JP7218911B2 - Water-dispersed polyurethane resin, method for producing the same, and clothing and leather products using the same - Google Patents

Description

TECHNICAL FIELD The present invention relates to a water-dispersed polyurethane composition (polyurethane resin) , a method for producing the same, and clothes, leather products, waterproof and moisture-permeable fabrics, and hair styling agents using the same.

Patent Literature 1 discloses a fabric having a glass transition temperature near room temperature and exhibiting a peak value of mechanical dynamic loss tangent substantially equal to that of the human body surface in that temperature range. A fabric having such properties can provide a comfortable fit when worn on the human body, both at rest and during exercise.

JP 2016-141709 A

The fabric described in Patent Document 1 is coated with a polyurethane composition. At this time, the polyurethane composition uses an organic solvent as a medium. However, the use of organic solvents is not preferable from the viewpoint of environmental pollution, ozone depletion, and worker safety.

Therefore, the sales channels of polyurethane compositions using organic solvents are becoming restricted, and the development of organic solvent-free (aqueous dispersion type) polyurethane compositions that do not use organic solvents is underway.

The present invention has been made in view of such circumstances, and an object thereof is to provide a water-dispersed polyurethane composition that does not use an organic solvent.

The present invention relates to a water-dispersible polyurethane composition (polyurethane resin) obtained by reacting a diisocyanate compound, a polyol, an internal emulsifier and a chain extender, and having a glass transition temperature in the operating environment temperature range (5 ° C. or higher and lower than 40 ° C.), the loss tangent at 5 ° C. or higher and lower than 40 ° C. is 0.2 or higher and 0.8 or lower, and the polyol is an ethylene oxide adduct of bisphenol A or a propylene oxide adduct of bisphenol A. and wherein the internal emulsifier is an anionic ionomer.

The internal emulsifier has a hydrophilic group. By introducing this into the polymer backbone, it becomes a water-dispersible (self-emulsifiable) polymer. Since the internal emulsifier is introduced into the polymer skeleton, it is less likely to come off than when an external emulsifier is used.

A water-dispersed polyurethane composition produced using the above compound as a polyol has a glass transition temperature within the operating environment temperature range, and has at least one of frequency dependence, water vapor permeability, and temperature-dependent shape memory properties. It becomes a thing.

In the above invention, the anionic ionomer is dimethylolcarboxylic acid (dimethylolbutanoic acid or dimethylolpropionic acid) .

In one aspect of the invention, the polyol is an ethylene oxide adduct of bisphenol A or a propylene oxide adduct of bisphenol A, and the glass transition temperature is 20°C or higher and lower than 40°C, preferably 25°C or higher and 35°C. Below, more preferably 25°C or higher and 30°C or lower.

By using an ethylene oxide adduct of bisphenol A or a propylene oxide adduct of bisphenol A, the glass transition temperature can be set within the above range. Polyurethane compositions having a glass transition temperature within the above range are suitable for use in clothing and leather products.
Since it has a glass transition temperature near the surface temperature of the human body, when it is worn on the surface of the human body, its height decreases and it becomes flexible, and the shape of the contact portion follows the shape of the body surface and changes.

In one aspect of the invention, the loss tangent at 20° C. or higher and lower than 40° C. is preferably 0.2 or higher and 0.8 or lower, and more preferably 0.3 or higher and 0.6 or lower.
In one aspect of the invention, it is preferable that the complex elastic modulus is three times or more in the range where the frequency is 100 times higher.

The loss tangent (Tan δ) is obtained by dividing the contribution of viscosity to the mechanical properties of a material by the contribution of elasticity. The closer the loss tangent is to 0, the closer to an elastic body, and the greater the loss tangent, the closer to a viscous body. If the loss tangent is within the above range at the operating environment temperature, the material will be excellent in fit to the human body regardless of whether it is at rest or during exercise.

In the reference embodiment of the invention, the glass transition temperature is higher than 0° C. and lower than 20° C., and the polyol may be an ethylene oxide adduct of bisphenol A, a propylene oxide adduct of bisphenol A, or polyethylene glycol.

A polyurethane composition produced using the above polyol and having a glass transition temperature within the above range has a large change in water vapor transmission rate across the glass transition temperature. Such polyurethane compositions are suitable for use in waterproof vapor-permeable fabrics.

In the reference embodiment of the invention, the glass transition temperature is 40° C. or higher and 60° C. or lower, and the polyol may be an ethylene oxide adduct of bisphenol A, a propylene oxide adduct of bisphenol A, or polyethylene glycol adipate.

The elastic modulus of a polyurethane composition produced using the above polyol and having a glass transition temperature within the above range changes greatly with respect to the glass transition temperature. Such polyurethane compositions are suitable for use in hair styling agents.

The present invention relates to a method for producing a water-dispersible water-dispersible polyurethane composition in which a diisocyanate compound, a polyol, an internal emulsifier and a chain extender are reacted by a self-emulsification method, wherein the polyol is ethylene oxide of bisphenol A. It is selected from adducts or propylene oxide adducts of bisphenol A, an anionic ionomer (dimethylolbutanoic acid or dimethylolpropionic acid) is selected as the internal emulsifier, and the glass transition temperature is in the operating environment temperature range (5 ° C. or higher and 40 ° C.) , and the composition ratio of the diisocyanate compound, the polyol, the internal emulsifier and the chain extender is set so that the loss tangent at 5 ° C. or higher and lower than 40 ° C. is 0.2 or higher and 0.8 or lower . Provided is a method for producing a water-dispersed polyurethane composition.

In one aspect of the invention, the polyol preferably has a weight-average molecular weight/number-average molecular weight ratio of 2.5 or less.

Thereby, the frequency dependence, water vapor permeability and temperature dependent shape memory can be further enhanced.

In one aspect of the invention, the glass transition temperature is 20° C. or higher and lower than 40° C., the anionic ionomer is dimethylolcarboxylic acid, and the polyol is an ethylene oxide adduct of bisphenol A or a propylene oxide of bisphenol A. It is an adduct and preferably has a loss tangent of 0.2 or more and 0.8 or less at 20°C or more and less than 40°C.

According to the present invention, it is possible to provide a water-dispersible polyurethane composition that does not use an organic solvent. Further, according to the present invention, by setting the glass transition temperature within the operating environment temperature range, the polyurethane composition has at least one of frequency dependence, water vapor permeability, and temperature-dependent shape memory properties.

1 is a diagram showing the relationship between dynamic viscoelasticity and temperature of the polyurethane composition of Test 1. FIG. 1 is a graph showing the relationship between dynamic viscoelasticity and frequency of the polyurethane composition of Test 1. FIG. FIG. 7 is a graph showing the relationship between dynamic viscoelasticity and temperature of the polyurethane composition of Test 7; FIG. 10 is a diagram showing the relationship between dynamic viscoelasticity and frequency of the polyurethane composition of Test 7;

An embodiment of a water-dispersed polyurethane composition (WPU: Waterbone Polyurethane), a method for producing the same, and a product using the same according to the present invention will be described below with reference to the drawings.

(Water-dispersible polyurethane composition)
A water-dispersible polyurethane composition is a polyurethane resin that is made dispersible in an aqueous medium by adding a hydrophilic group to the polymer skeleton. A water-dispersed polyurethane composition (hereinafter abbreviated as "polyurethane composition") according to the present disclosure is obtained by reacting a polyol, a diisocyanate compound, an internal emulsifier and a chain extender.

The compositional ratio of the polyol, diisocyanate compound, internal emulsifier and chain extender is set so that the glass transition temperature of the polyurethane composition is close to the operating environmental temperature of the product to which the polyurethane composition is applied.

Polyols are ethylene oxide adducts of bisphenol A or propylene oxide adducts of bisphenol A.
Depending on the product application, the polyol may be an ethylene oxide adduct of bisphenol A, a propylene oxide adduct of bisphenol A, or polyethylene glycol.
Depending on the product of application, the polyol may be an ethylene oxide adduct of bisphenol A, a propylene oxide adduct of bisphenol A, or polyethylene glycol adipate.

The diisocyanate compound has two or more terminal isocyanate groups. Diisocyanate compounds include, for example, tolylene diisocyanate (TDI) such as 2,4-tolylene diisocyanate and 2,6-tolylene diisocyanate, 4,4′-diphenylmethane diisocyanate (MDI), hexamethylene diisocyanate (HMDI), m- phenylene diisocyanate, p-phenylene diisocyanate, and isophorone diisocyanate. These may be used alone or in combination of two or more.

Internal emulsifiers are anionic ionomers such as dimethylolcarboxylic acid. More specifically, the internal emulsifier is dimethylolbutanoic acid (DMBA) or dimethylolpropionic acid (DMPA).

Chain extenders include glycols such as ethylene glycol, 1,4-butanediol and diethylene glycol, amines such as diethanolamine, triethanolamine, tolylenediamine and hexamethylenediamine, TDI (tolylene diisocyanate) adduct of trimethylolpropane, Polyisocyanates such as triphenylmethane triisocyanate, bis(2-hydroxyethyl)hydroquinone, ethylene oxide adduct of bisphenol A and bisphenol A propylene oxide.

(Production method)
The polyurethane composition can be produced by a self-emulsification method in which an internal emulsifier having a hydrophilic group is introduced into the polymer backbone. More specifically, the polyurethane composition according to this embodiment is obtained by reacting a polyol, a diisocyanate compound, an internal emulsifier and a chain extender by a one-shot method or a prepolymer method.

Polyols, diisocyanate compounds, internal emulsifiers and chain extenders are selected from the materials described above. It is preferable to use dehydrated polyols and chain extenders. A polyol and a chain extender are used by dissolving them in an organic solvent. Methyl ethyl ketone (MEK), toluene, etc. are used as the organic solvent.

The reaction is carried out under nitrogen atmosphere. The reaction temperature is selected from 20° C. to 70° C. (preferably 40° C. to 60° C.), and the reaction time is selected from the range of 1 hour to 24 hours.

An example of manufacturing by the one-shot method is given below.
In the one-shot method, the internal emulsifier is added all at once to the polyol and diisocyanate compound in the organic solvent, and the chain extender dissolved in the organic solvent is added dropwise.

After the dropping is completed, an additional diisocyanate compound is added. Addition of the diisocyanate compound is carried out mainly for the purpose of viscosity adjustment.

On the way, an increase in the viscosity of the reaction solution is checked, and an organic solvent is added appropriately so as to maintain a predetermined viscosity. The prescribed viscosity is appropriately set according to the product to which the polyurethane composition is applied. For example, in the case of coating on a fabric, it is preferable to set the viscosity to 10 Pa·Sec (=10000 mPa·S) or higher in order to prevent strike-through. For example, when applied to a hair styling agent, the viscosity should be 2 to 3 Pa·Sec.

After confirming that the NCO content has reached the theoretical value, a monohydric alcohol and an organic solvent are added to stop the reaction, and the reaction solution is cooled to room temperature. The NCO content is confirmed by titration or infrared absorption spectroscopy. Considering the boiling point and reactivity, ethanol (EtOH) is suitable as the monohydric alcohol. The theoretical value of the NCO content is the value at which the concentration of the active hydrogen group H- that reacts with NCO- is the same (equimolar).

Next, a neutralizing agent dissolved in an organic solvent is added dropwise to the reaction solution for neutralization over 20 to 30 minutes. Triethylamine (TEA, Et ₃ N) or the like is used as the neutralizing agent. "Neutralization" means adjusting to pH 7.0±1.0. A stable emulsion can be obtained by neutralization.

Ion-exchanged water is added dropwise to the solution after the neutralization reaction, the organic solvent is removed by azeotropy, and then the solution is cooled to room temperature to obtain a water-dispersed polyurethane composition. When cooling to room temperature, forced cooling in a short time may cause the solution to solidify, so cooling is preferably left to cool.

Polymer materials exist in a state in which crystalline and non-crystalline portions are mixed with each molecular chain randomly entangled, and the temperature/frequency dependence depends on the viscoelasticity of the molecules. The molecular chains of the polyurethane composition have a storage modulus at low temperatures and are in a glassy state in which segmental motion is frozen. However, the storage modulus gradually decreases with an increase in temperature, allowing movement at the segmental level (Brownian motion) (glass transition region). When the temperature is further increased, the molecular chains are allowed to move, but if there is entanglement, a region (rubber-like plateau region) appears that does not relax and the storage modulus does not decrease.

The change in temperature of the polymer can be converted to a change in frequency by the Arrhenius equation or the Williams-Randell-Ferry equation. That is, the law that a change in temperature by T is equivalent to a change in frequency by f can be applied over a wide range of temperatures and frequencies, and to both the storage modulus and the loss modulus simultaneously. can find out.

The more steep the transition angle of tan δ, the stronger the frequency dependence of the polyurethane composition.

The polyurethane composition according to the above embodiments can be applied to clothing, leather products, waterproof and moisture-permeable fabrics, and shape-memory products.

(Application example 1: clothing and leather products)
As used herein, "garment" includes exercise underwear, shaping underwear, post-surgical rehabilitation wear, supporters, medical bandages, wigs, and the like. The polyurethane composition according to this embodiment is particularly suitable for clothing that comes into direct contact with the human body (for example, straps for women's underwear, leggings, medical bandages, wigs, supporters, etc.).

As used herein, leather products include car seats, shoes, bags, gloves, and those used for sports (mitts, protectors, etc.).

The polyurethane composition can be applied to clothing by processing it into a film, attaching a film to the fabric, printing it on the surface of the fabric, or impregnating the fabric with it. Polyurethane compositions can be applied to leather as well as fabrics.

The temperature of the environment in which the clothes are supposed to be used is 5°C or higher and lower than 40°C. The envisaged operating environment temperature of clothing that directly touches the human body is 20°C or higher and lower than 40°C. The same applies to leather products.

The polyurethane composition has a loss tangent (tan δ) of 0.2 or more and 0.8 or less, preferably 0.3 or more and 0.6 or less, more preferably 0.4 or more and 0.6 or less. Designed. In order to set the loss tangent (tan δ) within this range, the glass transition temperature (Tg) should be set within the operating environment temperature range.

The composition ratio (molar equivalents) of the polyurethane composition excluding the additional diisocyanate compound is polyol: diisocyanate compound: internal emulsifier: chain extender = 10 to 40: 50: 5 to 20: 5 to 20, preferably polyol: diisocyanate. Compound: internal emulsifier: chain extender = 20:50:15:15. At this time, the equivalent ratio of the isocyanate group (--NCO) to the hydroxyl group (--OH) is 1:1. The --NCO/--OH equivalent ratio including the additional diisocyanate compound is 1-1.15.

The polyurethane composition having the above composition ratio has the property that the complex elastic modulus (E ^* ) changes depending on the frequency (deformation rate). The polyurethane composition having the above composition ratio should be designed so that the complex elastic modulus (E ^* ) is 3 times or more, preferably 3.5 times or more, in the range where the frequency is 100 times higher. For example, it is preferable that the complex elastic modulus at a frequency of 100 Hz at the operating environment temperature be three times or more larger than the complex elastic modulus at a frequency of 1 Hz at the same temperature. The complex modulus (E ^* ) can be derived from the storage modulus (E') and the loss modulus (E''). The square of the complex modulus (E ^* ) corresponds to the sum of the square of the storage modulus (E') and the square of the loss modulus (E''). Since the loss modulus (E'') is one order of magnitude smaller than the storage modulus (E'), the complex modulus (E ^* ) is substantially governed by the value of the storage modulus (E').

The closer the glass transition temperature of the polyurethane composition to the temperature of the environment in which it is used, the stronger the frequency dependence it exhibits. The glass transition temperature of the polyurethane composition can be controlled primarily by adjusting the molecular weight of the polyol. The use of higher molecular weight polyols lowers the glass transition temperature of the polyurethane composition. When a polyol having a large Mw (weight average molecular weight)/Mn (number average molecular weight) is used, the glass transition temperature of the polyurethane composition is lowered. The smaller the Mw/Mn, the steeper the molecular weight distribution. When a polyol having a narrow molecular weight distribution is used, the frequency dependence of the polyurethane composition becomes remarkable.

For example, when a polyol having an Mw of 500 or more and 2000 or less, preferably 500 or more and 1500 or less, and a Mw/Mn value of 3.8 or less, preferably 2.5 or less is used, a highly frequency-dependent polyurethane composition can be obtained. . Garments incorporating highly frequency dependent polyurethane compositions provide increased stiffness, muscle support and shock absorption during exercise. When applied to clothing such as bulletproof vests, the rigidity during exercise can be further increased by selecting and using a polyol with a smaller Mw/Mn value.

(Application example 2: Moisture-proof and breathable cloth)
Waterproof and breathable fabrics include raincoats, various humidity control membranes, and the like. The operating environmental temperature of the waterproof and moisture-permeable fabric is more than 0°C and less than 20°C. Mw of the polyol in the polyurethane composition may be 300 or more and 3000 or less. When a polyol having a Mw/Mn value of 3.8 or less, preferably 2.5 or less is used for the polyurethane composition, a polyurethane composition that exhibits high moisture permeability when the temperature rises can be obtained.

The glass transition temperature (Tg) of the polyurethane composition is higher than 0°C and lower than 20°C, preferably 0°C or higher and 15°C or lower. The glass transition temperature range is preferably within ±7°C, preferably within ±5°C. "Glass transition temperature region" is DMA (Differential Mechanical
Analysis (Analyzer)) is defined by the Onset and Offset temperatures. The polyurethane composition has a large change in water vapor transmission rate around the glass transition temperature.

(Application example 3: Shape memory product)
Shape memory products include hair styling agents, autoventilation clothing, and the like. The environment in which shape memory products are used is -40° C. or higher and 120° C. or lower, and varies depending on the type of product. In the case of a hair styling agent, the ambient temperature for use is 40° C. or higher and 60° C. or lower (temperature when using a dryer). Hair styling agents include hair waxes and the like. Mw of the polyol in the polyurethane composition may be 300 or more and 3000 or less. When a polyol having a Mw/Mn value of 3.8 or less, preferably 2.5 or less is used for the polyurethane composition, a polyurethane composition having a high shape memory property can be obtained.

The glass transition temperature (Tg) of the polyurethane composition applied to the styling agent is 40°C or higher and 60°C or lower. The glass transition temperature range is preferably within ±5°C. The complex elastic modulus of the polyurethane composition changes greatly around the glass transition temperature. When heated above the glass transition temperature, the shape is restored.

(Test 1)
Polyurethane compositions were produced according to the above embodiments using the following materials.
Polyol: ethylene oxide adduct of bisphenol A (BEO) (manufactured by Aoki Oil Industry Co., Ltd.)
Organic solvent: methyl ethyl ketone (MEK)
Diisocyanate compound: diphenylmethane diisocyanate (MDI)
Internal emulsifier: dimethylolbutanoic acid (DMBA)
Chain extender: ethylene glycol (EG)
Neutralizing agent: Triethylamine (TEA)

Table 1 shows the composition of the raw materials (including additional parts).

(Tests 2-4)
A polyurethane composition was produced in the same manner as in Test 1 using the same materials as in Table 1, except that the molecular weight of BEO in Test 1 was changed.

(Test 5)
A polyurethane composition was produced in the same manner as in Test 1 using the same materials as in Table 1, except that BEO in Test 1 was replaced with polypropylene glycol (PPG).

(Test 6)
A polyurethane composition was prepared in the same manner as in Test 1 using the same materials as in Table 1, except that BEO in Test 1 was replaced with polyethylene glycol adipate (PEGA).

(Test 7)
A polyurethane composition was produced in the same manner as in Test 1 using the same materials as in Table 1, except that BEO in Test 1 was replaced with polytetramethylene ether glycol (PTMG).

(Test 8)
A polyurethane composition was produced in the same manner as in Test 1 using the same materials as in Table 1, except that BEO in Test 1 was replaced with polyethylene glycol (PEG).

(Dynamic viscoelasticity evaluation)
The dynamic viscoelasticity of a nylon woven fabric to which the polyurethane composition of Test 1 was applied multiple times along the warp was evaluated. As a comparison (blank), a nylon fabric not coated with the polyurethane composition was also evaluated in the same manner.

FIG. 1 shows the relationship between the dynamic viscoelasticity of the polyurethane composition of Test 1 and temperature. In the figure, the horizontal axis is temperature (° C.), the vertical axis (left) is log|E ^* |, and the vertical axis (right) is loss tangent (tan δ). Here, tan δ is the tangent of the ratio (E″/E′) of the loss elastic modulus (E″) to the storage elastic modulus (E′) at a frequency of 1 Hz.

FIG. 2 shows the relationship between the dynamic viscoelasticity of the polyurethane composition of Test 1 and frequency. In FIG. 2, the horizontal axis is frequency (Hz), the vertical axis (left) is log|E ^* |, and the vertical axis (right) is loss tangent (tan δ). Here, tan δ is the tangent of the ratio (E″/E′) of the loss elastic modulus (E″) to the storage elastic modulus (E′) at a frequency of 1 Hz.

The polyurethane composition of Test 1 has a glass transition temperature (Tg) of about 25°C, a tan δ of 0.54 at 30°C (1 Hz), a log|E ^* | ^* (10 Hz)/E ^* (0.1 Hz) was 3.9.

On the other hand, tan δ at 30 ° C. (1 Hz) of Blank is 0.06, log | E ^* | at 30 ° C. (1 Hz) is 6.12, E ^* (10 Hz) / E ^* (0.1 Hz) at 30 ° C. .1.

According to FIG. 1, the tan δ of the fabric coated with the polyurethane composition of Test 1 changed greatly in the range of 25° C. to 35° C., which corresponds to the human body surface temperature. On the other hand, the blank nylon fabric did not show a large change in tan δ in the range of 25°C to 35°C, and further in the range of 5°C to 40°C.

According to FIG. 2, the tan δ of the polyurethane composition of Test 1 changed from 0.45 to 0.58 and the log|E ^* | from 6.8 to 7.55 in the range of 0.1 Hz to 10 Hz. The tan δ of test 1 was a high value exceeding 0.2 in the entire measurement frequency range. This confirms that the polyurethane composition of Test 1 has a high energy absorption capacity. Also, in Test 1, log|E ^* | near 10 Hz was 3.9 times higher than near 0.1 Hz. This result suggests that the garments to which the polyurethane composition of Trial 1 is applied can be functionally differentiated to be softer at rest and stiffer and stiffer during exercise.

The polyurethane composition of Test 1 has a loss tangent of 0.2 or more at the temperature of the environment in which it is used, and thus has high biocompatibility regardless of whether it is at rest or during exercise.

For reference, FIGS. 3 and 4 show the relationship between the elastic modulus of the polyurethane composition of Test 7, temperature and frequency. In FIG. 3, the horizontal axis is temperature (° C.), the vertical axis (left) is storage modulus (E′) and loss modulus (E″), and the vertical axis (right) is loss tangent (tan δ). , the horizontal axis is frequency (Hz), the vertical axis (left) is storage modulus (E′) and loss modulus (E″), and the vertical axis (right) is loss tangent (tan δ). is the tangent of the ratio of E" to E' (E"/E') at a frequency of 1 Hz.

The polyurethane composition of Test 7 had a glass transition temperature of about −25° C., tan δ at 30° C. (1 Hz) of 0.1, E′ at 30° C. (1 Hz) of 10 MPa, and E″ at 30° C. (1 Hz) of 1 MPa. there were.

According to FIG. 4, the tan δ, E′ and E″ of the polyurethane composition of Test 7 did not change as significantly as in Test 1 between 0.1 Hz and 100 Hz. It was as low as around 0.1 in all regions, which confirmed that test 7 had almost no energy absorption ability.In addition, test 7 had almost no frequency dependence of E', so it was applied to clothing. However, there is no difference in function between rest and exercise.

(Frequency Dependence, Water Vapor Permeability and Shape Memory)
Each of the polyurethane compositions of Tests 1 to 8 was processed into a film, and frequency dependence, water vapor permeability and temperature dependence were evaluated. Table 2 shows the results.

According to Table 2, the polyurethane compositions of Tests 1-3 change in storage modulus depending on the change in frequency. The frequency of the human body surface during slow motion is about 0.1 Hz to 1 Hz. On the other hand, the frequency of the surface of the human body when subjected to impact due to exercise is about 10 Hz to 50 Hz. The polyurethane compositions of Tests 1-3 are soft at low frequencies (0.1 Hz to 1 Hz) and hard at high frequencies (10 Hz to 50 Hz). Clothing to which a polyurethane composition having such properties is applied easily follows slow movements and provides a high degree of fit. On the other hand, since good shock absorption and a sense of fixation can be obtained during exercise, it can assist the breasts, muscles, joints, etc., thereby improving sports performance and reducing fatigue.

According to Table 2, the polyurethane compositions of Tests 1, 4, and 5 exhibited more than double the water vapor permeability when the temperature was changed from 0°C to 40°C. On the other hand, the polyurethane composition of Test 7 did not change its water vapor permeability even when the temperature changed.

According to Table 2, the complex elastic modulus of the polyurethane compositions of Tests 1 and 6 increased as the temperature decreased. On the other hand, in the polyurethane compositions of Tests 7 and 8, almost no change in complex elastic modulus due to temperature was observed.

Claims (11)

A water-dispersible polyurethane resin obtained by reacting a diisocyanate compound, a polyol, an internal emulsifier, and a chain extender, comprising:
a glass transition temperature of 5°C or higher and lower than 40°C;
The loss tangent at 5°C or higher and lower than 40°C is 0.2 or higher and 0.8 or lower,
The polyol is an ethylene oxide adduct of bisphenol A or a propylene oxide adduct of bisphenol A,
the internal emulsifier is an anionic ionomer,
The anionic ionomer is a water-dispersible polyurethane resin in which dimethylolbutanoic acid or dimethylolpropionic acid is used. The water-dispersible polyurethane resin according to claim 1, wherein the glass transition temperature is 20°C or higher and lower than 40°C, and the loss tangent at 20°C or higher and lower than 40°C is 0.2 or higher and 0.8 or lower. 3. The polyurethane resin according to claim 1 or 2, wherein the complex elastic modulus is 3 times or more in the range where the frequency is 100 times higher. 4. The water-dispersible polyurethane resin according to any one of claims 1 to 3, wherein the composition ratio is polyol: diisocyanate compound: internal emulsifier: chain extender = 20:50:15:15 in terms of molar equivalents. A garment comprising the water-dispersible polyurethane resin according to any one of claims 1 to 4. A leather product comprising the water-dispersible polyurethane resin according to any one of claims 1 to 4. A method for producing a water-dispersible water-dispersible polyurethane resin in which a diisocyanate compound, a polyol, an internal emulsifier and a chain extender are reacted by a self-emulsification method, comprising:
the polyol is selected from an ethylene oxide adduct of bisphenol A or a propylene oxide adduct of bisphenol A;
selecting dimethylolbutanoic acid or dimethylolpropionic acid as the internal emulsifier;
The diisocyanate compound, the polyol, the internal emulsifier and the chain so that the glass transition temperature is 5 ° C. or higher and lower than 40 ° C. and the loss tangent at 5 ° C. or higher and lower than 40 ° C. is 0.2 or higher and 0.8 or lower. A method for producing a water-dispersed polyurethane resin in which the composition ratio of an extender is set. 8. The method for producing a water-dispersible polyurethane resin according to claim 7, wherein the polyol has a weight average molecular weight/number average molecular weight ratio of 2.5 or less. The glass transition temperature is 20 ° C. or higher and lower than 40 ° C.,
9. The method for producing a water-dispersible polyurethane resin according to claim 7 or 8, wherein the loss tangent at 20°C or higher and lower than 40°C is 0.2 or higher and 0.8 or lower. 10. The method for producing a polyurethane resin according to any one of claims 7 to 9, wherein the composition ratio is designed so that the complex elastic modulus is 3 times or more in the range where the frequency is 100 times higher. 11. The production of a water-dispersible polyurethane resin according to any one of claims 7 to 10, wherein the composition ratio is polyol: diisocyanate compound: internal emulsifier: chain extender = 20:50:15:15 in terms of molar equivalents. Method.

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