CN110819123B

CN110819123B - Filling composition for cable

Info

Publication number: CN110819123B
Application number: CN201810899737.XA
Authority: CN
Inventors: 亨德里克·德·格鲁特; 杨慧娴; 马克·格弗尔特·卡里斯瓦特; 罗伯特·贝宁
Original assignee: Kraton Polymers LLC
Current assignee: Kraton Polymers LLC
Priority date: 2018-08-09
Filing date: 2018-08-09
Publication date: 2022-10-28
Anticipated expiration: 2038-08-09
Also published as: CN110819123A

Abstract

Disclosed is a filled composition comprising (i) 4 to 20 wt% of a selectively hydrogenated isoprene-styrene block copolymer having the structure S-EP, having a polystyrene content (PSC) of at least 40 wt%, an overall diblock apparent molecular weight of at least 160 kg/mol, a polystyrene block S having a true molecular weight of 60 to 110 kg/mol, and a polyisoprene block (EP) having a true molecular weight of 80 to 100 kg/mol; (ii) an oil; and (iii) optionally additives. The filled composition is characterized by having a contact rate of from 2 to 10, a drop point of at least 200 ℃, and a penetration of less than 500dmm at 25 ℃.

Description

Filling composition for cable

Technical Field

The invention relates to a filling composition for a cable and a preparation method thereof.

Background

Telecommunication cables (e.g., fiber optic cables) are subjected to stresses during manufacture, installation, and/or operation that may impair their intended function. Furthermore, to ensure an uninterrupted connection, the cable needs to resist and keep from water ingress which would normally cause signal loss or attenuation. In optical cables, a plurality of electrical cables are enclosed in an extended plastic tube. Reinforcing and/or protective materials may be introduced in the form of a fill composition to mitigate the effects of stress on the intended function of the material. The filling composition also serves to protect the structural and functional integrity of the cable. As another example, post-tensioned cables used for concrete reinforcement typically contain a plurality of wires that can be protected with a filler composition.

Improved filling compositions are needed to protect the structural and functional integrity of fiber optic cables, and may also be used in other applications.

Summary of The Invention

In one aspect, a filling composition for cables is disclosed. The fill composition comprises: a selectively hydrogenated isoprene-styrene block copolymer having the structure S-EP, having a polystyrene content (PSC) of at least 40% by weight, an overall diblock apparent molecular weight of at least 160 kg/mol, a true molecular weight of the polystyrene block S of 60 to 110 kg/mol, and a true molecular weight of the polyisoprene block (EP) of 80 to 100 kg/mol; an oil; optionally an additive. The filled composition is characterized by having a contact rate of from 2 to 10, a drop point of at least 200 ℃, and a penetration of less than 350dmm at 25 ℃.

In a second aspect, the filled composition comprises a selectively hydrogenated isoprene-styrene block copolymer having the structure S-EP, with a polystyrene block S having a true molecular weight Mw of 70 to 75 kg/mol and a polystyrene content of 42 to 45% by weight.

Detailed Description

The following terms are used in the specification and have the following meanings:

"Cable" generally refers to cables used in buildings (e.g., bridges, concrete structures) and electrical and/or optical equipment for cables, connectors, and components thereof.

Oil separation herein refers to the phenomenon of static oil droplets or lumps released from the oil in a thickened matrix associated with the oil, which is referred to herein as an oily material.

The dropping point is the temperature at which the oil-containing substance changes from a semi-solid state to a liquid state under the specific test conditions.

Molecular weight is polystyrene equivalent molecular weight and can be determined by Gel Permeation Chromatography (GPC), which represents the molecular weight at the peak of the distribution.

The present invention relates to a filling composition that combines optimum application and use temperature, consistency of viscosity and excellent oil retention for cables, e.g. as rubber compound for copper cables or shear thinning grease for optical cables, with consistent viscosity at increased shear rates. The fill composition comprises: i) A styrenic block copolymer, ii) an oil and optionally iii) an additive.

Styrene Block Copolymer (SBC) component: an SBC is a selectively hydrogenated isoprene-styrene block copolymer having an S-EP structure with a polystyrene content (PSC) of at least 40 wt%, preferably 40-50 wt%, a true molecular weight of the polystyrene block of at least 60 kg/mole, and an overall diblock apparent molecular weight of at least 160 kg/mole.

In some embodiments, the polystyrene block (S) has a true molecular weight of 60 to 110 kg/mole, 65 to 105 kg/mole, 70 to 100 kg/mole, 85 to 95 kg/mole, or 65 to 75 kg/mole. In some embodiments, the polyisoprene block (EP) has a true molecular weight of 80 to 100 kg/mole, 85 to 95 kg/mole, at least 80 kg/mole or 90 to 110 kg/mole. In some embodiments, the polystyrene content is 42 to 46 weight percent or 44 to 48 weight percent, or at least 45 weight percent. The total diblock apparent molecular weight is 160-360 kg/mol, 160-340 kg/mol or 200-320 kg/mol.

In some embodiments, SBC' S are characterized by having a polystyrene block S with a true molecular weight of 70 to 75 kg/mole and a polystyrene content of 42 to 45 weight percent. In some embodiments, SBC may be dissolved in the oil at temperatures below 185 ℃, or below 150 ℃, or in the range of 125-145 ℃, allowing the use of lower cost oils.

SBCs can be prepared by contacting one or more monomers with an organic alkali metal compound in a suitable solvent at a temperature of-150 ℃ to 300 ℃, preferably at a temperature of 0-100 ℃. The selective hydrogenation is carried out under conditions such that at least 90 mole% or at least 95% or at least 98% of the isoprene double bonds have been reduced and 0-10 mole% of the arene double bonds present in the polymerized styrene units have been reduced. The process is used for hydrogenating polymers containing aromatic or ethylenic unsaturation and is carried out in the presence of suitable catalysts based on nickel, cobalt or titanium.

The SBC is present in the fill composition in an amount of from 4 to 20 wt%, or from 6 to 15 wt%, or from 8 to 12 wt%, based on the total weight of the fill composition.

In some embodiments, the filled composition is formed from additional styrene polymers (i.e., in addition to SBCs of the type disclosed herein), such as styrene-ethylene/propylene block copolymers SEPS, or hydrogenated, controlled distribution S-EB/S or S-EB/S-S or (S-EB/S) nX (where X is the residue of a coupling agent), or SEB block copolymers, wherein the S block comprises any of styrene, alpha-methylstyrene, p-methylstyrene, vinyltoluene, vinylnaphthalene, diphenylethylene, p-butylstyrene, or mixtures thereof; the B block comprises any of conjugated 1, 3-butadiene or conjugated substituted butadienes, such as piperylene, 2, 3-dimethyl-1, 3-butadiene and 1-phenyl-1, 3-butadiene, or mixtures thereof and/or mixtures in combination with isoprene. The ratio of SBC to additional styrene polymer is 50-90.

Oil component: the fill composition further comprises an oil selected from the group consisting of: paraffinic oil, paraffin-rich oil, mineral oil, GTL-based process oil (or fischer-tropsch derived oil), synthetic oil, or mixtures thereof. Examples of suitable oils include paraffinic hydrocarbons having an average number of carbon atoms of from 16 to 30, or chemically inert oils consisting essentially of linear, branched and naphthenic hydrocarbons (paraffins) of various molecular weights. In one embodiment, the oil is a group II mineral oil having a Viscosity Index (VI) of from 80 to 120. Examples of commercially suitable oils include alpha-olefins, such as AlphaPlus, group II oils from Handi sunshinne, group II oils from ExxonMobil, such as PRIMOL352, and Shell's GTL Risella X420.

Oils of the type disclosed herein (e.g., paraffin oils, mineral oils, group II oils, GTL oils, etc.) are present in the fill composition in an amount of from 80 to 96 percent by weight, based on the total weight of the gel composition. In one embodiment, the oil is a group II base oil having greater than 90% saturates, less than 0.03% sulfur, and a viscosity index of 80-120.

In some embodiments, a second (different) oil may be added in an amount of 0 to 30 weight percent, such as a polybutene oil having a molecular weight of at least 900.

Optional additives: the fill composition may include various additives to meet one or more user and/or process objectives. Additives may also be used to modify one or more properties of the filled composition. Examples include colorimetric indicators, corrosion inhibitors, corrosion indicators, antioxidants, metal deactivators, rheology modifiers, fillers such as fumed silica or specialty clays such as attapulgite, castor oil based thixotropic agents, and the like, and hydrocarbon resins. Several types of antioxidants can be used, primary antioxidants such as hindered phenols, or secondary antioxidants such as phosphite derivatives, or blends thereof.

Any hydrocarbon resin compatible with the S block of the polymer may be used, such as Kristalex ^TM 5140 or rosin esters Sylvares ^TM And SA-140. Examples of colorimetric indicators include the types used to detect metal ions, such as rare earth salts, lithium salts, alkali metal salts of dithiozonates or erythrosine chelators. In one embodiment, the indicator is used in conjunction with an absorbent carrier and then incorporated into the fill composition.

Optional additives may be added in amounts of 0.001 to 20 weight percent, based on the total weight of the fill composition. In one embodiment, the amount of optional additives is from 0.5 to 4.0 wt%. For example, the antioxidant may be added in an amount of 0.5 to 1.0% by weight.

Preparation method: the filled composition comprising the block copolymer, oil and optional additives may be prepared using any suitable method. For example, an oil (e.g., mineral oil) is heated to a temperature of at least 120 ℃, and then the block copolymer is dissolved in the preheated oil for a suitable time and at a sufficient temperature to produce a homogeneous mixture under high shear mixing. Alternatively, the components (e.g., block copolymer, oil, optional additives) can be mixed together at room temperature or higher temperature under low shear. The mixture is then heated to 120-180 ℃ depending on the type of oil used and the mixing speed until the block copolymer is completely dissolved in the oil. The fill composition may then be cooled to 25 ℃ under vacuum to remove any entrained bubbles.

Performance of: the use of SBC's, which have excellent compatibility with mineral oils, helps prevent oil exudation at high temperatures. The filling composition also has a sufficiently low viscosity to be easily introduced into the tube (of the cable) during the manufacturing process and to allow substantially free relative movement of the fibres within the tube, but also a sufficiently high viscosity to resist any sufficient physical barrier present.

The composition has a low cut viscosity (e.g. 25 ℃ and 6/s) of 10000-750000cps (centipoise), or 20000-500000cps, or 10000-60000cps, or 100000-300000cps, or 20000-50000 cps.

The composition has a cut-off viscosity (e.g., 25 ℃ and 50/s) of 4000 to 100000cps or 5000 to 80000cps or 8000 to 75000cps or 3000 to 9000cps or 5000 to 4800cps or 4400 to 8000 cps.

The composition has a high shear viscosity (e.g., 25 ℃ and 200/s) of 3000-20000cps, or 3000-10000cps, or 4000-8000 cps.

The composition is characterized by a shear rate (ratio of viscosity at low shear rate to viscosity at high shear rate) of from 2 to 10, alternatively from 2.5 to 8.0, alternatively from 3.0 to 6.0.

The composition is characterized in that the dropping point is more than or equal to 150 ℃, or more than or equal to 200 ℃, or 200-300 ℃, or 210-250 ℃.

The composition is also characterized by a penetration of less than or equal to 500 decimillimeters (dmm), preferably less than or equal to 400dmm, most preferably less than or equal to 350dmm, at 25 ℃.

The filled composition is further characterized by an oil separation at 80 ℃ of 0.001 to 80%, alternatively 0.001% to less than 2%, alternatively less than 0.1%. Oil separation at 100 ℃ is less than 0.5%.

Applications of: the filling composition can be pumped into the cable on a high speed cable production line. The composition may also be used as a component of a flooding gel. Other non-limiting examples of materials that may include this type of fill composition include heat transfer fluids and the like.

Examples: one or more of the following tests were used in the examples:

the viscosity and flow curves were Pascal-second or Pa.s or centipoise (cps) measured according to DIN 53019 at 6/s, 50/s and 200/s.

Molecular weight is polystyrene equivalent molecular weight or apparent molecular weight and is measured by Gel Permeation Chromatography (GPC) using polystyrene calibration standards, such as per ASTM D529 6.

Polystyrene content (PSC) is determined by a suitable method such as proton Nuclear Magnetic Resonance (NMR).

The penetration was determined with a penetrometer according to ASTM 937, GBT 269-91 at a temperature of 25. + -. 2 ℃.

Oil separation was determined according to ASTM 6184, FED 321.3 at 80 ℃ and 100 ℃ for 24 hours.

The drop point can be determined according to ASTM D566.

The polymers used in the examples are shown in table 1.

TABLE 1

Examples 1 to 3: a fill composition was prepared with 8 wt% polymer, 0.1 wt% antioxidant, balance pharmaceutical grade white oil (68/32 paraffinic/naphthenic oil) having a kinematic viscosity of 65mm at 40 ℃ ² (s) a density of 863kg/m at 15 ℃ ³ Pour point-12 ℃, flash point 240 ℃, and viscosity index 100. For the comparative example, the mixture of oil and antioxidant was heated to 110 ℃, polymer a to 180 ℃, polymer B to 140 ℃, then polymer was added and mixed at low speed (500 rpm) until the polymer dissolved. The properties of the compositions are listed in table 2:

TABLE 2

Examples 4 to 6: a filling composition was prepared with 8 wt% polymer, 0.1 wt% antioxidant and balance group II base oil from Handi Sunshine. The viscosity index of the oil is more than or equal to 95, and the kinematic viscosity of the oil at 40 ℃ is 28.0-34.0mm ² (s) a density at 20 ℃ of 843.5kg/m ³ The pour point is less than or equal to-20 ℃, and the flash point is more than or equal to 200 ℃. For the comparative example, the mixture of oil and antioxidant was heated to 120 ℃, polymers a and B were heated to 140 ℃, then the polymers were added and mixed at high speed (4000 rpm) for 1 hour until the polymers dissolved. The properties of the compositions are listed in table 3.

TABLE 3

The examples show that polymers a and B provide excellent retention of properties at high temperatures, increased dropping point temperatures for filled compositions, while exhibiting acceptable viscosities within an acceptable processing temperature range (e.g., 140 ℃ for a group II oil).

Claims

1. A fill composition comprising:

4-20 wt% of a selectively hydrogenated isoprene-styrene block copolymer having the structure S-EP with a polystyrene content of at least 40 wt%, an overall diblock apparent molecular weight of at least 160 kg/mol, a polystyrene block S with a true molecular weight of 60-110 kg/mol, and a polyisoprene block (EP) with a true molecular weight of 80-100 kg/mol;

80-96% by weight of an oil selected from: a paraffinic oil, a paraffin-rich oil, a mineral oil, a fischer-tropsch derived oil, a synthetic oil, or mixtures thereof; based on the total weight of the fill composition;

optionally, an additive; and

wherein the fill composition has a contact variability of from 2 to 10, a drop point of at least 210 ℃, and a penetration of less than 400dmm at 25 ℃.

2. The filled composition of claim 1, wherein the polystyrene block S has a true molecular weight of 70-75 kg/mole and a polystyrene content of 42-45 wt.%.

3. The filled composition of claim 1 or 2, wherein the selectively hydrogenated isoprene-styrene block copolymer is soluble in the oil at a temperature below 185 ℃.

4. The filled composition of claim 3, wherein the selectively hydrogenated isoprene-styrene block copolymer is soluble in the oil at a temperature of 125-145 ℃.

5. The filled composition according to claim 1 or 2, wherein the composition has a drop point of 210-300 ℃.

6. The filled composition of claim 1 or 2, wherein the composition has an oil separation of 0-2% at 100 ℃.

7. The fill composition of claim 1 or 2, wherein the composition has a viscosity of 10,000-60,000cps at 25 ℃ and 50/s.

8. The fill composition of claim 1 or 2, wherein the optional additives comprise at least one of: corrosion inhibitors, colorimetric indicators, antioxidants, metal deactivators, rheology modifiers, hydrocarbon resins, fumed silica, organophilic clays, and combinations thereof.

9. The filling composition according to claim 1 or 2, wherein the oil is a paraffinic oil having a saturation fraction of more than 90%, less than 0.03% of sulphur and a viscosity index of 80-120.

10. A cable comprising the fill composition of any one of claims 1-9, wherein the fill composition protects the cable from water ingress or corrosion.

11. A method of preparing a fill composition comprising dissolving 4 to 20 weight percent of a selectively hydrogenated isoprene-styrene block copolymer in 80 to 96 weight percent of an oil selected from the group consisting of paraffinic oils, paraffin-rich oils, mineral oils, fischer-tropsch derived oils, synthetic oils, or mixtures thereof, based on the total weight of the fill composition;

wherein the selectively hydrogenated isoprene-styrene block copolymer has an S-EP structure, has a polystyrene content of at least 40 wt.%, an overall diblock apparent molecular weight of at least 160 kg/mol, a true molecular weight of the polystyrene block S of from 60 to 110 kg/mol, and a true molecular weight of the polyisoprene block (EP) of from 80 to 100 kg/mol; and

12. The method of claim 11, wherein the oil is a paraffinic oil having greater than 90% saturates, less than 0.03% sulfur, and a viscosity index of 80-120, and wherein the selectively hydrogenated isoprene-styrene block copolymer is dissolved in the oil at a temperature of less than 180 ℃.