Reiwa Chemist Yōko Takatsukasa Reincarnation: Saving Japan with Plastic Material

A Calm State of Mind Can Make Even Fire Itself Cool

As for the title, apparently it was said by a monk who was set on fire at a temple because he was too skinny. I have not confirmed this.

Manager Yokohara and Mr. Murase are fictional characters.

- Toshitsugu Utei

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Generally speaking, Yōko's courage led to the development of the bulletproof vest with the Army Clothing Depot, but the production cost of Conex was high, and therefore, the "prototype bulletproof vest" that was produced was rejected by the army as "too cost-ineffective."

"Well, up to this point, it's as expected."

"No matter how much money the Army has, they won't buy it if it can only stop handgun bullets."

The prototype bulletproof suit was effective against major handgun bullets, including the 8mm Nambu, 9mm Parabellum, and .45 ACP, but it struggled to withstand rifle bullets, including the Type 38 cartridges.

"I'm sorry to the Army, but we were only commissioned for the development because we lack the necessary facilities. It may sound harsh, but that's not something that can match the 'cheap' lives of soldiers."

Cruel as it may be, while stating what was relatively common sense at the time, the sales manager, Yokohara, lit a cigarette.

"People whose lives are more valuable... like ministers or royals, could you sell it to them at a higher price?"

According to the joint development contract with the army, if the prototype bulletproof suit was not officially adopted, it was acceptable to refine it for civilian use. The army's job was essentially to determine the thickness of the fabric required for bullet resistance through testing and to manufacture prototypes. There was no need to disclose military secrets, especially since the fiber itself, Conex, was protected by the patent for the polyamide and interfacial polymerization method that Yōko had obtained. Even if its structure were identified using state-of-the-art spectroscopy at the time, it would be almost impossible to reproduce, and it was deemed fine for the public to know about it.

"That's right. I think it could sell well, especially in Europe with many nobles or in America with a high crime rate and gun culture."

While responding to his subordinate Murase's words, Yokohara exhaled white smoke.

In fact, after this, Teijin's bulletproof vests were purchased by government officials and royals from major powers, and especially after saving the life of Russian Empire Prime Minister Stolypin, the price went well above the already high list price. The Teijin Company couldn't stop laughing.

"But that will also reach its limit eventually. Firstly, there are too few potential buyers. So, we need to find another use and identify a continuous customer base..."

"That's right, but actually, I came up with an idea recently."

"Oh?"

. . .

Later on, Murase visited the Kobayashi Sashiko store in Shibuya. This was a small-town factory that produced fire-resistant clothing for firefighters.

"Aramid fibers?"

"Could you step outside for a moment? We're going to use fire... Here's commercially available cotton fabric, and this is the fabric woven with our aramid fibers."

With the shop owner, Kikutarō Kobayashi, they went outside, and Murase took an experimental device out of his bag. Inside the device, two candles were set up, with cotton fabric on one side and Conex fabric on the other.

"They're both dry, but when we set them on fire..."

"...Hmm, indeed, that, um, fiber fabric is clearly fire-resistant."

When Murase lit both candles, the cotton fabric scorched and eventually caught fire, while the Conex fabric melted slightly at the edges and darkened but didn't do anything significant for a long time.

"The price is quite high, but what do you think?"

"Well... it sure is amazing, but if the Tokyo Metropolitan Police Fire Department buys it, it's a fifty-fifty chance..."

Kobayashi hesitated, but he agreed to make a prototype for now, and the prototype was used by the fire department. The performance of the golden Conex fire-resistant suit was unmatched compared to the previous cotton fire-resistant suits, and its impressive appearance also garnered positive feedback from the field.

"So, we managed to get them to adopt it, but..."

"Cost is still the issue, huh..."

Just like the bulletproof vests, the cost was a barrier, so only the municipalities with established fire departments, Tokyo and Osaka, could implement them. Even in these two cities, due to budget constraints, they could only place orders for about one or two suits a year, so they couldn't scale up production and reduce costs. As the sales team was struggling with this, a Navy officer approached them.

"Sorry to intrude. I'd like to talk about that thread that can't burn..."

It was Captain Tomojirō Chisaka from the Navy. He had become interested in Conex through an introduction from his brother, Takamasa Chisaka, who was the factory manager at the Teijin Yonezawa Plant. The Chisaka family had a long history of serving the Uesugi clan in Yonezawa, and there was a connection to Teijin through Yōko's sister, Fusako.

"...So, you've already commercialized it as fire-resistant clothing?"

"Yes, but due to the high cost, we haven't been able to secure large orders. As a result, we couldn't increase the production scale of Conex, which led to an inability to reduce costs..."

"I see. In that case, I'll try to push for the development of emergency firefighter gear with the Navy high command. If it gets adopted, there may be a need to lower the unit price to some extent..."

"Of course, we'll study that, so please help us with this."

The Navy was keen on improving damage control capabilities as part of enhancing the survivability of their ships. As part of this effort, the equipment improvement for damage control personnel was being considered, and Conex fire-resistant suits seemed attractive to the Navy. Ironically, the fact that it was a material rejected by the Army despite its excellence also helped secure its adoption.

The prototype struggled with a defect that caused it to deteriorate quickly due to salt damage, but this problem was overcome by coating it with a flame-retardant rubber, and in 1913 it was officially adopted as the Type 2 fire-resistant suit, contributing significantly to the protection and capability enhancement of Japanese ship damage control personnel.

Furthermore, as a result of this, the price of Conex dropped, leading to a reduction in the price of fire-resistant clothing for fire departments, and the equipment of the Tokyo and Osaka fire departments was improved. This played a role in rescuing numerous residents from burning houses during the later Great Kantō Earthquake.

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Conex probably underwent research on flame retardant formulations before being taken to Kobayashi's place, as it likely wouldn't work as is. In OTL, Takamasa Chisaka-san appears to establish a silk mill in Nasu at a later date, but in this timeline, he seems to have leveraged his knowledge of textiles acquired while studying under his uncle in Yonezawa. This led to him becoming the factory manager at the Teijin Yonezawa Plan. Even in OTL, Fusako, the MC's sister (the one teased by her older brother Nobusuke), married into the Uesugi clan in Yonezawa. What's going on with these miraculous connections...

- Toshitsugu Utei