Flexible strength members for wire cables.

(54) Title: ELEMENTS OF FLEXIBLE STRENGTH FOR CABLES. (54) Title: FLEXIBLE STRENGTH MEMBERS FOR WIRE CABLES.

(57) Summary

The present invention relates to a fiber reinforced plastic material with improved flexibility and high elastic force for use in optical cables. The composition of the force element comprises a thermoplastic ream based on polypropylene, a continuous fiber that has a modulus greater than 80 PGa, and talc.

(57) Abstract

This invention relates to a fiber reinforced plastic material with improved flexibility and high tensile strength for use in optic cables. The strength member composition comprises a polypropylene based thermoplastic resin, a continuous fiber having a modulus greater than 80 PGa, and tale.

<img file="MX337207B_D0001.tif" />

Institute

Mexican Property

Industrial

<img file="MX337207B_D0002.tif" />

PATENT TITLE NO. 3372Q7

Owner (s): DOW GLOBAL TECHNOLOGIES LLC.

Address: 2040 Dow Center, Midland, Michigan, 48674, USA

Denomination: ELEMENTS OF FLEXIBLE STRENGTH FOR CABLES. Classification: lnt.CI.8: C08J5 / 04; C08L23 / 10

To go

<img file="MX337207B_D0003.tif" />

action V mado the

07/01/2002, 07/15/2004, 07/28/2004 and 09/07/2007); Articles 1, 3, 4, 5, section V, subsection a), 16 sections I and III and 30 of the Organic Statute of the Mexican Institute of Industrial Property (DOF) 12/27/1999, amended on 10/10/2002, 07/29/2004, 08/04/2004 and 09/13/2007); 1, 3 and 5, subsection a) of the Agreement that delegates powers to the Deputy Directors General, Coordinator, Divisional Directors, Heads of Regional Offices, Divisional Deputy Directors, Departmental Coordinators and other subordinates of the Mexican Institute of Industrial Property. (DOF 12/15/1999, amended on 02/04/2000, 07/29/2004, 08/04/2004 and 09/13/2007).

<img file="MX337207B_D0004.tif" />

Issue Date: February 17, 2016

THE DIVISIONAL DIRECTOR OF PATENTS

NAHANNY CANAL REYES

Arenal No. 550. Floor 1. ol. Pueblo Santa María Tepepan, Xochimílco, CP 16020,

Mexico City

Tei. (55) 53 34 07 00 www.impieob.mx

<img file="MX337207B_D0005.tif" />

MXZ2016 / 13957

331 ί — r

IMPI

MEXICAN INSTITUTE

ELEMENTS OF FLEXIBLE FORCE FOR ΟΑ-ΒβΕΒ?

<img file="MX337207B_D0006.tif" />

Cross Reference for Related Applications

This application claims priority for Provisional North American Patent Application Serial No.

61 / 387,581, filed on September 29, 2010, I content of which is incorporated by reference herein.

Field of the Invention

The present invention relates to a fiber reinforced plastic material with improved flexibility and high elastic strength for use as a force element in optical cables.

Background of the Invention

The present invention relates to the construction of a force element used in a fiber optic cable (FOC). In the absence of metallic conductors, fiber optic cables reside in a design that comprises a force element to provide sufficient protection for the fibers from longitudinal and transverse stresses either during installation or last during service. Force elements are typically made of fiber-reinforced plastic (FRP), also called glass-reinforced plastic (GRP).

Forced r fiber plastics are ___- i materials

IHSTJTOTOmfcXWO

BíUrecwEDA »

INDUSTIUAL Sh5¿V computes made from a pollméikLa matrix reinforced with fibers. The fibers, usually glass (most popular), carbon or aramid, while conventionally the polymer is usually an epoxy or vinyl ester.

Using the conventional resin system, the FRP is very rigid. Typically, it has a bending stiffness greater than 6 x 10-³ Pa m⁴ for a rod diameter of 2 millimeters (mm), resulting in a fiber optic cable that is very hard to bend. While bending stiffness is preferred in some exterior applications (i.e., sometimes, cables need to be pushed through small diameter conduit during installation), this is highly undesirable for other applications (exterior / interior), where a cable needs to go inside a building and make several turns before it reaches its destination. To increase cable flexibility, you have to either reduce the size of the FRP (which will reduce the total elastic force of the cable) or change the design of the cable. For example, some cable manufacturers have modified traditional round FOC cable with a flat in-center force element, ribbon-like cable, which uses a flat geometry (rather than a circular shape) with multiple FRPs in parallel along of its width. The FRPs used in flat cable design have a relatively small diameter, although their total elastic force is equivalent to traditional round cable. In comparison ♦

MEXICAN INSTITUTE OF PROPERTY

INDUSTRIAL

<img file="MX337207B_D0007.tif" />

With traditional round cable with a central strength element, the flat cable design offers greater flexibility on one axis (along the direction of its width) while maintaining the total elastic force of the cable unchanged. However, changing the cable design does not cause further complexity during manufacturing.

Brief Description of the Invention

In one embodiment, the present invention is a force element comprising: (a) a polypropylene-based thermoplastic resin composition and (b) a continuous fiber having a modulus greater than 80 gigapascals (GPa). The polypropylene-based thermoplastic resin may additionally comprise a reinforcing filler material, such as talc. The composition is useful in the manufacture of reinforcing elements for cable and wire, particularly fiber optic cable.

In one embodiment, the present invention is a process for manufacturing a reinforcing element comprising the steps of: (a) heating a polypropylene based resin composition, optionally including a filler material, in an extruder, preferably a twin screw, to form a molten filled compound; (b) feeding continuous fibers through an extruder to combine with the molten filled compound to form a bundle of wet fiber filled composites; and (c) passing the beam of the filled compound ^ TrcyTOMKICANO DS THE INDUSTRIAL PROPERTY

<img file="MX337207B_D0008.tif" />

of fiber wet through a pari punch of force.

Brief Description of Drawings

Figure 1 is a graph of the elastic modulus FRP against bending stiffness.

Detailed description of the invention

Definitions

Unless otherwise stated, implicit in the context, or customary in the matter, all parts and percentages are based on weight and all test methods are those existing as of the date of presentation of this description. For the purposes of United States patent practice, the contents of any patent, Referenced patent application or publication is incorporated by reference in its entirety (or its equivalent North American version is incorporated by reference) especially with respect to the description of the definitions (to the extent of not being inconsistent with any of the definitions specifically provided in this description) and general knowledge in the matter.

The numerical ranges in the present description are approximate, and therefore may include values ​​outside the range unless otherwise indicated. Numerical ranges include all values ​​and include values

IMPI r: xa

MEXICAN INSTITUTE OF INDUSTRIAL PROPERTY, provided that two units are higher. As a lower and upper, in increments of one there is a separation of at least any lower value and any example value, whether a compositional, physical, or other property, such as, for example, molecular weight, etc., s from 100 to 1,000, then all individual values ​​s, such as 100, 101, 102, etc., and sub-ranges, such as from 100 to 144, from 155 to 170, from 197 to 200, etc., are expressly listed. For ranges that contain values, which are less than one or contain numbers in fractions greater than one (for example,

1.1, 1.5, etc.,), a unit is considered 0.0001, 0.001, 0.01 or 0.1, as the case may be. For ranges containing one-digit numbers less than ten (for example, from 1 to 5), a unit is normally considered to be 0.1. These are examples only of what is specifically intended, and all possible combinations of numerical values ​​between the lowest value and the highest value listed will be considered to be expressly stated in the present description. Numerical ranges are provided within the present description for, among other things, the amount of the various components of the composition, the process parameters, and the like.

A thermoplastic material is a linear or branched polymer, which can be repeatedly softened and py &lt;, _s

MEXICAN INSTITUTE ¹ - J

OF PROPERTY O '.9 industrial «VI i í XV Ja. J ± Jl,

1TUT0 MEXICAN D £ INDUSTRIAL PROPERTY makes it suitable to flow when heated and returns to a hard state when cooled to room temperature. In the context of the present invention, the thermoplastic material generally has an elastic modulus greater than 10,000 psi (68.95 MPa) using the method of ASTM D638-72. Furthermore, thermoplastics can be molded or extruded into articles of any predetermined shape when heated to the softened state.

Propylene-based polymer means a polymer that comprises a majority of the weight percentage of the polymerized propylene monomer (based on the total amount of monomers that can be polymerized), and optionally may comprise at least one polymerized comonomer.

The elastic force at break is measured in accordance with ASTM D628.

Continuous fiber, as used herein, is a continuous fiber in its length through the entire fiber. Depending on the size of the fiber, the length of the continuous fiber can vary over a large range such as 5 to 30 km.

Force element

The force element of the present invention comprises a continuous fiber and thermoplastic resin composition as a reinforcement in the manufacture of the force element. Possible fibers include, without limitation, glass,

Ι »1 · ι · ΜΠ | · Ι Mmm lh MUI

<img file="MX337207B_D0009.tif" />

aramid, polyester, high molecular weight polytethylene and carbon fibers. The fibers of the present invention typically have a modulus above 80 CPa, preferably between 80 and 90 GPa. The force element has greater flexibility while maintaining high elastic force compared to conventional FRP used in fiber optic cable. The flexibility of the force element, as characterized by the bending stiffness, can be tailored within a wide range through the effective resin formulation, for example, about 0.1 x 10-³ up to approximately 2.5 x 10-³ Pa m⁴, from 0.1 x 10-³ up to approximately 6.0 x 10-³ Pa m⁴, 3.0 x 10-³ up to 6.5 X 10-³ Pa m⁴ , and preferably 3.26 x 10-³ up to approximately 6.08 x 10-³ Pa m⁴ . The elastic modulus FRP of the force element is normally between 49 GPa and 59

GPa.

Resin composition

The present invention uses a composition comprising polypropylene-based thermoplastic material as its resin system. Table 1 shows the possible formulations for the resin system. The various levels of talc can optionally be used as a filler in the formulation to tailor the elastic modulus of the resin and consequently the bending stiffness of the force element. The filling material includes, without

MEXtCZuNO INSTITUTE OF PROPERTY

INDUSTRIAL

<img file="MX337207B_D0010.tif" />

reinforcing filler. The 30 Dor hundredth limitation, to talc, or other talc materials, is normally present at 0, weight relative to the weight of the resin composition.

Table 1

Resin composition formulation

<td>Component</td><td>Wide (wt%)</td><td>Preferred (wt%)</td><td>Most preferred (wt%)</td>

<td>Polypropylene</td><td> 40-99</td><td> 50-93</td><td> 70-85</td>

<td>Filling material</td><td> 0.0-45.0</td><td> 0.0-40.0</td><td> 0.0-30.0</td>

<td>Packaging additive</td><td> 0.12-35.0</td><td> 0.36-28.0</td><td> 0.7-22.0</td>

<td>Antioxidant</td><td> 0.01-100</td><td> 0.05-80</td><td> 0.1-60</td>

<td>Processing stabilizer</td><td> 0.01-10.0</td><td> 0.01-8.0</td><td> 0.1-6.0</td>

<td>Adhesion promoter</td><td> 0.1-15.0</td><td> 0.3-12.0</td><td> 0.5-10.0</td>

By using a thermoplastic system, the force element can be easily recycled, in contrast to conventional FRP that uses thermo-adjustable materials, which cannot be easily recycled. Additionally, the polypropylene-based resin system of the present invention has a relatively low viscosity and the force element can be reverse extruded through an extruder with a reverse fiber extrusion boss. This is in contrast to the conventional FRP manufacturing process, which is essentially the traditional resin bath and in-line curing type of the reverse extrusion process. With the low viscosity of the resin under the temperature of the reverse extrusion crosshead, the fibers can be wetted much more efficiently. In addition, the low viscosity will also help remove excess resin (in the flow form

<img file="MX337207B_D0011.tif" />

11'lSTiTüTO MEZ'CzANO OF INDUSTRIAL PROPERTY (later) adhered to the fibers as the beam passes through the die. Under conventional manufacturing processes it is difficult and expensive to make common cross-sectional geometries. However, with the present invention, a force element having a common shape cross-section geometry can be made more efficient because the thermoplastic resin has a relatively low viscosity and can be easily formed in any shape. . Also, no cure is required for the thermoplastic resin.

Furthermore, the various optional components are also advantageously employed in the resin composition of the present invention. For example, additives, which can be used include antioxidants, UV stabilizers, thickening agents, bactericides, processing stabilizers, heat stabilizers, adhesive resins, colorants, coupling agents, flame retardants, mold release agents, anti-static agents, nucleating agents, fillers, or any combination thereof. The additives can be dispersed in a polymeric matrix that includes a carrier polymer that is the same or different than the polypropylene resin.

By way of specific example, in one embodiment, it is contemplated that one or more of an anti-oxidant (for example, Ciba's IRGANOX® 1010 antloxldant, IRGANOX® antioxidant

Ρ- * \ £ Ϊ} ·? Χ ·? ΊΓ ··· J'.T'XUrKV 1¾&gt;. '··&gt; \, INSTITUTO MEXICANO F

OF PROPERTY V

INDUSTRIAL Xí¿T-Wj ~

PS 802) and a processing stabilizer (eg an i — iiiiii II. .Mu WII IB _{1 &lt;w} Active phosphate, such as trls- (2,4-dlter-butylphenyl) phosphite (IRGAFOS®168 from Ciba) will be compounded in the resin composition. A coupling agent, or adhesion promoter, such as Arkema's OREVAC ™ CA-I00 resin may be included.

Fabrication process

The polymeric compound to be reverse extruded onto the continuous fiber to make the FRP strength element can be made using conventional compound making processes, such as batch mixers (Banbury, etc.) or continuous mixers (FCM, etc.). In one embodiment, said compound is made and isolated as a granulated intermediate for sr used later in the Reverse extrusion process. In some cases, it may also be desirable to pre-compound some of the ingredients and subsequently add others during the reverse extrusion process. It may additionally be desirable to compound all ingredients during the reverse extrusion process. For example, during reverse extrusion, the polymeric compound is melt extruded at elevated temperatures to ensure that the resins are completely molten and achieve adequately low viscosity. The fibers are then fed through the extruder and wetted with the resin.

MEXICAN INSTITUTE

OF ΙΛ INDUSTRIAL PROPERTY

<img file="MX337207B_D0012.tif" />

melted inside the chamber inside the crosshead, where a high pressure (greater than 2000 psi) is used to ensure good fiber wetting with more than 85% resin coverage on the fibers. The wet fiber / resin bundle is then polished through a continuous die and cooled to maintain its shape.

In one embodiment, the force element is formed by heating a polypropylene resin composition comprising a reinforcing filler material to form a molten filler compound. The continuous fibers are fed through an extruder to combine the continuous fibers with the molten filled compound to form a bundle of molten filled compound. The bundle of the wet fiber filler compound is passed through a die to form the force element.

Specific Modalities

The formulation of Examples 1, 2 and 3 are in Table 2. Owns Corning SE4121 continuous Advantex® E-glass fiber (modulus = 81-83 GPa) was used in the examples.

<img file="MX337207B_D0013.tif" />

MEXICAN INSTITUTE OF PROPERTY

INDUSTRIAL

<img file="MX337207B_D0014.tif" />

Table 2

Composition Percentage of Examples

<td>Material</td><td>Example 1 (wt%)</td><td>Example (wt%)</td><td>Example (wt%)</td>

<td>Polypropylene</td><td> 82.3</td><td> 70.0</td><td> 54.6</td>

<td>ACHIEVE 6936GI (Exxon Mobile)</td><td> 10.0</td><td> 8.5</td><td> 10.0</td>

<td>Linear low density polyethylene</td><td> 3.0</td><td> 2.6</td><td> 2.1</td>

<td>IRGANOX 1010 (Clba)</td><td> 0.2</td><td> 0.2</td><td> 0.1</td>

<td>IRGAFOX 168 (Clba)</td><td> 0.4</td><td> 0.4</td><td> 0.3</td>

<td>IRGANOX PS 802 (Ciba)</td><td> 0.4</td><td> 0</td><td> 0.3</td>

<td>Maleic Anhydride Modified Polypropylene</td><td> 3.8</td><td> 3.2</td><td> 2.6</td>

<td>JetFil 700 Talc</td><td> 0</td><td> 15.0</td><td> 30.0</td>

<td>Material</td><td>Example 2 (wt%)</td><td>Example 2 (wt%)</td><td>Example 3 (wt%)</td>

<td>Fiberglass (Owen Corning SE 4121)</td><td>81.0% wt of final force element</td><td>80.5% wt of final force element</td><td>81.0% wt of final force element</td>

ACHIEVE 6936GI and Linear Low Density Polyethylene and Rheology Resin Modifiers used to optimize the viscosity of the compound. IRGANOX 1010, IRGAFOX 168, and IRGANOX PS 802 are used as antioxidants. Maleic anhydride modified polypropylene is used as an adhesion promoter. The polypropylene used in Examples 1 to 3 is a homopolymer with an MFR of 52 g / 10 min, a density of 0.9 g / cm³, and a flexural modulus of 1.65 GPa. Linear low-density polyethylene has an MFR of 10 g / 10 min, a density of 0.924 g / cm³, and a flexural modulus of 0.38 GPa.

Examples 1 to 3 are made by a reverse extrusion procedure. The individual resin components including talc are first fed into

X JL

MEXICAN INSTITUTE; OF THE PROPERTY ;·' . industrial?! ·· an extruder through a main hopper;¹¹ Cl moaolodo ociu-rse. In-line as the material passes through the extruder to the crosshead, where a high temperature of 300 ° C is used to ensure that the resins melt completely and reach a desirably low viscosity. The glass fibers are then fed through the extruder and wetted with the molten compound within the chamber within the crosshead, where high pressure (greater than 2000 psi) is used to ensure good fiber wetting. The wet fiber / resin bundle is then polished through a continuous die at a rate of 60.96 cm / minute and cooled to maintain its shape.

Table 3 indicates the properties of the examples, compared to the known conventional resins used in FRP.

<img file="MX337207B_D0015.tif" />

MEXICAN INSTITUTE OF PROPERTY

INDUSTRIAL

<img file="MX337207B_D0016.tif" />

Table 3 ...

Modulus, Bending Stiffness, v Elastic Force for

Resins

Examples 1 to 3 and Comparative Examples 1 to 10

<td>Example</td><td>Resin composition</td><td>Resin modulus (GPa)</td><td>Rigidity of bent (10³Pam⁴)</td><td>Force Elastic (GPa)</td>

<td>Example 1</td><td>(see Table 2)</td><td> 1.7</td><td> 3.26</td><td> 49</td>

<td>Example 2</td><td>(see Table 2)</td><td> 2.34</td><td> 4.48</td><td> 49</td>

<td>Example 3</td><td>(see Table 2)</td><td> 3.17</td><td> 6.08</td><td> 49</td>

<td>Comparative Example one</td><td>Derakane 411-350 Epoxy Vinyl Ester Resin</td><td> 3.2</td><td> 6.13</td><td> 49</td>

<td>Comparative Example 2</td><td>Derakane Momentum ™ 640900 Epoxy Vinyl Ester Resin</td><td> 3.4</td><td> 6.52</td><td> 49</td>

<td>Comparative Example 3</td><td>Derakane Momentum ™ 510C350 Epoxy Vinyl Ester Resin</td><td> 3.2</td><td> 6.13</td><td> 49</td>

<td>Comparative Example 4</td><td>Epoxy Vinyl Ester Resin Derakane 470HT-400</td><td> 3.5</td><td> 6.71</td><td> 49</td>

<td>Comparative Example 5</td><td>Epoxy Vinyl Ester Resin Derakane 510-40</td><td> 3.4</td><td> 6.52</td><td> 49</td>

<td>Comparative Example 6</td><td>Epoxy Vinyl Ester Resin Derakane 510C-350</td><td> 3.2</td><td> 6.13</td><td> 49</td>

<td>Comparative Example 7</td><td>Derakane 8084 Epoxy Vinyl Ester Resin</td><td> 2.9</td><td> 5.56</td><td> 49</td>

<td>Comparative Example 8</td><td>Epoxy Ester Resin Derakane 8090</td><td> 32</td><td> 5.75</td><td> 49</td>

<td>Comparative Example 9</td><td>Derakane Momentum ™ 411-350 Epoxy Vinyl Resin</td><td> 3.2</td><td> 6.13</td><td> 49</td>

<td>Comparative Example 10</td><td>Derakane Momentum ™ 470300 Epoxy Vinyl Ester Resin</td><td> 3.6</td><td> 6.90</td><td> 49</td>

<td>Comparative Example 11</td><td>Epoxy Vinyl Ester Resin Derakane 470-300</td><td> 3.6</td><td> 6.90</td><td> 49</td>

module of the components and dimensions of the element of

The resin modulus was measured following the ASTM D790 test standard.

Bending stiffness was measured following test standard ASTM D790 (Examples 1 to 3) or calculated from d I

ΠΚ j |||| X. I:

<img file="MX337207B_D0017.tif" />

VA force (Comparative Examples 1 to 10). _.,

One of the advantages of the force element under the present invention is the improved flexibility while keeping the elastic force high. For a fiber reinforced force element (aligned in the length direction), its bending stiffness is mostly determined by the flexural modulus of the resin. The comparative examples in Table 3 include some of the popular commercially available epoxy vinyl ester resins which are used in current FRP products. Derakane® epoxy vinyl ester resins are manufactured by Ashland. For the purpose of comparison, the FRP under consideration is round and has a diameter of 2 mm.

The force element under the present invention offers a broader bending stiffness range for currently used epoxy vinyl ester resins, while the elastic modulus remains the same. Figure 1 shows the comparison in terms of the elastic modulus and the bending stiffness between the conventional FRPs of the Comparative Examples and the force elements of Examples 1 to 3. The figure demonstrates that using different commercially available epoxy vinyl ester resins, the bending stiffness of FRP can be varied, although limited to being within a relatively tight range of less than 15% of the mean value. On the other hand, through the use of formulations d

<img file="MX337207B_D0018.tif" />

Different, the force element under the _pr.es.fi.nte invention offers a much wider range of bending stiffness. More specifically, the force element made using the formulation of Examples 1 or 2 is very flexible (with a bending stiffness of less than 2.5xl0-³ Pam⁴), while the force element that is made using the formulation of Example 3 has a similar rigidity as the

Current FRPs made using DERAKANE MOMENTUM ™ 640-900 Epoxy Vinyl Ester Resin (with bending stiffness about 6xl0-³ Pa m⁴). Most importantly, the force element of the present invention achieves flexibility without sacrificing the elastic modulus: it essentially offers the same elastic modulus as FRPs on the market today.

Although the present invention has been described in certain details through the foregoing description of preferred embodiments, this detail is for the primary purpose of illustration. Many variations and modifications can be made by one skilled in the art without departing from the spirit and scope of the present invention as described in the following claims.

<img file="MX337207B_D0019.tif" />

MEXICAN INSTITUTE OF PROPERTY

INDUSTRIAL

<img file="MX337207B_D0020.tif" />