COPOLYMER OF DODECANE TEREPHTHALAMIDE

Abstract: The present invention is an improved polyamide copolymer having monomer units including repeat units of formula (I), where n is from 10 to 14 and preferably is 12 (1,12-dodecanediamine), units derived from a symmetrical diacid or derivative of said diacid, preferably a symmetrical aromatic dicarboxylic acid. The copolymer has minor amounts, preferably 3 to 30 and more preferably 5 to 10 mol percent, of units derived from an additional comonomer.

Description: COPOLYMER OF DODECANE TEREPHTHALAMIDE BACKGROUND OF THE INVENTION The present invention is in the field of poly- amides, more particularly, the present invention relates to copol mers derived from long chain diamines, a sym¬ metrical diacid or derivative thereof, and at least one specifically selected additional comonomer. Conventional aliphatic nylons such as polycapro- lactam (nylon 6), poly(hexamethylene adipamide) (nylon 6,6) have high melting points and are therraoplastically processable. However, they have undesirably high water absorption characteristics, absorbing from 8 to 12 wt. percent water. Water absorption causes dimensional growth, and plasticization with a significant reduction in stiffness. This makes them unsuitable for various end use applications. Long chain aliphatic polyamides such as poly- laurolactam (nylon 12), and poly(1,12-dodecamethylene dodecanamide) (nylon 12,12) have low moisture-absorbing properties, but have undesirably low itelting points (below 180*C). Symmetrical rigid, aromatic diacids, such as terephthalic acid monomers used with aliphatic diamines having from 6 to 12 carbon atoms result in polyamides having low moisture absorbing characteristics but undesir¬ ably high melting points (greater than 300*C). Such melting points are often above the nylon degradation temp¬ eratures so that the polyamide cannot be melt-polymerized or melt-processed. SUMMARY OF THE INVENTION The present invention is an improved polyamide copolymer derived from a long chain diamine, preferably RHNtCH j .-NHR, where n is from 10 to 14, and preferably is 12 (i.e., 1,12-dodecanediamine) and R is preferably H or π an alkyl carbonyl group such as CH 3 C-; resulting in the H H monomer repeat unit -N[CH 2 l n N-, and a symmetrical diacid or derivative thereof, preferably R'C-Ar-C-R' where Ar is an aromatic group, and R' is preferably -OH, alkoxy group such as -OCH., or a halogen, resulting in the monomer repeat unit -C-Ar-c-. Preferably the diacid is a sym¬ metrical aromatic dicarboxylic acid. The symmetrical aromatic diacid or derivative thereof is preferably selected from the group consisting of terephthalic acid, 2,6-naphthalene dicarboxylic acid, 4,4'-biphenyl dicarboxylic acid and dimethyl terephthalate. The copolymer has minor amounts, preferably 3 to 30 and more preferably 5 to 10 mol percent, of an additional comonomer. Useful and preferred additional comonomβrs in¬ clude units derived from monomers which are difunctional. 5The functional groups are groups which are reactive with the amine groups of the diamine or the acid groups of the diacid. Preferred functional groups include amine groups, hydroxyl groups and carbox lic acid groups. Specific and lOpreferred comonome s include lactams having up to 9 raethylene groups, nonsymmetrical aromatic diacids, and hydroxy terminated polyolefins or polyethers. Depending upon the comonomer, the resulting polyamide copolymer will have high crystallinity and low moisture absorption, or the additional comonomer will contribute a "soft segment" making the polyamide copolymer more flexible. 20 Additional coraonomers which result in the improved crystallinity and low moisture absorption of the polyamide copolymer are preferably present in an amount ...sufficient to reduce the melting point while at the same time enable the polymer to have high crystallinity and low moisture absorption properties. Preferably, the addi¬ tional comonomer results in a polyamide copolymer having 3(-relatively high crystalline melting points of preferably from 250*C to 300*C, and more preferably 270*C to 290*C, high crystallinity, preferably at least 20 percent, and low moisture absorption, preferably below 5 percent, and 35 more preferably below 3 weight percent based on the weight of polyamide eopolymer and moisture. The additional co¬ monomer can be preferably present in random or block segments thereby resulting in a random or block copolymer. The major blocks of polyamide are derived from the long chain diamine and the symmetrical diacid. Preferred additional comonomers include diamines and nonsymmetrical diacids. Preferred diamines include 4,9-dioxa-dodecane- -1,12-diamine; 4,ll-dioxa-tetradecane-l,14-diamine; capro- lactara^ and laurolactam. Preferred nonsymmetrical diacids include phthalic acid and isophthalic acid. Comonomers which result in a polyamide copolymer having a flexible (low glass transition temperature, Tg), hydrophobic structure include block segments of polyolefin polyether and polysiloxane and the like. Preferred seg¬ ments include tβlechβlic amine terminated polyolefins including polyethylene, poly(ethylene-propylene), polyiso- butylene, poly(βthylenβ-butβnβ) , and the like. Preferred polyether, is bisa ino alkyl, pol tetramethyleneoxide (derived from polytetrahydrafuran), and preferred polysiloxane is poly(dimethyl siloxane); i.e., alpha,- omega-bisaminoalky poly(dimethyl siloxane). These comonomers have been found to act as a "soft segment" when used in the form of a block copolymer. The resulting copolymer has a combination of properties including high ductility (tensile-elongation), heat and chemical resistance, and low moisture absorption properties. They are useful for extrusion and molding applications. DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention is a polyamide copolymer comprising units derived from a long chain diamine preferably RHN[CH 2 _ n NHR, where n is from 10 to 14 and preferably is 12 (i.e., 1,12-dodecanediamine); and R is preferably H or an alkyl carbonyl group such as CH 3 C-, H H resulting in the monomer repeat unit -N[CH 2 - n N-,; a symmetrical diacid and derivatives thereof, preferably a symmetrical aromatic diacid and derivatives thereof, preferably R'C-Ar-C-R*, where Ar is an aromatic group, and R 1 is preferably -OH, alkoxy group such as -OCH j , or a halogen resulting in the monomer repeat unit -fi-Ar-C-; and an additional comonomer. Useful Ar's include \°V 'JC?JC®J ' \®/\®/ ' and tnβ likβ# Tnβ aromatic groups can contain substituents which do not adversely affect the properties of the polyamide copolymer. The symmetrical aromatic diacid is preferably selected from the group consisting of terephthalic acid, 2,6-naphthalene dicarboxylic acid, 4,4'-biphenyl dicarboxylic acid and dimethyl terephthalate. The preferred polyamide copolymer has units derived from 1,12-dodecanediamine copolymerized with a terephthalic acid and the additional comonomer. The copolyraer=comprises from 35 to 48.5 mol, and preferably 40 to 45 mol percent of units derived from the 5 long chain diamine preferably dodecanediamine, from 35 to 48.5, and preferably from 40 to 45 mol percent of units derived from terephthalic acid or derivatives thereof. Additionally, the copolymer comprises at least 3, and pre- 0 fβrably from 3 to 30, and more preferably from 5 to 10 mol percent of units derived from the additional comonomer. A preferred embodiment has units derived from at least one additional comonomer which results in a copolymer having a relatively high melting point, high crystallinity, and has low moisture absorption characteristics. The preferred polyamide copolymer has a 20 melting point below a copolymer derived from a corresponding long chain diamine and symmetrical diacid or derivative thereof (i.e., dodecanediamine and terephthalic __acid) of the same molecular weight. The melting point of the preferred polyamide copolymer is preferably in the range of from 250*C to 300*C, and more preferably 270*C to 290*C. The polyamide copolymer is highly crystalline as 30mβasured by X-ray diffraction. The polyamide copolymer is preferably at least 20 percent, and more preferably at least 30 percent. The upper range of crystallinity is typically 40 percent mol and preferably 50 percent 35 crystalline. Additionally, the polyamide copolymer has low moisture absorption characteristics as measured according to ASTM D 570-81. Preferably the polyamide copolymer absorbs less than 5 percent by weight, and preferably less than 3 percent by weight of moisture based on the weight of the polyamide copolymer and moisture. Preferred additional comonomers which lead to co- crystallizable segments, or at least do not significantly reduce crystallinity are diamines such as 4,9-dioxa-l,12- diaminododecane; 4, ll-dioxa-tetradecane-l,14-diamine; non-symmetrical diacids including isophthalic acid; lactams having up to 8 methylene groups, preferably laurolactam and caprolactara. Copol amides made using these additional comonomers have been found to have crystalline melting points of from 270-285*C, a low water absorption character of 1.7-3 percent by weight when measured according to ASTM D 570-81, good melt processability, at or below 300*C, and satisfactory mechanical properties including strength and toughness. The copolyamides have been found to have excellent chemical resistance, particularly to aqueous zinc chloride solutions. Additionally, the polyamide copolymers have been found to be dimensionally stable when exposed to heat and -8- moisture, and have chemical resistance to gasoline and alcohol as well as a variety of other organic materials. This makes the copolymers of the present invention useful for a variety of high-performance engineering resin appli¬ cations, such as automotive under-the-hood parts, fuel lines, and fuel component parts. An alternate embodiment of the polyamide copoly¬ mer can include comonomer units to improve flexibility of the copolymer. Comonomers having a flexible hydrophobic structure resulting in a soft segment include the olefins present as polyolefin segments such as polyethylene, poly(ethylene-propylenβ) , polyisobutylene, poly(eth lenβ- butene), and the like. A preferred ether is a polyether such as bis[arainopropyl]polytetrahydrafuran (derived from polytβtramβthylenβoxide); alpha,omβga-bis(a inoalkyl)- poly(tetramethyleneoxide); alpha,oraβga-diaraino polyolβfins; i.e., telechelic, a ino terminated polyethylene; and polysiloxanes such as pol (dimethyl siloxane); i.e., alpha,omega-bisaminoalkyl poly(dimethyl siloxane). The molecular weight of the soft segments pre¬ ferably range from 200 to 6,000 and more preferably from 750 to 2100. Polyethylene oxide is not preferred because of the high water absorption. The additional comonomer preferably is derived from comonomers resulting in units having the formula 0 R" 0 II I II — C -{CH 2 -CH-C-CH 2 *-- C — -NH- H 2 ) χ tO(CH 2 ) χ ] r (CH 2^ ■ NH- wherein R 2 is selected from -H, -CH 3 , -C 2 H 5 , -Cl, -CH » CH 2 , and mixtures thereof, R 3 is selected from -H, -CH 3 , -C 2 H 5' "CH"^' and mixtures thereof, A is selected from H, a halogen, and a hydro¬ carbon having from 1 to 4 carbon atoms, p is from 5 to 80, q is from 10 to 80, r is from 1 to 30, preferably 5 to 30, s is* from 4 to 9, x is from 4 to 6, and 5 κ' is from 2 to 6. The copolymer of the present invention can be made by conventional methods to copolymerize polyamides. 10 Particularly preferred are melt polymerization techniques in which the monomers are melted together under an inert atmosphere. The melt polymerization preferably is conducted at from 275-320 # C, and more preferably from 15 295-320"C. In addition to the three principle monomeric con¬ stituents, which together produce the copolymer of this 20 invention, other polymerizable monomers can also be used to prepare copoly ers. Included in these are vinyl com¬ pounds and other monomers which could be polymerized 2 _ directly into a linear polymer chain. The quantity of such additional monomers can vary and can be up to 30 mol percent of the total number of polymerizable constituents but preferably is limited to quantities of less than 15 30 mol percent, more preferably less than 5 mol percent. Several Examples are set forth below to illus¬ trate the nature of the invention and the manner of carry- 35 ing it out. However, the invention should not be con¬ sidered as being limited to the details thereof. All parts are by weight unless otherwise indicated. EXAMPLES The following are Examples of copolymerizations of 1,2-dodecanediamine, terephthalic acid and the indi¬ cated additional comonomer. The copolymβrizationβ were performed in the indicated equipment with mechanical stirring under a sweep of an inert gas (either nitrogen or argon) . In each case the polymerizations were run until a significant increase in viscosity was noted and then the sample was allowed to cool. The resulting solid was broken up and ground in a Wiley* mill to produce a powder. Melting points were determined by a differential scanning calori etry (DSC) on a Perkin-Elmer DSC 2 calorimeter. Reduced viscosities were determined by samples dissolved in m-cresol or concentrated sulfuric acid. Samples to be tested in accordance with ASTM tests were injection molded using an Arburg* injection molding machine at 320*C and 450 psi conditions. Tensile tests were performed on molded samples according to ASTM D-638 procedures. Water absorption measurements were performed on thin compression-molded films according to ASTM-D-570-81. Films were compression-molded at 300 β C for 1 minute at 10 to 20 tons of pressure. The films were 0.1 mm thick. The films were submerged in water and their change in weight monitored until equilibrium. Zinc chloride resistance was measured by immer¬ sing a bent 1/8 inch test bar in a 50 wt. percent solution of zinc chloride. The test bars were molded as described above, 7 inches long by 3/4 inch at the tabs, 1/4 inch in the neck region and 1/8 inch thick (ASTM-D-638 test bars). The bars were bent 180 degrees. The appearance of the bar and its structural integrity were noted with time. j Comparative Example 1 A 0.5 L stainless steel resin kettle (wide mouth kettle) was charged with 24.4 g (122 raraol) of 1,12-do¬ decanediamine, 20.3 g (122 mmol) of terephthalic acid, and 40 ml of water. The reaction mixture was slowly heated to 300*C. The material was intractable and never melted out properly. Example 1 A 500 ml stainless steel resin kettle with a mechanical stirrer was charged with 51.1 g (0.255 mol) of 1,12-dodecanediamine, 5.79 g (0.28 mol) of 4,9-dioxa- dodecane-l,12-diamine, 44.9 (0.270 mol) of terephthalic acid, and 50 ml of water. The polymerization mixture was slowly heated to 320°C to give a clear viscous melt. The polymer was allowed to cool and broken up. The resulting resin was dried overnight at 110*C under vacuum. Example 2 A three liter glass resin kettle was charged with 540.9 (2.70 mol) of 1.12-dodecanβdiamine, 61.3 g (0.30 mol) of 4,9-dioxadodβcanβ-l,12-diarainβ, 473.5 g (2.85 mol) of terephthalic acid and 400 ml of water. The mixture was slowly heated 300*C. The resulting viscous melt was Cooled to room temperature, broken up, and dried at 100*C under vacuum overnight. Example 3 A three liter glass resin kettle was charged with 517.1 g (2.58 mol) of 1,12-dodecanediamine, 226.9 g (0.30 mol) of bisaminopropoxypolytetrahydrofuran 750, 456.0 g (2.74 mol) of terephthalic acid, and 400 ml of water. The mixture was siowly heated to 293 β C to give a viscous melt. The melt was allowed to cool to room temperature, ground up, and dried overnight at 100 β C under vacuum. This sam¬ ple was unaffected by immersion in a zinc chloride solu¬ tion for over one month. Example 4 A three liter stainless steel resin flask was charged with 336 g (1.68 mol) of 1,12-dodecanediamine, 84 g (0.112 mol) of bisaminopropoxypolytetrahydrofuran 750, 282.8 g (1.70 mol), and 250 ml of water. The mixture was slowly heated to 300*C to give a viscous melt. The reac¬ tion mass was allowed to cool to room temperature, ground up, and dried overnight at 100*C vacuum. Example 5 A one liter stainless steel resin kettle fitted with a mechanical stirrer and an argon sweep was charged with 286.1 g (1.43 mol) of 1,12-dodecanediamine, 203.6 g (1.23 mol) of terephthalic acid, 22.6 g (0.14 mol) of isophthalic acid, and 400 ml of water. The kettle was slowly heated to 300*C under a sweep of argon. The resulting polymer was broken up, and dried (110 # C, vacuum ) . _ overnight. Example 6 , A 0.5 L stainless steel kettle was charged with 6.8 g (60.0 mraol) of caprolactam, 113.6 g (567 ramol) of 1,12-dodecanediamine, 89.7 g (540 ramol) of terephthalic acid and 200 ml of water. The reaction mixture was slowly heated to 300 β C which resulted in a viscous melt. The resulting material was allowed to cool, broken up, and dried overnight at 110*C under vacuum. Samples were tested for physical properties and results are summarized in Table 1 below. R.V. is relative viscosity, Tra is crystalline melt temperature. Table 1 Water Ex. R.V. Tm Modulus Strength Elongation Absorptio *C kpsl kpsi % % 1 1.6K*) 274,283 371 7.9 2.3 3.3 2 0.36 280,293 303 9.8 27.0 3 0.31 274,288 257 7.9 150.0 3.5 4 0.49 284,293 276 10.6 117.0 5 1.48(*) 284 - 367 12.0 11.3 1.7 6 - 289 - - - 2.0 * measured in m-cresol While exemplary embodiments of the invention have been described, the true scope of the invention is to be determined by the following claims.

Claims: CLAIMS: 1. A polyamicle copolymer comprising monomer repeat H H I i units derived from the formula -N[CH 2_.]nN- where n is from 10 to 14, units derived from a symmetrical diacid or derivative of said diacid, the repeat unit having the formula 0 0 II 11 -C-Ar-C- where Ar is an aromatic group, c h a r a c t e r i z e d by; further including at least one additional comonomer in monomer units having the formula -NH-*CH 2 ) χ lO<CH 2 ) χ l r (CH j ^NH- , 7 - Si wherein R 2 i.s selected from -H, -CH_, -C_H-., -Cl, -CH=CH_, and mixtures thereof, R 3 is selected from -H, -CH_, -C-H.., —CH=CH 2, and mixtures thereof, A is selected from H, a halogen, and a hydrocarbon having from 1 to 4 carbon atoms, p is from 5 to 80, q is from 10 to 80, r is from 1 to 30, s is from 4 to 9, x is from 4 to 6, and x' is from 2 to 6. 2. The polyamide copolymer according to claim 1 further c h a r a c t e r i z e d by; the additional comonomer is derived from one or more units selected from: 4,11-dioxa-tetra-decane-l,14-diamine, 4,9-dioxa-l,12diaminododecane, phthalic acid, isophthalic acid, lactams having up to 9 methylene groups, telechelic terminated polyolefins including polyethylene, poly(ethylenepropylene) and polyisobutylene, and telechelic amine terminated polyolefins including bis(aminoalkyl)polytetramethylene oxide and bis(aminoalkyl)poly(dimethylsiloxane) . 3. The polyamide copolymer according to claim 1 or 2 further c h a r a c t e r i z e d by; sufficient units of the additional comonomer whereby the polyamide copolymer has a melting point below a copolymer of the same diamine and a diacid without the additional comonomer and having the same molecular weight. - ϊ i.9. - 4. The copolymer of claim 3 further c h a r a c t e r i z e d by; in that the diamine is 1,12-dodecanediamine. 5. The copolymer of claim 3 further c h a r a c t e r i z e d by; in that the diacid is one or more acids selected from: terphthalic acid, derivatives of terephthalic acid, 2,6-naphthalene dicarboxylic acid, 4, '-biphenyl dicarboxylic acid, dimethyl terephthalate. 6. The copolymer according to any preceeding claim further c h a r a c t e r i z e d by; having crystalline melting point between 250 and 300 degrees C. 7. The copolymer according to any preceeding claim further c h a r a c t e r i z e d by; having a crystallization of at least 20 percent when measured according by X-ray diffraction. 8. The copolymer according to any preceeding claim further c h a r a c t e r i z e d by; having less than 5 percent by weight water absorption when measured according to the testing standards of ASTM D 570-81 9. The copolymer according to any proceeding claim further c h a r a c t e r i z e d by; in consisting of up to 30 mole percent of the additionaL comonomer.

Inventors: AKKAPEDDI MURALI KRISHNA, GLANS JEFFREY HARPER, AKKAPEDDI, MURALI, KRISHNA, GLANS, JEFFREY, HARPER
Applicants: ALLIED SIGNAL INC, ALLIED-SIGNAL INC.
Application year: 1990
Main classification: C08G69
IPC codes: C08G69