The weight percentages of the neutralizing agents and the MFI (melt flow index 190°C/2.16kg) of the ionomers are shown in Table I. TABLE 1
• the Examples described below were run by preparing a sheet of the respective resin or the resin plus masterbatch blend on a laboratory 2-roll mill and pressing the so-obtained ionomer resin sheet in a hydraulic press into plaques of the dimensions 100x100x3 mm. These plaques were then tested after 1 month, for scratch resistance using a scratch-resistance tester by Eirichsen according to ISO 1518, where a weight between 0.1 and 2 kg is applied onto a needle which is drawn over the surface of the plaque. This apparatus measures the weight in Newton at which a scratch mark is visible on the surface.
• a Taber abrasion test according to ASTM D3389 was also run. This test indicates the weight loss in g/2000 revolutions, average of two samples. A wheel with H-18 roughness was used, with a 250g weight on each arm. The weight was checked and wheel cleaned every 500 revolutions.
• Flex Modulus was measured according to ASTM D790 and hardness according to ASTM D2240.
• composition of Examples Table 2a indicates the composition of the control ionomers Cl to C7 and of Examples 1 to 4 according to the invention in terms of the corrected amount of methacylic acid (MAA), the % neutralization for the Zn and Mg ions, and the total % neutralization.
• MAA methacylic acid
• Table 2b shows the ionomer and additive (masterbatch or Magnesium hydroxide) included in each control ionomer Cl to C7 and in Examples 1 to 4 according to the invention, as well as the calculated weight % of the Zn and Mg ions and the Zn/Mg equivalent ratio for those ionomers with 2 ions.
• Table 2b thus represents the composition of the various examples and comparative examples taking into account the composition of the ionomer mentioned in Table 1 and the information about the master batches CSl and CS2.
• Table 2b Using the molecular weight of ZnO and Mg(OH) 2 respectively we have calculated the weight % of Zn and Mg in the respective compounds and the above-defined "equivalent ratio of Zn Mg" taking account of the valences and molecular weight (Mw) of the mixed ions.
• Table 3 shows the results, namely the scratch resistance (SCR) measured as the weight in Newton after which a scratch mark is visible after 4 weeks at room temperature, the Abrasion (ABR) measured by the Taber test in g/2000 revolutions, the Stiffness (STF), i.e. the flex modulus in Mpa, the shore hardness (HRD) and viscosity (VIS), which is the melt flow index MFI (190°C/2.16kg).
• SCR scratch resistance
• ABR Abrasion measured by the Taber test in g/2000 revolutions
• STF Stiffness
• HRD shore hardness
• VIS viscosity
• Table 3 presents results that have been obtained on ionomers with identical chemical composition but which have been neutralized either with Zn or Mg alone or combined.
• control ionomers that are neutralized solely by Zn or Mg ions.
• 13, 14, 15 are ionomers according to the invention that contain both Mg and Zn ions.
• Mg Ions provide less stiffness than Zn Ions (lower flex modulus), but abrasion resistance and scratch resistance is the same.
• a low MFI Zn ionomer (without Mg incorporated), or as shown by comparative Example C7 a Mg ionomer (ionomer 16) with a MFI of 0.7, when compared to the mixed ionomer (15) with almost identical MFI, does NOT improve the scratch resistance even after aging or Taber Abrasion resistance.
• Fig. 1 illustrates the measured weight at which a scratch mark appears for the comparative Examples and the Examples according to the invention, after an aging period of 4 weeks.

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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)
• Manufacturing & Machinery (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• General Chemical & Material Sciences (AREA)
• Compositions Of Macromolecular Compounds (AREA)
• Laminated Bodies (AREA)
• Manufacture Of Macromolecular Shaped Articles (AREA)
• Wrappers (AREA)

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• 1999
  • 1999-11-04 WO PCT/US1999/025994 patent/WO2000027892A1/en not_active Application Discontinuation
  • 1999-11-04 CA CA002346072A patent/CA2346072A1/en not_active Abandoned
  • 1999-11-04 JP JP2000581069A patent/JP2002529553A/ja active Pending
  • 1999-11-04 EP EP99962689A patent/EP1141041A1/en not_active Withdrawn

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