Films for multiple layers assemblies

Abstract

The present invention relates to assembly comprising a first component and a second component, each component comprising a polymer, as well as a film positioned between and bonded to the first component and the second component. The film is such that it comprises at least one poly(ether ketone ketone) (PEKK) polymer and at least one nucleating agent. The assembly has an improved fracture toughness and overall good mechanical properties.

Claims

1. An assembly comprising: a first component comprising a polymer (P1), a second component comprising a polymer (P2) and a film positioned between and bonded to the first component and the second component, wherein the film comprises or is made of: a) at least one poly(ether ketone ketone) (PEKK) polymer, wherein the PEKK polymer comprises at least 50 mol. % of recurring units of formulas (M) and (P), the mol. % being based on the total number of moles in the polymer: ##STR00015## wherein R.sup.1 and R.sup.2, at each instance, is independently selected from the group consisting of an alkyl, an alkenyl, an alkynyl, an aryl, an ether, a thioether, a carboxylic acid, an ester, an amide, an imide, an alkali or alkaline earth metal sulfonate, an alkyl sulfonate, an alkali or alkaline earth metal phosphonate, an alkyl phosphonate, an amine, and a quaternary ammonium; and i and j, at each instance, is an independently selected integer ranging from 0 to 4; wherein the molar ratio of recurring units (P) to recurring units (M) is from 50:50 to 56:44, and b) at least one nucleating agent.

2. The assembly according to claim 1 wherein i and j are 0 for each R.sup.1 and R.sup.2 group.

3. The assembly according to claim 1 wherein the PEKK polymer comprises at least 95 mol. % of the recurring units of formulae (M) and (P).

4. The assembly according to claim 1 wherein the molar ratio of recurring units (P) to recurring units (M) is from 51:49 to 55:45.

5. The assembly of claim 1 wherein the PEKK polymer exhibits a melting temperature Tm ranging from 270 to 310 C., as measured by DSC according to ASTM D3418.

6. The assembly of claim 1 wherein the PEKK polymer is such that the heat of fusion H.sub.f meets the following equation:
H.sub.f>1.69T.sub.m480(eq 1) wherein: Tm is the PEKK melting temperature in C. and H.sub.f is in J/g.

7. The assembly of claim 1 wherein the PEKK polymer complies with the set of the following properties: a melting point T.sub.m310 C.; and a heat of fusion H.sub.f>5 J/g; and
H.sub.f>1.69T.sub.m480(eq 1) wherein: Tm is the PEKK melting temperature in C. and H.sub.f is in J/g.

8. The assembly of claim 1 wherein the heat of fusion H.sub.f of the PEKK polymer is at least 5.0 J/g.

9. The assembly of claim 1, wherein the film comprises at least one nucleating agent selected from the group consisting of boron-containing compounds, alkaline earth metal carbonates, oxides, silicates, salts of alkaline earth metals, nitrides and carbon-based compounds.

10. The assembly of claim 1, wherein the PEKK polymer is such that it has been manufactured in a solvent in the absence of a Lewis acid or in the presence of an amount of Lewis acid of less than 2 wt. %, based on the total weight of the monomers.

11. The assembly of claim 1, wherein the PEKK polymer contains polymer-bound fluorine in an amount higher than 100 ppm.

12. The assembly of claim 1, wherein the amount of Al in the PEKK polymer is below 50 ppm.

13. The assembly of claim 5, wherein the PEKK polymer exhibits a Td(1%) of at least 500 C., as measured by thermal gravimetric analysis according to ASTM D3850, with a heating from 30 C. to 800 C. under nitrogen using a heating rate of 10 C./min.

14. The assembly of claim 1, wherein the film has a thickness ranging from 15 to 800 m.

15. The assembly of claim 1, wherein polymer (P1) and polymer (P2) are independently selected from the group consisting of poly(aryl ether ketones) (PAEK), poly(etherimides) (PEI), poly(amide imides) (PAI), poly(aryl ether sulfones) (PAES), poly(arylene sulphides) (PAS), poly(phthalamides) (PPA), polyamides (PA), polycarbonates (PC), liquid crystal polymers (LCP), poly(aromatic esters) (PAE) and blends thereof.

16. The assembly of claim 1, wherein polymer (P1) and/or polymer (P2) are independently selected from the group consisting of PEEK and PEKK, wherein: PEEK denotes any polymer comprising at least 10 mol. % of the recurring units are recurring units (R.sub.PEEK) of formula (J-A): ##STR00016## the mol. % being based on the total number of moles of recurring units in the polymer and PEKK denotes any polymer comprises at least 50 mol. % of recurring units of formulas (J-B.sub.1) and (J-B.sub.2), the mol. % being based on the total number of moles of recurring units in the polymer: ##STR00017##

17. The assembly of claim 1, wherein polymer (P1) and polymer (P2) are independently selected from PEKK polymers with a T/I ratio in the range from 55/45 to 85/15 and mixtures thereof.

18. The assembly of claim 1, wherein: the first component is a composite material comprising one or more layers comprising fibers and polymer (P1), the second component is a composite material comprising one or more layers comprising fibers and polymer (P2), and/or the film comprises at least one scrim, nonwoven or lightweight fabric.

19. The assembly of claim 1 wherein the proportion of nucleating agent(s) is lower than 2.0 wt. %, this proportion being relative to the weight of the PEKK polymer.

20. A method of making the assembly of claim 1, which comprises the steps of: arranging the film between a first component comprising a polymer (P1) and a second component comprising a polymer (P2); and subjecting the film to a temperature (T.sub.m.sup.x), suitable to melt the film but not to melt polymer (P1) and polymer (P2).

Description

EXAMPLES

(1) Raw Materials Used

(2) 1,2-dichlorobenzene, terephthaloyl chloride, isophthaloyl chloride, 3,5-dichlorobenzoylchloride, aluminum chloride (AlCl.sub.3), methanol were purchased from Sigma Aldrich.

(3) 1,4-Bis(4-phenoxybenzoyl)benzene was prepared according to IN patent 193687 (filed on Jun. 21, 1999 and incorporated herein by reference).

(4) Diphenyl sulfone (polymer grade) was procured from Proviron (99.8% pure).

(5) Sodium carbonate, light soda ash, was procured from Solvay S.A., France and dried before use. Its particle size was such that its d.sub.90 was 130 m.

(6) Potassium carbonate with a d.sub.90<45 m was procured from Armand products and dried before use.

(7) Lithium chloride (anhydrous powder) was procured from Acros.

(8) NaH.sub.2PO.sub.4.Math.2H.sub.2O and Na.sub.2HPO.sub.4 were purchased from Sigma-Aldrich.

(9) 1,4-bis(4-fluorobenzoyl)benzene (1,4-DFDK) and 1,3 bis(4-fluorobenzoyl)benzene (1,3-DFDK) were prepared by Friedel-Crafts acylation of fluorobenzene according to Example 1 of U.S. Pat. No. 5,300,693 to Gilb et al. (filed Nov. 25, 1992 and incorporated herein by reference in its entirety). Some of the 1,4-DFDK was purified as described in U.S. Pat. No. 5,300,693 by recrystallization in chlorobenzene, and some of the 1,4-DFDK was purified by recrystallization in DMSO/ethanol. The 1,4-DFDK purified by recrystallization in DMSO/ethanol was used as the 1,4-DFDK in the polymerization reactions to make PEKK described below, while 1,4-DFDK recrystallized in chlorobenzene was used as precursor for 1,4-bis(4-hydroxybenzoyl)benzene (1,4-BHBB).

(10) 1,4-BHBB and 1,3-bis(4-hydroxybenzoyl)benzene (1,3-BHBB) were produced by hydrolysis of the 1,4-DFDK, and 1,3-DFDK, respectively, following the procedure described in Example 1 of U.S. Pat. No. 5,250,738 to Hackenbruch et al. (filed Feb. 24, 1992 and incorporated herein by reference in its entirety). They were purified by recrystallization in DMF/ethanol. Boron nitride: Boronid S1-SF, a hexagonal boron nitride grade available commercially from 3M Corporation

(11) Determination of the Glass Transition Temperature (Tg). Melting Temperature (T.sub.m), Crystallization Temperature (Tc) and Heat of Fusion (H.sub.f)

(12) The glass transition temperature (Tg), melting temperature (T.sub.m), crystallization temperature (Tc) and heat of fusion (H.sub.f) is determined by differential scanning calorimeter (DSC) according to ASTM D3418, using a heating and cooling rate of 10 C./min.

(13) T.sub.g (mid-point, using the half-height method), heat of fusion H.sub.f and T.sub.m (peak temperature of the melting endotherm) were determined on the 2.sup.nd heat scan. T.sub.c was determined as the peak temperature of the crystallization exotherm on the 1.sup.st cool scan.

(14) The melting of the composition was taken as the area over a linear baseline drawn from 220 C. to a temperature above the last endotherm. When assessing the crystallinity of the film in the bonded structure (part), the heat of fusion was determined on the 1.sup.st heat scan.

(15) Details of the procedure are as follows: a TA Instruments DSC Q20 was used with nitrogen as carrier gas (99.998% purity, 50 mL/min). Temperature and heat flow calibrations were done using indium. Sample size was 5 to 7 mg. The weight was recorded 0.01 mg. The heat cycles were: 1.sup.st heat cycle: 30.00 C. to 400.00 C. at 10.00 C./min, isothermal at 400.00 C. for 1 min; 1.sup.st cool cycle: 400.00 C. to 30.00 C. at 10.00 C./min, isothermal for 1 min; 2.sup.nd heat cycle: 30.00 C. to 400.00 C. at 10.00 C./min, isothermal at 400.00 C. for 1 min.
Determination of the Melt Flow Index

(16) The melt flow index was determined according to ASTM D1238 at the indicated temperature (340 to 380 C. depending on the melting point of the material) with a 3.8 kg weight. The final MFI for a 8.4 kg weight was obtained by multiplying the value obtained by 2.35.

Synthesis Examples

(17) PEKK #1 with T/I=71/29

(18) In a 500 mL 4-neck reaction flask fitted with a stirrer, a N.sub.2 inlet tube, a Claisen adapter with a thermocouple plunging in the reaction medium, and a Dean-Stark trap with a condenser and a dry ice trap were introduced 112.50 g of diphenyl sulfone (DPS), 23.054 g of 1,3-BHBB, 16.695 g of 1,4-BHBB and 41.292 g of 1,4-DFDK. The flask content was evacuated under vacuum and then filled with high purity nitrogen (containing less than 10 ppm O.sub.2). The reaction mixture was then placed under a constant nitrogen purge (60 mL/min). The reaction mixture was heated slowly to 270 C. At 270 C., 13.725 g of Na.sub.2CO.sub.3 and 0.078 g of K.sub.2CO.sub.3 was added via a powder dispenser to the reaction mixture over 60 minutes. At the end of the addition, the reaction mixture was heated to 310 C. at 1 C./minute. After 2 minutes at 310 C., 1.107 g of 1,4-DFDK were added to the reaction mixture while keeping a nitrogen purge on the reactor. After 5 minutes, 0.741 g of lithium chloride were added to the reaction mixture. 10 minutes later, another 0.402 g of 1,4-DFDK were added to the reactor and the reaction mixture was kept at temperature for 15 minutes. Another charge of 15 g of diphenyl sulfone was added to the reaction mixture, which was kept under agitation for 15 minutes.

(19) The reactor content was then poured from the reactor into a stainless steel pan and cooled. The solid was broken up and ground in an attrition mill through a 2 mm screen. Diphenyl sulfone and salts were extracted from the mixture with acetone and water at pH between 1 and 12. 0.67 g of NaH.sub.2PO.sub.4-2H.sub.2O and 0.62 g of Na.sub.2HPO.sub.4 were dissolved in 1200 mL DI water for the last wash. The powder was then removed from the reactor and dried at 120 C. under vacuum for 12 hours yielding 72 g of a yellow powder.

(20) PEKK #2 and PEKK #3: PEKK Polymers with Variable T/I and Different Melt Viscosity (MV)

(21) The same procedure as example 1 was followed with the amounts of reagents indicated in table 1 below.

(22) TABLE-US-00001 TABLE 1 Example Quantities #1 #2 #3 T/I 71/29 58/42 54/46 DPS g 112.50 112.50 119.82 1,3-BHBB g 23.054 33.389 38.950 1,4-BHBB g 16.695 6.360 3.387 1,4-DFDK g 41.292 41.292 43.723 Na.sub.2CO.sub.3 g 13.725 13.725 14.618 K.sub.2CO.sub.3 g 0.078 0.078 0.092 1,4-DFDK g 1.107 0.906 1.072 LiCl g 0.741 0.953 0.564 1,4-DFDK g 0.402 0.402 0.214 DPS g 15 40 30 MFI g/10 min 100 33 30 MFI Temp C. 360 340 340

(23) TABLE-US-00002 TABLE 2 Example Quantities #1 #2 #3 (MOH) mol 0.072 0.105 0.122 (POH) mol 0.052 0.020 0.011 (MOH) + (POH) mol 0.125 0.125 0.133 (PF) mol 0.125 0.125 0.133 Na.sub.2CO.sub.3 + K.sub.2CO.sub.3 mol 0.130 0.130 0.139 Molar ratio (PF)/ 1 1 1 (MOH) + (POH) Molar ratio (PF) + 2.45 1.38 1.17 (POH)/(MOH)
General Procedure for Solution Blending of PEKK Composition of Example 4

(24) In a 500 mL 4-neck reaction flask fitted with a stirrer, a N.sub.2 inlet tube, a Claisen adapter with a thermocouple plunging in the reaction medium, and a condenser were introduced 235.00 g of diphenyl sulfone (DPS), as well as boron nitride as a nucleating agent (table 3). The flask content was heated slowly to 330 C. At 330 C., 100 g of the PEKK polymer powder #3 was slowly added via a flex tube into the molten DPS. At the end of the addition, the agitation speed was increased to provide good mixing and the mixture was held at 330 C. for another hour.

(25) The reactor content was then poured from the reactor into a stainless steel pan and cooled. The solid was broken up and ground in an attrition mill through a 2 mm screen. Diphenyl sulfone was extracted from the mixture with acetone and water. 0.67 g of NaH.sub.2PO.sub.4.Math.2H.sub.2O and 0.62 g of Na.sub.2HPO.sub.4 were dissolved in 1200 mL DI water for the last wash. The powder was then removed from the reactor and dried at 120 C. under vacuum for 12 hours yielding 90-95 g of a yellow powder.

(26) TABLE-US-00003 TABLE 3 Example 1c 2c 3c 4 Boron nitride pph 0 0 0 1.2 PEKK #1 wt. % 100 PEKK #2 wt. % 100 PEKK #3 wt. % 100 100
Thermal Properties

(27) TABLE-US-00004 Minimal Measured Hf (J/g) Meets T.sub.g ( C.) T.sub.m ( C.) T.sub.c ( C.) Hf (J/g) (eq 1) eq 1? 1c 160 346 304 49 105 no 2c 159 297 217 22 22 no 3c 159 nd nd nd 0 no 4 160 284 nd 7 0 yes

(28) As shown by data collected above, the PEKK composition of example 4 (according to the invention) exhibits an improved crystallization and crystallinity as compared to the PEKK compositions of examples 1-3 (no nucleating agent).

(29) The measured enthalpy of fusion Hf of the PEKK composition of example 4 is higher than the minimal Hf, as calculated per equation 1 below, which means that the PEKK composition of example 4 meets the following equation:
H.sub.f>1.69T.sub.m480(eq 1)
wherein: T.sub.m is the melting point in C. and H.sub.f is in J/g

(30) The PEKK composition of example 4, according to the invention, therefore presents a set of properties: a melting point T.sub.m310 C.; a heat of fusion H.sub.f>5 J/g; and a H.sub.f meeting equation 1,
which makes it well-suited to be processed into a film to be used in a laminate structure.

(31) As far as the comparative examples are concerned: PEEK#1 with a T/I ratio equals to 71/29 presents too high a T.sub.m, which is higher than 310 C., and does not meet equation 1; PEKK#2 with a T/I ratio equals to 58/42 does not meet equation 1 as its measured heat of fusion H.sub.f equals the minimal heat of fusion H.sub.f as calculated in equation 1; and PEKK#3 with a T/I ratio within the inventive range (50:50 to 56:44) is amorphous (no T.sub.m), therefore not suitable for use in structural applications as being prone to attack by fluids and thereby leading to premature failure of the structure.