News Release
November 15, 2023
Proterial, Ltd.

Silicone Sheath with Superior Sliding Properties
and its Application Product Received
the Minister of Education, Culture, Sports, Science and Technology
Award at the Kanto Region Invention Honors for Fiscal Year 2023
Proterial, Ltd. (hereinafter “Proterial”) has been awarded the Minister of Education, Culture, Sports,
Science and Technology Award at the Kanto Region Invention Honors by the Japan Institute ofInvention and Innovation for its silicone sheath with superior sliding properties and its application
product (invented by Seiichi Kashimura, Masamichi Kishi, Takanobu Watanabe, Kimika Kudo, andMasashi Arai). The award ceremony is scheduled to take place at Hotel Associa Shizuoka on
Wednesday, November 29.
1. Invention
Silicone sheath with superior sliding properties and its application product (Patent number: 6699782)
2. Awardees“Minister of Education, Culture, Sports, Science and Technology Award (MEXT Minister’s Award)”
Seiichi Kashimura,Materials & Processing Research Dept., Electric Wire & Cable Research Laboratory,
Electric Wire& Cable Business Unit, Proterial, Ltd.
Masamichi Kishi,
Materials & Processing Research Dept., Electric Wire & Cable Research Laboratory,
Electric Wire & Cable Business Unit, Proterial, Ltd.
Takanobu Watanabe,Engineering Dept. Ⅰ, Electric Wire & Cable Business Unit, Proterial, Ltd.
Kimika Kudo,
Engineering Dept. Ⅰ, Electric Wire & Cable Business Unit, Proterial, Ltd.
Masashi Arai.
Intellectual Property Dept., R&D Division, Proterial, Ltd.
3. Invention overview(1) BackgroundNow, in clinical practice, healthcare professionals
are required to sterilize medical devices andconnected cables to control infections in hospitals
every time they use these devices. Therefore, it isexpected that more medical facilities will introduce
cables for medical use that have a silicone-based
protective outer layer (a sheath) with excellent
resistance to chemicals and sterilization processes
and excellent biocompatibility. However, siliconebased sheaths have some issues: They become dirty
because of the ease of dust adhering to their surface
due to stickness, they have poor handleability, andProterial, Ltd.
Toyosu Prime Square, 5-6-36 Toyosu, Koto-ku, Tokyo 135-0061, Japanwww.proterial.com

Product using the silicone sheathwith superior sliding properties(Silicone cable for medical use SilMED®)they are not comfortable to patients when they contact the patient’s skin. Therefore, the research team tried
to overcome the stickiness peculiar to silicone by forming an uneven coating film on the sheath surface
using a condensation reaction material as raw material.*1However, this approach brought about a newissue: A gas was generated on the hardening of the raw material, and the gas caused voids in the coatingfilm. Consequently, the voids reduced the strength of the adhesion between the coating film and the sheath,and decreased the sliding properties when the surface was wiped repeatedly (wipe durability).

Coating filmmaterialConventional

The present invention

Condensation reaction type

Addition reaction type

ConvexVoidConvex

SurfaceCoating film

Coating film

No voids

Static friction coefficient(2) Description of the invention
In the present invention, the team focused on the property of the addition-reactive materials*2 that do noteasily generate gas. The team formed a void-free silicone rubber coating film by applying a unique surface
treatment that suppressed gas generation as the coating film material hardened (see Fig. 1). This approachallowed the team to create a silicone sheath that is highly resistant to chemicals in addition to having
superior sliding properties that can prevent the decrease of adhesion strength and wipe durability, whichwere issues with the previous approach (see the table). The silicone sheath with superior sliding properties
can maintain its sliding properties even after 10,000 wipes with a nonwoven fabric impregnated with adisinfectant (see Fig. 2). Additionally, it has been confirmed that the sheath hardly became discolored evenwhen exposed to various types of medical device disinfectants used at hospitals.
More and more medical institutions in Japan and abroad have introduced the product as medical devices
such as ultrasonic diagnostic equipment, endoscopes and catheters increasingly require frequentdisinfection and sterilization. The development and expansion of this technology is expected to broaden inthe future.

Condensation
reaction type

Addition reaction type

Cross section
VoidSheath
Adhesionstrength

Number of times of wiping off (times)

SheathLess than 0.30 MPa

30.30 MPa or more

Fig. 1. The conventional coating film
and the coating film achieved using the invention

Fig. 2. Number of times of wiping off
and static friction coefficient

Table. Properties
Sliding properties
Wipe durability *3 (nonwoven fabricimpregnated with disinfectant *4)
Chemical resistance *5
Biocompatibility

Static friction coefficient: 0.20 or less *6
Static friction coefficient: 0.22 or less (after 10,000 wipes) *3
Hardly discolored (color difference: ⊿E*ab < 2.5 *6)
No cytotoxicity *6 (ISO 10993-5)(3) Patents
14 patents in total granted in foreign countries (U.S., Europe, China, and South Korea) in addition to 4
patents in Japan
Proterial, Ltd.
Toyosu Prime Square, 5-6-36 Toyosu, Koto-ku, Tokyo 135-0061, Japanwww.proterial.com

[Contact for press] Corporate Communications Department, Proterial
https://www.proterial.com/e/contact/
SilMED is a registered trademark or a trademark of Proterial, Ltd.
*1 A material that forms the main product and a by-product made by separating some of compounds as a result of thecombination of multiple compounds. The silicone generates a small amount of gas as a by-product as it hardens.
Hardening causes its volume to contract as well.
*2 A material in which multiple compounds combine to form only the main product. The silicone does not generate any
by-products and its volume contracts very little when hardening.
*3 The sliding properties of the sheath may deteriorate depending on the type of nonwoven fabric used for wiping, themedical device disinfectant and the method of wiping.
*4 Nonwoven fabric impregnated with ethanol for disinfection, such as Sani-Cloth®HB or Soflight™ (Sani-Cloth is atrademark or registered trademark of PDI, Inc. and Soflight is a trademark or registered trademark of Asahi KaseiAdvance Corporation.)*5 Ethanol for disinfection and many other medical device disinfectants*6 This represents a test result, not a guaranteed performance standard.

■About PROTERIAL“Proterial” reflects the essence of our corporate philosophy, which consists of three elements: Mission: “Make thebest quality available to everyone;” Vision: “Leading sustainability by high performance;” and Values:“Unfaltering integrity” and “United by respect.” It combines “pro-” with the word “material.”“Pro-” represents our “three pros”:
 Professional — work that exceeds expectations
Progressive — a spirit that keeps challenging Proactive —an enterprising attitude“Material” refers to the high-performance materials that our original technologies produce and underpinned by
the three pros. With our focus on solving customer issues and bringing new levels of value, we promise tocontribute to the realization of a sustainable society through the products and services that embody our philosophy.

■Proterial, Ltd. — Company Overview
Established: April 1956
Head office: Toyosu Prime Square, 5-6-36 Toyosu, Koto-ku, Tokyo 135-0061, Japan
Capital: 310 million yen (as of March 31, 2023)
Representative: Sean M. StackRepresentative Director, Chairman, President and Chief Executive Officer (CEO)Sales revenue: 1,118.9 billion yen (Term ended March 2023)
History:
1910: Founded as Tobata Foundry Co.
1937: Merged with Hitachi, Ltd.
1956: Established separately as Hitachi Metals Industries, Ltd.
2023: Company separated from the Hitachi Group, and renamed
from Hitachi Metals, Ltd. to Proterial, Ltd.

Proterial, Ltd.
Toyosu Prime Square, 5-6-36 Toyosu, Koto-ku, Tokyo 135-0061, Japanwww.proterial.com