CN101563407A - Foamed fluoropolymer article - Google Patents
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- CN101563407A CN101563407A CNA2007800471101A CN200780047110A CN101563407A CN 101563407 A CN101563407 A CN 101563407A CN A2007800471101 A CNA2007800471101 A CN A2007800471101A CN 200780047110 A CN200780047110 A CN 200780047110A CN 101563407 A CN101563407 A CN 101563407A
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Abstract
The present invention discloses an article made from a foamable thermoplastic polymer composition. The foamable composition of the article includes a partially-crystalline melt processible perf luoropolymer and a foam nucleating package. The foamed article has a uniform foam cell size where the foam cell size of at least 90% of the foamed cells is 50 micrometers or less. The foam nucleating package ranges from 0.1 to 10 wt% of the combined weight of the perf luoropolymer and the foam nucleating package.
Description
Invention field
The present invention relates to use the goods of thermoplastic foam polymer.More particularly, the present invention relates to the goods that made by the thermoplastic foam polymer composition, described composition mixes the combination of foam nucleation with high melt fluidity fluoropolymer.
Background of invention
The manufacturers's (for example, insulated conductor manufacturers) that fluoropolymer is used for foam article faces great number of issues, and described problem can't solve with current obtainable conductor insulation material.One of this type of problem that these manufacturerss face is, implements to extrude under multiple condition and parameter/the fusion drafting process, causes the physical property and the electrical specification of the foamed fluoropolymer that manufacturers obtains to change.The minimize variations with the foamed fluoropolymer characteristic is attempted by manufacturers.
Another problem of manufacturers is to extrude fluoropolymer for multi-purpose economy.Owing to face the problem that insulation quality (spark and/or concavo-convex) produces, and at least by changing the long uncertainty that produces of ratio of drawing (DDR), service temperature and awl, therefore insulated conductor manufacturers reduces linear speed usually, and until reaching desired insulated conductor quality, this causes productivity to reduce.
Following discloses relate to many aspects of the present invention, and can be summarized as follows:
According to disclosed in the United States Patent (USP) 4,764,538 of authorizing people such as Buckmaster, the synergistic combination of boron nitride (BN) and some inorganic salt can provide enhanced foam nucleogenesis in fluoropolymer.
The United States Patent (USP) 4,877,815 of authorizing people such as Buckmaster discloses a class sulfonic acid and a phosphonic acids, and the salt of described acid, and it provides very effective abscess nucleogenesis to a variety of thermoplastic materials under lower concentration.In addition, these acid and salt can advantageously be used in combination with boron nitride and calcium tetraborate with trace, promptly are subjected to United States Patent (USP) 4,764, the combination of 538 protections.Above-mentioned patent does not have the insulation anti-collapse performance and the electric property that openly can provide desired, the composition that the high speed of simultaneously can manufacturers looking for such as insulated conductor manufacturers is extruded.
Be desirable to provide a kind of goods with foamy structure, described foamy structure can reduce finished product processing and changes of properties.It would also be desirable to provide a kind of goods that contain foamable composite, described foamable composite can reduce the amount of the required polymer materials of application such as cable application.Also wish to have a kind of goods that can contain foamable fluoropolymer composition, described composition can higher speed be extruded with the speed that may reach than current commercial polymer, and can not make compromised quality, productivity reduces or lose the electric property of desired characteristic such as insulated conductor.
Summary of the invention
In brief, and according to an aspect of the present invention, the foamed polymer Tetramune is provided, described goods comprise: a) (per) fluoropolymer of the melt-processable of partial crystallization, and b) foam nucleation combination, described combination comprises uniform abscess-size, and wherein 90% abscess-size is 50 microns or littler, and foam nucleation combination by the combined wt of (per) fluoropolymer and the combination of foam nucleation in 0.1-10 weight % scope.
According to another aspect of the present invention, provide the foamed polymer Tetramune, described goods comprise: a) (per) fluoropolymer of the melt-processable of partial crystallization, wherein said (per) fluoropolymer is fluoridized in molten state, and b) combination of foam nucleation, described combination comprises:
I) boron nitride,
Ii) synergy amount at least a heat-staple inorganic salt under the fluoropolymer extrusion temperature, and described salt is made of metallic cation and polyatom negatively charged ion, and satisfy following relation:
0.36×[14-pKa]-0.52≥[r-0.2q]2≥0.11×[14-pKa]-0.28
Wherein
The described cationic crystal ionic radius of R=is a unit with the dust
The described cationic valency of Q=
The Ka of the following reaction of pKa=-the log value
HA
-(n-1)<＝>H
++A
-n
Wherein A is the negatively charged ion of described salt, and H is a hydrogen, and the absolute value of the described negatively charged ion chemical combination of n=valency; And
Iii) has formula [Z (CF
2)
x(CF
2CFX)
p(R ')
y(CH
2)
zRO
3]
nThe foam nucleator of M structure
Wherein:
Z is CCl
3, CCl
2H, H, F, Cl or Br;
Each X is independently selected from H, F or Cl;
R is sulphur or phosphorus; M is the ammonium cation or the quaternary ammonium cation of H or metallic cation, ammonium cation, replacement;
X is integer and is 0 to 10;
P is integer and is 0 to 6;
Y is 0 or 1;
Z is integer and is 0 to 10;
X+y+z+p is a positive integer, if perhaps x+y+z+p is 0, then Z is CCl
3Or CCl
2H;
N is the valency of M; And
R ' is selected from
C
5-6Perfluorination alicyclic ring diradical;
C
1-16Perfluorination aliphatic polyether diradical, described diradical have and are selected from [CF
2O], [CF
2CF
2O] and [CF
2CF (CF
3) O] and repeating unit; With
Replace or unsubstituted aromatics diradical, wherein Z is H;
And the combination of described foam nucleation by the combined wt of described (per) fluoropolymer and the combination of described foam nucleation in 0.1-10 weight % scope.
The accompanying drawing summary
Read following detailed Description Of The Invention in conjunction with the drawings, can more completely understand the present invention, wherein:
Fig. 1 (a) shows the partial view of the form of the commercially available acquisition foam sample that comprises about 15% pore volume under 75 times enlargement ratio.
Fig. 1 (b) shows the form partial view of the foam sample that comprises about 22% pore volume under 75 times enlargement ratio in the foam article of the present invention.
Fig. 1 (c) shows the amplification sectional view (295 times enlargement ratios) of 1 (a) cross section partial view.
Fig. 1 (d) shows the amplification sectional view (295 times enlargement ratios) of 1 (b) cross section partial view.
Fig. 2 (a) shows the cross section of the cable that comprises unshielded twisted pair and adopt solid polymer composition.
Fig. 2 (b) shows the cross section that comprises unshielded twisted pair and adopt the cable of foam article of the present invention.
Although will describe the present invention, be to be understood that it is not intended to limit the invention to this embodiment in conjunction with its preferred embodiment.On the contrary, it is intended to contain all replacement schemes, modification and equivalent in the spirit and scope of the invention that may be included in the appended claims qualification.
Detailed Description Of The Invention
Definition:
Mode according to using them in the context of this specification and the appended claims provides following definition as a reference.
Cat 5/5e is also referred to as 5/5e class cable, is unshielded twisted pair (UTP) type of cable that is designed to the highest 100Mbit/s speed reliable transmitting data, for example 100BASE-T. Cat 5/5e comprises four pairs of twisted-pair feeders in single cable jacket, the every pair of twisted-pair feeder is with stranded three times of every inch of No. 24 wire gauge copper cash of insulation. Cable stranded reduces electrical interference and crosstalks. Another important characteristic is that low dispersion is that dielectric constant is not with the Frequency generated great changes with plastic material (for example FEP) wire rod that insulate with low dispersion. Also must pay special attention to make the impedance mismatch minimumization at tie point place. The Cat 5e cable that substitutes Cat 5 is the enhancement mode version of Cat 5, and it has added the specification of crosstalking for far-end.
Cat 6, are also referred to as 6 class cables, are to be designed to the speed of the highest 1Gbit/s UTP type of cable of the transmission of data reliably. Be noted that Cat 6 backward compatible Cat 5/5e and Cat 3 standards, but with system noise stricter standard arranged to crosstalking. Cat 6 comprises four pairs of twisted-pair feeders in single cable jacket, every pair of twisted-pair feeder is different with every inch stranded number of times of No. 23 wire gauge copper cash of insulation. This cable standard is applicable to 10base-T/100BASE-T and 1000BASE-T.
Cat 7, are also referred to as 7 class cables, are to be designed to the highest 10Gbit/s speed Shielded Twisted Pair cable of the transmission of data reliably. Be noted that Cat 7 backward compatible Cat 6, Cat 5/5e and Cat 3 (namely 3 classes are first generation utp cables, and it is applicable to 100 meters Ethernet signal transmission) standard, but have even stricter standard with system noise crosstalking. As early stage standard, Cat 7 also comprises four pairs of twisted-pair feeders, and different is that each has been added shielding to twisted-pair feeder with to whole cable.
Crosstalk is that harmful energy from a signal path coupling near adjacent or signal path shifts. The faint sound of the example of crosstalking for during telephone talk, running into sometimes. Crosstalking can be capacitive (electric field) or inductive (magnetic field), and usually can produce harmful or wrong data in computer link or data system.
Dielectric constant, εr, be the physical quantity of describing Effect of Materials electric field degree, it is relevant with the ability of partly eliminating electric field with material generation polarization. More particularly, it is the ratio of institute's stored electric energy and vacuum institute stored electric energy, εr=1. The ε of wire insulation bodyrAll influential to cable resistance and spread speed.
Shielded Twisted Pair (STP) wiring is mainly used in computer networking. Every pair of twisted-pair feeder is entwined each other by two bar insulation conductors, and uses the conduction overwrap to cover to protect wire rod to avoid disturbing and being used as ground connection. The extra protection of this kind has limited the pliable and tough property of wire rod and has made STP more more expensive than other type of cables. Every the conductor insulated body surrounds. Conductive shielding layer can surround twisted-pair feeder. Many twisted-pair feeder is wrapped in the crust. Crust can comprise conductive shield. These shieldings comprise sheet metal wrappage or metal wire knitted layer.
Even twisted-pair feeder is that wherein ring-type is stranded is the twisted-pair feeder of constant along the length of twisted pair direction.
Unshielded twisted pair (UTP) wiring is the main wire rod type for phone application, and also is usually used in computer networking. Every pair of twisted-pair feeder is entwined each other by two bar insulation conductors, and its purpose is can cause the electromagnetic interference of crosstalking in order to offset. But stranded wire rod reduce disturbance, reason is: the anchor ring between the wire rod amasss and reduces (described area is determining to enter the magnetic coupling in the signal); And the sense of current that produces of the magnetic field of evenly coupling stranded for each be opposite, thereby cancel each other out. Every meter stranded number of times is more, and crosstalking of reduction is just more. Every all insulated body encirclement of conductor. Many twisted-pair feeder is wrapped in the crust.
With reference now to detailed Description Of The Invention,, it includes but not limited to embodiment disclosed herein. The invention provides the goods that comprise composition, described composition is constituted by fluoropolymer and the foam nucleation of the melt-processable of partially crystallizable. According to the present invention, described fluoropolymer is partially crystallizable; Be that they are not amorphous, for example they are not elastomers. Partially crystallizable refers to that described polymer has certain degree of crystallinity, and is characterised in that, measure according to ASTM D 3418 to have the fusing point that can detect, and melting heat absorption amount is about at least 3J/g. They are copolymers of tetrafluoroethene (TFE) and hexafluoropropene (HFP), and the copolymer of TFE and perfluor (alkyl vinyl ether). Copolymer is defined as the polymer that formed by two or more monomer polymerizations herein.
Melt-processable refers to that described polymer can be fully mobile, namely has enough low viscosity, so that it can be processed such as extruder and injection molding machine with conventional device of plastic processing. MFR is measuring of polymer viscosity, and MFR is higher, and polymer viscosity is just lower. MFR refers to, under the actual temp of in the ASTM test that relates to concrete (per) fluoropolymer, determining, under ordinance load, in 10min from the Plastometer of ASTM D 1238-94a
The polymer grams of middle outflow. Melt processable polymers has the MFR in about 1 to 100g/10min above scope. Usually, melt processable polymers is in 1 to 50g/10min scope.
Tetrafluoroethene (PTFE) homopolymers and modified ptfe be not in the melt processible fluoropolymer scope, and described modified ptfe comprises the comonomer of a small amount of and tetrafluoroethene, usually less than about 1 % by weight. These polymer are not because therefore their very high viscosity be melt-processable. They show without mobile at the equipment that is used for mensuration MFR, MFR=0g/10min, and can extrude processing such as sintering and paste by special method.
Preferred fluoropolymer is (per) fluoropolymer in the goods of the present invention. Preferably prepare (per) fluoropolymer by polymerization TFE, HFP and perfluor (alkyl vinyl ether). The content of HFP in described (per) fluoropolymer is in about 3 % by weight to 20 % by weight scopes. Described (per) fluoropolymer is fluorinated in the melting attitude, and is substantially free of the metal ion. Make described (per) fluoropolymer polymerization and separation, and need not to use the reagent that comprises the metal ion. Described (per) fluoropolymer comprises at least a perfluor (alkyl vinyl ether) of about 0.5 % by weight to 10 % by weight. Perfluor (alkyl vinyl ether) embodiment (PAVE) comprise perfluor (ethyl vinyl ether) (PEVE), perfluor (propyl vinyl ether) (PPVE) or perfluor (methyl vinyl ether) (PMVE).
The preferred (per) fluoropolymer of another kind is TFE and perfluor (alkyl vinyl ether) copolymer (PAVE), and wherein the straight or branched alkyl comprises 1 to 5 carbon atom. Preferred PAVE monomer comprises: perfluor (methyl vinyl ether) (PMVE), perfluor (ethyl vinyl ether) (PEVE), perfluor (propyl vinyl ether) (PPVE) and perfluor (butyl vinyl ether) (PBVE). Can prepare copolymer with multiple PAVE monomer, TFE/ perfluor (methyl vinyl ether)/perfluor (propyl vinyl ether) copolymer for example, manufacturer is called MFA sometimes. The TFE/PAVE copolymer is commonly referred to PFA, contains the PAVE (comprising when PAVE is PPVE or PEVE) of about at least 2 % by weight, and usually contains the PAVE of 2 to 15 % by weight of having an appointment. When PAVE contains PMVE, consist of the perfluor (methyl vinyl ether) of about 0.5 to 13 % by weight and the PPVE of about 0.5 to 3 % by weight, reach the remainder that amounts to 100 % by weight and be divided into TFE, and as mentioned above, it can be called as MFA.
In the situation that does not add alkali metal salt, implement polymerisation. According to United States Patent (USP) 5,677, the general method of embodiment 1 in 404. Yet initator only is made of ammonium persulfate. Do not use potassium peroxydisulfate, potassium peroxydisulfate is the alternative initiator commonly used or forms coinitiator with ammonium persulfate. Also can use such as United States Patent (USP) 5,182 disclosed organic initiators in 342. The water that is used for polymerisation and washing removes ion. In above-described embodiment 1, described copolymer is TFE/HFP/PEVE, however PPVE, PMVE and other PAVE monomer, and the combination of these monomers, can be substituted. Join speed in the polymerisation by initator, control melt flow rate (MFR). (per) fluoropolymer of the present invention preferably has the MFR in about 25g/10min to 35g/10min scope. After polymerisation, by mechanical agitation the resulting polymers dispersion is condensed. Also can condense by freeze thawing or by adding chemicals. Acid or ammonium salt can be used in the chemical coagulation, but metal salt, and especially alkali metal salt is not useable in the chemical coagulation. Alkali salt does not also preferably use in described process and for example is used as coagulating agent, and selects the building material of polymerization equipment and treatment facility, so that corrosion can not become metal ion source. Content by alkali metal ion in the described polymer of x ray fluorescence spectrometry. During take potassium as analyte, be limited to 5ppm under the detection in the polymer. According to the present invention, polymer has less than 50ppm, preferably less than about 25ppm, is more preferably less than about 10ppm, and most preferably less than the alkali metal ion of about 5ppm.
Use deionized water preparation and polymerization not to use the polymer of alkali metal salt to be known as herein with separating to be substantially free of (for example not metalline) of metal ion.
Find, apply in the operation at conductor, under high linear speed, the existence of alkali metal salt in the fluoropolymer, can promote on the extrusion die outer surface and/or mould core guider that the conductor in the punch die passes through forms the fluoropolymer tear drop, and described tear drop periodically is carried to along pyrometric cone on the insulator of conductor, to be rendered as unacceptable insulator convex-concave. This is not unique source of convex-concave. Polymer melting temperature is too high or too low, also can cause convex-concave. The existence of alkali metal salt is the factor that inspires the convex-concave problem in the fluoropolymer. Copolymer of the present invention does not contain and does not namely comprise alkali metal salt and refer to, does not use alkali metal salt in polymerisation or in the separation of gained fluoropolymer.
The method of measuring alkali metal ion in the polymer can be illustrated by the K~+ determination example. Analytical method is x-ray fluorescence method (XRF). With the polymer that comprises known amount potassium ion with the standardization of XRF instrument. Carry out polymerisation without the potassium prescription and formulate the 0ppm standard by in the environment that does not contain potassium ion, using. For the standard under other concentration, measure the absolute value of potassium content by proton induce x-ray emission (PIXE).
According to the present invention, can come fluorinated polymer by disclosed method in the United States Patent (USP) 4,743,658, be transformed into stable-CF with the end group of heat is unstable or hydrolytically unstable3End group. Unstable the referring to of heat, described end group generally between 300 ℃ to 400 ℃, reacts by decomposition under the fluoropolymer melt processing temperature usually. The example that is subjected to fluorine to process the unstable end group that affects is-CF2CH
2OH、-CONH
2,-COF and-COOH. Enforcement is fluoridized, and is reduced to the sum with the unstable end group of Four types and is not more than about 50/106Carbon atom in the individual polymer main chain. The sum of these unstable end groups preferably was not more than about 20/10 after fluorine was processed6Individual carbon atom, and for first three kind appointment end group, preferably less than about 6 this type of end group/106Individual carbon atom. Such as United States Patent (USP) 4,743,658 is disclosed, after fluorine is processed, with the pellet that for example nitrogen blowing fluorine was processed, removes from fluoropolymer with the fluorine that can propose. Preferred fluorination process is described in United States Patent (USP) 6,838, and in 545, wherein said polymer is fluoridized in the melting attitude. Namely when being exposed to fluorine, described polymer is melting.
Foam nucleation combination of the present invention provides uniform abscess-size. Abscess-size refers to steep the diameter in hole, and described bubble hole is spherical or approximate spherical. If described bubble hole is obviously not round, namely be tending towards oval, then described size is its longer size that presents under microscope. Average cell size is less than 10% of foam insulator insulation wall thickness. About 90% bubble hole is preferably 50 microns or less. The combination of described foam nucleation by the total weight percent of the fluoropolymer of melt-processable and the combination of foam nucleation preferably in 0.1 to 10 % by weight, more preferably 0.1 to 5 % by weight, and most preferably in 0.1 to the 0.6 % by weight scope.
The foam nucleator is heat-stable compound, and it is selected from sulfonic acid and phosphonic acids and their salt. Preferred (a) comprised cycloalkyl and/or the aliphatic sulfonic acid of ether oxygen and free acid and salt of phosphonic acids of partially or completely fluoridizing; (b) free acid and the salt of aromatic sulfonic acid and phosphonic acids, wherein said aromatic ring are chosen wantonly by alkyl, are contained fluoroalkyl and/or hydroxyl replacement.
Consisting of the combination of foam nucleation or being in the foam nucleator of foam nucleation combination partner, it is the foam nucleator that can be expressed from the next
Z(CF
2)
x(CF
2CFX)
p(R’)
y(CH
2)
z(RO
3)
nM
Wherein: except RO3In addition, divalent group can any sequence present;
Z is selected from CCl3、CCl
2H, H, F, Cl and Br;
Each X is independently selected from H, F, Cl and CF3；
R is selected from sulphur and phosphorus;
M is selected from the ammonium cation and the quaternary ammonium cation of H and metallic cation, ammonium cation, replacement;
Among x and the z each is integer independently, and is 0 to 20;
P is an integer, and is 0 to 6;
Y is 0 or 1;
X+y+z+p is a positive integer, if perhaps x+y+z+p is 0, then Z is CCl
3Or CCl
2H;
N is the valency of M; And
R ' is selected from
C
5-6Perfluorination alicyclic ring diradical;
C
1-16Perfluorination aliphatic polyether diradical, described diradical have and are selected from [CF
2O], [CF
2CF
2O] and [CF
2CF (CF
3) O] and repeating unit; With
Replace or unsubstituted aromatics diradical, in the case, Z is H.
Foam nucleator of the present invention has at least a heat-stable compound of nucleation significant quantity, and described compound is selected from sulfonic acid and phosphonic acids and/or their salt.The example of foam nucleator is shown in Table 1." TBSA " is F (CF
2)
nCH
2CH
2SO
3H, wherein n is 6,8,10, and may be 12, is mainly 8.
Table 1
| ZrS-10 | The zirconium of TBSA (+4) salt |
| CrS-10 | The chromium of TBSA (+3) salt |
| CeS-10 | The cerium of TBSA (+4) salt |
| KS-10 | The sylvite of TBSA |
| HS-10 | TBSA |
| AS-10 | The aluminium salt of TBSA |
| SrS-10 | The strontium salt of TBSA |
| CaS-10 | The calcium salt of TBSA |
| ZnS-10 | The zinc salt of TBSA |
| BaS-10 | The barium salt of TBSA |
| LS-10 | The lithium salts of TBSA |
| FS-10 | The iron of TBSA (+3) salt |
| TEAS-10 | The triethyl amine salt of TBSA |
| BS-6A | Right-(perfluor [1, the 3-dimethylbutyl]) barium benzosulfonate |
| BS-9A | Right-(perfluor [1,3,5-trimethylammonium hexyl]) barium benzosulfonate |
| BaS-A1(H) | Tosic acid barium |
| BaP-A | Phosphenylic acid barium |
| NaP-A | Sodium benzene phosphinate |
| NaS-A(II) | 4, benzene disulfonic acid disodium salt between the 5-dihydroxyl |
| NaS-6 | The own sodium sulfonate of perfluor |
| BS-6 | The own barium sulfonate of perfluor |
| BS-8 | Perfluorooctane sulfonate barium |
| KS-6 | The own potassium sulfonate of perfluor |
| KS-8 | Perfluorooctane sulfonate potassium |
| KS-8C | Perfluor cyclohexyl ethyl sulfonic acid potassium |
| NaS-1 | Trifluoromethanesulfonic acid sodium |
| KS-1 | Trifluoromethanesulfonic acid potassium |
| KS-1(H) | Methylsulfonic acid potassium |
| BaS-3(H) | Propanesulfonic acid barium |
| NaTCA | Sodium trichloroacetate |
| BTBP | F(CF 2) nCH 2CH 2PO 3The barium salt of H, wherein n is 6,8,10 and possible 12 mixing, is mainly 8 |
| NTBP | F(CF 2) nCH 2CH 2PO 3The sodium salt of H, wherein n is 6,8,10 and possible 12 mixing, is mainly 8 |
| LL1121B | Perfluor (2, the 5-dimethyl)-3,6-two oxa-tridecanoic acid barium |
| BC14(06) | Perfluor-3,5,7,9,11,13-six oxa-tetradecanoic acid barium |
| BS-12(H) | Lauryl sulfate barium |
| NS-12(H) | Sodium Lauryl Sulphate BP/USP |
| CC-18(H) | Calcium stearate |
| BaC-8 | Perfluorocaprylic Acid barium |
| BaC-9 | Perfluoro-pelargonic acid barium |
| AWG-26 | The solid copper wire that diameter is 404 microns |
| AWG-24 | The solid copper wire that diameter is 510 microns |
| AWG-22 | The solid copper wire that diameter is 635 microns |
Foam article of the present invention has the tensile strength and at least 200% of 2000psi (13.8MPa) at least, and more preferably 250% elongation.
The invention has the advantages that electric property, specifically, the specific inductivity of foam wire rod isolator reduces.Transmission speed and the insulative dielectric constant of signal in insulated conductor is inversely proportional to.(per) fluoropolymer has the specific inductivity for about 2.Air (specific inductivity=1) is incorporated into the foaming effect in the isolator, can reduces the insulative dielectric constant pro rata with pore volume.Therefore, the cellular insulation body except its other advantage, transmission signal quickly.
The goods of the present invention of wire insulation bodily form formula have and are not more than 1% the electric capacity variation coefficient (COV).For embodiment of the present invention, table 2 shows the COV data from embodiment 1.
Embodiment 1
Sample preparation and method are described
Use is by boron nitride (91.1 ± 0.5 weight %), calcium tetraborate (2.5 ± 0.2 weight %) and Zonyl
The ternary foam nucleation combination of the present invention that BAS (6.4 ± 0.2 weight %) constitutes.The combination of this nucleation can be mixed into melt flow rate (MFR) for the TFE/HFP/PEVE (per) fluoropolymer of about 30g/10min-FEP TE9494 fluoropolymer (by E.I.DuPont de Nemours ﹠amp; Co. in (Wilmington, DE) preparation), be the masterbatch of about 4 weight % to form boron nitride content in resulting composition.Form pellet via the married operation on the Kombi-plast forcing machine, described Kombi-plast forcing machine is made up of 28mm twin screw extruder and 38mm single screw extrusion machine.Do mixed masterbatch pellet and fluoropolymer substrate (FEP TE9494) pellet with 1: 9 ratio, to form the thermoplastic foam composition, subsequently described composition is given and expected that Nokia-Maillefer 45mm extrudes on the wire rod production line, isolator is expressed into AWG 23 solid copper conductors (on 22.6 mils=0.57mm).Described forcing machine has 30: 1 length/diameter ratio, and is equipped with mixing screw, so that uniform temperature to be provided, and nitrogen is distributed in the described melts.
Speed with about 1000ft/min is expressed into the thermoplastic foam composition material on the wire rod, and to prepare the isolator of thick about 7.9 mils (about 0.20mm), described isolator has the pore volume in 15 to 35 weight % scopes.Use the combination of punch die and core rod guider, described combination can obtain 30 to 40 ratio of drawing (cross-sectional area of the cross-sectional area in punch die zone/final extrudate) usually.
Table 2
| The space % that estimates | Capacitor C OV | Diameter COV | The spark counting (kV, #) |
| ～14 | 0.30％ | 0.34 | 1.5，2 |
| ～14 | 0.33％ | 0.34 | 2.5，0 |
| ～24 | 0.29％ | 0.29％ | 2.5，7 |
| ～24 | 0.32％ | 0.29％ | 2.5，2 |
| ～27 | 0.48％ | 0.36％ | 2.5，7 |
| ～27 | 0.45％ | 0.36％ | 2.5，8 |
| ～35 | 0.48％ | 0.52％ | 1.0，4 |
| ～35 | 0.43％ | 0.47％ | 1.5，7 |
| ～35 | 0.44％ | 0.34 | 1.5，2 |
By the capacity standard deviation is come the electric capacity variation coefficient in the reckoner 2 divided by the condenser paper average.Foam article of the present invention has 10% to 50%, and the more preferably pore volume in 15% to 35% scope.
The pore volume of cellular insulation body can be calculated by following formula:
Pore volume (%)=100 * (1-d (foamy)/d (not foaming))
By cutting one section insulated conductor, remove isolator, be the volume that unit measures isolator with the cubic centimetre, and be worth to determine the density of cellular insulation body for the isolator weight of unit divided by this in order to gram.Described density is the mean value that at least 5 samples are measured, and each sample is about 30cm.The density of foamed insulation body is not 2.15.
Table 2 shows for 20, the spark number of 000ft (6100m) spool.By determining the spark number with described spark number (being shown in last hurdle of table 2) divided by 20, this has produced the spark number less than a spark of per 1000 feet (300m) cables.
Referring now to accompanying drawing.Fig. 1 (a) and 1 (b) show the cross section of the insulating tape sample that removes conductor (being wire rod).Fig. 1 (a) shows the thermoplastic foam sample of about 15% pore volume of having of commercially available acquisition.Described isolator has the external diameter of about 0.045 inch (1.14mm) and the internal diameter of 0.022 inch (0.56mm).As shown in Fig. 1 (a), under 75 times enlargement ratio, in this foam sample form a plurality of air pockets are arranged, 10 are high-visible.These air pockets that show inhomogeneous foam structure are more high-visible under 295 times the enlargement ratio of Fig. 1 (c).The foam structure of Fig. 1 (a) lacks uniform foam structure.Fig. 1 (b) shows the foam article of the present invention that uses 0.4% nucleator to make.This sample has about 22% pore volume.Described isolator sample has the external diameter of 0.0427 inch (1.085mm) and the internal diameter of about 0.0226 inch (0.574mm).Opposite with Fig. 1 (a), under 75 times enlargement ratio, Fig. 1 (b) does not appear and has air pocket in the foam sample, but has uniform foam structure 20.Even (Fig. 1 (d)) do not have the visible air pocket yet in the foam sample under 295 times enlargement ratio.The homogeneity of foam structure of the present invention can keep and improve electrical specification of the present invention and anti-collapse performance, makes it be better than the insulated conductor of other commercially available acquisition.
Foam article of the present invention also can be from skinning, such as in the wire rod isolator.By being provided, successive fluoropolymer layer or coating improved the internal surface of insulator surface from skinning on metallic conductor.By preventing by the abscess aperture to provide this successive fluoropolymer layer or coating directly towards the discontinuity of the fluoropolymer that contacts with conductor that metallic conductor caused.For example, extend to conductive surface, can reduce the variation of specific inductivity, thereby better insulated conductor electric property is provided by preventing foam.The pore volume influence is from skinning.
Goods such as " crust " in the cellular insulation body is meant (the tight amount relatively) zone of more not foaming that extends inward from isolator internal surface or outside surface, and wherein said inside is the shortest part of distance between internal surface and the outside surface.Specifically, the crust in the goods of the present invention has by described isolator integral body less than about 50%, preferably less than about 25%, and be more preferably less than about 20%, and most preferably less than 10% pore volume.Described crust from insulate the surface to isolator inner extend shortest distance between isolator internal surface and outside surface at least about 5%, preferably at least about 7%, more preferably at least about 10%, and more preferably at least about 15%.Crust on the insulator outside surface does not need to have and identical pore volume or the thickness of crust on the isolator internal surface.
By cross section, or analyze the photo of using microscope photographing, determine the pore volume in crust zone at the test under microscope isolator.Cross section should thick about 0.1mm.Space in the cross section is rounded, measures the space of representative number, and is positioned at wherein the total area with their area divided by the survey space.
A wonderful aspect of foam article of the present invention is that it can be extruded with the speed of 1000ft/min (300m/min).Shown in commercially available foamy structure such as Fig. 1 (a) those are extruded with the speed of maximum 500ft/min (150m/min) to multipotency.Attempt to increase rate of extrusion, but can cause isolator to have coarse and be rendered as the surface of pitted skin sometimes, this is unacceptable situation for salable product.On the contrary, commercially available solid promptly not foamed fluoropolymer wire insulation body can 1000ft/min (300m/min) or faster speed extrude, prepare insulation wire rod with good quality.Abscess is too near the surface of extruding isolator due to for the problem that presents when the extruded velocity of commercially available foam article surpasses 500ft/min (150m/min), and the polymer foil that the abscess that these are too approaching is kept apart is not enough to be fastened to can resist tearing or destruction that extruded velocity produces when excessive.Cellular insulation body formed according to the present invention can be extruded quickly, and this is because abscess is concentrated to the isolator center, more away from the surface, causes to form aforesaid crust.The similar not foamed insulation of crust body with extremely low pore volume.It is believed that this is that cellular insulation body of the present invention is opposite with the low speed of commercially available isolator, the reason that can extrude with the speed roughly close with possible those speed of foamed insulation body not.
Referring again to Fig. 1 (c) and 1 (d).Fig. 1 (d) shows the centralization in space, and this can go up the more uniform surface of formation in insulator outside surface and internal surface (near surface of conductors).This provides greatly from encrustation.Prior art shown in this and Fig. 1 (c) forms contrast, and prior art presents uneven abscess, and lacks even abscess centralization effect.This form has stoped formation successive structure (crust) on the isolator internal surface of proximity conductor and insulator outside surface.These two has all influenced the mutability of insulated conductor electric property.Promptly with in the interface of conductor lack continuous structure in inside, conductor is exposed under the variation of specific inductivity, this causes the variation of electric property then.As described below, the homogeneity of insulator outside surface is useful.
In the present invention, provide foam article.When described composition was squeezed in the insulating material, when for example making conductor form insulated conductor, described goods had uniform small cells size.This insulated conductor can be used as and one or more pairs ofly comprises the twisted-pair feeder of unshielded twisted pair and/or Shielded Twisted Pair and be used in the cable.Foam article of the present invention can be extruded with higher speed, and can not reduce the performance of insulated conductor, thereby makes cables manufacturing merchant cost saving.Abscess-size also provides the anti-collapse performance to insulated conductor uniformly, promptly uniform compressibility.
Stranded process provides the power of the abscess that is tending towards crushing on isolator.Thoroughly do away with the edge conductors by stranded or be intertwined when forming twisted-pair feeder when two, stranded process applies force of compression on isolator.The insulated conductor that is used for high performance cable has more tight stranded usually, thereby stands higher force of compression.The cellular insulation body is more compressible than the not foamed insulation body that is manufactured from the same material usually, therefore can stand high slightly force of compression when stranded.Can be by changing stranded condition, for example by the tension force that reduces twisting speed, applied etc., alleviate force of compression.Also can when the design cable, offset force of compression by for example increasing insulation diameter, thereby alleviate described force of compression.Yet, if intensity of compression changes along the conductor length direction, will influence the electric property of cable unfriendly, if similarly the compressibility of isolator changes along the conductor length direction, also will influence the electric property of cable unfriendly.The homogeneity of even cell size distribution of the present invention and insulator outside surface makes this minimize variations of electric property by compressibility is consistent along the conductor direction.By making isolator have little and highly uniform abscess, can realize this purpose best.
The uniform abscess-size of foam article makes needs less polymkeric substance to form the insulating material that for example is used for conductor.Homogeneity provides consistent specific inductivity with the small cells size to isolator.The additional beneficial effect of insulated conductor of the present invention comprises: 1) have when being the identical thickness of solid insulator with foamed insulation conductor not when the cellular insulation conductor, because the specific inductivity of cellular insulation body is lower, therefore improved electric property.Because the specific inductivity of cellular insulation body is lower, therefore improved electric property.2) with can provide the composition of big abscess-size and/or broad cell size distribution to compare to isolator, can provide the foamable composite of small cells size and narrow cell size distribution can be squeezed into littler diameter and wall thickness, keep the electric property of cellular insulation body simultaneously.For the insulated conductor that uses foam article of the present invention, the thickness of isolator is preferably in 6 to 12 mils (150 to 300 μ m) scope.The variation of abscess-size (distribution of sizes) should be narrow, and abscess too much is seldom occurred, and can not cause the problem of isolator anti-collapse performance, and make the insulator dielectric constant unanimity.3), make the littler cellular insulation conductor of preparation diameter become possibility by the reduction of insulation thickness provided by the invention.Because size is littler and replace a part of polymkeric substance with the air in the abscess, therefore the material that uses still less.In addition, the cable by the littler cellular insulation conductor preparation of diameter is also thinner.
Foam article of the present invention is commercial favourable, because it provides the fluoropolymer of the insulating material that can be used as insulated conductor, keeps or improved the electric property of insulated conductor simultaneously.When foam article of the present invention is that the electric property in the insulated conductor improves when having with conductor insulation body that can more solid composition insulated conductor same diameter.When foam article of the present invention for when can more solid composition insulated conductor comparing the littler insulated conductor of diameter dimension, insulated conductor keeps the electric property of larger-diameter more solid composition insulated conductor usually.When foam article of the present invention is that this advantage also can come across in the whole cable when being used for the wire insulation body of the alternative solid fluoro-containing copolymer composition of cable.
Referring now to Fig. 2 (a), Fig. 2 (a) shows the sectional view of four pairs of unshielded twisted pairs.Show typical cable, described cable comprises four pairs of twisted pairs of insulated conductors 60, wherein via dividing plate (spacer) or keyway (spline) 40 twisted-pair feeder is isolated to 60.Keyway is an Any shape, comprises central shaft and optional a series of radiation projections or sawtooth.Keyway 40 is made by solid polymer composition.With many twisted-pair feeder 60 is placed in external jacket, shell or the involucrum of being made by polymkeric substance 90.Every strip conductor 70 is all centered on by isolator 80.Every pair of twisted-pair feeder 60 is entwined each other by two bar insulation conductors 70, its objective is in order to offset to cause the electromagnetic interference of crosstalking.Stranded wire rod can reduce interference, and reason is: the anchor ring between the wire rod amasss and reduces (described area is determining the magnetic coupling in the entering signal); And evenly the sense of current that produced of coupled magnetic field is stranded for each is opposite, thereby cancels each other out.Every meter stranded number of times is many more, and crosstalking of reduction is just many more.Solid polymkeric substance is used as the polymkeric substance in the cable shown in Fig. 2 (a).
If in cable, use the thin insulated conductor of strand, all cable assembly all thin (for example having less diameter) then.By adopting the present invention to prepare one or more polymer assemblies in the cable, can make thinner insulated conductor.For example, Fig. 2 (b) shows the sectional view of four pairs of unshielded twisted pairs shown in Fig. 2 (a), yet keyway 50 is foam articles of the present invention.By changing keyway into foam article of the present invention by solid polymer composition, can reduce the diameter of described cable.This is shown among Fig. 2 (a) and 2 (b), and the typical cable (Fig. 2 (a)) that wherein has solid polymkeric substance keyway shows relatively that with the cable (Fig. 2 (b)) with the keyway that makes according to the present invention cable size reduces, and electric property keeps identical simultaneously.Similarly, foamable composite can be used to cable other use in the assembly of polymkeric substance, such as the isolator 60 and the chuck 90 of conductor,, keep the electric property of cable simultaneously to reduce the size of whole cable.By making the insulating material foaming, can increase snappiness, thus the control electric property.
Foam composition of the present invention is except being used as the wire insulation body, it also can be used for preparing other foam article, such as pipeline, be used for isolating keyway (dividing plate), foam sheet, bedding and padding (gasketing) and the isolator of cable twisted-pair feeder, especially can be used for the high-temperature behavior of fluoropolymer wherein and thermotolerance and chemical-resistant and be under the useful situation.
Therefore, obviously satisfy target proposed above and advantage fully according to the goods that make by the expandable thermoplastic polymer composition provided by the invention.Though be to describe of the present inventionly in conjunction with specific embodiments in this article, obviously many selective replacement schemes, modification and modification will be conspicuous to those skilled in the art.Therefore, the present invention is intended to be encompassed in the essence of claims and all these type of selective replacement schemes, modification and the modification in the broad range.
Claims (25)
1. foamed polymer Tetramune, described goods comprise foamable composite, and described composition comprises:
A) (per) fluoropolymer of the melt-processable of partial crystallization provides foam composition, wherein 90% described cell diameter be 50 microns or littler and
B) foam nucleator, described foam nucleator by the combined wt of described (per) fluoropolymer and described foam nucleator in 0.1-10 weight % scope.
2. according to the goods of claim 1, wherein said foam nucleator has at least a heat-staple compound of nucleation significant quantity, and described compound is selected from sulfonic acid and phosphonic acids and their salt.
3. according to the goods of claim 1, wherein said (per) fluoropolymer has about melt flow rate of 25 to 35g/10min.
4. according to the goods of claim 1, wherein at least 90% described cell diameter is less than 25 microns.
5. according to the goods of claim 1, wherein said (per) fluoropolymer prepares by monomer polymerization, and described monomer is selected from: tetrafluoroethylene, R 1216 and perfluor (alkyl vinyl ether).
6. according to the goods of claim 5, wherein said (per) fluoropolymer is by fluorizated in molten state.
7. according to the goods of claim 1, wherein said (per) fluoropolymer is substantially free of metal ion.
8. according to the goods of claim 1, wherein under the situation of not using the reagent that comprises metal ion polymerization with separate described (per) fluoropolymer.
9. according to the goods of claim 1, wherein said cellular insulation body has the tensile strength of 2000psi (13.8MPa) and at least 200% elongation at least.
10. according to the goods of claim 1, wherein said (per) fluoropolymer comprises at least a perfluor (alkyl vinyl ether) of about 0.5 to 10 weight %.
11. according to the goods of claim 1, wherein said foamable composite has the pore volume of about 10-50%.
12. according to the goods of claim 1, wherein when testing under 1.5kV, described foamable composite has the spark resistance less than per 1000 feet (300m) sparks.
13. according to the goods of claim 1, described goods also comprise pipe or the thin plate that is made by described foamable composite.
14. according to the goods of claim 1, described goods also comprise the cellular insulation body that is made by described foamable composite.
15. according to the goods of claim 14, wherein said cellular insulation body is from skinning.
16. according to the goods of claim 14, wherein said cellular insulation body has and is less than or equal to 1% the electric capacity variation coefficient.
17. according to the goods of claim 14, wherein said cellular insulation body is positioned on the conductor.
18. according to the goods of claim 17, wherein said conductor is a wire rod.
19. according to the goods of claim 17, described goods comprise cable.
20. the foamed polymer Tetramune, described goods comprise foamable composite, and described composition comprises:
A) (per) fluoropolymer of the melt-processable of partial crystallization, wherein said (per) fluoropolymer be molten state by fluorizated and
B) foam nucleation combination, described combination comprises
I) boron nitride,
Ii) synergy amount at least a heat-staple inorganic salt under the fluoropolymer extrusion temperature, and described salt is made of metallic cation and polyatom negatively charged ion, and satisfy following relation:
0.36×[14-pKa]-0.52≥[r-0.2q]2≥0.11×[14-pKa]-0.28
Wherein
The described cationic crystal ionic radius of R=is a unit with the dust
The described cationic valency of Q=
The Ka of the following reaction of pKa=-the log value
HA
-(n-1)<＝>H
++A
-n
Wherein A is the negatively charged ion of described salt, and H is a hydrogen, and the absolute value of the described negatively charged ion chemical combination of n=valency; And
Iii) has formula [Z (CF
2)
x(CF
2CFX)
p(R ')
y(CH
2)
zRO
3]
nThe foam nucleator of M structure
Wherein:
Z is CCl
3, CCl
2H, H, F, Cl or Br;
Each X is independently selected from H, F or Cl;
R is selected from sulphur or phosphorus; M is selected from the ammonium cation or the quaternary ammonium cation of H or metallic cation, ammonium cation, replacement;
X is integer and is 0 to 10;
P is integer and is 0 to 6;
Y is 0 or 1;
Z is integer and is 0 to 10;
X+y+z+p is a positive integer, if perhaps x+y+z+p is 0, then Z is CCl
3Or CCl
2H;
N is the valency of M; And
R ' is selected from
C
5-6Perfluorination alicyclic ring diradical;
C
1-16Perfluorination aliphatic polyether diradical, described diradical have and are selected from [CF
2O], [CF
2CF
2O] and [CF
2CF (CF
3) O] and repeating unit; With replacement or unsubstituted aromatics diradical, wherein Z is H;
And the combination of described foam nucleation by the combined wt of described (per) fluoropolymer and the combination of described foam nucleation in 0.1-5 weight % scope.
21. according to the goods of claim 20, wherein said (per) fluoropolymer prepares by monomer polymerization, described monomer is selected from: tetrafluoroethylene, R 1216 and perfluor (alkyl vinyl ether).
22. according to the goods of claim 1, described goods comprise keyway or dividing plate, cable jacket, cable shoe (cable shield), crust, thin plate, bedding and padding, pipe or conductor insulation body.
23. according to the goods of claim 20, the described at least a inorganic salt in the wherein said foam nucleation combination comprise calcium tetraborate.
24. according to the goods of claim 20, the described foam nucleator in the wherein said foam nucleation combination comprises
BAS.
25. according to the goods of claim 20, wherein said foam nucleation combination comprises the boron nitride by described foam nucleation combination general weight per-cent 91.1 ± 0.5 weight %, the calcium tetraborate of 2.5 ± 0.2 weight % and 6.4 ± 0.2 weight %'s
BAS.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US87630506P | 2006-12-21 | 2006-12-21 | |
| US60/876,305 | 2006-12-21 | ||
| US60/881,046 | 2007-01-18 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN101563407A true CN101563407A (en) | 2009-10-21 |
Family
ID=41221558
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNA2007800471101A Pending CN101563407A (en) | 2006-12-21 | 2007-12-20 | Foamed fluoropolymer article |
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| Country | Link |
|---|---|
| CN (1) | CN101563407A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104867628A (en) * | 2015-05-14 | 2015-08-26 | 湖州讯腾电缆材料科技有限公司 | Preparation method for PEP foaming cable |
| CN105829441A (en) * | 2013-05-13 | 2016-08-03 | 着色剂色彩公司 | Thermoplastic polymers |
-
2007
- 2007-12-20 CN CNA2007800471101A patent/CN101563407A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105829441A (en) * | 2013-05-13 | 2016-08-03 | 着色剂色彩公司 | Thermoplastic polymers |
| CN104867628A (en) * | 2015-05-14 | 2015-08-26 | 湖州讯腾电缆材料科技有限公司 | Preparation method for PEP foaming cable |
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Application publication date: 20091021 |