JP2022152669A - Reactive hot-melt adhesive, bonded body, method for producing the same, and garment - Google Patents

Abstract

To provide a reactive hot-melt adhesive capable of giving a cured product excellent in yellowing resistance.SOLUTION: The reactive hot-melt adhesive contains: a urethane prepolymer having a polyol-derived structural unit and a polyisocyanate-derived structural unit; a phenolic antioxidant; and an ultraviolet absorber. The polyisocyanate-derived structural unit contains a structural unit derived from diphenylmethane diisocyanate.SELECTED DRAWING: None

Description

TECHNICAL FIELD The present disclosure relates to reactive hot melt adhesives, adhesives and methods of making the same, and clothing.

Hot-melt adhesives are non-solvent type adhesives, so they are less harmful to the environment and the human body, and can be adhered in a short period of time, so they are suitable for improving productivity. Hot-melt adhesives can be broadly classified into those containing a thermoplastic resin as a main component and those containing a reactive resin as a main component. Urethane prepolymers having isocyanate groups at their terminals are mainly used as reactive resins.

A reactive hot-melt adhesive containing urethane prepolymer as a main component develops a certain degree of adhesive strength in a short period of time by cooling and solidifying the adhesive itself after application. After that, the terminal isocyanate group of the urethane prepolymer reacts with moisture (moisture in the air or on the surface of the adherend) to increase the molecular weight and cause cross-linking, thereby exhibiting heat resistance. Such an adhesive is called a moisture-curable reactive hot-melt adhesive. A reactive hot-melt adhesive containing urethane prepolymer as a main component exhibits good adhesive strength even when heated.

For example, Patent Document 1 discloses a reactive hot-melt adhesive composed of a urethane prepolymer formed from polyisocyanate and polyol.

JP-A-2008-063568

In recent years, reactive hot melt adhesives have been used for clothing. Incidentally, reactive hot-melt adhesives may yellow due to ultraviolet rays (UV) and nitrogen oxides (NOx) in the air when they are washed, dried, and dried outside. Therefore, reactive hot-melt adhesives are required to have long-term reliability that can withstand yellowing.

Therefore, the main object of the present disclosure is to provide a reactive hot-melt adhesive capable of giving a cured product having excellent yellowing resistance.

One aspect of the present disclosure relates to reactive hot melt adhesives. The reactive hot melt adhesive contains a urethane prepolymer having a polyol-derived structural unit and a polyisocyanate-derived structural unit, a phenolic antioxidant, and an ultraviolet absorber. Structural units derived from polyisocyanate include structural units derived from diphenylmethane diisocyanate. According to studies by the present inventors, chemical changes in structural units derived from diphenylmethane diisocyanate in urethane prepolymers due to ultraviolet (UV) or nitrogen oxides (NOx) (e.g., generation of quinoids, generation of nitro compounds, etc.) was found to be one of the causes of the occurrence of yellowing. Therefore, the present inventors believe that chemical changes in structural units derived from diphenylmethane diisocyanate can be suppressed by combining a predetermined urethane prepolymer, a phenolic antioxidant, and an ultraviolet absorber. , the reactive hot-melt adhesive can give a cured product excellent in yellowing resistance.

Reactive hot-melt adhesives may be used to bond together multiple adherends selected from cloth and paper. Here, the adherend combination may be cloth and cloth, paper and paper, or cloth and paper. The present disclosure further comprises a composition containing a predetermined urethane prepolymer, a phenolic antioxidant, and an ultraviolet absorber, and is used to bond together a plurality of adherends selected from cloth and paper. It may also relate to applications as reactive hot-melt adhesives or applications for the production of reactive hot-melt adhesives used to bond together a plurality of adherends selected from cloth and paper.

Another aspect of the present disclosure relates to adhesives. The adherend includes a first adherend, a second adherend, and an adhesive layer that adheres the first adherend and the second adherend to each other. The adhesive layer contains a cured product of the above reactive hot melt adhesive.

Another aspect of the present disclosure relates to clothing. The clothing may comprise the above adhesive, and the first adherend and the second adherend may be cloth. The garment may be a seamless garment.

Another aspect of the present disclosure relates to a method of manufacturing an adhesive body. The method for producing the adhesive body comprises the steps of: forming an adhesive layer by melting the reactive hot melt adhesive and applying it to a first adherend; and forming a second adhesive layer on the adhesive layer. The method includes a step of placing an adherend and pressing a second adherend to obtain a laminate, and a step of curing an adhesive layer in the laminate to obtain an adherend.

According to the present disclosure, there is provided a reactive hot-melt adhesive capable of giving a cured product with excellent yellowing resistance. Further, according to the present disclosure, an adhesive body using such a reactive hot-melt adhesive and a manufacturing method thereof are provided. Additionally, according to the present disclosure, a garment comprising an adhesive is provided.

FIG. 1 is a schematic diagram showing a method for manufacturing an adhesive body according to one embodiment, and FIGS. 1(a), (b), (c), and (d) are schematic diagrams showing each step.

Hereinafter, embodiments for implementing the present disclosure will be described in detail. However, the present disclosure is not limited to the following embodiments.

As used herein, "polyol" means a compound having two or more hydroxy groups in the molecule.

As used herein, "polyisocyanate" means a compound having two or more isocyanate groups in the molecule.

In this specification, "amorphous" and "crystalline" can be determined by the presence or absence of a melting point (Tm) (an endothermic peak associated with melting in DSC), and "crystalline" refers to the melting point ( Tm), and "amorphous" is one that does not have a melting point (Tm). As used herein, "amorphous polyol" means a polyol that does not have a melting point (Tm), and "crystalline polyol" means a polyol that does have a melting point (Tm).

In this specification, when the term "system" is attached to the name of a compound, etc., the term means a derivative of the compound to which the "system" is attached. For example, "phenol-based antioxidant" means an antioxidant composed of a derivative of a compound having phenol as a base skeleton and a substituent bonded to the phenol.

In this specification, a numerical range indicated using "to" indicates a range including the numerical values before and after "to" as the minimum and maximum values, respectively. In the numerical ranges described stepwise in this specification, the upper limit value or lower limit value of the numerical range at one step may be replaced with the upper limit value or lower limit value of the numerical range at another step. In the numerical ranges described herein, the upper or lower limits of the numerical ranges may be replaced with the values shown in the examples. "A or B" may include either A or B, or may include both. The materials exemplified in this specification can be used singly or in combination of two or more unless otherwise specified. As used herein, the content of each component in the composition refers to the total amount of the multiple substances present in the composition unless otherwise specified when there are multiple substances corresponding to each component in the composition. means.

[Reactive hot melt adhesive]
The reactive hot-melt adhesive of one embodiment is one that can develop adhesive strength and the like by increasing its molecular weight through a chemical reaction. Reactive hot-melt adhesives are derived from structural units derived from polyol (hereinafter sometimes referred to as "(A1) component") and polyisocyanate (hereinafter sometimes referred to as "(A2) component"). A urethane prepolymer having a structural unit (hereinafter sometimes referred to as "(A) component"), a phenolic antioxidant (hereinafter sometimes referred to as "(B) component"), and an ultraviolet absorber ( Hereinafter, it may be referred to as "(C) component"). The reactive hot-melt adhesive may further contain, for example, a curing catalyst (hereinafter sometimes referred to as "component (D)").

<(A) component: urethane prepolymer>
The (A) component may be, for example, a urethane prepolymer having isocyanate groups. A urethane prepolymer having an isocyanate group usually has a polymer chain containing a structural unit derived from a polyol and a structural unit derived from a polyisocyanate, and an isocyanate group bonded to the end of the polymer chain.

Structural units derived from polyisocyanate include structural units derived from diphenylmethane diisocyanate. The component (A) in which structural units derived from polyisocyanate contain structural units derived from diphenylmethane diisocyanate can usually be obtained by reacting a polyol with a polyisocyanate containing diphenylmethane diisocyanate. That is, component (A) can be a reaction product of a polyol and a polyisocyanate including diphenylmethane diisocyanate. The content of the structural unit can be adjusted by changing the mixing ratio of the polyol that provides the structural unit and the polyisocyanate that provides the structural unit. Moreover, since a urethane bond is formed by reacting a polyol and a polyisocyanate, the polymer chain of the component (A) may have a urethane bond. Also, by increasing the equivalent weight of polyisocyanate relative to the equivalent weight of polyol, an isocyanate group can be introduced at the end of the polymer chain.

(A1) Component: Polyol The structural unit derived from component (A1) is not particularly limited, but may contain, for example, a structural unit derived from polyester polyol.

In component (A), the solidification time and viscosity of the reactive hot-melt adhesive can be adjusted by including a structural unit derived from polyester polyol in the polymer chain. The polyester polyol may be a polycondensation reaction product of a polyhydric alcohol and a polycarboxylic acid, or a polycondensation reaction product of a dihydric alcohol and a dihydric carboxylic acid. The polyester polyol may be a polyester diol composed of a dihydric alcohol and a divalent carboxylic acid, or may be a polyester triol composed of a trihydric alcohol and a divalent carboxylic acid. A polyester triol can also be obtained by reacting a dihydric alcohol and a trihydric carboxylic acid.

Examples of polyhydric alcohols include ethylene glycol, 1,2-propanediol, 1,3-propanediol, isomers of butanediol, isomers of pentanediol, isomers of hexanediol, 2,2- Dimethyl-1,3-propanediol, 2-methylpropanediol, 2,4,4-trimethyl-1,6-hexanediol, 2,2,4-trimethyl-1,6-hexanediol, diethylene glycol, dipropylene glycol , triethylene glycol, tripropylene glycol, etc., wherein some of the carbon atoms (--CH.sub.2-- ₍ methylene group)) may be substituted with oxygen atoms (--O--); 1,4 - Alicyclic dihydric alcohols such as cyclohexanediol and 1,4-cyclohexanedimethanol; dihydric alcohol having) and the like. One type of polyhydric alcohol may be used alone, or two or more types may be used in combination. Among these, the polyhydric alcohol is preferably an aliphatic dihydric alcohol, more preferably a dihydric alcohol having 2 to 6 carbon atoms, in which some carbon atoms may be substituted with oxygen atoms. be.

Examples of polycarboxylic acids include aromatic polycarboxylic acids (polycarboxylic acids having an aromatic ring) such as phthalic acid, isophthalic acid, terephthalic acid, and 1,2,4-benzenetricarboxylic acid; Aliphatic polycarboxylic acids such as acid, aconitic acid, 1,2,3-propanetricarboxylic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, azelaic acid, sebacic acid; cyclohexane-1,2- Dicarboxylic acids, alicyclic polyvalent carboxylic acids such as 1,4-cyclohexanediene-1,2-dicarboxylic acid, and the like. The aromatic polycarboxylic acid may be a polycarboxylic acid having a benzene ring and two or more carboxy groups bonded to the benzene ring, and is a group consisting of phthalic acid, isophthalic acid, and terephthalic acid. It may be at least one selected from. Polyvalent carboxylic acid may be used individually by 1 type, and may be used in combination of 2 or more type. Among these, the polyvalent carboxylic acid is preferably an aliphatic divalent carboxylic acid or an aromatic divalent carboxylic acid, more preferably 2 to 6 carbon atoms (excluding the carbon atoms constituting the carboxylic acid). is a dihydric alcohol with

Polyvalent carboxylic acid derivatives such as carboxylic acid anhydrides and compounds in which a part of the carboxyl groups are esterified can be used instead of the polyvalent carboxylic acids. Examples of polyvalent carboxylic acid derivatives include phthalic anhydride, dimethyl terephthalate, dodecyl maleic acid, octadecenyl maleic acid and the like.

The polyester polyol may be a crystalline polyester polyol or an amorphous polyester polyol. Polyester polyols may include both crystalline polyester polyols and amorphous polyester polyols.

The polyester polyol may have a number average molecular weight (Mn) of 500 to 12,000 from the viewpoint of adhesion. The number average molecular weight (Mn) of the polyester polyol may be 1000 or more, 1500 or more, or 1800 or more, and may be 10000 or less, 8000 or less, or 6000 or less. In addition, in this specification, Mn is a value measured by gel permeation chromatography (GPC) and converted into standard polystyrene.

In the present specification, GPC measurement for determining the number average molecular weight (Mn) can be performed, for example, under the following conditions.
Column: "Gelpack GLA130-S", "Gelpack GLA150-S" and "Gelpack GLA160-S" (manufactured by Showa Denko Materials Co., Ltd., packed column for HPLC)
Eluent: Tetrahydrofuran Flow rate: 1.0 mL/min Column temperature: 40°C
Detector: RI

The content of polyester polyol (structural unit derived from polyester polyol) is 60 to 100% by mass, 70 to 100% by mass, or It may be 80 to 100% by mass.

In addition to the polyester polyol, the component (A1) may contain a polyol other than the polyester polyol (hereinafter sometimes referred to as "other polyol"). Other polyols include, for example, polyether polyols, polyether ester polyols, polyurethane polyols, polycarbonate polyols, polyolefin polyols, and the like. Other polyols may be used singly or in combination of two or more.

The content of other polyols (structural units derived from other polyols) is 0 to 40% by mass, 0 to 30% by mass, based on the total amount of component (A1) (structural units derived from component (A1)). or less, or 0 to 20% by mass.

(A2) Component: Polyisocyanate The (A2) component contains diphenylmethane diisocyanate (4,4'-diphenylmethane diisocyanate, MDI). Since the component (A2) contains diphenylmethane diisocyanate, the hot-melt adhesive tends to be excellent in reactivity and adhesive strength.

The content of diphenylmethane diisocyanate (structural unit derived from diphenylmethane diisocyanate) is 60 to 100% by mass, 70 to 100% by mass, or It may be 80 to 100% by mass.

In addition to diphenylmethane diisocyanate, the component (A2) may contain polyisocyanates other than diphenylmethane diisocyanate (hereinafter sometimes referred to as "other polyisocyanates"). Other polyisocyanates include, for example, aromatic isocyanates such as dimethyldiphenylmethane diisocyanate, tolylene diisocyanate, xylylene diisocyanate and p-phenylene diisocyanate; alicyclic isocyanates such as dicyclohexylmethane diisocyanate and isophorone diisocyanate; and aliphatic isocyanates. Other polyisocyanates may be used singly or in combination of two or more.

The component (A) can be synthesized by reacting the component (A1) with the component (A2) containing diphenylmethane diisocyanate. Component (A) may have, for example, a polymer chain containing a structural unit derived from component (A1) and a structural unit derived from diphenylmethane diisocyanate, and an isocyanate group bonded to the end of the polymer chain. . When synthesizing such a component (A), the equivalent ratio of the isocyanate group (NCO) of the component (A2) to the hydroxy group (OH) of the component (A1) (isocyanate group (NCO) equivalent of the component (A2) / ( The hydroxy group (OH) equivalent (NCO/OH) of component A1) may be 1.1 or more, and may be from 1.1 to 2.1. When NCO/OH is 1.1 or more, the component (A) has an isocyanate group bonded to the end of the polymer chain, and an increase in the viscosity of the component (A) can be suppressed, resulting in better workability. tend to improve. When the NCO/OH ratio is 2.1 or less, foaming is less likely to occur during the moisture-curing reaction of the reactive hot-melt adhesive, and a decrease in adhesive strength tends to be more easily suppressed.

The content of component (A) is 80% by mass or more, 85% by mass or more, 90% by mass or more, 92% by mass or more, 95% by mass or more, 97% by mass or more, based on the total amount of the reactive hot melt adhesive. , or 99% by mass or more.

<(B) Component: Phenolic Antioxidant>
Component (B) can suppress chemical changes in structural units derived from diphenylmethane diisocyanate by being combined with component (C), which will be described later. Component (B) includes, for example, hindered phenol compounds. Here, the hindered phenol-based compound is a phenol having a sterically hindered substituent (e.g., t-butyl group, etc.) on at least one carbon atom adjacent to the hydroxyl group in the phenol as the base skeleton. means a compound.

Examples of hindered phenol compounds include compounds described in International Publication No. 2015/046422. Commercially available hindered phenol compounds include Irganox 1010, Irganox 1035, Irganox 1076, Irganox 1098, Irganox 1135, Irganox 1141, Irganox 1222, Irganox 1330 (all manufactured by BASF Japan Ltd.), AO-20, AO-40, AO-40, AO. -50, AO-60, AO-80, AO-330 (adekastab AO series, all manufactured by ADEKA Corporation), and the like.

The content of component (B) is 0.01 part by mass or more, and 0.01 part by mass or more, based on 100 parts by mass of the total amount of component (A), from the standpoint of suppressing yellowing of the cured product of the reactive hot-melt adhesive. 03 parts by weight or more, 0.05 parts by weight or more, 0.08 parts by weight or more, or 0.1 parts by weight or more, and 1.0 parts by weight or less, 0.8 parts by weight or less, or 0.6 parts by weight Below, it may be 0.4 parts by mass or less, or 0.2 parts by mass or less.

In addition to the (B) component, the reactive hot-melt adhesive may further contain an antioxidant other than the phenolic antioxidant (hereinafter sometimes referred to as "(B') component"). . When the reactive hot-melt adhesive further contains the component (B') in addition to the component (B), the cured product of the reactive hot-melt adhesive tends to be more excellent in suppressing yellowing. (B') component includes, for example, thioether-based antioxidants, thiol-based antioxidants, and the like. The (B') component may be, for example, a thioether antioxidant.

Thioether-based antioxidants include, for example, ditridecyl 3,3-thiobispropionate (ADEKA Corporation, trade name: Adekastab AO-503), 2,2-bis{[3-(dodecylthio)-1-oxopropoxy ]methyl}propane-1,3-diyl bis[3-(dodecylthio)propionate] (ADEKA Corporation, trade name: ADEKA STAB AO-412S).

Examples of thiol-based antioxidants include compounds having a thiol group. Examples of compounds having a thiol group include pentaerythritol tetrakis (3-mercaptobutyrate) (Showa Denko Co., Ltd., trade name: Karenz MT-PE1), 1,3,5-tris (3-mercaptobutyryloxyethyl )-1,3,5-triazine-2,4,6(1H,3H,5H)-trione (Showa Denko KK, trade name: Karenz MT-NR1).

The content of the component (B') is 0.01 part by mass or more when the total amount of the component (A) is 100 parts by mass, from the standpoint of more excellent suppression of yellowing of the cured product of the reactive hot-melt adhesive. 0.03 parts by mass or more, 0.05 parts by mass or more, 0.08 parts by mass or more, or 0.1 parts by mass or more, 1.2 parts by mass or less, 1.0 parts by mass or less, 0.8 It may be no more than 0.6 parts by mass, or no more than 0.4 parts by mass.

<(C) component: UV absorber>
Component (C) can suppress chemical changes in structural units derived from diphenylmethane diisocyanate by being combined with component (B) described above. Component (C) includes, for example, benzotriazole-based, cyanoacrylate-based, dihydroxybenzophenone-based, benzotriazole-based, triazine-based, benzophenone-based, and benzoate-based UV absorbers. The (C) component may be, for example, a benzotriazole-based UV absorber. Commercially available products of component (C) include, for example, the KEMIISORB series (manufactured by Chemipro Kasei Co., Ltd.), the ADEKA STAB LA series (manufactured by ADEKA Corporation), the Ubinal series, and the Tinuvin series (manufactured by BASF Japan Ltd.).

From the standpoint of suppressing yellowing of the cured product of the reactive hot melt adhesive, the content of component (C) is 0.01 part by mass or more and 0.01 part by mass or more when the total amount of component (A) is 100 parts by mass. 05 parts by mass or more, 0.1 parts by mass or more, 0.2 parts by mass or more, or 0.3 parts by mass or more, 3.0 parts by mass or less, 2.5 parts by mass or less, 2.0 parts by mass Below, it may be 1.8 parts by mass or less, or 1.5 parts by mass or less.

<(D) component: curing catalyst>
The reactive hot-melt adhesive may further contain component (D) from the viewpoint of promoting curing of the urethane prepolymer and developing higher adhesive strength. Component (D) includes, for example, dibutyltin dilaurate, dibutylthione octate, dimethylcyclohexylamine, dimethylbenzylamine, trioctylamine, dimorpholinodiethyl ether (bis(2-morpholinoethyl) ether), and the like. The content of component (D) may be 0.01 to 0.5 parts by mass when the total amount of component (A) is 100 parts by mass.

The reactive hot-melt adhesive may further contain a thermoplastic polymer from the viewpoint of enhancing rubber elasticity of the formed adhesive layer and further improving impact resistance. Examples of thermoplastic polymers include polyurethanes, ethylene-based copolymers, propylene-based copolymers, vinyl chloride-based copolymers, acrylic copolymers, and styrene-conjugated diene block copolymers. The content of the thermoplastic polymer may be 0.1-20% by weight, based on the total amount of the reactive hot melt adhesive.

The reactive hot-melt adhesive may further contain a tackifying resin from the viewpoint of imparting stronger adhesive strength to the adhesive layer to be formed. Examples of tackifying resins include rosin resins, rosin ester resins, hydrogenated rosin ester resins, terpene resins, terpene phenol resins, hydrogenated terpene resins, petroleum resins, hydrogenated petroleum resins, coumarone resins, ketone resins, styrene resins, Modified styrene resins, xylene resins, epoxy resins and the like can be mentioned. The content of the tackifying resin may be 0.1-20% by weight, based on the total amount of the reactive hot-melt adhesive.

The reactive hot-melt adhesive may further contain other components as necessary. Other components include, for example, antifoaming agents, nucleating agents, pigments, surfactants, flame retardants, fillers, photocoloring agents, thermal coloration inhibitors, fragrances, imaging agents, thermal crosslinking agents, and the like. The content of other components may be 0.001 to 10% by mass based on the total amount of the reactive hot melt adhesive.

Reactive hot melt adhesives can be produced, for example, by reacting components (A1) and (A2) to synthesize component (A), synthesized components (A), components (B), and (C ) and the like to obtain a reactive hot-melt adhesive. Further, the reactive hot-melt adhesive, for example, in the presence of the component (B), the component (C), etc., by reacting the component (A1) and the component (A2), the step of synthesizing the component (A). It can also be obtained by a manufacturing method including:

The temperature and time for reacting component (A1) and component (A2) when synthesizing component (A) are not particularly limited, but may be, for example, 85 to 120° C. and 0.1 minute to 48 hours. .

Reactive hot-melt adhesives react with moisture in the air or moisture on the surface of the adherend. It can be cured by leaving (curing) at RH (relative humidity) for 24 hours or more. Thus, a cured product of reactive hot-melt adhesive can be obtained.

Reactive hot-melt adhesives can be used, for example, by melting at 60 to 130° C. and applying them to adherends. The coating method is not particularly limited, and examples thereof include a method using a coating device such as a bar coater, a die coater, a roll coater, and a sprayer. A dispenser is suitable for application to narrow areas such as small parts. The application pattern of the reactive hot-melt adhesive can be appropriately set, and examples thereof include dot, linear, zigzag, planar, and curved application patterns.

Reactive hot-melt adhesives can adhere various adherends via a cured product (adhesive layer) of the reactive hot-melt adhesive. Examples of the adherend include metal substrates such as stainless steel (SUS) and aluminum, and non-metal substrates such as cloth, paper, polycarbonate, polyamide, polyetherimide, glass, and carbon fiber. Among these, the adherend may be, for example, cloth or paper. A reactive hot-melt adhesive can be suitably used for bonding together a plurality of adherends selected from cloth and paper. In this case, the adherend combination can be cloth and cloth, paper and paper, or cloth and paper. Reactive hot melt adhesives can be suitably used for clothing such as clothing (apparel products), supporters, bags, wallets, interiors, various covers, cases, wearable devices, etc., and can be particularly suitably used for clothing. .

The reactive hot melt adhesive may be formed into a film and used as an adhesive film. Such an adhesive film can be obtained, for example, by applying a reactive hot-melt adhesive onto a support film such as a PET (polyethylene terephthalate) film to form an adhesive layer. can be done. The thickness of the adhesive layer (adhesive film) may be 10 μm or more, 20 μm or more, or 30 μm or more, and may be 500 μm or less, 400 μm or less, or 300 μm or less. The thicker the film, the more adhesive force can be secured, and the thinner the film, the easier it is to ensure stretchability.

[Adhesive and its manufacturing method]
An adherend in one embodiment comprises a first adherend, a second adherend, and an adhesive layer that adheres the first adherend and the second adherend together. The adhesive layer contains a cured product of the above reactive hot melt adhesive. Articles having adhesive bodies include, for example, clothing (especially non-sewn clothing), semiconductor devices, electronic devices, and the like.

The first adherend and the second adherend can be the same as those exemplified for the above-mentioned adherends. The first and second adherends may be, for example, cloth or paper, and the combination of the first and second adherends may be cloth and cloth, paper and paper, or cloth and paper. When the article provided with the adherend is clothing, the first adherend and the second adherend are cloth.

The adhesive body of the present embodiment comprises a step of melting the above reactive hot melt adhesive and applying it to a first adherend to form an adhesive layer, and forming an adhesive layer on the adhesive layer. and pressing a second adherend to obtain a laminate, and curing the adhesive layer to obtain an adherent.

The temperature for melting the reactive hot melt adhesive may be, for example, 60-130°C. Examples of the method of applying the reactive hot-melt adhesive to the first adherend include a method using a coating device such as a die coater, a roll coater, and a sprayer. A dispenser is suitable for application to narrow areas such as small parts.

As a method of pressure-bonding the second adherend, for example, a method of pressure-bonding using a pressure roll or the like can be mentioned.

The reactive hot melt adhesive in the adhesive layer can be cured, for example, by leaving (curing) for 24 hours at a temperature of 23° C. and 50% RH (relative humidity). Thereby, the adhesive layer can contain a cured product of a reactive hot-melt adhesive.

FIG. 1 is a schematic diagram showing a method for manufacturing an adhesive body according to one embodiment, and FIGS. 1(a), (b), (c), and (d) are schematic diagrams showing each step. Hereinafter, a method for manufacturing a bonded body using stretch fabrics, which are cloths, as the first adherend and the second adherend will be described with reference to FIG.

First, the elastic fabric 1 is placed along the jig 10 (see FIG. 1(a)). Next, the reactive hot-melt adhesive of this embodiment is applied to a predetermined portion of the elastic fabric 1 to form an adhesive layer 4 (see FIG. 1(b)). The material and shape of the jig 10 are not particularly limited, and can be appropriately selected according to the purpose. Application of the reactive hot melt adhesive may be performed, for example, using a dispenser. Next, the stretchable fabric 2 is placed on the adhesive layer 4, and the stretchable fabric 1 and the stretchable fabric 2 are pressed together via the adhesive layer 4 while applying pressure with a roll or the like from above the stretchable fabric 2. to obtain a laminate 20 (see (c) and (d) of FIG. 1). After that, by leaving (curing) the laminate 20, the reactive hot-melt adhesive in the adhesive layer 4 is moisture-cured, and a bonded body in which the elastic fabrics are bonded to each other can be obtained. The adhesive layer 4 in the adhesive body contains a cured reactive hot-melt adhesive.

In FIG. 1(b), an adhesive film made of a reactive hot-melt adhesive that has been previously formed on a release base material is transferred onto the elastic fabric 1 to form an adhesive layer 4. You may Alternatively, an adhesive may be applied to the elastic fabric 2 and attached to the elastic fabric 1 .

[clothing]
A garment of one embodiment comprises the above-described adhesive body. In this case, the first adherend and the second adherend may be cloth. The garment can be a seamless garment.

Hereinafter, the present disclosure will be described more specifically with reference to examples. However, the present disclosure is not limited to these examples.

(Examples 1 to 6 and Comparative Examples 1 and 2)
<Preparation of reactive hot melt adhesive>
Polyol ((A1) component), polyisocyanate ((A2) component), phenolic antioxidant ((B) component), thioether antioxidant ((B') component) of the type and mass parts shown in Table 1 , an ultraviolet absorber (component (C)), and a curing catalyst (component (D)), reactive hot melt adhesives of Examples 1 to 6 and Comparative Examples 1 and 2 were prepared. More specifically, component (A1), component (B), component (B'), and component (C) are dehydrated in advance by a vacuum dryer, and component (A2) and component (D) are added to the reaction vessel. and mixed until uniform at 110° C. for 1 hour. Next, the components (A1) and (A2) are reacted in the system by degassing and stirring under reduced pressure at 110° C. for 1 hour, and then further degassed and stirred at 110° C. for 1 hour under reduced pressure to form a polyol. A urethane prepolymer (component (A)) having a structural unit derived from polyisocyanate and a structural unit derived from polyisocyanate was synthesized to obtain reactive hot melt adhesives of Examples 1 to 6 and Comparative Examples 1 and 2.

Details of each component shown in Table 1 are as follows.
(A) Urethane prepolymer (A1) Polyol (A1-1) Amorphous polyester polyol ( Number of hydroxyl groups: 2, number average molecular weight: 2000, melting point (Tm): none)
(A1-2) Amorphous polyester polyol (number of hydroxyl groups: 2, number average molecular weight: 2000, melting point ( Tm): None)
(A1-3) Amorphous polyester polyol (number of hydroxyl groups: 2, number average molecular weight: 3000, melting point ( Tm): None)
(A1-4) Crystalline polyester polyol (number of hydroxyl groups: 2, number average molecular weight: 5000, melting point (Tm): 56°C)
(A1-5) Crystalline polyester polyol (number of hydroxyl groups: 2, number average molecular weight: 2, number average molecular weight: 2000, melting point (Tm): 20°C)

(A2) Polyisocyanate (A2-1) Diphenylmethane diisocyanate (manufactured by Tosoh Corporation, trade name: Millionate MT, number of isocyanate groups: 2)

［式（Ｂ－１）中、^ｔＢｕはｔ－ブチル基を示す。］
（Ｂ－２）下記式（Ｂ－２）で表される化合物（株式会社ＡＤＥＫＡ製、商品名：アデカスタブＡＯ－８０）

［式（Ｂ－２）中、Ｍｅはメチル基、^ｔＢｕはｔ－ブチル基を示す。］ (B) Phenolic antioxidant (B-1) Compound represented by the following formula (B-1) (manufactured by BASF Japan Ltd., trade name: Irganox 1076)

[In formula (B-1), ^t Bu represents a t-butyl group. ]
(B-2) A compound represented by the following formula (B-2) (manufactured by ADEKA Corporation, trade name: ADEKA STAB AO-80)

[In formula (B-2), Me represents a methyl group, and ^t Bu represents a t-butyl group. ]

(B') Thioether-based antioxidant (B'-1) Compound represented by the following formula (B'-1) (manufactured by ADEKA Co., Ltd., trade name: ADEKA STAB AO-412S)

(C) UV absorber (C-1) Benzotriazole compound (manufactured by Chemipro Kasei Co., Ltd., trade name: KEMISORB71)

(D) Curing catalyst (D-1) 2,2′-dimorpholinodiethyl ether (manufactured by San-Apro Co., Ltd., trade name: UCAT660M)

[Yellowing resistance test]
(Preparation of evaluation sample)
The reactive hot melt adhesives of Examples 1 to 6 and Comparative Examples 1 and 2 were each melted at 100° C. to form films with a thickness of 200 μm. The formed film was allowed to stand in a thermo-hygrostat at a temperature of 23° C. and a humidity of 50% for 3 days to prepare a cured film (cured film), which was used as an evaluation sample.

(NOx resistance test and UV resistance test)
Various exposure tests based on NOx resistance (JIS L 0855 strong test) and UV resistance (JIS L 0842 grade 4 irradiation) were performed on the evaluation samples. For the cured film before the exposure test and the cured film after the exposure test, using a spectral colorimeter SD6000 (manufactured by Nippon Denshoku Industries Co., Ltd.), L ^* a ^* b ^* curing per 200 μm thickness of the color system The internal b ^* value of the film was measured. Table 1 shows the results. In addition, Δb ^* (200 μm) is the difference between the internal b ^* value of the cured film after the exposure test and the internal b ^* value of the cured film before the exposure test ((internal b ^* value of the cured film after the exposure test) - (internal b ^* value of cured film before exposure test)).

As shown in Table 1, the cured films of the reactive hot-melt adhesives of Examples 1 to 6 had higher Δb ^* and It was excellent in terms of Δb ^* in the NOx resistance test. From this, it was confirmed that the reactive hot-melt adhesive of the present disclosure can give a cured product with excellent yellowing resistance.

DESCRIPTION OF SYMBOLS 1, 2... Stretch fabric, 4... Adhesive layer, 10... Jig, 20... Laminate.

Claims (5)

a urethane prepolymer having a structural unit derived from a polyol and a structural unit derived from a polyisocyanate;
a phenolic antioxidant;
a UV absorber;
contains
The structural unit derived from the polyisocyanate comprises a structural unit derived from diphenylmethane diisocyanate,
Reactive hot melt adhesive. Used for bonding together multiple adherends selected from cloth and paper,
The reactive hot melt adhesive according to claim 1. a first adherend;
a second adherend;
an adhesive layer that bonds the first adherend and the second adherend to each other;
with
The adhesive layer contains a cured product of the reactive hot melt adhesive according to claim 1,
adhesive. Equipped with the adhesive body according to claim 3,
The first adherend and the second adherend are fabrics,
clothing. A step of forming an adhesive layer by melting the reactive hot melt adhesive according to claim 1 and applying it to a first adherend;
a step of placing a second adherend on the adhesive layer and pressing the second adherend to obtain a laminate;
obtaining an adhesive body by curing the adhesive layer in the laminate;
comprising
A method for manufacturing an adhesive body.

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