Sheet-like material
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Solution Overview
Problem
Sheet-like materials with a suede-like or nubuck-like surface, impregnated with a polyurethane resin, face challenges in achieving a soft texture while maintaining durability and abrasion resistance, as reducing crystallinity of polycarbonate diol to soften the texture often results in insufficient mechanical strength and abrasion resistance.
Innovation Solution
A sheet-like material comprising a nonwoven fabric of ultrafine fibers with an average diameter of 0.3 to 7 µm, coated with a polyurethane resin containing a copolymerized polycarbonate diol with specific molar ratios of C3-5 and C8-12 alkane diols, a polycarbonate diol with C4-6 alkane diol units, and an organic diisocyanate, which has controlled heat quantities of fusion and melting points to balance texture and durability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the crystallinity of polycarbonate diol is reduced to soften the texture, then the texture becomes softer, but mechanical strength and abrasion resistance become insufficient
Solution Approach 1:
The invention uses a composite polyurethane resin system combining polycarbonate diol (providing durability, hydrolysis resistance, and heat resistance) with polyester diol or polyether diol (providing softness and elasticity). This composite approach allows the material to achieve both soft texture and high mechanical strength simultaneously, resolving the contradiction between texture softness and mechanical strength.
Solution Approach 2:
The invention changes the chemical composition parameters of the polyurethane resin by specifying precise ratios of different diol components (polycarbonate diol 20-80 mass%, polyester diol 10-70 mass%, polyether diol 10-70 mass%). By adjusting these compositional parameters, the material achieves optimal balance between texture softness and mechanical strength for practical applications.
2Reliability
If polycarbonate diol with high crystallinity is used to ensure durability, then hydrolysis resistance and weatherability are excellent, but the texture becomes hard
Solution Approach 1:
The invention creates a composite polyurethane resin where polycarbonate diol (20-80 mass%) provides excellent durability, hydrolysis resistance, and weatherability, while polyester diol (10-70 mass%) or polyether diol (10-70 mass%) contributes softness and flexibility. This composite structure resolves the contradiction between reliability and texture softness.
Solution Approach 2:
The invention modifies the resin composition parameters by controlling the ratio of crystalline polycarbonate diol to amorphous polyester/polyether diol components. This parameter optimization allows the material to maintain high reliability through polycarbonate diol while achieving soft texture through the amorphous components.
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 solution provides a sheet-like material with a soft texture, enhanced durability, and improved abrasion resistance, specifically suitable for practical use with a napped surface.
Implementation Method 1
the crystallinity of the polycarbonate diol is reduced... a copolymerized polycarbonate diol of a C6 alkanediol and a C9 alkanediol... a copolymerized polycarbonate diol composed of a C5 alkanediol and a C6 alkanediol... the copolymerized polycarbonate diol (A1) has a heat quantity of fusion (ΔH) of 40 to 100 J/g
Implementation Method 2
a polycarbonate diol (A2) containing a structural unit derived from a C4-6 alkane diol (a3)... The polycarbonate diol (A2) has a heat quantity of fusion (ΔH) of 0 J/g... the elastic resin is a polyurethane resin (D)
Data Source
AI summary
The present invention provides a sheet-like material having soft texture, durability capable of withstanding practical use, and abrasion resistance. The sheet-like material of the present invention is a sheet-like material containing a nonwoven fabric composed of an ultrafine fiber having an average single fiber diameter 0.3 to 7 µm; and an elastic resin, wherein the elastic resin is a polyurethane resin (D) which contains: as essential constituent monomers, a copolymerized polycarbonate diol (A1) which contains a structural unit derived from C3-5 alkane diol (a1) and a structural unit derived from C8-12 alkane diol (a2), the molar ratio of the alkanediol (a2) with respect to the total number of moles of the alkanediol (a1) and the alkanediol (a2) being 50 to 95 mole%; a polycarbonate diol (A2) containing a structural unit derived from a C4-6 alkane diol (a3); an organic diisocyanate (B); and a chain extender (C), and the polyurethane resin (D) satisfies the following conditions (1) to (3): (1) The copolymerized polycarbonate diol (A1) has a heat quantity of fusion (ΔH) o 40 to 100 J/g, the heat quantity of fusion (ΔH) being determined according to a melting point measuring method provided in JIS K7121-1987. (2) The polycarbonate diol (A2) has a heat quantity of fusion (ΔH) of 0 J/g. (3) A difference (ΔTm) in a melting point (Tm) between a mixture (A12) of the copolymerized polycarbonate diol (A1) with the polycarbonate diol (A2) and the copolymerized polycarbonate diol (A1) is 1.5°C or lower, the melting point (Tm) being determined by a melting point measuring method provided in JIS K7121-1987.