JP2022060141A - Urethane prepolymer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a urethane prepolymer which can give a laminate having excellent moisture permeability, and excellent adhesion, hydrolysis resistance, washing durability and feeling.

SOLUTION: A urethane prepolymer has an isocyanate group at a terminal that is a reactant of polyol (A) and polyisocyanate (B), in which the polyol (A) contains at least a polycarbonate polyol (A-1) containing a crystalline polycarbonate polyol (a) having at least a structural unit derived from alkane diol having 6 or more carbon atoms and an EO/PO copolymer polyol (A-2), as a bifunctional polyol, a content of the crystalline polycarbonate polyol (a) in the bifunctional polyol is 20 mass% or more and 50 mass% or less, a content of the polycarbonate polyol (A-1) in the bifunctional polyol is 30 mass% or more, and a molar ratio [EO/PO] of the EO/PO copolymer polyol (A-2) is 25/75 to 80/20.

SELECTED DRAWING: None

COPYRIGHT: (C)2022,JPO&INPIT

Description

The present invention relates to urethane prepolymers, moisture-curable urethane hot melt resin compositions, and laminates.

Moisture-permeable waterproof fabric has both high waterproofness to prevent rain and moisture permeability to reduce discomfort caused by stuffiness when sweating, so it is not only general rain gear but also mountaineering clothes, hiking wear, and sports. It is used for clothing and the like.
As a method for producing a moisture-permeable waterproof fabric, a method in which a base fabric and a film-like material having moisture permeability are bonded to each other via an adhesive is the mainstream. In this case, it is desired that the adhesive also has moisture permeability from the viewpoint of obtaining more excellent moisture permeability.

As a method for producing a moisture-permeable adhesive, for example, in Patent Document 1, a polyol composed of an oxyethylene group having excellent hydrophilicity is used to impart moisture permeability, and a highly crystalline polyester polyol is used. Therefore, a method of imparting adhesiveness has been proposed.
Further, Patent Document 2 proposes an adhesive having adhesiveness and durability using a highly crystalline polycarbonate polyol (for example, Nipponporan 980R) as a polyol component.

International Publication No. 2017/104266 Japanese Patent Application Laid-Open No. 2003-246830

While the conventional adhesive has moisture permeability, the concentration of the polyoxyethylene group of the polyol is high, so that the water resistance is impaired and the durability to washing (hereinafter, also referred to as "washing durability") tends to be poor. There was a problem.
In addition, the adhesive containing a polyester polyol may deteriorate within 2 to 3 years from the start of use due to hydrolysis caused by rain, sweat, washing, etc., and has a problem that it is not suitable for long-term use. ..
Further, when a highly crystalline polycarbonate polyol is used from the viewpoint of improving the adhesiveness, there is a problem that the texture is impaired and the comfort is deteriorated.

The present invention has been made in view of the above-mentioned conventional problems, and is a urethane that has excellent moisture permeability and can provide a laminate having excellent adhesiveness, hydrolysis resistance, washing durability, and texture. Provides a prepolymer. Further, the present invention provides a moisture-curable urethane hot-melt resin composition containing the urethane prepolymer, and a laminate containing these cured products.

That is, the gist of the present invention is the following [1] to [5].
[1] A urethane prepolymer having an isocyanate group at the terminal, which is a reaction product of the polyol (A) and the polyisocyanate (B).
The polyol (A) is used as a bifunctional polyol.
A polycarbonate polyol (A-1) containing a crystalline polycarbonate polyol (a) having at least a structural unit derived from an alkanediol having 6 or more carbon atoms, and a polycarbonate polyol (A-1).
Containing at least EO / PO copolymer polyol (A-2),
The content of the crystalline polycarbonate polyol (a) in the bifunctional polyol is 20% by mass or more, and
The content of the polycarbonate polyol (A-1) in the bifunctional polyol is 30% by mass or more, and the content is 30% by mass or more.
A urethane prepolymer characterized in that the molar ratio [EO / PO] of the EO / PO copolymer polyol (A-2) is 25/75 to 80/20.
[2] The urethane prepolymer according to [1], wherein the content of the EO / PO copolymer polyol (A-2) in the bifunctional polyol is 50 to 70% by mass.
[3] The urethane prepolymer according to [1] or [2], wherein the polyisocyanate (B) contains an aliphatic polyisocyanate and an aromatic polyisocyanate.
[4] A moisture-curable urethane hot-melt resin composition containing the urethane prepolymer according to any one of [1] to [3].
[5] A laminate containing the urethane prepolymer according to any one of [1] to [3] or the cured product of the moisture-curable urethane hot-melt resin composition according to [4].

According to the present invention, it is possible to provide a urethane prepolymer having excellent moisture permeability and capable of providing a laminate having excellent adhesiveness, hydrolysis resistance, washing durability, and texture. Further, it is possible to provide a moisture-curable urethane hot-melt resin composition containing the urethane prepolymer, and a laminate containing these cured products.

It is a schematic explanatory drawing explaining the form of the sample used in the evaluation of an Example. It is explanatory drawing explaining the form of the gear oven used in the evaluation of an Example.

[1] Urethane prepolymer The urethane prepolymer of the present invention is a urethane prepolymer having an isocyanate group at the terminal, which is a reaction product of the polyol (A) and the polyisocyanate (B).
The polyol (A) is used as a bifunctional polyol.
A polycarbonate polyol (A-1) containing a crystalline polycarbonate polyol (a) having at least a structural unit derived from an alkanediol having 6 or more carbon atoms, and a polycarbonate polyol (A-1).
Containing at least EO / PO copolymer polyol (A-2),
The content of the crystalline polycarbonate polyol (a) in the bifunctional polyol is 20% by mass or more, and
The content of the polycarbonate polyol (A-1) in the bifunctional polyol is 30% by mass or more, and the content is 30% by mass or more.
It is characterized in that the molar ratio [EO / PO] of the EO / PO copolymer polyol (A-2) is 25/75 to 80/20.

Hereinafter, aspects of the present invention will be described in detail. In the present specification, the "crystalline polycarbonate polyol (a) having at least a structural unit derived from an alkanediol having 6 or more carbon atoms" may be simply referred to as "crystalline polycarbonate polyol (a)".

[Polyformer (A)]
The polyol (A) used in the present invention is a bifunctional polyol.
It contains at least a polycarbonate polyol (A-1) containing the crystalline polycarbonate polyol (a) and an EO / PO copolymer polyol (A-2).

<Bifunctional polyol>
[Polycarbonate polyol (A-1)]
The polycarbonate polyol (A-1) contains at least a crystalline polycarbonate polyol (a) having at least a structural unit derived from an alkanediol having 6 or more carbon atoms. When the polycarbonate polyol (A-1) contains the crystalline polycarbonate polyol (a), both the adhesiveness and the hydrolysis resistance are improved.
In the present invention, "crystallinity" refers to a substance in which the peak of heat of crystallization or heat of fusion can be confirmed in DSC (differential scanning calorimetry) measurement based on JIS 7121-1987.

The crystalline polycarbonate polyol (a) has at least a structural unit derived from an alkanediol having 6 or more carbon atoms, and the carbon number of the alkanediol is preferable from the viewpoint of improving adhesiveness and hydrolysis resistance. Is 6 to 16, more preferably 6 to 10. The alkanediol used for the crystalline polycarbonate polyol (a) is preferably a linear alkanediol.

Specific examples of the alkanediol having 6 or more carbon atoms include 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, and 1, Examples thereof include 11-undecanediol and 1,12-dodecanediol, and among these, 1,6-hexanediol, 1,9-nonanediol and 1,10-decanediol are preferable.

The crystalline polycarbonate polyol (a) may have other structural units derived from compounds other than the alkanediol having 6 or more carbon atoms.
As the compound constituting the other structural unit, an alkanediol having an even number of linear carbon atoms is preferable, and examples thereof include ethylene glycol and 1,4-butanediol.
The structural unit as described above may contain one type alone or two or more types as long as it contains "a structural unit derived from an alkanediol having 6 or more carbon atoms" as an essential component. That is, it may be a homopolymer, it may be two or more kinds of copolymers, or two or more kinds of homopolymers may be mixed and used.

The content of the structural unit derived from the alkanediol having 6 or more carbon atoms is preferably 20 mol% or more, more preferably 50 mol% or more, based on the total alkanediol in the crystalline polycarbonate polyol (a). , More preferably 70 mol% or more. When the content of the structural unit derived from the alkanediol having 6 or more carbon atoms is within the above range, it is possible to improve both the adhesive performance and the hydrolysis resistance.

The number average molecular weight of the crystalline polycarbonate polyol (a) is preferably 500 to 6,000, more preferably 700 to 5,000, and even more preferably 1,000 to 4,000. When the number average molecular weight is within the above range, the viscosity of the urethane prepolymer does not become too high, and the handleability is improved.
In the present specification, the number average molecular weight refers to a value measured by gel permeation chromatography (GPC method) using polystyrene as a standard substance.

The content of the crystalline polycarbonate polyol (a) in the polycarbonate polyol (A-1) is preferably 30 to 100% by mass, more preferably 50 to 100% by mass, still more preferably 70 to 100% by mass. Is. When the content of the crystalline polycarbonate polyol (a) in the polycarbonate polyol (A-1) is within the above range, the water-resistant adhesive strength is particularly improved.

The polycarbonate polyol (A-1) may contain other polycarbonate polyols other than the crystalline polycarbonate polyol (a). As the other polycarbonate polyol, an amorphous polycarbonate polyol is preferable.
As the amorphous polycarbonate polyol, those in which the peak of heat of crystallization or heat of melting cannot be confirmed in DSC (Differential Scanning Calorimeter) measurement according to JIS 7121-1987 can be used, for example, 1, Examples thereof include, but are not limited to, polycarbonate polyols in which 2-propanediol, 1,3-butanediol, 1,5-pentanediol, and neopentyl glycol are polymerized alone or with other alkanediols. In the present invention, the texture can be improved by using an amorphous polycarbonate polyol.
The alkanediol used for the amorphous polycarbonate polyol may be a linear alkanediol, a branched alkanediol, or an alicyclic alkanediol. Further, the alkanediol preferably contains both an alkanediol having an even number of carbon atoms and an alkanediol having an odd number of carbon atoms.

The number average molecular weight of the other polycarbonate polyols is preferably 500 to 6,000, more preferably 700 to 5,000, and even more preferably 1,000 to 4,000. When the number average molecular weight is within the above range, the viscosity of the urethane prepolymer does not become too high, and the handleability is improved.

When the polycarbonate polyol (A-1) contains another polycarbonate polyol, the content thereof is preferably 30% by mass or less, more preferably 20% by mass or less, and further preferably 20% by mass or less in the polycarbonate polyol (A-1). It is preferably 10% by mass or less.

[EO / PO copolymer polyol (A-2)]
The EO / PO copolymer polyol (A-2) used in the present invention is a copolymer containing a unit derived from ethylene oxide and a unit derived from propylene oxide, and is a copolymer containing an ethylene oxide unit (EO) and a propylene oxide unit (PO). The molar ratio [EO / PO] of is 25/75 to 80/20.
In the present invention, by using the EO / PO copolymer polyol (A-2), the urethane prepolymer can be imparted with moisture permeability, and the water-resistant adhesive strength can be further improved, so that the washing durability is also improved. Can be improved.

Of the molar ratios, if the EO ratio is less than 25, the moisture permeability is lowered, which is not preferable. On the other hand, if it exceeds 80, the water-resistant adhesive strength is lowered, and the texture is also lowered, which is not preferable.
The molar ratio [EO / PO] is preferably 30/70 to 80/20, more preferably 30/70 to 75/25, from the viewpoint of improving the texture while achieving both moisture permeability and water resistance. Yes, more preferably 50/50 to 75/25.
The copolymer containing a unit derived from ethylene oxide and a unit derived from propylene oxide may be a block copolymer, a random copolymer, or an alternate copolymer.

The number average molecular weight of the EO / PO copolymer polyol (A-2) is preferably 100 to 10,000, more preferably 300 to 9,000, and even more preferably 500 to 5,000. When the number average molecular weight is within the above range, the viscosity of the urethane prepolymer does not become too high, and the handleability is improved.

[Other bifunctional polyols]
In the present invention, other bifunctional polyols other than the above (A-1) and (A-2) may be used.
Examples of other bifunctional polyols include polyethylene glycol, polypropylene glycol, and polytetramethylene glycol, but in the present invention, it is preferable not to use polyester polyol.

[Amount of each component in bifunctional polyol]
In the present invention, the content of the crystalline polycarbonate polyol (a) in the bifunctional polyol is 20% by mass or more. If the content of the crystalline polycarbonate polyol (a) is less than 20% by mass, sufficient adhesive strength, hydrolysis resistance, and washing durability (water-resistant adhesive strength) may not be obtained. Therefore, from the viewpoint of improving these characteristics, the content of the crystalline polycarbonate polyol (a) in the bifunctional polyol is preferably 25 to 80% by mass, more preferably 25 to 65% by mass. More preferably, it is 25 to 55% by mass.

In the present invention, the content of the polycarbonate polyol (A-1) in the bifunctional polyol is 30% by mass or more. If the content of the polycarbonate polyol (A-1) in the bifunctional polyol is less than 30% by mass, the hydrolysis resistance and the like deteriorate. Therefore, from the viewpoint of improving hydrolysis resistance and the like, the content of the polycarbonate polyol (A-1) in the bifunctional polyol is preferably 30 to 70% by mass, more preferably 30 to 60% by mass. It is more preferably 30 to 55% by mass.

The content of the EO / PO copolymer polyol (A-2) in the bifunctional polyol is preferably 50 to 70% by mass, more preferably 50 to 65% by mass, and further preferably 50 to 60% by mass. %. As a result, when the content of the EO / PO copolymer polyol (A-2) in the bifunctional polyol is 50% by mass or more, the moisture permeability is improved, and when it is 70% by mass or less, the water resistance is improved. It will show excellent washing durability.

[Polycarbonates other than bifunctional polyols]
In the present invention, a polyol other than the bifunctional polyol may be used. For example, a polyol having a hydroxyl group of preferably 3 to 6, more preferably 3 to 4, and triol is preferable.
Triols include the triol type of polypropylene glycol, 1,2,6-hexanetriol, 1,2,3-butanetriol, pentantriol, 1,2,4-butanetriol, 1,1,1-trimethylol propane. , Triethanolamine, 1,2,3-propanetriol (glycerin), those derived from castor oil and the like, and among these, the triol type of polypropylene glycol is preferable.

The molecular weight of the polyol other than the bifunctional polyol is preferably 100 to 1,000, more preferably 100 to 800. When the molecular weight is within the above range, the viscosity of the urethane prepolymer does not become too high, and the handleability is improved.

The content of the bifunctional polyol in the polyol (A) is preferably 90% by mass or more, more preferably 95% by mass or more.
On the other hand, the content of the polyol other than the bifunctional polyol in the polyol (A) is preferably 20 parts by mass or less, more preferably 10 parts by mass or less, still more preferably, with respect to 100 parts by mass of the bifunctional polyol. Is 5 parts by mass or less. When the content of the polyol other than the bifunctional polyol is not more than the upper limit value, the amount of the bifunctional polyol is relatively large, and as a result, a urethane prepolymer having excellent moisture permeability can be obtained.

<Polyisocyanate (B)>
Examples of the polyisocyanate (B) include known aromatic polyisocyanates, aliphatic polyisocyanates, aromatic aliphatic polyisocyanates, and alicyclic polyisocyanates.
Aromatic polyisocyanates include 1,3-phenylenediocyanate, 4,4'-diphenyldiisocyanate, 1,4-phenylenediisocyanate, 4,4'-diphenylmethane diisocyanate, 2,4-tolylene diisocyanate, and 2,6-tolylene diisocyanate. Isocyanate, 4,4'-toluidine diisocyanate, 2,4,6-triisocyanate toluene, 1,3,5-triisocyanate benzene, dianisidine diisocyanate, 4,4'-diphenyl ether diisocyanate, 4,4', 4 "- Examples thereof include triphenylmethane triisocyanate.

Examples of the aliphatic polyisocyanate include trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, pentamethylene diisocyanate, 1,2-propylene diisocyanate, 2,3-butylene diisocyanate, 1,3-butylene diisocyanate, dodecamethylene diisocyanate, and 2,4. , 4-trimethylhexamethylene diisocyanate and the like.

As aromatic aliphatic polyisocyanates, ω, ω'-diisocyanate-1,3-dimethylbenzene, ω, ω'-diisocyanate-1,4-dimethylbenzene, ω, ω'-diisocyanate-1,4-diethylbenzene, 1, Examples thereof include 4-tetramethylxylylene diisocyanate and 1,3-tetramethylxylylene diisocyanate.

As the alicyclic polyisocyanate, 3-isocyanate methyl-3,5,5-trimethylcyclohexylisocyanate, 1,3-cyclopentanediisocyanate, 1,3-cyclohexanediisocyanate, 1,4-cyclohexanediisocyanate, methyl-2,4- Cyclohexanediisocyanate, methyl-2,6-cyclohexanediisocyanate, 4,4'-methylenebis (cyclohexylisocyanate), 1,4-bis (isocyanatemethyl) cyclohexane, 1,4-bis (isocyanatemethyl) cyclohexane and the like can be mentioned. ..

Further, the polyisocyanate (B) can be used in combination with the trimethylolpropane adduct body of the polyisocyanate (B), a biuret body reacted with water, a trimer having an isocyanurate ring, or the like.
In the present invention, the polyisocyanate (B) preferably contains an aliphatic polyisocyanate and an aromatic polyisocyanate. By containing the above two types, a laminated body having an excellent texture can be obtained.

Among the above, the polyisocyanate (B) used in the present invention is preferably 4,4'-diphenylmethane diisocyanate, hexamethylene diisocyanate, 3-isocyanatemethyl-3,5,5-trimethylcyclohexylisocyanate (isophorone diisocyanate) or the like.

<Additives>
The urethane prepolymer of the present invention may contain additives as needed.
As the additive, for example, a light resistant agent, an antioxidant, a lubricant, a flame retardant and the like can be used. These additives may be used alone or in combination of two or more.

When the urethane prepolymer of the present invention contains an additive, the content thereof is preferably 20% by mass or less, more preferably 10% by mass or less, still more preferably 5% by mass or less in the urethane prepolymer. be. When the content of the additive is within the above range, the effect of the additive can be obtained while the effect of the urethane prepolymer can be obtained.

<Manufacturing method of urethane prepolymer>
The urethane prepolymer of the present invention is obtained by reacting the polyol (A) with the polyisocyanate (B), and reacts with water existing in the air or in the base material to which the urethane prepolymer is applied. It has an isocyanate group capable of forming a crosslinked structure.

As a method for producing the urethane prepolymer of the present invention, for example, the isocyanate group of the polyisocyanate (B) is placed in a reaction vessel so as to be excessive with respect to the hydroxyl group of the polyol (A), and further. It can be produced by adding the necessary components of the above, heating and reacting.

The equivalent ratio [NCO / OH] of the isocyanate group of the polyisocyanate (B) to the hydroxyl group of the polyol (A) in producing the urethane prepolymer is preferably 1.1 to 5.0. Yes, more preferably 1.5 to 3.0, still more preferably 1.5 to 2.0. When the equivalent ratio is within the above range, the peel strength when the urethane prepolymer is used as an adhesive is further improved.

The isocyanate group content of the urethane prepolymer of the present invention (hereinafter, also referred to as “NCO%”) is preferably 1.7 to 5.5, more preferably 1.8 to 3.5.
When the NCO% is within the above range, the peel strength is further improved.
The NCO% of the urethane prepolymer is based on JIS K1603-1: 2007 and indicates a value measured by a potentiometric titration method.

[2] Moisture Curable Urethane Hot Melt Resin Composition The moisture curable urethane hot melt resin composition of the present invention is not particularly limited as long as it contains the urethane prepolymer of the present invention as an essential component, and is not particularly limited. May contain an additive.
As the additive, for example, a curing catalyst, an antioxidant, a tackifier, a plasticizer, a stabilizer, a filler, a dye, a pigment, a fluorescent whitening agent, a silane coupling agent, a wax, a thermoplastic resin and the like are used. be able to. These additives may be used alone or in combination of two or more.

When the moisture-curable urethane hot-melt resin composition of the present invention contains an additive, the content thereof is preferably 20% by mass or less, more preferably 10% by mass or less, still more preferably 5% by mass. It is as follows. When the content of the additive is within the above range, the effect of the additive can be obtained while the effect of the urethane prepolymer can be obtained.

[3] Laminated body The laminated body of the present invention is a laminated body containing a cured product of the urethane prepolymer of the present invention or a cured product of the moisture-curable urethane hot-melt resin composition of the present invention. Specific examples of the laminated body include a laminated body having the base cloth described later, the cured product, and the moisture permeable film described later in this order.
As described above, the urethane prepolymer and the moisture-curable urethane hot-melt resin composition of the present invention are obtained because they have excellent moisture permeability and are also excellent in adhesiveness, hydrolysis resistance, washing durability, and texture. The laminate can be suitably used for breathable waterproof fabric, synthetic leather, rain gear, mountain clothing, hiking wear, sportswear and the like.

Examples of the base fabric constituting the laminate of the present invention include chemical fibers such as polyester fiber, nylon fiber, acrylic fiber, polyurethane fiber, acetate fiber, rayon fiber, and polylactic acid fiber; cotton, linen, silk, wool, and the like. Examples include those using the blended fibers of.
Further, as the moisture permeable film constituting the laminated body of the present invention, for example,
(I) A moisture-permeable film obtained by applying a resin solution containing a thermoplastic resin having a hydrophilic group and an organic solvent to a release paper and volatilizing the organic solvent.
(Ii) A moisture-permeable film obtained by molding a thermoplastic resin pellet having a hydrophilic group.
(Iii) A porous film having fine pores formed by applying a resin solution containing a thermoplastic resin and an organic solvent to a release paper and volatilizing the organic solvent.
(Iv) A porous film or the like in which a resin composition containing a thermoplastic resin and an inorganic filler incompatible with the thermoplastic resin is melt-kneaded and extruded and extruded to a predetermined magnification to have fine pores is formed. Can be mentioned.

As a method for producing the laminate of the present invention, for example, the urethane prepolymer of the present invention or the moisture-curable urethane hot-melt resin composition melted at preferably 50 to 130 ° C. is applied onto the moisture-permeable film, and then the moisture-curable urethane hot-melt resin composition is applied. Examples thereof include a method of laminating a base cloth and then curing a urethane prepolymer or a moisture-curable urethane hot-melt resin composition. According to this method, a laminate having the base cloth, the cured product and the moisture permeable film in this order can be easily obtained.

Examples of the embodiment in which the urethane prepolymer or the like is applied onto the moisture permeable film include an embodiment in which the urethane prepolymer or the moisture-curable urethane hot melt resin composition is intermittently applied in a dot shape or a mesh shape, and is easy to manufacture. From the viewpoint of the above, it is preferable to apply in a dot shape.
Examples of the method of applying to the above-mentioned intermittent include a method using a gravure transfer coating method in which a roll is engraved, a screen coating method, a T-die coating method, a die coater method having a gear pump, a fiber coating method, and the like.

The thickness of the cured product of the urethane prepolymer in the laminate or the cured product of the moisture-curable urethane hot-melt resin composition is preferably 0.1 to 100 μm, more preferably 1 to 50 μm, still more preferably. It is 5 to 30 μm. When the thickness of each cured product is within the above range, it is possible to improve the comfort of clothes using the laminated body while maintaining the moisture permeability.

In the production of the laminate, it is preferable that the urethane prepolymer or the moisture-curable urethane hot-melt resin composition is cured by drying and curing by a known method. The curing conditions are preferably 40 to 130 ° C. and crimped to the base fabric, and after crimping, it is preferably cured at about 30 ° C./65% RH for about 1 to 7 days.

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.
<Example 1>
Nipponporan 980R (manufactured by Toso Co., Ltd., number average molecular weight 2000) and EO / PO copolymer polyol as crystalline polycarbonate polyol (a) in a glass reaction vessel provided with a stirrer, thermometer, gas inlet, etc. As BP-3025 (manufactured by Favor Polymer Chemistry Co., Ltd., molar ratio [EO / PO] = 30/70, number average molecular weight 2500), polyoxypropylene triol (manufactured by Mitsui Chemicals Co., Ltd., number average) A molecular weight of 700) and 4,4'-diphenylmethane diisocyanate (MDI) were added in the amounts shown in Table 1, respectively.
Then, the inside of the reaction vessel was heated and depressurized to perform dehydration treatment, and then nitrogen gas was further sealed and the reaction was carried out by stirring at an internal temperature of 100 ° C. for 120 minutes. Then, a light resistant agent was added to obtain a polyurethane prepolymer. The obtained urethane prepolymer was evaluated as follows. The results are shown in Table 1.

<Examples 2 to 14, Comparative Examples 1 to 6>
A polyurethane prepolymer was produced in the same manner as in Example 1 except that the formulations were changed to those shown in Table 1 or Table 2. The obtained urethane prepolymer was evaluated as follows. The results are shown in Tables 1 and 2.

[Evaluation methods]
<Physical characteristics of film>
With respect to the urethane prepolymers obtained in Examples and Comparative Examples, the physical characteristics of the film were measured in the following manner.
First, the obtained urethane prepolymer was melted at 100 ° C. and coated on a release paper so that the film thickness after coating was 50 to 70 μm. As an aging step, the film was allowed to stand in an environment of a temperature of 30 ° C. and a relative humidity of 65% for 4 days, and further allowed to stand at room temperature (20 ° C.) for 1 day to obtain a film. The breaking strength and thermal softening temperature of the obtained film were measured as follows.

[Measuring method of breaking strength]
The obtained film was punched out from a dumbbell-shaped test piece according to JIS3, and was pulled at a speed of 200 mm / min under the conditions of 25 ° C./30% RH or less using Shimadzu Autograph AGS-J to break the tensile strength. The intensity was measured. In this evaluation, it is shown that the higher the breaking strength, the higher the strength of the film.

[Measurement method of thermal softening temperature (thermal softening point)]
(1) Preparation of sample A translucent film having a width of 1.5 cm and a length of 6 cm was obtained by peeling from the release paper. As shown in FIG. 1, clips 12 are attached to the top and bottom of the translucent film 10, the clips 12 are further fixed with cellophane tape (registered trademark), and a load of 450 g / cm ² is applied when the clips 12 are suspended from one of the clips 12. A sample 16 was prepared by attaching such a weight 14. The central portion of the film 10 in the longitudinal direction of 2 cm is not covered with cellophane tape (registered trademark).
(2) Measurement As shown in FIG. 2, the clip 12 to which the weight 14 of the sample 16 of each example is not attached was attached to the turntable 22 of the gear oven 20. Then, while rotating the turntable 22 at 5 rpm, the temperature inside the gear oven 20 was raised from room temperature at a speed of 3 ° C./min. The temperature at which the film 10 was cut or stretched twice was defined as the softening point.
In this evaluation, the higher the thermal softening temperature (thermal softening point), the higher the resistance as a film (for example, resistance to hot melt tape sticking and ironing).

<Creation of moisture permeable waterproof cloth for evaluation>
In order to measure the adhesive strength, moisture permeability, hydrolysis resistance, and water-resistant adhesive strength of the laminate, a moisture-permeable waterproof cloth for evaluation was prepared as follows.

(1) Preparation of skin (moisture permeable film) 100 parts by mass of Heimlen Y-208-2 (manufactured by Dainichi Seika Kogyo Co., Ltd.), which is a solvent-based urethane resin, coloring agent [Seikabun DUT 4093 White (Dainichi Seika Kogyo (Dainichi Seika Kogyo) Co., Ltd.)] 10 parts by mass, dimethylformamide (DMF) 10 parts by mass, and methyl ethyl ketone (MEK) 5 parts by mass were mixed to obtain a compounding solution. Using a clearance coater, the compounding solution was uniformly applied on the release paper with a coating amount of 50 μm / wet. Then, it was dried at 80 ° C. for 2 minutes and further at 120 ° C. for 3 minutes to obtain a moisture-permeable waterproof cloth skin (moisture-permeable film) having a film thickness of 10 to 15 μm.

(2) Adhesion between the skin and the base cloth The urethane prepolymers obtained in Examples and Comparative Examples were melted at 100 ° C. and applied onto the skin (moisture permeable film). Next, the urethane prepolymer was adjusted to have a film thickness of 15 μm by a pressure treatment after coating, and then the base cloth (nylon taffeta) was processed and pressure-bonded at a laminating temperature of 100 ° C. As an aging step, it was aged for 4 days in an environment with a temperature of 30 ° C. and a relative humidity of 65%. The obtained laminate was used as a moisture-permeable waterproof cloth for evaluation, and the following evaluation was performed.

[Measurement method of adhesive strength]
A hot melt tape was laminated on the skin surface of the obtained moisture-permeable waterproof cloth for evaluation, and the pressure was applied by pressing an iron at 140 ° C. for 1 minute. After cooling this at room temperature (20 ° C.) for 1 hour, the base cloth and the epidermis in close contact with the hot melt tape are peeled off, and the adhesive strength is measured by measuring the strength with an autograph, and the adhesive strength is measured according to the following criteria. evaluated.
(standard)
⊚: ≧ 1.3 kg / inch
◯: ≧ 0.8 kg / inch
×: <0.8 kg / inch

[Measurement of moisture permeability]
The moisture permeability of the obtained moisture-permeable waterproof cloth for evaluation was measured according to the A-1 method (potassium chloride method) of JIS L 1099: 2012, and evaluated according to the following criteria.
(standard)
⊚: ≧ 5,000 g / m ^2.24h
◯: ≧ 3,000 g / m ^2.24h

[Hydrolysis resistance]
The obtained moisture-permeable waterproof cloth for evaluation was placed in a tank under 70 ° C./95% RH conditions, and the adhesive strength before being placed was compared with the adhesive strength after storage in the tank for a predetermined period. The hydrolyzability was evaluated. The retention rate of the adhesive strength means the ratio of the adhesive strength after being stored in the tank for a predetermined period to the adhesive strength before being put in the tank.
(standard)
×: When the retention rate of the adhesive strength after storage for 5 weeks is less than 70% 〇: When the retention rate of the adhesive strength after storage for 5 weeks is 70% or more ◎: When the retention rate of the adhesive strength after storage for 8 weeks When the retention rate is 70% or more

[Water resistant adhesive strength (washing durability test)]
Regarding the obtained moisture-permeable waterproof cloth for evaluation, in accordance with JIS L-1930, washing by a C-type standard washing machine (paraseta type) and drying by the drying C method (flat-drying) were alternately repeated 20 times in total. After that, the adhesive strength was measured. If the retention rate of the adhesive strength is 70% or more, it has excellent water-resistant adhesive strength (○ evaluation), and if the retention rate is less than 70%, the water-resistant adhesive strength is insufficient and the washing durability is poor. It was judged as (× evaluation). The adhesive strength was measured by the same method as described above.

The details of the components used in the examples and comparative examples are as follows.
<Crystalline Polycarbonate Polyol (a)>
-Nipporan 980R: 1,6-hexanediol homopolymer (manufactured by Tosoh Corporation, number average molecular weight 2000)
Duranal G4672: 1,4-butanediol / 1,6-hexanediol (70 mol% / 30 mol%) copolymer (manufactured by Asahi Kasei Corporation, number average molecular weight 2000)
BENEBioL NL2020DB: 1,4-butanediol / 1,10-decanediol (80 mol% / 20 mol%) copolymer (manufactured by Mitsubishi Chemical Corporation, number average molecular weight 2000)

<Amorphous polycarbonate polyol>
Duranal T5652: 1,5-pentanediol / 1,6-hexanediol (50 mol% / 50 mol%) copolymer (manufactured by Asahi Kasei Corporation, number average molecular weight 2000)

<EO / PO copolymer polyol>
BP-3025: manufactured by Polonium Polymerization Chemicals Co., Ltd., molar ratio [EO / PO] = 30/70, number average molecular weight 2500
BP-2896: Manufactured by Gakuen Kagaku Kogyo Co., Ltd., molar ratio [EO / PO] = 28/72, number average molecular weight 960
BE-5028: manufactured by Favor Polymer Chemistry Co., Ltd., molar ratio [EO / PO] = 50/50, number average molecular weight 2800
DE-8735: manufactured by Polonium Polymerization Chemicals Co., Ltd., molar ratio [EO / PO] = 87/13, number average molecular weight 3500
-DP-7530: Manufactured by Polonium Polymerization Chemicals Co., Ltd., molar ratio [EO / PO] = 75/25, number average molecular weight 3000

<Polyethylene glycol>
PEG2000: Sanyo Chemical Industries, Ltd., number average molecular weight 2000
<Polyester polyol>
-TEPE 85: manufactured by Tai Chin Chemical Industry Co., Ltd., number average molecular weight 2000

<Triol>
-T-700: Mitsui Chemicals, Inc., polyoxypropylene triol, number average molecular weight 700

<Isocyanate>
-MDI: Tosoh, 4,4'-diphenylmethane diisocyanate-C-2770: Tosoh, aliphatic polyisocyanate (HDI-based allophanate type polyisocyanate)
<Additives>
CHISORB 770 (light resistant agent): Double bond chemical, bis sebacate (2,2,6,6-tetramethyl-4-piperidyl)

<Examples 15 to 16>
A urethane prepolymer was produced in the same manner as in Example 1 except that the formulation was changed to the description in Table 3 and the reaction temperature was set to 110 ° C. Further, with respect to the obtained urethane prepolymer, a moisture-permeable waterproof cloth for evaluation was prepared by the above-mentioned method, and the following texture was evaluated together with the above-mentioned Examples 1 and 8. The results are shown in Table 3.

[Texture]
The flexibility of the obtained moisture-permeable waterproof cloth for evaluation was compared with the feeling of being rubbed by hand and evaluated according to the following criteria. The standard breathable waterproof cloth was created as follows.
〔standard〕
◎: Softer than standard breathable waterproof cloth ○: Softer than standard breathable waterproof cloth

-Standard moisture permeable waterproof cloth As a raw material for adhesives, Heimlen Y-173 (polyurethane resin adhesive, manufactured by Dainichi Seika Kogyo Co., Ltd.), 100 parts by mass, NE-crosslinking agent (isocyanate-based crosslinking agent, Dainichi Seika Kogyo () Co., Ltd.) 10 parts by mass, 20 parts by mass of dimethylformamide (DMF), and 40 parts by mass of methyl ethyl ketone (MEK) were mixed to prepare an adhesive compounding solution.
The obtained adhesive compounding liquid was applied onto the epidermis (moisture permeable film) at 50 μm / wet using a clearance coater and dried at 80 ° C. for 2 minutes to form an adhesive layer having a thickness of about 15 μm.
Next, the base cloth (nylon taffeta) was laminated on the obtained adhesive layer, and processed and pressure-bonded at a laminating temperature of 40 ° C. Then, it was aged at 50 ° C. for 48 hours to prepare a standard moisture permeable waterproof cloth.

As is clear from the above results, according to the present invention, a urethane prepolymer which has excellent moisture permeability and can provide a laminate having excellent adhesiveness, hydrolysis resistance, washing durability, and texture. Can be provided.

10 Film 12 Clip 14 Weight 16 Sample 20 Gear Oven 22 Turntable

Claims (3)

A urethane prepolymer having an isocyanate group at the terminal, which is a reaction product of the polyol (A) and the polyisocyanate (B).
The polyol (A) is used as a bifunctional polyol.
A polycarbonate polyol (A-1) containing a crystalline polycarbonate polyol (a) having at least a structural unit derived from an alkanediol having 6 or more carbon atoms, and a polycarbonate polyol (A-1).
Containing at least EO / PO copolymer polyol (A-2),
The content of the crystalline polycarbonate polyol (a) in the bifunctional polyol is 20% by mass or more and 50% by mass or less, and
The content of the polycarbonate polyol (A-1) in the bifunctional polyol is 30% by mass or more, and the content is 30% by mass or more.
A urethane prepolymer characterized in that the molar ratio [EO / PO] of the EO / PO copolymer polyol (A-2) is 25/75 to 80/20. The urethane prepolymer according to claim 1, wherein the content of the EO / PO copolymer polyol (A-2) in the bifunctional polyol is 50 to 70% by mass. The urethane prepolymer according to claim 1 or 2, wherein the polyisocyanate (B) contains an aliphatic polyisocyanate and an aromatic polyisocyanate.

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