Question: What year was the high strength synthetic fiber, which was the subject of a lawsuit between DuPont and Kolon Industries, developed?

Context paragraphs:
Reinforced thermoplastic pipe: Reinforced thermoplastic pipe (RTP) is a generic term referring to a reliable high strength synthetic fibre (such as glass, aramid or carbon), initially developed in the early 1990s by Wavin Repox, Akzo Nobel and by Tubes d'Aquitaine from France, who developed the first pipes reinforced with synthetic fibre to replace medium pressure steel pipes in response to growing demand for non-corrosive conduits for application in the onshore oil and gas industry, particularly in the Middle East.

Taklon: Taklon is the common name for a synthetic fiber used in artist-quality paint, makeup and pin stripe brushes.  It is a smooth, soft, and somewhat fragile polyester derivative devoid of any protein component or allergen elements and is therefore used in the cosmetic industries as a "green," "vegan," "allergy free" or synthetic alternative to animal hair brushes.

Polybenzimidazole fiber: Polybenzimidazole (PBI, short for poly[2,2’-("m"-phenylen)-5,5’-bisbenzimidazole]) fiber is a synthetic fiber with a very high melting point.  It has exceptional thermal and chemical stability and does not readily ignite.  It was first discovered by American polymer chemist Carl Shipp Marvel in the pursuit of new materials with superior stability, retention of stiffness, toughness at elevated temperature.  Due to its high stability, polybenzimidazole is used to fabricate high-performance protective apparel such as firefighter’s gear, astronaut space suits, high temperature protective gloves, welders’ apparel and aircraft wall fabrics.  In recent years, polybenzimidazole found its application as a membrane in fuel cells.

Vinylon: Vinylon, also known as Vinalon, is a synthetic fiber produced from polyvinyl alcohol, using anthracite and limestone as raw materials.  Vinylon was first developed in 1939 by Ichiro Sakurada, Ri Sung Gi, and H. Kawakami.  Production of this fiber was delayed for World War II.  The fiber was largely ignored in Korea until Ri defected to North Korea in 1950.  Trial production began in 1954 and in 1961 the massive February 8 Vinylon Complex was built in Hamhung.  Vinylon's widespread usage in North Korea is often pointed to as an example of a success of the "juche" philosophy, and it is known as the "juche" fiber.

M5 fiber: M5 fiber (polyhydroquinone-diimidazopyridine or PIPD) is a high-strength synthetic fiber first developed by the Dutch chemical firm AkzoNobel.  It is produced in the United States by the Magellan Systems International, which became a division of DuPont.

Robert Boyer (chemist): Robert Allen Boyer (September 30, 1909 in Toledo, Ohio – November 11, 1989 in Dunedin, Florida) was a chemist employed by Henry Ford, he was extremely proficient at inventing ways to convert soybeans into paints and plastic parts used on Ford automobiles.Robert Allen Boyer, your average “B” chemistry student was given an extraordinary opportunity that changed his future and the future of automobile production in the U.S. (Plastic) Boyer, born on 30 September 1909 in Toledo, Ohio was given this chance when Ford hired his father to run the nation's oldest hotel, the Wayside Inn, in South Sudbury, Massachusetts.  Ford frequented the inn and that is where Boyer was discovered.  Ford claimed that Boyer had a “keen active mind”.  He asked Boyer to enroll in the new Henry Ford Trade School and participate in its unique work-study program instead of following his plans to enter Andover prep school and then Dartmouth College (Shurtleff).  Boyer excelled in the Ford Trade School and took to exploring concepts such as how to manufacture synthetic wool from soybeans.  These were the types of problems that stumped the experts (Plastic).  Boyer graduated the Ford Trade School at the age of 21 with a promising chemistry career in front of him.  He started this career as the head of the soybean lab at the Edison Institute (Shurtleff).  Here Boyer’s career took off.  He started working to use soybeans in ways they had never been used before.  Boyer has done things from extracting lubricating and paint oils from the soybean to creating a synthetic wool made from soybeans and pressing insulating varnish for starters and generators (Plastic).  One of Boyer’s first projects began in 1932 and included building “a small solvent extractor to separate the bean into soy oil and protein-rich meal” (Shurtleff).  The soybean oil became the most crucial commercial soy products on Ford cars.  In 1934 the five to eight coats of lacquer that cars previously had been finished with was replaced with a synthetic baked enamel paint which contained about 35% soy oil.  This new synthetic paint with soy oil saved considerable time and money.  In 1937, Boyer developed a curved plastic sheet which he hoped would replace steel in the auto bodies of ford cars.  He was so confident in his product that he took an axe to it in the middle of a crowd of reporters and critics.  He also jumped up and down on the curved sheet.  When there was no bending in the sheet and no shattering due to the axe and the weight of him jumping on the sheet, people were astounded (shurtleff).  This soy protein plastic sheet consist of 70% cellulose and 30% resin binder pressed into cloth.  “The new rust-free, dent-proof plastic was reportedly 50% lighter and 50% cheaper to produce than steel” (Shurtleff).  This new plastic body cut the total weight of the car from 3,000 lb.  to 2,000 (Dearborn).  The sheets look like polished steel and can be bent but just snap back into place, therefor when caught in fender benders, the fender would bounce back like “rubber balls” (Shurtleff).  Needless to say, this product was a breakthrough in the world of automobile production.  Boyer also used the soy isolates to produce the world's first plant protein fiber in 1938.  (Shurtleff.)  This fiber resembled a soft wool, it was tan in color, had a medium luster and a soft warm feel.  “it has 80% the strength of wool, took the same dyes, had good elongation, and did not wet as easily as wool.” (Shurtleff).  Boyer figured this fiber could be used for upholstery in cars, filling in felt hats, or for clothing.  Boyer changed the way the soybean was used and created innovative products we use daily.

DuPont v. Kolon Industries: DuPont v. Kolon Industries is an intellectual property lawsuit centering on the allegation that Kolon Industries (of ), a South Korea-based company, stole trade secrets concerning the production and marketing of Kevlar from DuPont, an American chemical company.  Kevlar is a high strength synthetic fiber used in applications as diverse as bicycle tires and body armor.  On September 14, 2011, a jury found in favour of DuPont and awarded damages of $919.9 million.  A 2015 settlement reduced the damages to $275 million.

Kolon Industries: Kolon Industries is a Korean manufacturing company.  It was founded in 1957 as Korea Nylon Inc., an early manufacturer in the Korean nylon industry.  It has since expanded to produce chemicals, other materials and fashion.  In 2015 Kolon Industries opened a shopping mall built with shipping containers, the first of its kind in South Korea.  It has a US subsidiary, Kolon USA Inc., selling polyester film and nylon film.

Kevlar: Kevlar is the registered trademark for a para-aramid synthetic fiber, related to other aramids such as Nomex and Technora.  Developed by Stephanie Kwolek at DuPont in 1965, this high-strength material was first commercially used in the early 1970s as a replacement for steel in racing tires.  Typically it is spun into ropes or fabric sheets that can be used as such or as an ingredient in composite material components.

Al-Ca composite: Al-Ca composite is a high-conductivity, high-strength, lightweight composite consisting of sub-micron-diameter pure calcium metal filaments embedded inside a pure aluminium metal matrix.  The material is still in the development phase, but it has potential use as an overhead high-voltage power transmission conductor.  It could also be used wherever an exceptionally light, high-strength conductor is needed.  Its physical properties make it especially well-suited for DC transmission.  Compared with conventional conductors such as aluminium-conductor steel-reinforced cable (ACSR), all aluminium alloy conductors (AAAC), aluminium conductor alloy reinforced (ACAR), aluminium conductor composite reinforced ACCR and ACCC conductor that conduct AC current well and DC current somewhat less well (due to the skin effect), Al-Ca conductor is essentially a single uniform material with high DC conductivity, allowing the core strands and the outer strands of a conductor cable to all be the same wire type.  This conductor is inherently strong so that there is no need for a strong (usually poorly conductive) core to support its own weight as is done in conventional conductors.  This eliminates the "bird caging", spooling, and thermal fatigue problems caused by thermal expansion coefficient mismatch between the core and outer strands.  The Al-Ca phase interfaces strengthen the composite substantially, but do not have a noticeable effect on restricting the mean free path of electrons, which gives the composite both high strength and high conductivity, a combination that is normally difficult to achieve with both pure metals and alloys.  The high strength and light weight could reduce the number of towers needed per kilometer for long distance transmission lines.  Since towers and their foundations often account for 50% of a powerline's construction cost, building fewer towers would save a substantial fraction of total construction costs.  The high strength also could increase transmission reliability in wind/ice loading situations.  The high conductivity has the potential to reduce Ohmic losses.

Supporting paragraphs: DuPont v. Kolon Industries Kevlar
Answer: 1965