Adhesive compositions including partially cross-linked resins and methods for use thereof

THE REPUBLIC OF POLAND (12) TRANSLATION OF THE EUROPEAN PATENT (19) PL (11) PL / EP 3203285

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The Patent Office of the Republic of Poland (96) Date and number of the European patent application: 09.10.2013 17162373.9 (97) The grant of the European patent was announced:

01.08.2018 European Patent Bulletin 2018/31

EP 3203285 B1 (13) T3 (51) Int.CI.

G02B 6/38 (2006.01) (54) Title of the invention:

Adhesive compositions containing partially cross-linked resins and methods of using them (³°) o ·,.

Priority:

2012-10-15 US 201261713788 P

2012-10-15 US 201261713779 P

2013-03-05 US 201313785472

03/13/2013 US 201313799255 (43) Application announced:

09.08.2017 in the European Patent Bulletin No. 2017/32 (45) The following was announced about the submission of the translation of the patent:

31.12.2018 2018/12 Patent Office News (73) Patent holder:

Corning Optical Communications LLC, Hickory, US (72) Inventor (s):

CO and what CM CO O CM CO (74)

Jagiellonian University - and Fr.

EDWARD JOHN FEWKES, Corning, US JOHN PAUL KRUG, Painted Post, US ZIWEI LIU, Worth, US

Proxy:

thing, pat. Tadeusz Rejman PATENT OFFICE REJMAN SC ul. Ciepła 15 lok. 41

50-524 Wrocław

Attention:

Within nine months of the publication of the information on the grant of the European patent, any person may file an objection to the European Patent Office against the European patent granted. The objection must be submitted in the form of a written statement of reasons. It is considered brought only when the opposition fee has been paid (Art. 99 (1) of the Convention on the Grant of European Patents).

ΕΡ3203285Β1

[0001] This application claims priority benefits under 35 USC § 119, from provisional patent applications serial numbers 61/713788 and 61/713779, both filed on October 15, 2012, and further claims priority benefits under 35 USC § 120 of Provisional Patent Applications Serial Numbers 13/799255, filed March 13, 2013, and 13/775472, filed March 5, 2013, the contents of each of the four are referenced and incorporated herein by reference in their entirety.

BACKGROUND

Field

[0002] The present patent generally relates to materials and methods for gluing parts inside optical connectors, and more particularly to adhesive compositions for use in gluing optical fibers to ferrules in optical connectors, and methods of using them.

Technical background

[0003] Adhesives can be used in an optical connector set to bond optical fibers to ferrules. Typically, the adhesives may be thermosetting resins such as, for example, epoxies. The present inventors have discovered that there is a need for an optical fiber adhesive with improved bonding properties. WO 99/67316 discloses a curable epoxy adhesive composition for adhering optical fibers to a ferrule.

BRIEF SUMMARY

[0004] The concepts of the present invention are generally applicable to adhesive compositions for use in adhering optical fibers to ferrules within optical connectors and methods of using them. According to one embodiment of the present invention, an optical connector for terminating an optical fiber may include a ferrule, an optical fiber and an adhesive composition. The ferrule may include an optical fiber receiving channel defining an inner surface, and the adhesive composition may be positioned inside the ferrule and contact the inner surface of the ferrule. The adhesive composition may include a partially cross-linked resin and a coupling agent. The adhesive composition may contain from about 0.1 to about 10 parts by weight of a coupling agent per 100 parts by weight of the partially cross-linked resin.

and

ΕΡ3203285Β1

[0005] According to another embodiment of the present invention, the ferrule adhesive system may be used in an optical connector for termination of an optical fiber. The ferrule adhesive system may include the ferrule and the adhesive composition. The ferrule may include an optical fiber receiving channel defining an inner surface, and the adhesive composition may be positioned inside the ferrule and contact the inner surface of the ferrule. The adhesive composition may include a partially cross-linked resin and a coupling agent. The coupling agent may contain at least one of an alkoxysilane, oximosilane, acetoxysilane, zirconate, titanate, silane with an epoxy ring at one end and a trimethoxy function at the other end, or combinations thereof. The adhesive composition may contain from about 0.1 to about 10 parts by weight of a coupling agent per 100 parts by weight of the partially cross-linked resin.

According to yet another embodiment of the present invention, a method of attaching a short optical fiber to an optical connector ferrule may include the steps of providing a ferrule adhesive system, wherein the ferrule adhesive system comprises the ferrule and the adhesive composition, heating the adhesive composition to a temperature sufficient to melt the adhesive composition. feeding a short optical fiber to the fiber receiving channel, defining the inner surface of the ferrule, and for contacting the adhesive composition and cooling the adhesive composition. The adhesive composition may be placed inside the ferrule and make contact with the inner surface of the ferrule. The adhesive composition may contain a partially cross-linked resin and a coupling agent prior to the heating step. The adhesive composition may contain from about 0.1 to about 10 parts by weight of a coupling agent per 100 parts by weight of the partially cross-linked resin.

[0007] Additional features and advantages of the technology disclosed herein will be set forth in the following detailed description, and in part, will be readily understood by those skilled in the art of this description or recognized through practicing the technology as described herein, including the detailed description below, claims, such as also attached drawings.

[0008] It is to be understood that both the foregoing general description and the following detailed description represent embodiments of the technology and are intended to

"3203285 "1 provide a general outline or diagram to understand the nature and nature of the technology as claimed. The attached drawings are included for a better understanding of the technology and are incorporated into and form part of this description. The drawings illustrate various embodiments and together with the description serve to explain the principles and operation of the technology. Additionally, the drawings and descriptions are intended to be illustrative only and are not intended to limit the scope of the claims in any way.

BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The following detailed description of certain embodiments of the present invention may best be understood when read in conjunction with the drawings below, in which like structures are denoted by like reference numerals, and in which:

FIG. 1 is a longitudinal cross-sectional view of a mechanical optical fiber splicing connector to be mounted on an end portion of a field optical fiber; and

FIG. 2 shows a channel receiving an optical fiber ferrule connector.

FIG. 3 shows a perspective view of a ferrule according to another exemplary embodiment.

FIG. 4 illustrates a longitudinal cross-sectional view of a joint according to another exemplary embodiment.

DETAILED DESCRIPTION

[0010] Reference will now be made in more detail to various embodiments, some of which are illustrated in the accompanying drawings. Whenever possible, the same reference numbers will be used throughout the drawings to refer to the same or similar parts. Generally, various embodiments of adhesive compositions for use in adhering optical fibers to ferrules within optical connectors, and methods of using them, are disclosed in the following document. Various embodiments of adhesive compositions described herein may provide desirable properties such as, for example, but not limited to, high adhesive strength and / or improved environmental aging properties. Various embodiments of the adhesive compositions disclosed herein may also have other desirable properties for the process of attaching the optical fiber inside the ferrule, such as, for example, but

ΕΡ3203285Β1 not only, reduced process cycle time, no mixing required and / or no pot life issues.

[0011] Referring to FIG. 1, a field mountable mechanical splicing optical fiber connector 10 is shown suitable for use with the present technology. Fiber optic connector 10 may include features similar to those of the UNICAM® member of the family of mechanical connectors available from Corning Cable Systems, LLC of Hickory, North Carolina, United States. While one embodiment of a fiber optic connector is shown in FIG. 1, it should be understood that the adhesive compositions and methods for adhering glass fiber to ferrule as described herein are applicable to any optical fiber connector of any design. Such fiber optic connectors include, but are not limited to, single fiber connectors (see, for example, ferrule 12 of connectors 10, 10 ', as shown in FIG. 1 and 4) or multi-fiber (see, for example, ferrule 12 'as shown in FIG. 3), such as, for example, fusible splice joints or mechanical splice joints. Examples of typical single-fiber mechanical bonding joints are provided in US Patent Nos. 4,755,018; 4,923,274; 5,040,867; and 5,394,496. Examples of typical multi-filament mechanical seals are provided in US Patent Nos. 6,173,097; 6379054; 6,439,780; and 6,816,661.

[0012] As illustrated further with reference to FIG. 2, the mechanical contact joint 10 includes a connector ferrule 12 defining an elongated longitudinal opening, referred to herein as a fiber receiving channel 30. The fiber receiving channel 30, which is illustrated on an exaggerated scale in FIG. 2, defines an inner surface of the ferrule 12 that can contact the adhesive composition 40 for attaching an optical fiber, such as, for example, a short optical fiber 14. The adhesive composition 40 may be positioned within the ferrule 12 and contact the inner surface of the ferrule 12 and the short optical fiber 14. Various embodiments of the adhesive composition 40, including variations of the adhesive compositions, are detailed herein. In various embodiments, the adhesive composition 40 may generally include a partially cross-linked resin and a coupling agent as detailed herein.

ΕΡ3203285Β1

Ferrula 12 may typically comprise a ceramic material such as, for example, but not limited to, zirconium oxide, alumina, titanium-doped alumina, PPS glass filled, or combinations thereof. However, other construction materials of the ferrule are contemplated herein, such as, for example, metals, ceramics, polymers, or combinations thereof.

[0014] The short optical fiber 14 may be a flexible, transparent optical fiber made of glass or plastic. It can serve as a waveguide to transmit light between the two ends of an optical fiber. Optical fibers typically contain a transparent core surrounded by a transparent sheath material of a lower refractive index. The light can be held in the core by total internal reflection. The glass optical fibers may contain silica, but some other materials may be used, such as, for example, fluorosirconate, fluoroaluminate, and chalcogenide glasses, as well as crystalline materials, such as, for example, sapphire. Although shown as short fiber 14 in FIG. 1, in other embodiments, optical fibers that are not short fibers may be included and used in conjunction with ferrule 12, 12 'and the methods disclosed herein.

[0015] Light may be directed downstream of the optical fiber core 14 through an optical cladding with a lower refractive index that captures the light in the core by total internal reflection. The jacket may be covered with a buffer and / or other coating (s) which protects / protects against moisture and / or physical damage. These coatings can be ultraviolet light curable carbamate-acrylate composite materials applied to the outer surface of the optical fiber 14 during the drawing process. The coatings can protect the strands of the glass fiber. The optical fiber 14 may include an inner primary coating and an outer secondary coating. Optical fiber coatings can be applied in concentric layers.

[0016] Still referring to FIG. 1, the front end (also referred to herein as the end face) 11 of the ferrule 12 is typically precision polished so that the optical fiber 14 is aligned with (as shown) or slightly protruding above the end face of the ferrule 12.

ΕΡ3203285Β1

However, if desired, the light pipe 14 may also extend outwardly from the end face 11 of the ferrule 12 by a predetermined distance. Moreover, in a known manner, the end face 11 may be oriented generally perpendicular to the optical fiber receiving channel to provide a UPC (Ultra-Physical Contact) connector, or it may be formed at a specific angle to provide an APC (Angular Physical Contact) connector. Further, while a single fiber ferrule 12 is shown for convenience, ferrule 12 itself may define a plurality of optical fiber receiving longitudinal channels for receiving a plurality of corresponding optical fibers to provide a multi-fiber mechanical splice or other multi-fiber connector (see generally 12 'multi-fiber ferrule, such as shown in FIG. 3 for a multi-fiber connector).

[0017] Generally the rear end 13 of the ferrule 12 is inserted into and secured inside the front end of the crimp of the ferrule 22 such that the short optical fiber 14 extends rearwardly a predetermined distance from the ferrule between a pair of opposing clamping elements 17, 18 spaced apart. in the ferrule holder. In turn, the ferrule holder 16, containing the ferrule 12 and the securing elements 17, 18, are arranged inside the connector housing 19. The cam element 20 is movably mounted between the ferrule holder 16 and the connector housing 19 to engage the keel portion of the lower locking component 18 as will be described. If desired, ferrule 12, ferrule holder 16, and cam element 20 may be pressed against the connector housing 19, e.g. by a helical spring 21, to provide physical contact between the end face 11 of the ferrule 12 and the end face of the opposite ferrule in the associated optical fiber connector or device. optical. Finally, a spring retainer 22 may be disposed between the connector housing 19 and the center portion of the cam member 20 and attached to the connector housing so as to hold one end of the spring 21 relative to the connector housing. As a result, the ferrule 12, the ferrule holder 16, and the cam member 20 are biased forward but able to be stamped rearward relative to the connector housing 19.

[0018] As illustrated by the horizontal direction arrow in FIG. 1, the field optical fiber 15 can be inserted into the rear end of the ferrule holder 22 opposite the ferrule 12 and optical fiber 14. Although

ΕΡ3203285Β1 is not required, the mechanical joint 10 may be provided with means, e.g., an input tube 24 (FIG. 4), for inserting the field optical fiber 15 into the ferrule holder 16 and between the splicing components 17, 18 in general alignment with the short optical fiber. 14. Preferably, at least one of the linking components 17, 18 has a groove formed therein for receiving the short optical fiber 14 and the field optical fiber 15. As shown herein, the lower clamping component 18 is provided with a longitudinal V-shaped groove to receive and guide the optical fiber 14 and the terrain optical fiber 15 for fine alignment. Typically field optical fiber 15 is covered or sealed buffered with a buffer 25 that is removed back to expose a predetermined length of the field end of the optical fiber. The mechanical clamping joint 10 may additionally be provided with a corrugated tube or other stress release mechanism (not shown) to maintain and relieve stress on the field optical fiber buffer 15. After buffer 25 is removed, field optical fiber 15 can be inserted and moved to the back of mechanical coupling 10 between link components 17, 18 until the end portion of field optical fiber 15 makes physical contact with the end portion of short optical fiber 14. Cam element 20 is actuated by sliding or rotating cam element 20 relative to ferrule holder 16 about the longitudinal axis of joint 10 to engage the keel on joint 18 and thereby force lower link component 18 to move towards upper link component 17. Movement of the lower clamping component 18 causes the end portion of the short fiber 14 and the end portion of the field optical fiber 15 to sit in a V-shaped groove formed in the lower clamping component 18, thereby aligning and simultaneously securing the terrain optical fiber 15 to the short fiber. fiber 14 between the splicing components. Accordingly, field optical fiber 15 is optically coupled to short optical fiber 14. Further, as used herein, the portion of the connector where optical coupling occurs is referred to as the "terminating region". For example, in others

The ΕΡ32032851 roof of the field optical fiber 15 or other optical fiber can be inserted directly into the ferrule and attached to it as disclosed herein in place of the short fiber 14.

[0019] In general, it should be understood that the adhesive compositions described herein may be useful in adhering an optical fiber to any part of an optical connector and is not limited to adhering an optical fiber to the inner wall of a ferrule. For example, the adhesive compositions described herein can be used to adhere any portion of an optical connector to any optical fiber connected thereto, including short optical fiber and field optical fiber.

[0020] Also described herein are ferrule adhesive systems for use in an optical connector for termination of an optical fiber. The ferrule adhesive system may include a ferrule 12 having a fiber receiving channel 30 defining an inner surface and an adhesive composition 40 disposed inside ferrule 12 and contacting the inner surface of ferrule 12. Various embodiments of the adhesive composition of ferrule adhesive systems are described in detail herein. Such an adhesive system may contain an adhesive composition for a long time before heating to bond the fiber inside the ferrule, for example 8 hours, 16 hours, 1 day, 1 week, 1 month, 6 months, 1 year or even several years. For example, the adhesive composition 40 may be in a solid powder form, such as, for example, packaged within the fiber receiving channel 30 prior to heating, or otherwise activated and / or cured (e.g., using a chemical catalyst). Alternatively, the adhesive composition may be in solid form molded in the fiber receiving channel 30 and then may be heated prior to insertion of the optical fiber.

[0021] Generally disclosed herein are methods of attaching short optical fibers to optical connector ferrules 10. The method may generally include the steps of providing the adhesive system of the ferrule, heating the adhesive composition to a temperature sufficient to melt the adhesive composition, supplying the optical fiber to the fiber receiving channel, and contacting the adhesive composition; and cooling the adhesive composition. Adhesive composition

"3203285 "1 may contain partially cross-linked resin and a coupling agent prior to the heating step. The adhesive composition may contain from about 0.1 to about 10 parts by weight of a coupling agent per 100 parts by weight of the partially cross-linked resin.

The ferrule with the adhesive composition therein may be heated to melt the adhesive composition to allow the optical fiber to slide into the opening of the ferrule. Heating may occur at an elevated temperature, such as, for example, to allow cross-linking or other chemical reactions to occur in certain embodiments of the adhesive composition. Heating may be performed with a laser (e.g., a commercially available industrial CO laser₂ at least 100 W) or any other type of heating. The laser heating step may be less than about 15 seconds, such as less than 10 seconds, less than 8 seconds, or less than 6 seconds. The adhesive composition can then be allowed to cool by any method such as, for example, accelerated cooling or by simple cooling in an ambient atmosphere at or around room temperature. The cooled adhesive composition is fixed and can permanently adhere the optical fiber to the ferrule. In some embodiments, the ferrule and the adhesive composition may be substantially cooled to establish the adhesive composition for 5 minutes, 2 minutes, 1 minute, 30 seconds, or even 15 seconds in air at room temperature (25 ° C) at sea level pressure and zero humidity. .

[0023] Various embodiments of adhesive compositions are now disclosed herein. As used herein, "adhesive" is a substance capable of holding materials together by attaching surfaces. In one embodiment, the adhesive composition may generally include a partially cross-linked resin and a coupling agent. In some embodiments, there may be from about 0.1 to about 10 parts by weight of the coupling agent per 100 parts by weight of the partially cross-linked resin. In various embodiments, about 0.1, about 0.5, about 1, about 2, about 4, about 6, about 8, or about 10 parts by weight of the coupling agent may be present per 100 parts by weight of the partially cross-linked resin or condition.

The "3203285" value may range between any combination of the above-mentioned weight ratios.

[0024] As used herein, a "thermoplastic resin" is a material that contains a polymeric material that will soften repeatedly when heated and harden when cooled, without cross-linking the polymer chains. For example, a thermoplastic resin can become many times soft and hard during the heating and cooling cycles. As used herein, the term "cross-linked" or "cross-linked" refers to a chemical bond that connects a polymer chain to an adjacent polymer chain while "crosslinkable" describes a chemical compound that becomes at least partially cross-linked when sufficient amount is used. warm. As used herein, the term "partially cross-linked" or "partially cross-linked" refers to a chemical bond that connects a polymer chain to an adjacent polymer chain where not all adjacent chains are bonded, unlike thermoplastic and thermosetting resins; and "partially crosslinkable" describes a chemical compound that becomes partially cross-linked when sufficient heat is applied. It should be understood that when the terms "partially cross-linked" and "partially cross-linkable" are used to describe the polymers of the adhesive compositions described herein, the same resin is described at a specific time before or after cross-linking. For example, a resin is described as partially cross-linked when packed in a ferrule and not yet heated to partially cross-link. The resin may be partially cross-linked when heated. In another embodiment, the resin may be cross-linked prior to the heating step immediately prior to introducing the optical fiber, such as where the adhesive composition is injection molded prior to insertion into the ferrule. However, the injection molded adhesive composition can still be described as partially crosslinkable since the crosslinking can take place in a heating step immediately prior to the introduction of the optical fiber. It should further be understood that when the adhesive composition is described herein, when the adhesive composition is said to contain partially cross-linked resin, this is tantamount to saying that the adhesive composition comprises partially

ΕΡ3203285Β1 cut resin before this cross-linking step. While cross-linking may provide durability to bond structures stably during joint assembly, and thermoplastic resins may allow materials to flow in a controlled manner to form ferrules, partially cross-linking materials may uniquely and synergistically have the advantages of both types of materials.

[0025] In one embodiment, the adhesive composition may have the property that at least about 5% by weight of the resin is cross-linked or cross-linkable and at least about 5% by weight of the resin is not cross-linked or cross-linkable. In one embodiment, the adhesive composition may have the property that at least about 10% by weight of the resin is cross-linked or cross-linkable and at least about 10% by weight of the resin is not cross-linked or cross-linkable. In one embodiment, the adhesive composition may have the property that at least about 20% by weight of the resin is cross-linked or cross-linkable and at least about 20% by weight of the resin is not cross-linked or cross-linkable.

[0026] In some embodiments, the partially cross-linked resin materials can have a melting point at temperatures of at least about 250 ° C, 270 ⁰ or 290 ° C. In some embodiments, partially cross-linked resin materials can cross-link in the presence of air at temperatures of at least about 300 ° C, 325 ° C, or 350 ° C. Additionally, the partially cross-linked resin may be able to bind in less than about 5 minutes, 3 minutes, 1 minute, 30 seconds, or even 15 seconds. In the contemplated embodiments, the partially cross-linked resin requires no mixing, no air purging, and / or no pot life problems. In one embodiment, the adhesive composition may include one or more partially cross-linked resins such as, for example, but not limited to, partially cross-linked poly (phenylene sulfide).

[0027] In other embodiments, the adhesive composition may include one or more partially or partially cross-linked resins such as, for example, but not limited to, poly (phenylene oxide), polyamideimide, liquid crystal polymer, polycetone ether-ether, cyclic olefin copolymer, or their combinations. For example, the poly (phenylene sulfide) may include, but is not limited to, Ryton® V-1, available from Chevron Phillips Chemical Company LLC of The u

ΕΡ3203285Β1

Woodlands, Texas, USA or Fortran® 0205P4 or Fortran® 0203P6, available from Ticona GmbH of Frankfurt, Germany. The poly (phenylene oxide) may include, but is not limited to, Saba SA-102, available from SABIC of Riyadh, Saudi Arabia. The liquid crystal polymer may include Veectra® A950 VF3001, available from Ticona of Florence, Kentucky, United States. The polyether ketone may include Ketaspire® KT-851 available from Solvay SA of Brussels, Belgium. The cyclic olefin copolymer may include TOPAS® 5013L-10 from Topas Advanced Polymers.

[0028] The coupling agent may include a wide variety of one or more suitable coupling agents. In one embodiment, the coupling agent may comprise an epoxy, amine, or thiol-functional silane. The silane group in the coupling agent may contain alkoxysilane, oximosilane, acetosilane. Alternatively or in combination with the above-mentioned silane coupling agent, the coupling agent may comprise zirconate, titanate, or combinations thereof. In one embodiment, the coupling agent may comprise glycidoxypropyltrimethoxysilane, such as, for example, gamma-glycidoxypropyltrimethoxysilane. For example, coupling agents may include Silquest® A-187, Silquest® A-1100, available from Crompton Corp. of Middlebury, Connecticut, United States, or Ken-React® KR55, available from Kenrich Petrochemicals, Inc. from Bayonne, NJ, United States.

[0029] The combination of a coupling agent and a partially cross-linked resin can result in increased adhesion strength. Without being bound by theory, it is believed that the coupling agent can provide chemical coupling between the inorganic surface of the optical fiber and / or ferrule and the polymer matrix of the adhesive. Upon cooling, the partially cross-linked resin, which may not have functional groups that can react with the inorganic surfaces, may be covalently bonded to one or both of the optical fiber or ferrule through a coupling agent. The coupling agent may contain functional groups specifically capable of covalently bonding with inorganic materials and groups specifically capable of reacting with organic functional groups. The organic functional group on the coupling agent may contain epoxy, amino, thiol, acrylic ester or any other organic group

ΕΡ3203285Β1 functional group. In one embodiment, the functional group of the coupling agent that reacts with the inorganic materials is an alkoxysilane. Other possible groups include an oxime or an acetoxysilane group. In addition to the silane coupling agents, also zirconates and titanates have shown to have such coupling abilities.

[0030] The adhesive composition described herein may additionally comprise at least one thermosetting resin. A wide variety of thermosetting resin materials can be used as a component of the adhesive composition. As used herein, a "thermosetting resin" is a material that contains at least one polymeric material that will undergo a chemical reaction when exposed to heat, catalysts, ultraviolet light and the like, leading to a relatively non-fusible state. Examples of suitable thermosetting resins may include, but are not limited to, epoxy resins such as, for example, bisphenol A based epoxy or novolak type epoxy resins. In one embodiment, there may be from about 1 to about 85 parts by weight of the thermosetting resin per 100 parts by weight of the partially cross-linked resin. In various embodiments, about 1, about 5, about 10, about 30, about 50, about 70, about 80, or about 85 parts by weight of the thermosetting resin per 100 parts by weight of the partially cross-linked resin may be present, or the value may range between any combination of the abovementioned weight ratios.

[0031] The combination of a thermosetting resin and a partially cross-linked resin can provide increased adhesive strength. Without being bound by theory, it is believed that, when cured above 300 ° C, the adhesive can form a uniform thermoplastic array and cross-linked network structures throughout the matrix. The cross-linked structure can be formed not only by thermosetting materials, but also between thermoplastics and thermosetting materials. For example, a partially cross-linked thermoplastic resin could react with the thermosetting resin at elevated temperatures through a phenolic group at the end of the polymer chain. The network structure formed can improve the integrity of the adhesives and the corresponding optical fiber connectors to counteract environmental aging and shear creep and promote bond strength on the substrates.

ΕΡ3203285Β1

[0032] In one embodiment, the adhesive composition may additionally contain a curing agent. Without wishing to be bound by theory, it is believed that the curing agent can aid the curing of a thermosetting resin, such as, for example, an epoxy resin, if the adhesive composition comprises a thermosetting resin and / or can assist the curing of the coupling agent. For example, the curing agent may react with the epoxy groups of the coupling agent and / or the thermosetting resin. The curing agent may contain one or more available curing agents such as, for example, but not limited to, anhydride curing agent, amide curing agent, aromatic amine curing agent, dianhydride curing agent, monoacid anhydride, guanidino compound, amine curing agent or combinations thereof. For example, the curing agent may include dicyandiamide, pyromellitic dianhydride, dodecylsuccinic anhydride, urea, urea, melamine, dicyandiamide, or combinations thereof. In one embodiment, the adhesive composition further comprises from about 0.2 to about 50 parts by weight of the curing agent per 100 parts by weight of the coupling agent. In various embodiments, there may be about 0.2, about 0.5, about 1, about 5, about 10, about 20, about 30, about 40, or about 50 parts by weight of the curing agent per 100 parts by weight of the coupling agent, or it may range between any combination of the abovementioned weight ratios. In another embodiment, the adhesive composition further comprises from about 0.2 to about 50 parts by weight of a hardener per 100 parts by weight of a thermosetting resin. In various embodiments, about 0.2, about 0.5, about 1, about 5, about 10, about 20, about 30, about 40, or about 50 parts by weight of the hardener per 100 parts by weight of the thermosetting resin may be present, or may be be between any combination of the abovementioned weight ratios. In yet another embodiment, the adhesive composition further comprises from about 0.2 to about 100 parts by weight of the hardener per 100 parts by weight of the sum of the weight of the thermosetting resin and the weight of the coupling agent. In various embodiments, it may be about 0.2, about 0.5, about 1, about 5, about 10, about 30, about 50, about 70, about 90, or about 100 parts by weight of hardener per 100 parts by weight.

The "3203285" 1 value of the thermosetting resin may range between any combination of the abovementioned weight ratios.

[0033] In one embodiment, the adhesive composition may additionally include one or more filler materials. In one embodiment, the filler material is a mineral composition such as, for example, at least one metal pyrophosphate. For example, the metal may include cobalt or magnesium such that the filler material is magnesium pyrophosphate, cobalt pyrophosphate, or combinations thereof. In one embodiment, the adhesive composition further comprises from about 0.5 to about 85 parts by weight of a filler material per 100 parts by weight of partially cross-linked resin. In various embodiments, about 0.5, about 1, about 5, about 10, about 30, about 50, about 70, about 80, or about 85 parts by weight of filler material per 100 parts by weight of thermosetting resin may be present, or the value may vary. be between any combination of the abovementioned weight ratios.

[0034] In one embodiment, the filler material may comprise a material with a negative coefficient of thermal expansion. As used herein, the term "negative coefficient of expansion material" refers to a material that passes through phase inversion accompanied by a reduction in volume at a temperature close to, for example, about 50 ° C, about 30 ° C, about 20 ° C. or about 10 ° C, the glass transition temperature of the partially cross-linked resin. Without being bound by theory, it is believed that the inclusion of a negative coefficient of expansion material can help maintain the density, and hence volume, of the adhesive composition when heated such that it does not expand to place excessive pressure on the ferrule, in some cases. causing the ferrule to break or break.

[0035] It should be understood that the various components of the adhesive composition embodiments disclosed herein may be combined in any combination in any ratio disclosed herein. Such various components include partially cross-linked resins, coupling agents, thermosetting resins, curing agents, and fillers. Moreover, while desirable properties of the adhesive composition may be brought about by combining only two or more of the different components herein

Any combination of components is contemplated as "3203285". It should further be understood that where reference is made to a component of the adhesive composition, it may be an optional component in some embodiments that is not required to be present in the adhesive composition in all embodiments.

[0036] For example, in one preferred embodiment, the adhesive composition may include a partially cross-linked resin, a coupling agent, a curing agent and a partially cross-linked resin. The adhesive composition may contain from about 0.1 to about 10 parts by weight of the coupling agent per 100 parts by weight of the partially cross-linked resin, from about 0.2 to about 5 parts by weight of the hardener per 100 parts by weight of the partially cross-linked resin, and from about 0.5 to about 85 parts by weight of filler material for 100 parts by weight of partially cross-linked resin.

[0037] In one embodiment, the adhesive composition is in the form of a solid powder. At least some of the various components of the adhesive composition may be solid and ground to a powder, such as, for example, any part or all of a partially cross-linked resin, thermosetting resin, curing agent and / or filler material. Solid powder materials can be thoroughly mixed. In one embodiment, the coupling agent may be a liquid. However, the proportion of the coupling agent in the blend is relatively small, so the coupling agent can be combined with one of the solid components of the adhesive composition, and the resulting blend can be a free flowing powder. For example, in one embodiment, the coupling agent can be pre-reacted with partially cross-linked resin powders in an organic solvent under reflux conditions. After removal of the solvent, a treated powder remains. While the solvent was heated to reflux, part of the coupling agent could be stably bound to the polymer.

[0038] In some embodiments, the adhesive composition may be in the form of a solid powder and may be packed directly into the fiber receiving channel of the ferrule (shown in FIG. 1 as space occupied by the short optical fiber 14 inside the ferrule 12). In certain other embodiments, particularly where the adhesive composition is resin-free

With the "3203285" 1 thermosetting adhesive composition, the adhesive composition can be extruded or injection molded into preforms as a solid material after a pre-heating step. Adhesive compositions containing a thermosetting resin may not be suitable for extrusion or injection molding into preforms because they may not be suitable for reheating inside the ferrule to receive and bond the optical fiber. As such, a partially cross-linked resin can provide the advantages of both thermosetting resins and thermoplastic resins.

Example

[0039] An adhesive composition with polyphenylene sulfide (Ryton® V-1) and gamma-glycolidoxypropyltrimethoxysilane, epoxysilane was prepared using 1.5 parts by weight of gamma-glycolidoxypropyl trimethoxysilane per 100 parts by weight of polyphenylene sulfide). The coupling agent was pre-reacted for 8 hours with partially cross-linked resin powders in a mixture of 99% organic solvent and 1% gamma-glycolidoxypropyltrimethoxysilane under reflux conditions. The pyromellitic dianhydride filler material was also mixed with the adhesive composition in a weight ratio of 0.5 per 100 parts of polyphenylene sulfide). The resulting adhesive composition was a free flowing powder which was then packed into the fiber receiving channel of the ferrule. Thereafter, the ferrule and the adhesive composition were heated by the laser until the adhesive composition melted, and the optical fiber was introduced into the fiber receiving channel. The ferrule and the adhesive composition were then cooled by exposure to the ambient conditions.

[0040] The adhesive strength was analyzed using a Chatillon tensile test kit. The fiber was wrapped around a mandrel and then pulled vertically until the fiber broke or the bond failed. The peak stretch was recorded. The ferrule associated with the optical fiber was also tested under the influence of 2-day and 7-day environmental conditions. A control group was also used that was not exposed to environmental conditions. Specimens that were subjected to environmental aging were subjected to an environmental cycle chart of a 6 hour cycle consisting of 2 hours at about 22 ° C, 2 hours at a temperature linearly varying from about 22 ° C to about -40 ° C, 2 hours at about -40 ° C, 2 hours at about -40 ° C to about 85 ° C, 2 hours at about 85 ° C, and

ΕΡ3203285Β1 humidity of about 90% and 2 hours at a temperature linearly varying from about 85 ° C to about 22 ° C. Samples from the 2-day environmental tests passed 8 cycles, while the samples from the 7-day environmental tests passed 28 cycles. Adhesive strength data are presented below for the adhesive composition described above as well as for other different comparative samples:

<td>Adhesive composition</td><td>Environmental cycling</td><td>Tensile Strength (Ibf)</td>

<td>100% Locite epoxy</td><td>lack</td><td> 4,0</td>

<td>100% polyphenylene sulfide)</td><td>lack</td><td> 3,1</td>

<td>100% poly (phenylene sulfide)</td><td>Two days</td><td> 2,5</td>

<td>polyphenylene sulphide), gamma-glycidoxypropyltrimethoxysilane, pyromellitic dianhydride (weight ratio 100: 1.5: 0.5)</td><td>lack</td><td> 6,5</td>

<td>polyphenylene sulphide), gamma-glycidoxypropyltrimethoxysilane, pyromellitic dianhydride (weight ratio 100: 1.5: 0.5)</td><td>Two days</td><td> 5,0</td>

<td>polyphenylene sulphide), gamma-glycidoxypropyltrimethoxysilane, pyromellitic dianhydride (weight ratio 100: 1.5: 0.5)</td><td>7 days</td><td> 4,5</td>

[0041] In one embodiment, the adhesive composition may generally comprise a partially cross-linked resin and a thermosetting resin. In one embodiment, there may be from about 1 to about 85 parts by weight of the thermosetting resin per 100 parts by weight of the partially cross-linked resin. In various embodiments, about 1, about 5, about 10, about 30, about 50, about 70, about 80, or about 85 parts by weight of the thermosetting resin per 100 parts by weight of the partially cross-linked resin may be present, or the value may range between any combination of the abovementioned weight ratios.

[0042] A wide variety of thermosetting resin materials can be used as a component of the adhesive composition. As used herein

In the document "3203285", a "thermosetting resin" is a material that contains at least one polymeric material that will undergo a chemical reaction when exposed to heat, catalysts, ultraviolet light, etc., leading to a relatively non-fusible state. Examples of suitable thermosetting resins may include, but are not limited to, epoxy resins such as, for example, bisphenol A based epoxy or novolak type epoxy resins.

[0043] The combination of a thermosetting resin and a partially cross-linked resin can provide increased adhesive strength. Without being bound by theory, it is believed that, when cured above 300 ° C, the adhesive can form a uniform system of partially cross-linked resins and a cross-linked network structure throughout the matrix. The cross-linked structure can be formed not only by thermosetting materials, but also between partially cross-linked resins and thermosetting resins. For example, a partially cross-linked thermoplastic resin could react with the thermosetting resin at elevated temperatures through a phenolic group at the end of the polymer chain. The network structure formed can improve the integrity of the adhesives and the corresponding optical fiber connectors to counteract environmental aging and shear creep and promote bond strength on the substrates.

[0044] The adhesive composition described herein may additionally contain at least one coupling agent. The coupling agent may include a wide variety of one or more suitable coupling agents. In one embodiment, the coupling agent may comprise an epoxy, amine, or thiol-functional silane. The silane group in the coupling agent may contain alkoxysilane, oximosilane, acetosilane. Alternatively or in combination with the above-mentioned silane coupling agent, the coupling agent may comprise zirconate, titanate, a silane with an epoxy ring at one end and a trimethoxy function at the other end, or combinations thereof. In one embodiment, the coupling agent may comprise glycidoxypropyltrimethoxysilane, such as, for example, gamma-glycidoxypropyltrimethoxysilane. For example, coupling agents may include Silquest® A-187, Silquest® A-1100, available from Crompton Corp. of Middlebury, Connecticut, United States, or Ken-React® KR55, available from Kenrich Petrochemicals, Inc. from Bayonne, NJ, United States.

ΕΡ3203285Β1

In some embodiments, there may be from about 0.1 to about 10 parts by weight of the coupling agent per 100 parts by weight of the partially cross-linked resin. In various embodiments, about 0.1, about 0.5, about 1, about 2, about 4, about 6, about 8, or about 10 parts by weight of the coupling agent per 100 parts by weight of the partially cross-linked resin may be present, or the value may be be between any combination of the abovementioned weight ratios.

[0045] Some or all of the following may be identically or inherently disclosed above and / or in the Figures.

[0046] In one embodiment, the adhesive composition may include a partially cross-linked resin in an amount greater than or equal to about 30% by weight of the adhesive composition. In other embodiments, the adhesive composition may include a partially cross-linked resin in an amount greater than or equal to about 40% by weight of the adhesive composition, greater than or equal to about 50% by weight of the adhesive composition, greater than or equal to about 60% by weight of the adhesive composition, greater than or equal to about 70% by weight, greater than or equal to about 80% by weight of the adhesive composition, greater than or equal to about 90% by weight of the adhesive composition. greater than or equal to about 95% by weight of the adhesive composition, or even greater than or equal to about 98% by weight of the adhesive composition.

[0047] In one embodiment, the partially cross-linked resin may contain two or more chemicals. In one embodiment, the partially cross-linked resin can be one chemical, such as, for example, poly (phenylene oxide), polyamideimide, liquid crystal polymer, polyether ether ketone, cyclic olefin copolymer, or combinations thereof. In one embodiment, the adhesive composition may contain one chemical that is a partially cross-linked resin in an amount greater than or equal to about 30% by weight of the adhesive composition. In other embodiments, the adhesive composition may contain a single chemical that is a partially cross-linked resin in an amount greater than or equal to about 40% by weight of the adhesive composition, greater than or equal to about 50% by weight of the adhesive composition, greater than or equal to about 60% by weight of the adhesive composition. tackifier, greater than or equal to about 70% by weight of the adhesive composition, greater than or equal to

ΕΡ3203285Β1 about 80% by weight of the adhesive composition, greater than or equal to about 90% by weight of the adhesive composition, greater than or equal to about 95% by weight of the adhesive composition, or even greater than or equal to about 98% by weight of the adhesive composition.

[0048] In one embodiment, the partially cross-linked resin may include polyphenylene sulfide. In one embodiment, the adhesive composition may include poly (phenylene sulfide) greater than or equal to about 30% by weight of the adhesive composition. In other embodiments, the adhesive composition may include poly (phenylene sulfide) in an amount greater than or equal to about 40% by weight of the adhesive composition, greater than or equal to about 50% by weight of the adhesive composition, greater than or equal to about 50% by weight of the adhesive composition, greater than or equal to. or equal to about 60% by weight of the adhesive composition, greater than or equal to about 70% by weight of the adhesive composition, greater than or equal to about 80% by weight of the adhesive composition. greater than or equal to about 90% by weight of the adhesive composition, greater than or equal to about 95% by weight of the adhesive composition, or even greater than or equal to about 98% by weight of the adhesive composition.

[0049] In one embodiment, the adhesive composition may contain a coupling agent in an amount less than or equal to about 30% and greater than about 0.1% by weight of the adhesive composition. In other embodiments, the adhesive composition may contain a coupling agent in an amount less than or equal to about 20% and greater than about 0.1% by weight of the adhesive composition, less than or equal to about 10% by weight of the adhesive composition, less than or equal to about 8%, and greater than about 0.1% by weight of the adhesive composition, less than or equal to about 6%, and greater than about 0.1% by weight of the adhesive composition. less than or equal to about 4% and greater than about 0.1% by weight of the adhesive composition, less than or equal to about 2% by weight of the adhesive composition, less than or equal to about 1%, and greater than about 0.1% by weight of the adhesive composition, or even less than or equal to about 0.5% and greater than about 0.1% by weight of the adhesive composition. In other embodiments, the adhesive composition may contain the coupling agent in an amount of from about 0.5% to about 20% by weight of the adhesive composition, from about 0.5% to about 10% by weight of the adhesive composition, from about 6% to about 1% by weight of the adhesive composition. they stick

From about 4% to about 1% by weight of the adhesive composition, or from about 3% to about 1% by weight of the adhesive composition, is 3203285Β1.

[0050] In one embodiment, the partially cross-linked resin may have a melting point of between about 200 ° C and about 350 ° C. In other embodiments, the partially cross-linked resin may have a melting point of between about 225 ° C and about 325 ° C, between about 250 ° C and about 300 ° C, between about 270 ° C and about 295 ° C, or between about 275 ° C and about 300 ° C. about 280 ° C. In one embodiment, the partially cross-linked resin may have a melting point of about 278 ° C.

[0051] In one embodiment, the partially cross-linked resin may be a polymer. In one embodiment, the coupling agent may provide a chemical coupling between the polymer and at least one of the optical fiber and the ferrule. As used herein, chemical conjugation refers to any chemical bond, including, but not limited to, one or more covalent bonds, ionic bonds, or intermolecular bonds, such as, for example, dipole-dipole interactions, hydrogen bonding, and London dispersion bonding. . In one embodiment, the partially cross-linked resin may be poly (phenylene sulfide). In one embodiment, the coupling agent may be a silane coupling agent, and the adhesive composition comprises from about 0.1 to about 10 parts by weight of the silane coupling agent per 100 parts of poly (phenylene sulfide). In one embodiment, the partially cross-linked resin can be one chemical. One chemical may be selected from the group consisting of poly (phenylene sulfide), poly (phenylene oxide), polyamideimide, liquid crystal polymer, polyether ether ketone, and cyclic olefin copolymer.

[0052] In one embodiment, an optical connector may be used to terminate an optical fiber. The optical connector may include a ferrule, the ferrule having a fiber-receiving channel defining an interior surface. The optical connector may also include an optical fiber extending through the fiber receiving channel. The optical connector may also include an adhesive composition, wherein the adhesive composition may be positioned within the fiber receiving channel of the ferrule and may contact the inner surface of the ferrule.

A "3203285 "1 face ferrule and an optical fiber, the adhesive composition comprising a partially cross-linked resin, and the adhesive composition comprising a partially cross-linked resin in an amount greater than or equal to about 30% by weight of the adhesive composition.

[0053] In one embodiment, the ferrule adhesive system may be used in an optical connector to terminate an optical fiber. The ferrule adhesion system may include a ferrule having a fiber receiving channel defining an interior surface; and the ferrule adhesive system may include an adhesive composition. The adhesive composition may be inserted into the fiber receiving channel of the ferrule and contact the inner surface of the ferrule. The adhesive composition may include the partially cross-linked resin in an amount greater than or equal to about 50% by weight of the adhesive composition. The adhesive composition can be a solid material without anchoring the optical fiber in the fiber receiving channel of the ferrule.

[0054] In one embodiment, the optical fiber may be attached to the ferrule. The method of attachment may include providing a ferrule adhesive system, the ferrule adhesive system comprising the ferrule and the adhesive composition. The method of attachment may also include heating the adhesive composition to a temperature sufficient to melt the adhesive composition. The method of attachment may also include feeding the optical fiber into a fiber-receiving channel defining the inner surface of the ferrule and in contact with the adhesive composition. The method of attachment may also include cooling the adhesive composition. The adhesive composition may be placed inside the ferrule and make contact with the inner surface of the ferrule. The adhesive composition may contain a partially cross-linked resin prior to the heating step. The adhesive composition may include the partially cross-linked resin in an amount greater than or equal to about 50% by weight of the adhesive composition after the cooling step.

[0055] In one embodiment, an optical connector may be used to terminate an optical fiber. The optical connector may include a ferrule, and the ferrule may include a fiber-receiving channel defining an interior surface. The optical connector may also include an optical fiber extending through the fiber receiving channel. Optical connector can

The "3203285 "1 also includes an adhesive composition, wherein the adhesive composition can be placed in the fiber receiving channel of the ferrule and contact the inner surface of the ferrule and the optical fiber. The adhesive composition may include a partially cross-linked resin, which may be a polymer. The adhesive composition may also include a coupling agent that provides chemical coupling between the polymer and at least one of the optical fiber and the ferrule, wherein the adhesive composition may contain from about 0.1 to about 10 parts by weight of the coupling agent per 100 parts by weight of the partially cross-linked resin. In one embodiment, the partially cross-linked resin can be one chemical. In one embodiment, one chemical may be selected from the group consisting of polyphenylene sulfide, poly (phenylene oxide), polyamideimide, liquid crystal polymer, polyether ether ketone, and cyclic olefin copolymer. In one embodiment, the partially cross-linked resin may be poly (phenylene sulfide). In one embodiment, the coupling agent may be a silane coupling agent, and the adhesive composition may contain from about 0.1 to about 10 parts by weight of silane coupling agent per 100 parts polyphenylene sulfide).

[0056] In one embodiment, the ferrule adhesion system may be used in an optical connector for termination of an optical fiber. The ferrule adhesion system may include a ferrule having a fiber receiving channel defining an interior surface. The adhesion system of the ferrule may also include an adhesive composition. The adhesive composition may be inserted into the fiber receiving channel of the ferrule and contact the inner surface of the ferrule. The adhesive composition may contain a partially crosslinkable resin, while the partially crosslinkable resin may contain polyphenylene sulfide. The adhesive composition may be a solid powder material packed into the fiber receiving channel of the ferrule.

[0057] In one embodiment, the optical fiber may be attached to the ferrule. The method of attachment may include providing a ferrule adhesive system, the ferrule adhesive system comprising the ferrule and the adhesive composition. The method of attachment may also include heating the adhesive composition to a temperature sufficient to melt the adhesive composition. Spo

The "3203285" method of attachment may also include feeding the optical fiber into a fiber-receiving channel defining the inner surface of the ferrule, and in contact with the adhesive composition. The method of attachment may also include cooling the adhesive composition.

[0058] The adhesive composition may be placed inside the ferrule and make contact with the inner surface of the ferrule. The adhesive composition may contain a partially cross-linked resin prior to the heating step. The adhesive composition may contain a partially cross-linked resin after the cooling step. The partially cross-linked resin may contain poly (phenylene sulfide). The adhesive composition may be in solid form prior to the heating step. The heating step may be performed using a laser with a power of at least 100 W and lasts less than 15 seconds until the adhesive composition is allowed to melt. The cooling step takes less than 5 minutes until the adhesive composition solidifies and partially cross-links to attach the optical fiber. In one embodiment, the coupling agent may be a silane coupling agent, and the adhesive composition may contain from about 0.1 to about 10 parts by weight of the silane coupling agent per 100 parts of poly (phenylene sulfide).

[0059] For purposes of describing and defining the present invention, it should be noted that the term "about" is used herein to represent the inherent degree of uncertainty that can be attributed to any quantitative comparison, value, measurement, or other representation. The term "about" is also used herein to represent the extent to which a quantitative representation can deviate from a given reference value without altering the essential function of the subject matter.

[0060] It should be noted that terms such as, for example, "preferably", "commonly" and "typically", when used herein, are not used to limit the scope of the claims or to imply that certain features are critical, relevant or even valid for the structure or function of the reservations. Instead, the terms are merely intended to identify specific aspects of one embodiment of the present invention, or to highlight alternative or additional features that may or may not be used in a particular embodiment of the present invention.

ΕΡ3203285Β1

[0061] It should be noted that one or more of the following claims use the term "where" as a transitional expression. For the purposes of defining this technology, it should be noted that the term is introduced in the claims as an open-ended transitional expression that is used to enumerate a number of structural features and should be interpreted in a similar manner to the more commonly used preamble terms "comprising" and "including" .

[0062] It should be understood that any two quantitative values ​​assigned to a property may constitute the range of that property, while all combinations of ranges made from all of the quantified values ​​of a given property are contemplated herein.

[0063] Having described the subject matter of the present invention in detail and by reference to specific embodiments thereof, it should be noted that the various details disclosed herein should not be taken as implying that these details refer to elements that are essential components of the various embodiments described herein. in this document, even where the specific item is illustrated in each of the drawings that accompany this description. Instead, the claims appended hereto are to be taken as the sole representation of the scope of the present invention and the corresponding scope of the various embodiments described herein. Moreover, it will be apparent that modifications and variations are possible without departing from the scope of the appended claims.

[0064] Embodiments of the invention include the following:

[1] Optical connector for terminating an optical fiber, the optical connector comprising:

a ferrule, the ferrule including a fiber-receiving channel defining an interior surface;

an optical fiber extending through the fiber-receiving channel; and an adhesive composition, the adhesive composition being disposed within the fiber-receiving channel and contacting the inner surface of the ferrule and the optical fiber, the adhesive composition comprising:

ΕΡ3203285Β1 partially cross-linked resin which is a polymer; and a coupling agent that provides chemical coupling between the polymer and at least one of the optical fiber and the ferrule, the adhesive composition comprising from about 0.1 to about 10 parts by weight of the coupling agent per 100 parts by weight of the partially cross-linked resin.

[2] Optical connector according to [1] above, wherein the partially cross-linked resin is one chemical compound.

[3] Optical interface according to [2] above, wherein one chemical is selected from the group consisting of polyphenylene sulfide, poly (phenylene oxide), polyamideimide, liquid crystal polymer, polyether ether ketone and cyclic olefin copolymer.

[4] Optical connector according to [2] or [3] above, wherein the partially cross-linked resin is polyphenylene sulfide).

[5] Optical connector according to [4] above, wherein the coupling agent is a silane coupling agent, the adhesive composition comprising from about 0.1 to about 10 parts by weight of the silane coupling agent per 100 parts of polyphenylene sulfide).

[6] The optical connector of any one of [1] to [5] above, wherein at least about 5% by weight of the partially cross-linked resin is cross-linked and at least about 5% by weight of the partially cross-linked resin is not cross-linked.

[7] The optical connector according to any one of [1] to [6] above, wherein the partially cross-linked resin has a melting point of at least about 290 ° C.

[8] A ferrule adhesive system for use in an optical connector for terminating an optical fiber, where the ferrule adhesive system comprises:

a ferrule including a fiber receiving channel defining an interior surface; and an adhesive composition, whereby:

The ΕΡ3203285Β1 adhesive composition is positioned in the fiber receiving channel of the ferrule and contacts the inner surface of the ferrule;

the adhesive composition comprises a partially crosslinkable resin, the partially crosslinkable resin comprising poly (phenylene sulfide); and the adhesive composition is a solid material without attaching an optical fiber to the fiber receiving channel of the ferrule.

[9] The ferrule adhesive system according to [8] above, wherein the adhesive composition additionally comprises a coupling agent, the coupling agent comprising at least one of alkoxysilane, oximosilane, acetoxysilane, zirconate, titanate, silane with an epoxy ring at one end and trimethoxy a functional group at the other end, or combinations thereof.

[10] The ferrule adhesive system according to [8] or [9] above, wherein the adhesive composition comprises from about 0.1 to about 10 parts by weight of a coupling agent per 100 parts by weight of the partially cross-linked resin

[11] The ferrule adhesive system according to any one of [8] to [10] above, wherein the coupling agent is pre-reacted with the partially crosslinkable resin by contacting a mixture of coupling agent and an organic solvent with the partially crosslinkable resin.

[12] The adhesive system of the ferrule according to any one of [8] to [11] above, wherein the ferrule is adapted to receive an optical fiber but does not currently contain such a fiber.

[13] The method of attaching an optical fiber to a ferrule comprises the following steps:

providing a ferrule adhesive system, the ferrule adhesive system comprising the ferrule and the adhesive composition;

heating the adhesive composition to a temperature sufficient to melt the adhesive composition;

ΕΡ3203285ania1 of feeding an optical fiber to a fiber-receiving channel defining the inner surface of the ferrule and contacting the adhesive composition; and cooling the adhesive composition;

wherein:

the adhesive composition is placed inside the ferrule and contacts the inner surface of the ferrule;

the adhesive composition comprises a partially crosslinkable resin prior to the heating step;

the adhesive composition comprises a partially crosslinkable resin after the cooling step.

[14] The method of [13] above further comprises heating the partially crosslinkable resin in the presence of air at a temperature of at least about 300 ° C to cross-link at least some of the polymer chains of the partially crosslinkable resin.

[15] A method according to [13] or [14] above, wherein the partially crosslinkable resin comprises polyphenylene sulfide).

[16] The method of any one of [13] to [15] above, wherein the adhesive composition is in solid form prior to the heating step.

[17] The method of any one of [13] to [16] above, wherein the heating step is performed using a laser of at least 100 W power for less than 15 seconds for the adhesive composition to melt, and wherein the step of cooling takes less than 5 minutes, until the adhesive composition solidifies and partially cross-linked to fix the optical fiber.

[18] An optical connector for terminating an optical fiber, the optical connector comprising:

a ferrule, the ferrule including a fiber-receiving channel defining an interior surface;

an optical fiber extending through the fiber receiving channel, and

A "3203285" 1 adhesive composition, wherein the adhesive composition is disposed in the fiber receiving channel of the ferrule and contacts the inner surface of the ferrule and the optical fiber, wherein the adhesive composition comprises a partially cross-linked resin in an amount greater than or equal to about 30% by weight of the adhesive composition.

[19] The optical connector of item [18] above, wherein the adhesive composition further comprises a coupling agent in an amount less than or equal to about 30% and greater than about 0.1% by weight of the adhesive composition.

[20] Optical connector according to [18] or [19] above, wherein the coupling agent comprises at least one of an alkoxysilane, oximosilane, acetoxysilane, zirconate, titanate, silane with an epoxy ring at one end and a trimethoxy functional group at the other end, or combinations of them.

[21] The optical connector according to any one of [18] to [20] above, wherein the partially cross-linked resin is one chemical.

[22] Optical connector according to [21] above, wherein the partially cross-linked resin is poly (phenylene oxide), polyamideimide, liquid crystal polymer, polyether ether ketone, cyclic olefin copolymer or combinations thereof.

[23] Optical connector according to [21] above, wherein the partially cross-linked resin is polyphenylene sulfide).

[24] The optical connector according to any one of [18] to [23] above, wherein the adhesive composition comprises a partially cross-linked resin in an amount greater than or equal to about 50% by weight of the adhesive composition.

[25] The optical connector of any of items [18] to [24] above, wherein the adhesive composition comprises a partially cross-linked resin in an amount greater than or equal to about 90% by weight of the adhesive composition.

ΕΡ3203285Β1

[26] A ferrule adhesive system for use in an optical connector for terminating an optical fiber, where the ferrule adhesive system comprises:

a ferrule including a fiber receiving channel defining an interior surface; and an adhesive composition, whereby:

the adhesive composition is positioned in the fiber-receiving channel of the ferrule and contacts the inner surface of the ferrule;

the adhesive composition includes a partially crosslinkable resin in an amount greater than or equal to about 50% by weight of the adhesive composition; and the adhesive composition is a solid material without attaching an optical fiber to the fiber receiving channel of the ferrule.

[27] The ferrule adhesive system according to item [26] above, wherein the adhesive composition further comprises a coupling agent in an amount less than or equal to about 30% and greater than about 0.1% by weight of the adhesive composition.

[28] A ferrule adhesive system for use in an optical connector for terminating an optical fiber, where the ferrule adhesive system comprises:

a ferrule including a fiber receiving channel defining an interior surface; and an adhesive composition, whereby:

the adhesive composition is positioned in the fiber-receiving channel of the ferrule and contacts the inner surface of the ferrule;

the adhesive composition comprises a partially crosslinkable resin, the partially crosslinkable resin containing polyphenylene sulfide); and the adhesive composition is a solid material without attaching an optical fiber to the fiber receiving channel of the ferrule.

ΕΡ3203285Β1

[29] A method of attaching an optical fiber to a ferrule, comprising the steps of:

providing a ferrule adhesive system, the ferrule adhesive system comprising a ferrule and an adhesive composition;

heating the adhesive composition to a temperature sufficient to melt the adhesive composition;

feeding an optical fiber into a fiber-receiving channel defining the inner surface of the ferrule and in contact with the adhesive composition; and cooling the adhesive composition;

wherein:

the adhesive composition is placed inside the ferrule and contacts the inner surface of the ferrule;

the adhesive composition comprises a partially crosslinkable resin prior to the heating step;

the adhesive composition comprises a partially crosslinkable resin after the cooling step.

the adhesive composition is in solid form prior to the heating step;

the heating step is carried out using a laser with a power of at least 100 W and takes less than 15 seconds until the adhesive composition is melted; and the cooling step takes less than 5 minutes, until the adhesive composition is solidified and partially cross-linked to secure the optical fiber.

[30] The method of [29] above, further comprising heating the partially crosslinkable resin in the presence of air at a temperature of at least about 300 ° C to cross-link at least some polymer chains of the partially crosslinkable resin.

ΕΡ3203285Β1