System for transporting ultra-pure water (UPW)

Abstract

This present invention pertains to a system for transporting UPW comprising at least one component, wherein said at least one component comprises a surface intended to be in contact with UPW and is made of or comprises a polymer composition (PC) comprising, consisting essentially of or consisting of: – at least 50.0 wt% (≥ 50.0 wt%) of at least one semi-crystalline polymer (P), this proportion being relative to the total weight of the polymer composition (PC); – optionally at least one additional polymer blended with polymer (P) and selected in the group consisting of polyaryletherketones (PAEK) different from semi-crystalline polymer (P), polysulfones (PSU), polyphenylesulfones (PPSU) and combinations thereof; wherein the semi-crystalline polymer (P) comprises the following recurring units with the following proportions: - between 65.0 and 95.0 mol% of units (RPEEK) of formula; -between 5.0 and 35.0 mol% of units (RP) selected in the group consisting of units (RPEDEK), units (RPEoEK) and combination thereof these proportions being given relative to the total amount of recurring units in the polymer (P); wherein UPW denotes a water exhibiting an electric resistivity at 25°C of at least 18.0 MΩ.cm and a Total Organic Carbon (TOC) of at most 10.0 µg / L.

Description

System for transporting ultra-pure water (UPW)[Reference to related applications]This application claims priority from US provisional application No. 63 / 515732 filed on 26 July 2023 and from European patent application No. 23207794.1 filed on 3 November 2023, the whole content of each of these applications being incorporated herein by reference for all purposes.[Technical field]

[0001] This present invention pertains to the transport of Ultra-pure Water (UPW).[Background art]

[0002] Ultra-pure water (UPW) is employed in many steps of fabrication of semiconductors. Water is used for washing and rinsing of semiconductor components during manufacture. Water is also used for cleaning and etching operations, making steam for oxidation of silicon surfaces, preparing photomasks and depositing luminescent materials. Water of a higher quality is also needed as the integration of semiconductors advances further.

[0003] Other high-tech applications requesting UPW are in the development and fabrication of solid-state devices, thin-film devices, communication lasers, light-emitting diodes, photodetectors, printed circuits, memory devices, vacuum-tube devices, or electrolytic devices.

[0004] As defined in ASTM D5127-07, UPW is required to prevent contamination of products during manufacture, since contamination can lead to an unacceptable, low yield of electronic devices. UPW thus needs to present very low levels of inorganic cations and anions, of organic contamination and or biological contamination.

[0005] The preparation of UPW involves the removal of ions, organic and biological contaminants and particulates. UPW typically exhibits an electric resistivity at 25°C of 18.1 MQ.cm or higher and a Total Organic Carbon level (TOC) of maximum 10.0 pg / L. Bacterial contamination can also be limited to 10.0 CFU / ml (CFU: colony forming unit).

[0006] US 5,106,503 and US 5,160,429 disclose an ultra-pure water piping system for conveying ultra-pure water that uses pipes made of PVC, PVDF or PEEK.

[0007] US 4,784,772 discloses a pipe in PEEK transporting ultra-pure water.

[0008] JP H04-34282 discloses a piping material for pure water or ultrapure water made of a blend of PEEK and polyetherimide or polysulfone.

[0009] US 1,1673,380 discloses a multilayer pipe for transporting UPW comprising layers made of a polyolefin. JP 2022 / 159129 also discloses a pipe in polyolefin for transporting UPW.

[0010] WO 2022 / 013520 discloses a copolymer with units of formula -O-Ph-O-Ph-CO-Ph- (I) and units (RPEDEK) wherein the units (I) consist of 50-90 mol% of units (RPEEK) and 10-50 mol%of units (PPEHIEK) of formula / ° or units (RPEOEK). WO 2022 / 013520 also discloses a pipe or sheath formed from a composition comprising or consisting of said copolymer. There is no disclosure of the transport of UPW. There is also no disclosure of a pipe nor any pipe connector as defined in the claims.

[0011] WO 2021 / 204718 discloses a PEDEK-PEoEK copolymer that can be used to prepare an article for automotive, for aerospace or for electronics.

[0012] US 2021 / 0384045 discloses a washing water supply arrangement.[Technical problem to be solved]

[0013] The material used for the transport of the water thus needs to be of high purity and not leach high levels of impurities into the transported water. PVDF and other fluororesins are widely used in pipe systems (e.g. pipes, connectors, etc.) used in the transport of UPW in the semiconductor industry (see e.g. "High quality PFA for semiconductors" , Valqua Review, March 1991, Vol. 35, N°3, pp.1-6, issn: 0385-6925).

[0014] With the development of smaller chips, the level of purity required for UPW is such that PVDF is no longer adapted in the entire transport system, notably due to the leaching of organic impurities and fluorides anions in places where higher temperatures are used (80- 120°C). Indeed, the general trend today is to produce electronic circuits with smaller and smaller line-widths. Today, some electronics producers offer commercially available chips with linewidth of around 400 nm. However, in research projects, even smaller linewidths down to 10 or even 5 nm have been reported.

[0015] Poly etheretherketone (PEEK) has been described as particularly well adapted for replacing PVDF in the transportation of UPW at higher temperature (80-120°C typically) as it presents reduced level of leaching as compared to PVDF. Yet, one drawback of thehomopolymer PEEK is its high melting temperature (340-345°C) requiring high processing temperature (360-420°C). Processing PEEK at high temperatures leads to off-gasing of some organic impurities during the extrusion process (with associated die deposit).

[0016] There is therefore a need for a polymeric component that can be extruded and welded at a lower temperature than PEEK to avoid the release of organic impurities. The component and the polymer should nonetheless still retain mechanical properties and should not contaminate the UPW, especially when the water is at a temperature above 70°C.

[0017] The invention disclosed herein aims at solving this technical problem.[Brief disclosure of the invention]

[0018] The invention is set out in the appended set of claims.

[0019] Thus, the invention relates to a system for transporting UPW as defined in any one of claims 1-10.

[0020] The invention also relates to a pipe as defined in claim 11.

[0021] The invention also relates to a pipe connector or fitting as defined in claim 12.

[0022] The invention also relates to a method for transporting UPW as defined in claim 13.

[0023] The invention also relates to the use as defined in any one of claims 14-20.

[0024] These subject-matters are now defined in more detail below.[Definition]

[0025] wt% and mol% designate respectively % by weight and by mole.

[0026] A “poly(aryl ether ketone) (PAEK) ” denotes a polymer, the recurring units of which comply with formula -Ar-Q- where Ar is an arylene group and Q is -O- or -C(=O)-, said recurring units being linked to one another by -O- or -C(=O)-. The arylene group is generally selected in the group consisting of phenylene group and biphenylene group.[Figure]

[0027] Fig. 1 illustrates embodiment (E2) and discloses a pipe (1) with layer (L) (2) and one outer layer (3).[Disclosure of the invention]

[0028] As a first aspect, the invention relates to a system for transporting UPW comprising at least one component, wherein said at least one component comprises a surface intended to be in contact with UPW which is made of or comprises a polymer composition (PC) as defined herein. The component is notably a pipe or a pipe connector.

[0029] The system generally also comprises at least one means (e.g. a pump) for creating a difference of pressure to transport the water.

[0030] A pipe connector is a component that can be mechanically attached to one end of a pipe. The pipe connector is intended to either (i) mechanically bond two pipes endings or (ii) mechanically bond one pipe ending to another component of the system. This includes notably elbows and T-fittings.

[0031] The component is prepared by techniques known to the skilled person such as (co)extrusion or injection moulding. The pipe is generally prepared by (co)extrusion. The pipe connector or fitting is generally prepared by injection moulding. It is an interest of using the polymer composition (P) or the polymer (P) disclosed herein since lower temperatures are required to melt and shape the composition into the component.

[0032] As a second aspect, the invention also relates to a pipe as defined in claim 24.

[0033] The pipe comprises one or more layers and the internal layer (L) intended to be in contact with water is made of or comprises a polymer composition (PC) as defined herein, notably as defined in the claims. The pipe contains UPW and / or is characterized by the amounts of eluted impurities given below.

[0034] According to an embodiment (El), the pipe of the invention is a monolayer pipe. In this case, the monolayer consists of the internal layer (L). It comprises only layer (L). The monolayer pipe can be prepared by extrusion.

[0035] According to another embodiment (E2), the pipe of the invention comprises more than one layer and layer (L) is the internal layer (L). For instance, the pipe may comprise layer (L) and one outer layer. See Fig. 1. According to embodiment (E2), as the layer(s) other than layer (L) is / are not intended to be in contact with water, there is less risk of contaminating the water with molecules leached from these layers. As a consequence, this / these layer(s) other than layer (L) may thus comprise at least one filler and / or at least plastic additive.

[0036] The multilayer pipe can be prepared by coextrusion or by overmoulding the other layer(s) around layer (L).

[0037] This / these layer(s) other than layer (L) may thus comprise at least one thermoplastic polymer, at least one filler and / or at least plastic additive, notably selected in the group consisting of colorants (e.g. dyes and / or pigments), impact modifiers, ultraviolet light stabilizer, heat stabilizers, antioxidants, internal lubricants and / or external lubricants, flame retardants, anti-static agents, anti-blocking agents and combinations thereof.

[0038] More particularly according to embodiment (E2), the pipe of the invention comprises:- an internal layer (L) intended to be in contact with water, said layer (L) being made of or comprising the polymer composition (PC) as defined herein, notably the polymer composition (PC) as defined in the claims;- at least one other layer which is made of or comprises a polymer composition comprising at least one polymer (P) as defined herein and (i) at least one filler and / or (ii) at least one plastic additive, notably selected in the group consisting of colorants (e.g. dyes and / or pigments), impact modifiers, ultraviolet light stabilizer, heat stabilizers, antioxidants, internal lubricants and / or external lubricants, flame retardants, anti-static agents, antiblocking agents and combinations thereof.

[0039] The pipe of the invention can be used to transport UPW since the layer (L) intended to be in contact with water is made or comprises polymer composition (PC).

[0040] The pipe can be characterized by the amounts of eluted impurities given herein. SEMI F40 and SEMI F57 are norms edited by association SEMI®, 673 S. Milpitas Blvd., Milpitas, CA95035 (USA) which are often followed to test polymer materials and components used in UPW systems to assess whether the material can suitably be used without contaminating UPW. Pursuant to these norms, the following protocol (pl) can be used for measuring the amounts of the eluted impurities:

[0041] The pipe of the invention is such that following this protocol, the amounts of elution of the impurities (Imp) released from layer (L) after bringing layer (L) in contact with UPW at 85°C for 7 days are less than the values indicated in the Table below:

[0042] The amounts of eluted impurities are expressed in pg / m2of surface of layer (L) in contact with water.

[0043] The diameter of the pipe is generally between 1 and 200 mm. The diameter may more particularly be between 20 and 150 mm.

[0044] The length of the pipe is generally at most 100 m. The length may more particularly be at most 50 m.

[0045] As a third aspect, the invention also relates to a pipe connector or fitting comprising a surface intended to be in contact with UPW and which is made of or comprises a polymer composition (PC) as defined herein, notably a defined in the claims.

[0046] The pipe connector or fitting of the invention can be used to transport UPW since the surface intended to be in contact in water is made or comprises polymer composition (PC). As for the pipe, SEMI F40 and SEMI F57 are norms that can be used to characterize the pipe connector or fitting. Pursuant to these norms, the following protocol (p2) can be used for measuring the amounts of the eluted impurities:

[0047] The amounts of elution of the impurities (Imp) released from the surface in contact with UPW are less than the values of eluted impurities expressed in pg / m2of the surface of the leaching area indicated in the Table below:

[0048] About UPW

[0049] Ultra-pure Water (UPW) generally denotes a water exhibiting an electric resistivity at 25°C of at least 18.0 MQ.cm and a Total Organic Carbon (TOC) of at most 10.0 pg / L. Both properties are generally measured by available appliances. TOC is preferably measured according to ASTM D5997 - 15.

[0050] The UPW may more particularly be any water conforming with any of the the recommendations of Table 1 of ASTM D5127 - 13 (Reapproved 2018).

[0051] The UPW may more particularly be any of the 4 following types of water as defined in Table 1 of ASTM D5127-13 (Reapproved 2018): type E-l, type E-l.1, type E-l.2 or type E-1.3. To be noted: ASTM Type E-l.3 is also identical to the SEMI (Semiconductor Equipment and Materials International) Guide for Ultrapure Water Used in Semiconductor Processing (F063), 2010 version.

[0052] As a fourth aspect, the invention relates to a method for transporting UPW wherein at least one pipe as defined herein is used to transport the water.

[0053] The temperature of water inside the pipe may notably at least 50°C, preferably at least 70°C.

[0054] As a fifth aspect, the invention relates to the use of a polymer composition (PC) as defined herein for the preparation of at least one surface of a pipe or a pipe connector intended to be in contact with UPW. The pipe may be a pipe as disclosed herein. The pipe connector may a pipe connector as disclosed herein.

[0055] More details about the polymer composition (PC) and the polymer (P) are provided below.

[0056] Polymer composition (PC)

[0057] Details about the polymer composition which is disclosed in the present invention are now given.

[0058] Polymer composition (PC) comprises:- at least 50.0 wt% (> 50.0 wt%) of at least one semi-crystalline polymer (P) as disclosed herein, this proportion being relative to the total weight of the polymer composition (PC);- optionally at least one additional polymer blended with polymer (P) and selected in the group consisting of polyaryl etherketones (PAEK) different from semi-crystalline polymer (P), polysulfones (PSU), polyphenylesulfones (PPSU) and combinations thereof.

[0059] The proportion of semi-crystalline polymer(s) (P) in the polymer composition (PC) disclosed in the invention is at least 50.0 wt% (> 50.0 wt%), this proportion being relative to the total weight of the polymer composition (PC). This proportion is preferably at least 60.0 wt%, preferably at least 65.0 wt%, preferably at least 70.0 wt%, preferably at least 75.0 wt%, preferably at least 80.0 wt%, preferably at least 85.0 wt%, preferably at least 90.0 wt%, preferably at least 95.0 wt%, preferably at least 99.0 wt%.

[0060] Polymer (P) is the essential or major component of polymer composition (PC).

[0061] It is preferable that polymer composition (PC) disclosed herein does not comprise any filler or any plastic additive, notably selected in the group consisting of colorants (e.g. dyes and / or pigments), impact modifiers, ultraviolet light stabilizer, heat stabilizers, antioxidants, internal lubricants and / or external lubricants, flame retardants, anti-static agents, anti-blocking agents and combinations thereof.

[0062] To avoid contamination of water, the polymer composition (PC) preferably consists essentially of or consists of:- at least 50.0 wt% (> 50.0 wt%) of at least one semi-crystalline polymer (P) as disclosed herein; this proportion being relative to the total weight of the polymer composition (PC);- optionally at least one additional polymer blended with polymer (P) and selected in the group consisting of polyaryl etherketones (PAEK) different from semi-crystalline polymer (P), polysulfones (PSU), polyphenylesulfones (PPSU) and combinations thereof.

[0063] The polymer composition (PC) preferably consists essentially of or consists of at least one semi-crystalline polymer (P) as disclosed herein.

[0064] Additional Polymer(s): polymer composition (PC) may comprise at least one additional polymer blended with polymer (P) and selected in the group consisting of polyaryletherketones (PAEK) different from semi-crystalline polymer (P), polysulfones (PSU), polyphenylesulfones (PPSU) and combinations thereof.

[0065] The semi-crystalline polymer(s) (P) and the additional polymer(s) preferably form an homogenous blend. This blend is prepared by well-known techniques known by the skilled person.

[0066] According to an embodiment, the additional polymer in the polymer composition (PC) is a PAEK.

[0067] The PAEK may more particularly be selected in the group consisting of polyetherketone (PEK), a polyetheretherketone (PEEK), a polyether-ether-ketone-ketone (PEEKK), a polyether-ether-ketone (PEKK), a polyether-ketone-ether-ketone-ketone (PEKEKK), a polyether-ether-ketone-ether-ketone (PEEKEK), a polyether-ether-ether-ketone (PEEEK), a polyether-diphenyl-ether-ketone (PEDEK) and combination thereof.

[0068] The PAEK is generally semi-crystalline.

[0069] The PAEK may more particularly be at least one PEEK. In this case, polymer composition is more particularly a polymer composition (PC*) comprising, consisting essentially of or consisting of:- at least 50.0 wt% (> 50.0 wt%) of at least one semi-crystalline polymer (P) as disclosed herein, this proportion being relative to the total weight of the polymer composition (PC);- optionally at least one PEEK.

[0070] All the embodiments and details disclosed herein for polymer composition (PC) and / or polymer (P) remains applicable for polymer composition (PC*).

[0071] In the context of the invention, a PEEK denotes a polymer comprising at least 96.0 mol% of recurring units (RPEEK). Preferably, the recurring units of the PEEK consist of recurring units (RPEEK).

[0072] According to an embodiment, the additional polymer in the polymer composition (PC) is a polysulfone (PSU). A polysulfone (PSU) denotes a polymer comprising at least 50.0 mol. % recurring units (Rpsu) of formula:

[0073] Recurring units (Rpsu) are preferably of formula:

[0074] The proportion of recurring units (Rpsu) is preferably at least 90.0 mol%, preferably at least 95.0 mol%, preferably at least 99.0 mol%.

[0075] The PSU may be an homopolymer or a copolymer.

[0076] The PSU is generally amorphous.

[0077] According to an embodiment, the additional polymer in the polymer composition (PC) is a polysulfone (PPSU). A polysulfone (PPSU) denotes a polymer comprising at least 50.0 mol. % recurring units (Rppsu) of formula:

[0078] Recurring units (Rppsu) are preferably of formula:

[0079] The proportion of recurring units (Rppsu) is preferably at least 90.0 mol%, preferably at least 95.0 mol%, preferably at least 99.0 mol%.

[0080] The PPSU may be an homopolymer or a copolymer.

[0081] The PPSU is generally amorphous.

[0082] Polymer (P)

[0083] Details about polymer (P) which is disclosed in the present invention are now given.

[0084] The semi-crystalline polymer (P) disclosed in the present invention comprises the following recurring units with the following proportions:- between 65.0 and 95.0 mol% of units (RPEEK) of formula:-between 5.0 and 35.0 mol% of units (Rp) selected in the group consisting of units (RPEDEK), units (RPEOEK) and combination thereof:these proportions being given relative to the total amount of recurring units of the polymer.

[0085] According to an embodiment, unit (Rp) is (RPEDEK).

[0086] According to another embodiment, (Rp) is (RPEOEK).

[0087] According to another embodiment, (Rp) is a combination of (RPEDEK) and (RPEOEK).

[0088] The recurring units of polymer (P) preferably consist of units (RPEEK) and units (Rp).

[0089] Polymer (P) preferably does not comprise (RPEHIEK) units.

[0090] The proportion of units (RPEEK) is between 65.0 and 95.0 mol%. This proportion may be more particularly between 65.0 and 85.0 mol%.

[0091] The proportion of units (Rp) is between 5.0 and 35.0 mol%. This proportion may be more particularly between 15.0 and 35.0 mol%.

[0092] The end-groups of polymer (P) are preferably according to formula -Ar-F or -Ar-H, where Ar designates an arylene group.

[0093] Polymer (P) is prepared by nucleophilic polycondensation. Polymer (P) is more particularly prepared by heating a reaction mixture (RM) comprising at least one solvent (S), a monomer mixture (MM) and at least one base selected in the group consisting of Na2COs, K2CO3 and mixtures thereof. The monomer mixture (MM) comprises or consists of the followingmonomers: 4,4’-difluorobenzophenone + hydroquinone + 4,4’-biphenol and / or pyrocatechol.

[0094] Solvent (S) is generally diphenyl sulfone.

[0095] The temperature at which the reaction mixture (RM) is heated is generally at least 250°C, preferably at least 270°C.The nucleophilic polycondensation may involve terminating the polycondensation reaction by reaction with at least one terminating agent selected in the group consisting of end-capping agents, terminating agents and combinations thereof.

[0096] An end-capping agent is a molecule that terminates the nucleophilic polycondensation and is incorporated in a polymer backbone through a condensation reaction. A terminating agent is a molecule that terminates the nucleophilic polycondensation and is incorporated in a polymer backbone through a condensation reaction.

[0097] The end-capping agent is notably selected in the group consisting of the molecules of formula (A):Rkph-R2(A) where R1is F, Cl or OH and R2is -C(O)-Ar-R3, -O-Ar-R3, -SO2-Ar-R3, -Ar-R3, an alkyl (e.g. a Ci-Cio alkyl, preferably a C1-C5 alkyl) or -H, with Ar being an arylene group comprising at least one benzene ring (z.e. one benzene ring or several benzene rings), and with R3being F, Cl or H.

[0098] R3is preferably F.

[0099] R1is preferably F or OH. More preferably, R1is F.

[0100] When R2is different from -H, R1and R2may be on ortho, meta or para relative position on the phenylene cycle.

[0101] The end-capping agent is more particularly selected in the group consisting of 4,4’- difluorobenzophenone, phenol, 4-phenoxyphenol, 4-phenylphenol, 4-fluorobenzophenone, 3 -fluorobenzophenone, 2-fluorobenzophenone, 4,4’ -di chlorodiphenylsulfone,4,4 ’difluorodiphenyl sulfone and a mixture thereof.

[0102] The end-capping agent is more particularly selected in the group consisting of 4,4’- difluorobenzophenone, 4-fluorobenzophenone, phenol, 4-phenoxyphenol, 4-phenylphenol and a mixture thereof.

[0103] The terminating agent is preferably lithium chloride.

[0104] The nucleophilic polycondensation may involve terminating the polycondensation reaction by reaction with lithium chloride and at least one end-capping agent as disclosed above, notably 4,4’-difluorobenzophenone.

[0105] As 4,4’-difluorobenzophenone is the monomer used in the preparation of polymer (P), it is therefore added to the reaction mixture (RM) at the inception of the polycondensation. In this case, the reaction mixture (RM) comprises this monomer with an excess of 4,4’ -difluorobenzophenone over the monomers bearing an OH group. The molar ratio r at the inception of the polycondensation is then > 1.000, preferably > 1.003, more preferably > 1.006, even more preferably > 1.010, r being defined as 4,4’ -difluorobenzophenone / [hydroquinone + 4,4’ -biphenol and / or pyrocatechol].

[0106] The conditions of preparation of the polymer of the invention given in the experimental section may be followed for the preparation of polymer (P).

[0107] After the polycondensation, polymer (P) is treated so as to obtain a polymer suitable for transporting UPW. The treatment of polymer (P) involves the following steps:(i) washing polymer (P) with an organic solvent, then with demineralized water(ii) then, heating polymer (P) at a temperature which is at least 100°C.These steps are performed preferably with polymer (P) in the powder form.

[0108] The organic solvent used in step (i) is generally selected in the group of Ci-Ce-alcohols, Cs-Ce-ketones and combinations thereof. The Ci-Ce-alcohol may be methanol, ethanol, propanol or butanol. The Cs-Ce-ketone may be acetone, butanone or methyl isobutyl ketone. The organic solvent is preferably acetone or ethanol.

[0109] The amount of organic solvent used for the treatment of polymer (P) is preferably at least 20 kg / kg polymer. This thorough treatment makes it possible to remove most of the solvent and other organic impurities.

[0110] The amount of demineralized water used for the treatment of polymer (P) is preferably at least 20 kg / kg polymer. This thorough treatment makes it possible to remove most of the salts.

[0111] The conditions of treatment provided in the experimental section may be followed for obtaining polymer (P) with an adequate purity.

[0112] Polymer (P) preferably contains at most 2000 mg / kg polymer (P) of residual solvent, preferably at most 1000 mg / kg polymer (P), such as diphenyl sulfone.

[0113] Polymer (P) preferably contains at most 200 mg / kg polymer (P) of residual monomer 4,4’- difluorobenzophenone, preferably at most 100 mg / kg polymer (P), more preferably at most 80 mg / kg polymer (P).

[0114] The proportions of residual solvent and residual monomer 4,4’-difluorobenzophenone are expressed in mg / kg of polymer (P).

[0115] These proportions can conveniently be measured by extraction of the polymer (P) powder with a solvent like acetone and analysis of the acetone extract by gas or liquid chromatography. These proportions are advantageously measured according to the conditions of Table B provided in the experimental section.

[0116] These proportions can be measured according to the conditions given in the experimental section.

[0117] These levels of residual solvent and 4,4’-difluorobenzophenone apply equally to polymer composition (PC).

[0118] The melt viscosity (MV) of polymer composition (PC) measured at 410°C and 46.3 s- 1 according ASTM D3885 is preferably at least 0.20 kN-s / m2, preferably at least 0.30 kN- s / m2, more preferably at least 0.40 kN-s / m2. This viscosity is preferably at most 1.50 kN- s / m2, preferably at most 1.00 kN-s / m2.

[0119] MV can be measured according to the conditions given in the experimental section.

[0120] The glass transition temperature (Tg) of polymer (P) as measured on the 2ndheat scan by DSC after a heating and cooling rate of 20°C / min and is preferably at least 135°C. Tg is preferably at least 138°C, more preferably at least 140°C. Tg is generally at most 160°C.

[0121] The melting temperature (Tm) of polymer (P) is measured on the 2ndheat scan by DSC after a heating and cooling rate of 20°C / min and is preferably at most 325°C, more preferably at most 320 °C. Tm is generally at least 270°C.

[0122] Likewise, melting temperature (Tm*) of polymer composition (PC) measured in the same conditions is preferably at most 325°C, more preferably at most 320 °C. Tm* is generally at least 270°C.

[0123] The crystallisation temperature (Tc) of polymer (P) is measured on the 1stcooling scan by DSC after a heating and cooling rate of 20°C / min and is preferably at most 270°C. Tc is generally at least 180°C.

[0124] Polymer (P) is semi-crystalline. The heat of fusion (Hm) of polymer (P) is measured on the 2ndheat scan by DSC after a heating and cooling rate of 20°C / min and is at least 5.0 J / g. Hm may more particularly be between 5.0 and 45.0 J / g.

[0125] The heat of fusion (Hm*) of the polymer composition (PC) is measured on the 2ndheat scan by DSC after a heating and cooling rate of 20°C / min and is at least 2.0 J / g polymer(s). Hm* may more particularly be between 2.0 and 45.0 J / g polymer(s).

[0126] Tm, Tg, Tc and Hm can be measured by DSC according ASTM D3418, more particularly according to the conditions of Table A provided in the experimental section.

[0127] Tm, Tg, Tc and Hm can be measured according to the conditions given in the experimental section.

[0128] The polymer composition (PC) preferably exhibits a tensile modulus (ASTM D638) of at least 400 ksi.

[0129] The polymer composition (PC) preferably exhibits an elongation at break at low speed (ASTM D638) of at least 5.0%.[Experimental section]

[0130] Raw materials

[0131] Hydroquinone, photo grade, was procured from Eastman, USA. It contained 0.38 wt% moisture, which amount was used to adapt the charge weights. All weights indicated include moisture.

[0132] Resorcinol, ACS reagent grade, was procured from Aldrich, USA

[0133] 4,4’ -Biphenol, polymer grade, was procured from SI, USA.

[0134] Pyrocatechol, flakes, was procured from Solvay USA. Its purity was 99.85% by GC. It contained 680 ppm moisture, which amount was used to adapt the charge weights. All weights indicated include moisture.

[0135] 4,4’-Difluorobenzophenone, polymer grade (99.8%+), was procured from Malwa, India

[0136] Diphenyl sulfone (polymer grade) was procured from Proviron (99.8% pure).

[0137] Sodium carbonate, light soda ash, was procured from Solvay S.A., France.

[0138] Potassium carbonate with a d90 < 45 pm was procured from Armand products.

[0139] Lithium chloride (anhydrous grade) was procured from Acros.

[0140] Thermal properties: determination of the melting temperature (Tm), crystallization temperature (Tc) and heat of fusion (Hm)

[0141] Tm, Tc and Hm are measured according to the following conditions:Table A: conditions of DSC00142] Further details of the procedure are also given: 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.

[0143] Determination of the melt viscosity (MV)

[0144] The melt viscosity was measured using a capillary rheometer according to ASTM D3835. Readings were taken after 10-minute and 40-minute dwell time at 410 °C and a shear rate of 46.3 s'1using a die with the following characteristics: diameter = 1.016 mm, length = 20.32 mm, cone angle = 120°.

[0145] Determination of the concentration of residual solvent and monomerTable B: conditions for determination of residual solvent and monomer

[0146] Further details of the procedure are also given: the supernatant was then sampled and analyzed by capillary GC (Shimadzu 2010) with flame ionization detector (FID), using external standards of diphenyl sulfone and 4,4’-difluorobenzophenone of known concentrations. The GC conditions were:- Column: DB-5- Length: 15 meter- Internal diameter: 0.25 mm- Film thickness: 0.25 pm- Carrier gas: nitrogen- Column flow: 0.56 mL / min.- Split: 80 mL / min- Septum Purge: 3.0 mL / min- Column Temperature: 100°C hold for 1.0 min, then increase to 300 °C at 20°C / min and hold at 300°C for 1 min- Injection Temperature: 300°C- Detector Temperature: 300°C- Injection volume: 1.0 pl.

[0147] Determination of tensile properties by compression molding

[0148] A 762 mm x 762 mm x 3.2 mm plaque was prepared from the polymer by compression molding of 30 g of polymer under the following conditions:• preheat at Ti,• Ti / 20 minutes, 2000 kg-f• Ti / 2 minutes, 2700 kg-f• cool down to 30 °C over 40 minutes, 2000 kg-fTi values used for the polymers are indicated in the results table. The plaques were then annealed at 200 °C for 3 hours.The 762 mm x 762 mm x 3.2 mm compression molded plaques were machined into Type V ASTM tensile specimens and these specimens of the various polymer compositions were subjected to tensile testing according to ASTM method D638 at 0.05 inch / minute room temperature (i.e. 23°C) on 3 specimens. The arithmetic average of the 3 specimens is presented.

[0149] Determination of surface extractable impurities

[0150] The polymer powder was pelletized and injection molded to provide plaques for testing._The pellets needed for injection molding were prepared by melt compounding using a 26 mm diameter Coperion® co-rotating partially intermeshing twin screw extruder having an L / D ratio of 48: 1. The extruder was equipped with 12 barrel sections, with barrel sections 2 through 12 being temperature controlled. The extruder was fitted with a 3 -mm diameter single-hole die. The resin feeder fed into the feed hopper (barrel section 1). Vacuum venting with a vacuum level > 25 in Hg was applied at barrel section 10 during the compounding to strip off moisture and any possible residual volatiles from the compounds. The extrudate from each of the compositions was stranded and the strands were cooled in a demineralized water trough and then pelletized using a Maag Primo 60 E pelletizer into pellets.Table 1: pelletization conditions for PEEK-PEoEK (80 / 20) of Example 4Table 2: injection molding conditions

[0151] The sample containers, containing one plaque each, were filled with ultrapure water (milliQ) for 2 minutes. Then the water was drained. This was repeated 10 times. For the actual leaching test the containers were filled an 11thtime either with just enough water to cover the plaque. The tests were carried out in triplicate for each plaque type.

[0152] In parallel, 5 ‘blank’ glass containers and 5 ‘blank’ HDPE containers, containing the same amount of ultrapure water but no plaques, were submitted to exactly the same procedure as the bottles containing the plaques. These are the ‘procedure blanks’.

[0153] The containers containing the plaques and the procedure blank containers were then placed in an oven for 7 days at 85°C. They were agitated once a day.

[0154] After the 7 days leaching, the sample solutions were transferred into clean recipients for the TOC, metals and anions measurements. The solutions for the metals determination were slightly acidified with cone. HNO3 immediately after the transfer in order to stabilize the metals.

[0155] The surface extractable metals (SEMI F57 list) were measured by high resolution ICP- MS using a Thermo Element 2 instrument.

[0156] The surface extractable anions (SEMI F57 list) were measured by ion chromatography (IC) using a Dionex ICS-5000 instrument.

[0157] The TOC (Total Organic Carbon) was measured as the difference between TC (Total Carbon) and TIC (Total Inorganic Carbon) using a Shimadzu TOC-L instrument.

[0158] Preparation of the polymers

[0159] Comparative Example 2: preparation of PEEK-PEmEK copolymer 75 / 25

[0160] In a 1000 mL 4-neck reaction flask fitted with a stirrer, a N2 inlet tube, a Clai sen adapter with a thermocouple plunging in the reaction medium, and a Dean- Stark trap with a condenser and a dry ice trap were introduced 338.33 g of diphenyl sulfone, 41.665 g of hydroquinone, 13.863 g of resorcinol and 112.593 g of 4,4’ -difluorobenzophenone. The flask content was evacuated under vacuum and then filled with high purity nitrogen (containing less than 10 ppm O2). The reaction mixture was then placed under a constant nitrogen purge (60 mL / min).

[0161] The reaction mixture was heated slowly to 150 °C. At 150 °C, a mixture of 55.482 g of Na2CO3and 0.174 g of K2CO3 was added via a powder dispenser to the reaction mixture over 30 minutes. At the end of the addition, the reaction mixture was heated to 300 °C at l°C / minute. After 36 minutes at 300°C, 13.169 g of 4,4’ -difluorobenzophenone were added to the reaction mixture while keeping a nitrogen purge on the reactor. After 5 minutes, 2.132 g of lithium chloride were added to the reaction mixture. 10 minutes later, another 4.390 g of 4, 4 ’-difluorobenzophenone were added to the reactor and the reaction mixture was kept at temperature for 15 minutes.

[0162] 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 solid with 6 x 1.2 L acetone and 7 x 1.2 L water at pH between 1 and 12. The powder was then removed from the reactor and dried at 100 °C under vacuum for 12 hours yielding 165 g of a light brown powder. The final polymer contained less than 500 mg / kg of diphenyl sulfone and less than 100 mg / kg of 4,4’- difluorobenzophenone. The other monomers are completely consumed in the polymerization and present at less than 3 mg / kg in the final polymer.

[0163] Example 3: preparation of PEEK-PEDEK copolymer 75 / 25

[0164] In a 500 mL 4-neck reaction flask fitted with a stirrer, a N2 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 128.21 g of diphenyl sulfone, 20.297 g of hydroquinone, 11.411 g of 4,4’-biphenol and 54.377 g of 4,4’ -difluorobenzophenone. The flask content was evacuated under vacuum and then filled with high purity nitrogen (containing less than 10 ppm O2). The reaction mixture was then placed under a constant nitrogen purge (60 mL / min).

[0165] The reaction mixture was heated slowly to 150 °C. At 150 °C, a mixture of 26.955 g of Na2CO3and 0.169 g of K2CO3 was added via a powder dispenser to the reaction mixture over 30 minutes. At the end of the addition, the reaction mixture was heated to 320 °C at l°C / minute. After 13 minutes at 320 °C, 3.742 g of 4,4’-difluorobenzophenone were added to the reaction mixture while keeping a nitrogen purge on the reactor. After 5 minutes, 1.039 g of lithium chloride were added to the reaction mixture. 10 minutes later, another 2.138 g of 4, 4 ’-difluorobenzophenone were added to the reactor and the reaction mixture was kept at temperature for 15 minutes.

[0166] 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 6 x 1.2 L acetone and 7 x 1.2 L water at pH between 1 and 12. The powder was then removed from the reactor and dried at 120 °C under vacuum for 12 hours yielding 74 g of a white powder. The final polymer contained less than 1000 mg / kg of diphenyl sulfone and less than 100 mg / kg of 4,4’ -difluorobenzophenone. The other monomers are completely consumed in the polymerization and present at less than 3 mg / kg in the final polymer.

[0167] Example 4: preparation of PEEK-PEoEK copolymer 70 / 30

[0168] In a 1000 mL 4-neck reaction flask fitted with a stirrer, a N2 inlet tube, a Clai sen adapter with a thermocouple plunging in the reaction medium, and a Dean- Stark trap with a condenser and a dry ice trap were introduced 343.63 g of diphenyl sulfone, 54.121 g of hydroquinone, 23.139 g of pyrocatechol and 153.351 g of 4,4’ -difluorobenzophenone. The flask content was evacuated under vacuum and then filled with high purity nitrogen (containing less than 10 ppm O2). The reaction mixture was then placed under a constant nitrogen purge (60 mL / min).

[0169] The reaction mixture was heated slowly to 150°C. At 150°C, a mixture of 76.938 g of Na2CO3 and 0.484 g of K2CO3 was added via a powder dispenser to the reaction mixture over 30 minutes. At the end of the addition, the reaction mixture was heated to 320 °C at l°C / minute. After 73 minutes at 320°C, the reaction was terminated in 3 stages: 18.329 g of 4,4’ -difluorobenzophenone were added to the reaction mixture while keeping a nitrogen purge on the reactor. After 5 minutes, 2.388 g of lithium chloride were added to the reactionmixture. 10 minutes later, another 6.110 g of 4,4’ -difluorobenzophenone were added to the reactor and the reaction mixture was kept at temperature for 15 minutes.

[0170] 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 by extracting successively with 6 x 1.2 L acetone and 7 x 1.2 L water at room temperature. The powder was then dried at 120 °C under vacuum for 12 hours yielding 188 g of a white powder. The final polymer contained less than 1000 mg / kg of diphenyl sulfone and less than 100 mg / kg of 4,4’- difluorobenzophenone. The other monomers are completely consumed in the polymerization and present at less than 3 mg / kg in the final polymer.

[0171] Example 5: preparation of PEEK-PEoEK copolymer 80 / 20

[0172] The same procedure as Example 4 was followed but with the following amounts of reagents.Table 3:

[0173] The properties of the polymers of Comparative Examples 1 and 2 and of Examples 3 to 5 are detailed in Table 4 below.Table 4 : Polymer propertiesa : ultimate strength is the greater of strength at yield and at break b : CM =compression molded c: IM = injection molded conversion: 1 psi = 0.0689476 bar

[0174] The data presented in Table 4 show that PEEK-PEDEK and PEEK-PEoEK exhibit a combination of properties that make them suitable for the preparation of pipes or pipe connector:- a Tm lower than the Tm of PEEK;- a Tg higher than or of the same order to magnitude of the Tg of PEEK;- an improved ductility (elongation at break) over PEEK-PEmEK.It thus shows that the presence of PEmEK repeat units is detrimental to the properties of the polymer.

[0175] The surface extractable impurities were measured for the low Tm PAEK = PEEK- PEoEK copolymer of Example 5. They are listed in Table 5. The levels detected matched the expected requirements for the transport of ultra-pure water indicating that the low melting PEEK-PEoEK copolymer matches the purity requirement of the application.Table 5: Extractable impurities from PEEK-PEoEK copolymer of Example 5

Claims

ClaimsClaim 1. System for transporting ultra-pure water (UPW) comprising at least one component, wherein said at least one component comprises a surface intended to be in contact with UPW and is made of or comprises a polymer composition (PC) comprising, consisting essentially of or consisting of:- at least 50.0 wt% (> 50.0 wt%) of at least one semi-crystalline polymer (P), this proportion being relative to the total weight of the polymer composition (PC);- optionally at least one additional polymer blended with polymer (P) and selected in the group consisting of polyaryl etherketones (PAEK) different from semi-crystalline polymer (P), polysulfones (PSU), polyphenylesulfones (PPSU) and combinations thereof; wherein the semi-crystalline polymer (P) comprises the following recurring units with the following proportions:- between 65.0 and 95.0 mol% of units (RPEEK) of formula:-between 5.0 and 35.0 mol% of units (Rp) selected in the group consisting of units (RPEDEK), units (RPEOEK) and combination thereof:these proportions being given relative to the total amount of recurring units in the polymer (P); wherein UPW denotes a water exhibiting an electric resistivity at 25°C of at least 18.0 MQ.cm and a Total Organic Carbon (TOC) of at most 10.0 pg / L.Claim 2. System according to claim 1, wherein the component is a pipe or a pipe connector.Claim 3. System according to any one of claims 1-2, wherein the proportion of semi-crystalline polymer(s) (P) in the polymer composition (PC) is at least 60.0 wt%, preferably at least 65.0 wt%, preferably at least 70.0 wt%, preferably at least 75.0 wt%, preferably at least 80.0 wt%, preferably at least 85.0 wt%, preferably at least 90.0 wt%, preferably at least 95.0 wt%, preferably at least 99.0 wt%, this proportion being relative to the total weight of the polymer composition (PC).Claim 4. System according to claim 1 or 2, wherein UPW is any one of the 7 types of water given in Table 1 of ASTM D5127 - 13 (Reapproved 2018).Claim 5. System according to any one of the preceding claims, wherein UPW is any of the 4 following types of water as defined in Table 1 of ASTM D5127-13 (Reapproved 2018): type E- 1, type E-l.l, type E-1.2 or type E-1.3.Claim 6. System according to any one of the preceding claims, wherein (Rp) is:- (RPEDEK); or- (RPEOEK); or- a combination of (RPEDEK) and (RPEOEK).Claim 7. System according to any one of the preceding claims, wherein the recurring units of polymer (P) consist of units (RPEEK) and units (Rp).Claim 8. System according to any one of the preceding claims, wherein:- the proportion of (RPEEK) is between 65.0 and 85.0 mol%; and / or- the proportion of (Rp) is between 15.0 and 35.0 mol%.Claim 9. System according to any one of the preceding claims, wherein polymer (P) contains at most 2000 mg / kgpoiymer (P) of residual solvent, such as diphenyl sulfone, preferably at most 1000 rng / kgpoiymer (P) and / or at most 200 mg / kgpoiymer (P) of residual monomer 4,4’- difluorobenzophenone, preferably at most 100 mg / kg polymer (P), more preferably at most 80 mg / kgpolymer (P).Claim 10. System according to any one of the preceding claims, wherein the melt viscosity (MV) of polymer composition (PC) measured at 410°C and 46.3 s'1according ASTM D3885 is at least 0.20 kN-s / m2, preferably at least 0.30 kN-s / m2, more preferably at least 0.40 kN-s / m2.Claim 11. Pipe comprising one or more layers, wherein the internal layer (L) intended to be in contact with UPW is made of or comprises a polymer composition (PC) comprising, consisting essentially of or consisting of:- at least 50.0 wt% (> 50.0 wt%) of at least one semi-crystalline polymer (P), this proportion being relative to the total weight of the polymer composition (PC);- optionally at least one additional polymer blended with polymer (P) and selected in the group consisting of polyaryl etherketones (PAEK) different from semi-crystalline polymer (P), polysulfones (PSU), polyphenylesulfones (PPSU) and combinations thereof; where UPW denotes a water exhibiting an electric resistivity at 25°C of at least 18.0 MQ.cm and a Total Organic Carbon (TOC) of at most 10.0 pg / L; wherein the semi-crystalline polymer (P) comprises the following recurring units with the following proportions:- between 65.0 and 95.0 mol% of units (RPEEK) of formula:-between 5.0 and 35.0 mol% of units (Rp) selected in the group consisting of units (RPEDEK), units (RPEOEK) and combination thereof:these proportions being given relative to the total amount of recurring units in the polymer (P); and wherein:- the pipe contains UPW; and / or- the amounts of elution of the impurities (Imp) released from layer (L) and expressed in pg / m2of the surface of the leaching area, after bringing layer (L) in contact with UPW according to protocol (pl) provided in the description are less than the values of eluted impurities indicated in the Table below:Claim 12. Pipe connector comprising a surface intended to be in contact with ultra-pure water (UPW) and which is made of or comprises a polymer composition (PC) as defined in any one of the preceding claims, where UPW denotes a water exhibiting an electric resistivity at 25°C of at least 18.0 MQ.cm and a Total Organic Carbon (TOC) of at most 10.0 pg / L, wherein the amounts of elution of the impurities (Imp) released from the surface in contact with UPW following protocol (p2) provided in the description are less than the values of eluted impurities expressed in pg / m2of the surface of the leaching area indicated in the Table below:Claim 13. Method for transporting ultra-pure water (UPW), wherein at least one pipe as defined in claim 11 or at least one pipe connector as defined in claim 12 is used to transport ultra-pure water, wherein UPW denotes a water exhibiting an electric resistivity at 25°C of at least 18.0 MQ.cm and a Total Organic Carbon (TOC) of at most 10.0 pg / L.Claim 14. Use of a polymer composition (PC) comprising, consisting essentially of or consisting of:- at least 50.0 wt% (> 50.0 wt%) of at least one semi-crystalline polymer (P), this proportion being relative to the total weight of the polymer composition (PC);- optionally at least one additional polymer blended with polymer (P) and selected in the group consisting of polyaryl etherketones (PAEK) different from semi-crystalline polymer (P), polysulfones (PSU), polyphenylesulfones (PPSU) and combinations thereof; wherein the semi-crystalline polymer (P) comprises the following recurring units with the following proportions:- between 65.0 and 95.0 mol% of units (RPEEK) of formula:-between 5.0 and 35.0 mol% of units (Rp) selected in the group consisting of units (RPEDEK), units (RPEOEK) and combination thereof:these proportions being given relative to the total amount of recurring units of the polymer; for the preparation of at least one surface of a pipe or a pipe connector intended to be in contact with ultra-pure water (UPW), where UPW denotes a water exhibiting an electric resistivity at 25°C of at least 18.0 MQ.cm and a Total Organic Carbon (TOC) of at most 10.0 pg / L.Claim 15. Use according to claim 14, wherein the proportion of semi-crystalline polymer(s) (P) in the polymer composition (PC) is at least 60.0 wt%, preferably at least 65.0 wt%, preferably at least 70.0 wt%, preferably at least 75.0 wt%, preferably at least 80.0 wt%, preferably at least 85.0 wt%, preferably at least 90.0 wt%, preferably at least 95.0 wt%, preferably at least 99.0 wt%, this proportion being relative to the total weight of the polymer composition (PC).Claim 16. Use according to any one of claims 14 and 15, wherein (Rp) is:- (RPEDEK); or- (RPEOEK); or- a combination of (RPEDEK) and (RPEOEK).Claim 17. Use according to any one of claims 14 to 16, wherein the recurring units of polymer (P) consist of units (RPEEK) and units (Rp).Claim 18. Use according to any one of claims 14 to 17, wherein:- the proportion of (RPEEK) is between 65.0 and 85.0 mol%; and / or- the proportion of (Rp) is between 15.0 and 35.0 mol%.Claim 19. Use according to any one of claims 14 to 18, wherein polymer (P) contains at most 2000 mg / kgpoiymer (P) of residual solvent, such as diphenyl sulfone, preferably at most 1000 rng / kgpoiymer (P) and / or at most 200 mg / kgpoiymer (P) of residual monomer 4,4’- difluorobenzophenone, preferably at most 100 mg / kg polymer (P), more preferably at most 80 mg / kgpolymer (P).Claim 20. Use according to any one of claims 14 to 19, wherein the melt viscosity (MV) of polymer composition (PC) measured at 410°C and 46.3 s'1according ASTM D3885 is at least 0.20 kN-s / m2, preferably at least 0.30 kN-s / m2, more preferably at least 0.40 kN-s / m2.

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