Patent Issued for Polyamide Moulding Materials Containing Cycloolefin Copolymers (USPTO 9290659)

By a News Reporter-Staff News Editor at Nanotechnology Weekly -- EMS-PATENT AG (Domat/Ems, CH) has been issued patent number 9290659, according to news reporting originating out of

The patent's inventors are Hoffmann, Botho (Domat/Ems, CH); Suetterlin, Martin (Chur, CH); Bass, Sepp (Domat/Ems, CH).

This patent was filed on October 2, 2014 and was published online on March 22, 2016.

From the background information supplied by the inventors, news correspondents obtained the following quote: "The present invention relates to transparent polyamide moulding materials containing cycloolefin copolymers and the use thereof.

"Polyamide moulding materials containing cycloolefin copolymers are known from patent specification DD 203 060 A. Thermoplastic combinations based on norbornene/ethylene copolymers and polyamides having approximately equal quantitative proportions of the two polymers are described there. As suitable polyamides mention is made of aliphatic polyamides, polyamides having cycloaliphatic chain building blocks, aliphatic-aromatic polyamides and/or aromatic polyamides, usually with specific compounds as an example. Transparency is not one of the requirements for the polyamide moulding materials described. The optical properties of those polyamide moulding materials are not disclosed.

"JP 2011-057864 A discloses moulding materials which are based on cycloolefin copolymers as the main component and which contain a smaller quantity of an added aliphatic polyamide in relation thereto. The cycloolefin copolymers claimed there have a glass transition temperature Tg from 50.degree. C. up to a maximum of 100.degree. C. Aliphatic polyamides having a fraction of at least 50 mol % lactamic or aminocarboxylic acid units are used. The transparency of these compositions is only low since merely a visual contact transparency is given.

"In the brochure 'TOPAS Cycloolefin Copolymer (COC)' of the COC manufacturer TOPAS Advanced Polymers, May 2007 edition, cycloolefin copolymers are described more accurately as a copolymerization product of the bicyclic olefin norbornene and ethylene. The good compatibility of COC with polyolefins to produce blends is mentioned and it is explicitly pointed out that the addition of foreign also transparent thermoplastics to COC leads to severe opacity. The designation TOPAS is a registered trademark.

"Compared with other thermoplastics, polyamides have the particular feature that according to the type, they can absorb a certain quantity of water from the ambient moisture, with the result that the volume or the dimensions of moulded parts or coatings fabricated therefrom or certain mechanical properties of the moulded parts or coatings fabricated therefrom can vary. This also applies to transparent polyamides.

"In order to achieve a good dimensional stability and more constant mechanical properties it is desirable to keep the water absorption of a polyamide moulding material low. To this end, the polyamide can, for example, be mixed with other components. In the case of transparent polyamides however, these components usually have a negative influence on the optical properties, i.e. the light transmission and the haze (opacity) of the resulting polyamide moulding material."

Supplementing the background information on this patent, VerticalNews reporters also obtained the inventors' summary information for this patent: "Consequently it was the object of the present invention to provide a transparent polyamide moulding material based on a polyamide which shows a reduced water absorption compared with the unmodified polyamide and which despite the other moulding material components still has good optical properties, i.e. a high light transmission and a low haze.

"This object is solved according to the present invention by a polyamide moulding material having the features of claim 1.

"The transparent polyamide moulding material according to the invention contains a polyamide as the main component and contrary to the statement in the TOPAS brochure, i.e. to the complete surprise of the person skilled in the art, at least one cycloolefin copolymer.

"At this point it should be pointed out that the term 'polyamide' is a generic term which comprises homopolyamides and copolyamides as well as mixtures thereof. The notations and abbreviations for polymers and the monomers thereof are specified in the ISO Standard 1874-1:1992(E).

"A transparent polyamide moulding material according to the invention containing at least one cycloolefin copolymer comprises a mixture of: (A) 55 to 99 wt % of at least one amorphous polyamide; (B) 1 to 30 wt % of the at least one cycloolefin copolymer, wherein in the at least one cycloolefin copolymer (B) the cycloolefin fraction is more than 40 mol %; and (C) 0 to 15 wt % of at least one additive; wherein the sum of the components (A) to (C) is 100 wt % of the polyamide moulding material; wherein this polyamide moulding material has a light transmission measured according to the ASTM D 1003 standard, which is at least 80%; and wherein the polyamide moulding material has a haze measured according to the ASTM D 1003 standard, which is at most 30%.

"The two said optical properties must be satisfied in order that a polyamide moulding material falls within the claimed range. If the polyamide moulding material contains no additive (C), the components (A) and (B) together yield 100 wt %. If an additive (C) is present, the sum of (A) and (B) is less than 100 wt % according to the fraction of component (C).

"Preferred embodiments of the transparent polyamide moulding material according to the invention are obtained from the dependent claims. In addition, the use of this polyamide moulding material is claimed.

"In differential scanning calorimetry, DSC, according to ISO 11357 at a heating rate of 20 K/min amorphous polyamides show a maximum heat of fusion of 5 J/g, preferably a maximum of 3 J/g, particularly preferably of 0 to 1 J/g.

"In the polyamide moulding material according to the invention, components (A) and (B) are preferably present in a fraction of: (A) 60 to 97 wt % and (B) 3 to 25 wt %; particularly preferably in a fraction of: (A) 62 to 96 wt % and (B) 4 to 23 wt %; and quite particularly preferably in a fraction of: (A) 72 to 96 wt % and (B) 4 to 13 wt %.

"Particularly preferably the at least one amorphous polyamide (A) contains at least one cycloaliphatic diamine, which is particularly preferably selected from a group consisting of bis(aminocyclohexyl)methane and its alkyl derivatives. The latter is understood to be bis(aminocyclohexyl)methane with alkyl substituents.

"Quite particularly preferably the at least one cycloaliphatic diamine is selected from a group consisting of bis(4-amino-cyclohexyl)methane, bis(3-methyl-4-amino-cyclohexyl)methane and bis(3,5-dimethyl-4-amino-cyclohexyl)methane.

"In a further preferred embodiment of the transparent polyamide moulding material according to the invention, in the at least one amorphous polyamide (A) hexamethylenediamine is excluded as a monomer and/or in the at least one cycloolefin copolymer (B) the cycloolefin fraction is preferably more than 40 mol %.

"In a preferred embodiment the transparent polyamide moulding material according to the invention containing at least one cycloolefin copolymer comprises a mixture of: (A) 55 to 99 wt % of at least one amorphous polyamide, wherein in each case hexamethylenediamine is excluded as a monomer; (B) 1 to 30 wt % of at least one cycloolefin copolymer, wherein each cycloolefin copolymer has a cycloolefin fraction of more than 40 mol %; and (C) 0 to 15 wt % of at least one additive; wherein the sum of components (A) to (C) is 100 wt % of the polyamide moulding material; wherein this polyamide moulding material has a light transmission measured according to the ASTM D 1003 standard, which is at least 80%; and wherein the polyamide moulding material has a haze measured according to the ASTM D 1003 standard, which is at most 30%.

"The relative viscosity (RV) of the at least one amorphous polyamide (A) of the polyamide moulding material according to the invention is preferably 1.40 to 2.15, particularly preferably 1.45 to 1.85, and quite particularly preferably 1.50 to 1.75, measured using 0.5 g polyamide in 100 ml m-cresol at 20.degree. C.

"The at least one amorphous polyamide (A) of the polyamide moulding material according to the invention is preferably at least one amorphous copolyamide (A).

"The amorphous copolyamide (A) preferably contains laurolactam as a monomer, and has a laurolactam content which is 10 to 45 mol %, particularly preferably 15 to 40 mol %, and quite particularly preferably 20 to 40 mol %, relative to the molar sum of all the monomers.

"Preferably the amorphous copolyamide (A) contains the cycloaliphatic diamine bis(3-methyl-4-amino-cyclohexyl)methane (MACM) as a monomer. Particularly preferably the amorphous copolyamide (A) contains MACMI repetition units composed of bis(3-methyl-4-amino-cyclohexyl)methane (MACM) and isophthalic acid (I).

"In a preferred embodiment the amorphous copolyamide (A) comprises a PA MACMI/12, composed of the monomers bis(3-methyl-4-amino-cyclohexyl)methane (MACM), isophthalic acid (I) and laurolactam (12). Especially preferably the PA MACMI/12 has the molar ratio 65/35.

"In a further preferred embodiment the amorphous copolyamide (A) comprises a PA MACMI/MACMT/12, composed of the monomers bis(3-methyl-4-amino-cyclohexyl)methane (MACM), isophthalic acid (I), terephthalic acid (T) and laurolactam (12).

"Among the PA MACMI/MACMT/12 those having an equimolar ratio of isophthalic acid to terephthalic acid are preferred. Especially preferably the PA MACMI/MACMT/12 has the molar ratio 38/38/24.

"The at least one cycloolefin copolymer (B) is composed of at least one cyclic olefin and at least one linear or branched olefin, wherein the cycloolefin fraction in each case is more than 40 mol %, preferably 45 to 75 mol %, particularly preferably 47 to 70 mol % and quite particularly preferably 52 to 68 mol %. Preferred cyclic olefins are norbornene, substituted norbornenes, norbornene derivatives or tetracyclododecene. The substituents can comprise alkyl or aryl groups. Among the linear or branched olefins, linear olefins are preferred, in particular ethene and propene. One, two or more cycloolefin copolymers can be used. More than one cycloolefin copolymer is also present if the cycloolefin copolymers consist of the same monomers but the cycloolefin fraction differs quantitatively.

"The at least one cycloolefin copolymer (B) has a glass transition temperature (Tg) which is preferably higher than 100.degree. C. Particularly preferably the glass transition temperature of the at least one cycloolefin copolymer (B) lies in the range of 110.degree. C. to 220.degree. C., quite particularly preferably in the range of 120.degree. C. to 210.degree. C.

"The at least one cycloolefin copolymer (B) has a cycloolefin fraction which is more than 40 mol % relative to the molar sum of all the monomers. Preferably the cycloolefin fraction of the cycloolefin copolymer is 43 to 75 mol %, particularly preferably 47 to 70 mol %, and quite particularly preferably 52 to 68 mol %.

"The at least one cycloolefin copolymer (B) can contain functional groups which enhance its compatibility with the at least one amorphous polyamide (A). Suitable functional groups are, for example, acrylic acid, succinic acid anhydride, glycidylmethacrylate and/or maleic acid anhydride.

"Preferably the at least one cycloolefin copolymer (B) consists of norbornene and/or norbornene derivatives and ethene.

"Particularly preferably the at least one cycloolefin copolymer (B) consists of norbornene and ethene, and is therefore a norbornene/ethene copolymer.

"In a preferred embodiment the transparent polyamide moulding material contains at least one additive (C). The fraction of the at least one additive (C) is preferably 0.1 to 6 wt %, particularly preferably 0.1 to 4 wt %. Preferably the quantity of an individual additive is no more than 3 wt %.

"Preferably the at least one additive (C) is selected from the group consisting of stabilizers, lubricants, dyes, marking substances, compatibilizers, inorganic pigments, organic pigments, antistatics, antiblocking agents, release agents, demoulding agents, optical brighteners, photochromic additives, halogen-free flame retardants, metal pigments, metal flakes, metal-coated particles, fillers, nanoscale fillers and mixtures thereof.

"Both the fillers and the nanoscale fillers can be surface-treated but also untreated. The nanoscale fillers preferably comprise minerals having a maximum particle size of 100 nm or natural or synthetic phyllosilicates or mixtures thereof. In the polyamide moulding materials according to the invention, for example, kaolins, serpentine, talc, mica, vermiculite, muscovite, illite, smectite, saponite, montmorillonite, hectorite, double hydroxides or mixtures thereof can be used.

"The stabilizers preferably comprise organic or inorganic stabilizers which are selected from the group of antioxidants, antiozonants, sun protection agents, UV stabilizers, UV absorbers and UV blockers. In a preferred embodiment the transparent polyamide moulding material according to the invention contains at least one stabilizer as additive (C).

"Polyamide moulding materials according to the invention have a light transmission which, measured according to the ASTM D 1003 standard, is at least 80%, preferably at least 85%, particularly preferably at least 88% and quite particularly preferably at least 90%. Polyamide moulding materials according to the invention additionally have a haze which, measured according to the ASTM D 1003 standard, is at most 30%, preferably at most 25%, particularly preferably at most 20% and quite particularly preferably at most 15%.

"Transparent polyamide moulding materials according to the invention containing cycloolefin copolymer in which the at least one copolyamide (A) is a PA MACMI/12 show a water absorption measured on plates according to the ISO Standard 62 of less than 4 wt %. In the case of unmodified PA MACMI/12 the water absorption on the other hand is 4 wt %.

"The polyamide moulding materials according to the invention preferably present in granular form can be used for coatings of objects or for manufacturing shaped bodies, in particular by extrusion or injection moulding.

"The coatings or shaped bodies are primarily suitable for use in the fields of electrical and electronics, telecommunications, optics, photovoltaics and automobile interiors. The shaped bodies preferably comprise lenses, spectacle frames, spectacle rims, spectacle parts, viewing windows, visors, filter cups, flowmeters, closures, covers, instrument covers, buttons, housings or housing parts, in particular for portable electrical or electronic equipment. The coatings preferably comprise protective layers for example for displays, optical filters, functional or decorative parts in vehicle interiors or the front side of photovoltaic modules. Preferably the polyamide moulding materials according to the invention are used to produce shaped bodies by injection moulding."

For the URL and additional information on this patent, see: Hoffmann, Botho; Suetterlin, Martin; Bass, Sepp. Polyamide Moulding Materials Containing Cycloolefin Copolymers.

Keywords for this news article include: Alkanes, Methane, Nanoscale, EMS-PATENT AG, Nanotechnology, Emerging Technologies.

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