Silicone Coating Agent for Injection Needles

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Solution Overview

Problem

Existing injection needles coated with silicone-based coating agents experience peeling of the coating film, leading to increased friction and pain during multiple uses, necessitating enhanced durability and piercing characteristics.

Innovation Solution

A coating agent comprising a specific ratio of hydroxyl-group-containing polyorganosiloxane, polydiorganosiloxane, and amino-group-containing polyorganosiloxane, which forms a firm film with improved adhesion and lubricating properties, reducing friction and preventing peeling.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a silicone coating agent is applied to the injection needle surface, then the lubricating property is improved and friction is reduced, but the coating film peels off during multiple uses and durability deteriorates

Engineering Contradiction:
Improvelubricating propertyVSAvoiddurability
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The coating agent uses a composite formulation combining polydiorganosiloxane (providing lubricating properties) with amino-group-containing polyorganosiloxane and hydroxyl-group-containing polyorganosiloxane (providing adhesion and durability). This composite material approach allows the coating film to maintain both low friction and resistance to peeling during multiple needle uses.

Inventive Principle:
Principle #40Composite materials

2Object-affected harmful factors

If the coating film is made thinner to reduce pain, then patient comfort is improved, but the coating film peels off more easily and durability is reduced

Engineering Contradiction:
Improvepain during injectionVSAvoiddurability
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The invention optimizes the compositional parameters of the coating agent by controlling the ratios of polydiorganosiloxane, amino-group-containing polyorganosiloxane, and hydroxyl-group-containing polyorganosiloxane. This parameter optimization enables the formation of a thin yet durable coating film that provides adequate lubrication to reduce injection pain while maintaining resistance to peeling through multiple uses.

Inventive Principle:
Principle #35Parameter changes

3Ease of operation

If the coating agent contains more polydiorganosiloxane to enhance lubrication, then friction is reduced, but the coating film adhesion deteriorates and peeling increases

Engineering Contradiction:
Improvefriction reductionVSAvoidcoating film adhesion
Core Design Contradiction:
Ease of operationVSStrength

Solution Approach 1:

The invention establishes specific compositional ratios where polydiorganosiloxane content is controlled at 5-80 mass% of the total coating agent, with amino-group-containing polyorganosiloxane at 10-70 mass% and hydroxyl-group-containing polyorganosiloxane at 5-50 mass%. This balanced parameter configuration ensures sufficient lubrication from polydiorganosiloxane while maintaining strong adhesion through the amino and hydroxyl groups that bond to the needle surface.

Inventive Principle:
Principle #35Parameter changes

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The coating agent significantly enhances the durability and lubricating properties of injection needles, reducing friction and pain during multiple uses while maintaining a stable coating film, thereby improving patient comfort and safety.

Implementation Method 1

a amino-group-containing polyorganosiloxane (3) containing at least one amino group in one molecule thereof

Methodology Applied
Scientific EffectChemical bonding: Chemical Bonding

Implementation Method 2

a hydroxyl-group-containing polyorganosiloxane (1) represented by the following general formula (1)

Methodology Applied
Scientific EffectChemical bonding: Chemical Bonding

Implementation Method 3

The silicone coating agents impart a lubricating property to the injection needle, thereby reducing friction at the time of puncture

Methodology Applied
Scientific EffectLubrication: Lubrication

Data Source

PatentEP3318614B1Coating agent and medical instrument surface treated with coating agent
Publication Date: 2020.02.19 TERUMO KK
  • EP3318614B1 patent drawingFigure 1A~1B
  • EP3318614B1 patent drawingFigure 1C
  • EP3318614B1 patent drawingFigure 2A

AI summary

The present invention provides a coating agent that has enhanced durability and a medical instrument (for example, a needle) that has been coated with the coating agent. The coating agent of the present invention includes a hydroxyl-group-containing polyorganosiloxane (1) represented by the following general formula (1), a polydiorganosiloxane (2) represented by the following general formula (2), and an amino-group-containing polyorganosiloxane (3) represented by the following general formula (3). The polydiorganosiloxane (2) is contained in a proportion of a mass ratio to the amino-group-containing polyorganosiloxane (3) of from 0.7 to 3.0. The hydroxyl-group-containing polyorganosiloxane (1) is contained in a proportion of 2.4 to 5.5 mass%, based on the total mass of the hydroxyl-group-containing polyorganosiloxane (1), the polydiorganosiloxane (2) and the amino-group-containing polyorganosiloxane (3).