JP7310317B2 - REACTIVE HOT MELT ADHESIVE, ADHESIVE, AND MANUFACTURING METHOD THEREOF - Google Patents

Description

The present invention relates to a reactive hot-melt adhesive, an adhesive and a method for producing the same.

Hot-melt adhesives are non-solvent adhesives, so they are less harmful to the environment and the human body, and can be adhered in a short period of time, making them 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 due to cooling and solidification of 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". Reactive hot-melt adhesives based on urethane prepolymers exhibit good adhesive strength even when heated. Also known are reactive hot-melt adhesives containing a urethane prepolymer, a thermoplastic resin, and a tackifier in order to improve initial and post-curing adhesive strength (see, for example, Patent Documents 1 to 3). .

JP-A-06-122860 JP-A-64-054089 JP-A-52-037936

In recent years, with the diversification of wearable terminals and the like, various reactive hot-melt adhesives are being used. However, conventional reactive hot-melt adhesive compositions do not have sufficient adhesive strength at the initial stage and after curing, leaving room for further improvement.

Accordingly, the main object of the present invention is to provide a reactive hot-melt adhesive that exhibits excellent initial and post-curing adhesive strength.

One aspect of the present invention is a polymer chain containing a structural unit derived from a polyol, a structural unit derived from a polyamine having a siloxane bond, and a structural unit derived from a polyisocyanate, and an isocyanate group bonded to the end of the polymer chain. and a reactive hot melt adhesive containing a urethane prepolymer having Such a reactive hot-melt adhesive can exhibit excellent initial and post-curing adhesive strength.

Reactive hot melt adhesives may be those used to adhere multiple fabrics or papers together. Here, objects to be pasted together may be cloth-to-cloth, paper-to-paper, or cloth-to-paper. The present invention further relates to the application of the composition containing the above urethane prepolymer as a reactive hot-melt adhesive used for laminating a plurality of cloths or papers together or for laminating a plurality of cloths or papers together. It may also relate to applications for the production of reactive hot-melt adhesives used in

In another aspect, the present invention provides a first adherend, a second adherend, and the reactive hot melt adhesive for bonding the first adherend and the second adherend to each other. and a cured product of

In another aspect, the present invention provides a process of melting the reactive hot melt adhesive and applying it to a first adherend to form an adhesive layer; and pressing a second adherend to obtain a laminate; and obtaining an adhesive by curing an adhesive layer in the laminate. .

INDUSTRIAL APPLICABILITY According to the present invention, there is provided a reactive hot-melt adhesive that exhibits excellent initial and post-curing adhesive strength. Further, according to the present invention, an adhesive body using such a reactive hot-melt adhesive and a manufacturing method thereof are provided.

FIG. 1 is a schematic diagram showing an example of a method for manufacturing an adhesive body according to one embodiment, and FIGS. be.

DETAILED DESCRIPTION OF THE INVENTION Embodiments for carrying out the present invention will be described in detail below. However, the present invention 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, "polyamine" means a compound having two or more amino groups in the molecule. The amino group means _-NH2 group or -NHR group (R represents an alkyl group, an aryl group, an alkoxy group, etc.).

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

[Reactive hot melt adhesive]
A reactive hot melt adhesive according to one embodiment includes a polymer chain containing a structural unit derived from a polyol, a structural unit derived from a polyamine having a siloxane bond, and a structural unit derived from a polyisocyanate, and at the end of the polymer chain It contains a urethane prepolymer with bound isocyanate groups. In general, reactive hot-melt adhesives are those that can develop adhesive properties and the like by increasing their molecular weight through chemical reactions. A urethane prepolymer having an isocyanate group attached to the end of a polymer chain cures (forms a cured product) by reacting with moisture, so the urethane prepolymer alone can act as a reactive hot-melt adhesive. . Also, the reactive hot-melt adhesive may contain components other than the urethane prepolymer.

<Urethane prepolymer>
A urethane prepolymer comprises a polymer chain containing structural units derived from a polyol, a structural unit derived from a polyamine having a siloxane bond, and a structural unit derived from a polyisocyanate, and an isocyanate group bonded to the end of the polymer chain. have. A urethane prepolymer can usually be obtained by reacting a polyol and a polyamine having a siloxane bond with a polyisocyanate. That is, the urethane prepolymer may be a reaction product of a polyol, a polyamine having siloxane bonds, and a polyisocyanate. In addition, the reaction between polyol and polyisocyanate forms a urethane bond, and the reaction between polyamine and polyisocyanate forms a urea bond. It may have a urea bond.

(polyol)
Any polyol can be used without particular limitation as long as it is a compound having two or more hydroxy groups. A polyol may be a compound having two hydroxy groups (a diol). The polyol may contain a polyester polyol from the viewpoint of further improving the adhesive strength. One polyol may be used alone, or two or more may be used in combination.

The setting time and viscosity of the reactive hot-melt adhesive can be adjusted by including structural units derived from polyester polyol in the polymer chain. A compound produced by a polycondensation reaction between a polyhydric alcohol and a polycarboxylic acid can be used as the polyester polyol. Polyester polyols have, for example, polyhydric alcohols having 2 to 15 carbon atoms and 2 or 3 hydroxy groups and 2 to 14 carbon atoms (including the carbon atoms in the carboxyl groups), 2 It may also be a polycondensate with a polycarboxylic acid having up to 6 carboxyl groups. One polyester polyol may be used alone, or two or more thereof may be used in combination.

The polyester polyol may be a linear polyester diol produced from a diol and a dicarboxylic acid, or a branched polyester triol produced from a triol and a dicarboxylic acid. Branched polyester triols can also be obtained by reacting diols with tricarboxylic acids.

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, 1,4-cyclohexane diols, aliphatic or alicyclic diols such as 1,4-cyclohexanedimethanol; aromatic diols such as 4,4′-dihydroxydiphenylpropane, bisphenol A, bisphenol F, pyrocatechol, resorcinol and hydroquinone. One type of polyhydric alcohol may be used alone, or two or more types may be used in combination. Among these, aliphatic diols are preferred, more preferably aliphatic diols having 2 to 6 carbon atoms.

Examples of polycarboxylic acids include aromatic polycarboxylic acids such as phthalic acid, isophthalic acid, terephthalic acid, and 1,2,4-benzenetricarboxylic acid; maleic acid, fumaric acid, aconitic acid, and 1,2,3-propane. Aliphatic acids such as tricarboxylic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, azelaic acid, sebacic acid, cyclohexane-1,2-dicarboxylic acid, 1,4-cyclohexanediene-1,2-dicarboxylic acid Alternatively, alicyclic polycarboxylic acids and the like can be mentioned. One type of polycarboxylic acid may be used alone, or two or more types may be used in combination.

A polycarboxylic acid derivative such as a carboxylic acid anhydride or a compound in which a part of the carboxyl group is esterified can be used instead of the polycarboxylic acid. Examples of polycarboxylic acid derivatives include dodecyl maleic acid and octadecenyl maleic acid.

The polyester polyol may be an amorphous polyester polyol or a crystalline polyester polyol. Here, amorphousness and crystallinity can be judged in the state at 25°C. As used herein, amorphous polyester polyol means a polyester polyol that is amorphous at 25°C, and crystalline polyester polyol means a polyester polyol that is crystalline at 25°C. The polyester polyol may contain amorphous polyester polyol.

The number average molecular weight Mn of the amorphous polyester polyol may be 3000 or less, and from the viewpoint of improving the adhesive strength of the reactive hot melt adhesive, it is preferably in the range of 500 to 3000, more preferably in the range of 1000 to 3000. is. In addition, in this specification, a number average molecular weight is a value measured by a gel permeation chromatography (GPC) and converted into standard polystyrene. GPC measurement can be performed under the following conditions.
Column: "Gelpack GLA130-S", "Gelpack GLA150-S" and "Gelpack GLA160-S" (manufactured by Hitachi Chemical Co., Ltd., packed column for HPLC)
Eluent: Tetrahydrofuran Flow rate: 1.0 mL/min Column temperature: 40°C
Detector: RI

The number average molecular weight (Mn) of the crystalline polyester polyol is preferably in the range of 500 to 10000, more preferably in the range of 800 to 9000, still more preferably in the range of 1000 to 8000, from the viewpoint of improving waterproofness and adhesive strength. be.

The polyester polyol content may be 70% by mass or more, 80% by mass or more, 90% by mass or more, or 95% by mass or more based on the total amount of polyols, from the viewpoint of further improving the adhesive strength.

Polyols may contain polyols other than polyester polyols. Examples of polyols other than polyester polyols include polyether polyols, polyether ester polyols, polyurethane polyols, polycarbonate polyols, and polyolefin polyols. Such polyols may be used alone or in combination of two or more.

(Polyamine with siloxane bond)
A polyamine having a siloxane bond is a compound having a siloxane containing silicon atoms and oxygen atoms which are alternately bonded and a group containing two or more amino groups bonded to the silicon atoms in the siloxane. . When the urethane prepolymer contains structural units derived from a polyamine having a siloxane bond, the reactive hot-melt adhesive can have excellent initial and post-curing adhesive strength. A polyamine having a siloxane bond may be, for example, a double-ended amino-modified silicone oil represented by the following general formula (1). A polyamine having a siloxane bond may be used alone or in combination of two or more.

In general formula (1), R ¹ represents an alkyl group having 1 to 5 carbon atoms, a phenyl group, or a phenoxy group, and multiple R ^1s may be the same or different. R ¹ is preferably a methyl group. R ² represents an alkylene group having 1 to 5 carbon atoms or a phenylene group which may have a substituent, and a plurality of R ² may be the same or different. R ³ represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, a phenyl group, or a phenoxy group, and multiple R ³ may be the same or different. ^R3 is preferably a hydrogen atom.

A commercially available product can be suitably used as the double-ended amino-modified silicone oil. Examples of commercial products of amino-modified silicone oils at both ends include PAM-E, KF-8010, X-22-161A, X-22-161B, KF-8012, and KF-8008 (all manufactured by Shin-Etsu Chemical Co., Ltd. ) and the like.

The content of polyamine having a siloxane bond is 0.1% by mass or more, 0.5% by mass or more, 1% by mass or more, 2% by mass or more, 3% by mass, based on the total amount of polyol and polyamine having a siloxane bond % or more, 4 mass % or more, or 5 mass % or more. When the content of the polyamine having a siloxane bond is within this range, the adhesive strength tends to be superior in the initial stage and after curing. From the viewpoint of suppressing gelation of the reactive hot melt adhesive, the content of the polyamine having a siloxane bond is 30% by mass or less, 20% by mass or less, 18% by mass or less, based on the total amount of the polyol and the polyamine having a siloxane bond. % by mass or less, 15% by mass or less, 12% by mass or less, or 10% by mass or less.

The content of the polyamine having a siloxane bond is 0.1 mol% or more, 0.5 mol% or more, 1 mol% or more, and 3 mol% when the total amount of the polyol and the polyamine having a siloxane bond is 100 mol%. Above, it may be 4 mol % or more, or 5 mol % or more. When the content of the polyamine having a siloxane bond is within this range, the adhesive strength tends to be superior in the initial stage and after curing. From the viewpoint of suppressing gelation of the reactive hot melt adhesive, the content of the polyamine having a siloxane bond is 35 mol% or less and 25 mol when the total amount of the polyol and the polyamine having a siloxane bond is 100 mol%. % or less, 20 mol % or less, or 15 mol % or less.

The mixing ratio of the polyamine having a siloxane bond and the polyol is such that the functional group ratio ((NH)/(OH)) of the amino group (NH) of the polyamine having a siloxane bond/the hydroxy group (OH) of the polyol is 0.001 or more. , 0.005 or greater, 0.01 or greater, 0.03 or greater, 0.04 or greater, or 0.05 or greater. When (NH)/(OH) is within such a range, the adhesive strength tends to be superior at the initial stage and after curing. In addition, (NH)/(OH) is 0.35 or less, 0.32 or less, 0.29 or less, 0.26 or less, or 0.23 from the viewpoint of suppressing gelation of the reactive hot melt adhesive. may be:

(polyisocyanate)
Polyisocyanate can be used without particular limitation as long as it is a compound having two or more isocyanate groups. A polyisocyanate may be a compound having two isocyanate groups (diisocyanate). Examples of polyisocyanates include aromatic isocyanates such as diphenylmethane diisocyanate, dimethyldiphenylmethane diisocyanate, tolylene diisocyanate, xylylene diisocyanate and p-phenylene diisocyanate; alicyclic isocyanates such as dicyclohexylmethane diisocyanate and isophorone diisocyanate; hexamethylene diisocyanate and the like. and aliphatic isocyanates. From the viewpoint of reactivity and adhesion, the polyisocyanate preferably contains aromatic diisocyanate, more preferably diphenylmethane diisocyanate. One type of polyisocyanate may be used alone, or two or more types may be used in combination.

A urethane prepolymer can be synthesized by reacting a polyol and a polyamine having a siloxane bond with a polyisocyanate. A urethane prepolymer comprises a polymer chain containing structural units derived from a polyol, a structural unit derived from a polyamine having a siloxane bond, and a structural unit derived from a polyisocyanate, and an isocyanate group bonded to the end of the polymer chain. have. When synthesizing such a urethane prepolymer, the equivalent ratio of the isocyanate group (NCO) of the polyisocyanate to the hydroxyl group (OH) of the polyol and the amino group (NH) of the polyamine having a siloxane bond (the isocyanate group of the polyisocyanate (NCO ) equivalent/(hydroxy group (OH) equivalent of polyol + amino group (NH) equivalent of polyamine having siloxane bond), NCO/(OH+NH)) may be 1.1 or more, and 1.1 to 2. can be 1. When NCO/(OH+NH) is 1.1 or more, the urethane prepolymer has an isocyanate group bonded to the end of the polymer chain, and an increase in the viscosity of the urethane prepolymer can be suppressed, resulting in better workability. tend to improve. When NCO/(OH+NH) is 2.1 or less, foaming is less likely to occur during the moisture curing reaction of the reactive hot-melt adhesive, which tends to make it easier to suppress reduction in adhesive strength.

The temperature and time for reacting a polyol and a polyamine having a siloxane bond with a polyisocyanate when synthesizing a urethane prepolymer are not particularly limited. .

The reactive hot-melt adhesive may further contain a catalyst from the viewpoint of accelerating curing of the urethane prepolymer and developing higher adhesive strength. Examples of catalysts include dibutyltin dilaurate, dibutylthione octate, dimethylcyclohexylamine, dimethylbenzylamine, trioctylamine and the like. The content of the catalyst may be 0.001-0.5% by weight, based on the total amount of the reactive hot melt adhesive.

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 0.1-50% 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 adhesiveness 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 0.1-50% 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, antioxidants, pigments, ultraviolet absorbers, surfactants, flame retardants, fillers, photocoloring agents, thermal coloring 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.

The viscosity of the reactive hot melt adhesive (reactive hot melt adhesive before curing) at 120° C. may be 1 Pa·s or more, 3 Pa·s or more, or 5 Pa·s or more, and may be 50 Pa·s or less, 40 Pa. · s or less, 30 Pa·s or less, or 20 Pa·s or less. When the viscosity at 120° C. is within the above range, workability is improved when applying with a dispenser or the like. As used herein, the viscosity at 120° C. of a reactive hot-melt adhesive (reactive hot-melt adhesive before curing) means a value measured by the method described in Examples.

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) for 24 hours at RH (relative humidity). Thereby, a cured product of the reactive hot melt adhesive can be obtained.

The adhesive strength (initial adhesive strength of the reactive hot-melt adhesive) measured before the reactive hot-melt adhesive cures after pressing the adherends together using the reactive hot-melt adhesive is 4. 0 N/8 mm or more, 4.1 N/8 mm or more, or 4.2 N/8 mm or more. The upper limit of the adhesive strength measured before curing the adhesive is not particularly limited, but may be 20 N/8 mm or less, 15 N/8 mm or less, or 10 N/8 mm or less. In addition, in this specification, an initial adhesive strength means the value measured by the method as described in an Example. That is, the initial adhesive strength is the reactive hot-melt adhesive strength of the pressed body obtained by pressing the adherends together at 120° C. after 5 minutes from the time of pressing. It means the adhesive strength of the melt adhesive.

After pressing the adherends together using the reactive hot melt adhesive, the adhesive strength measured after the reactive hot melt adhesive is cured (adhesive strength after curing of the reactive hot melt adhesive) is 20N. /8 mm, 22 N/8 mm or more, or 24 N/8 mm or more. The upper limit of adhesive strength after curing is not particularly limited, but may be 60 N/8 mm or less, 50 N/8 mm or less, or 40 N/8 mm or less. In addition, in this specification, the adhesive strength after hardening means the value measured by the method as described in an Example. That is, the adhesive strength after curing was measured by pressing the adherends together at 120°C using a reactive hot melt adhesive and curing the bonded body in a constant temperature bath at 23°C and 50% RH for 1 day. , means the adhesive strength after curing of the reactive hot melt adhesive of the resulting adhesive body.

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 of the reactive hot-melt adhesive. Examples of the adherend include metal substrates such as 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. Reactive hot-melt adhesives can be suitably used for laminating multiple fabrics or papers together. In this case, the objects to be bonded (adherends) may be cloth and cloth, paper and paper, or cloth and paper. Reactive hot-melt adhesives can be suitably used for apparel products such as clothes, supporters, bags, wallets, interiors, various covers, cases, wearable devices, and the like.

The reactive hot-melt adhesive may be used in the form of a film. Such films can be formed, for example, by applying a reactive hot-melt adhesive onto a support film such as a PET (polyethylene terephthalate) film. The thickness of the reactive hot melt adhesive may be 10 μm or more, 20 μm or more, or 30 μm or more, and may be 300 μm or less, 250 μm or less, or 200 μm or less. When the film is thick, the adhesiveness can be ensured, and when the film is thin, the elasticity tends to be more easily ensured.

[Adhesive and its manufacturing method]
The adhesive of one embodiment is the reactive hot melt adhesive for bonding the first adherend, the second adherend, and the first adherend and the second adherend to each other. and a cured product of Examples of the bonded body of the present embodiment include seamless clothing, semiconductor devices, electronic devices, and the like. Among these, the adhesive body may be a seamless garment.

The first adherend and the second adherend can be the same as those exemplified above for the adherend. Since the reactive hot-melt adhesive of the present embodiment is excellent in adhesive strength in the initial stage and after curing, the first adherend and the second adherend may be cloth and cloth, paper and paper, or cloth and It can be paper.

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 in the laminate 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, there is a method of pressure-bonding using a pressure roll or the like.

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

FIG. 1 is a schematic diagram showing an example of a method for manufacturing an adhesive body according to one embodiment, and FIGS. be. 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 (see (c) and (d) of FIG. 1). After that, the laminate is allowed to stand (cured) so that the adhesive layer 4 is moisture-cured, and a bonded body in which the elastic fabrics are bonded to each other can be obtained.

In (b) of FIG. 1 , the adhesive layer 4 may be formed by transferring an adhesive film previously formed on a release base material onto the elastic fabric 1 . Alternatively, an adhesive may be applied to the elastic fabric 2 and attached to the elastic fabric 1 .

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

(Examples 1 and 2 and Comparative Example 1)
<Preparation of reactive hot melt adhesive>
A polyol, a polyamine having a polysiloxane skeleton, and a polyisocyanate of the types and parts by mass shown in Table 1 were used. The equivalent ratio of the isocyanate groups of the polyisocyanate to the total of the hydroxyl groups of the polyol and the amino groups of the polyamine having a polysiloxane skeleton ( (NCO) equivalence/((OH) equivalence + (NH) equivalence) was added to the reaction vessel so that it became the numerical value shown in Table 1, and mixed until uniform at 110° C. for 1 hour.Then, the catalyst was added, Further, a urethane prepolymer was obtained by degassing and stirring under reduced pressure for 1 hour at 110° C. As shown in Table 1, (NCO) equivalent/((OH) equivalent + (NH) equivalent) is greater than 1, so the obtained It is speculated that the urethane prepolymer has an isocyanate group bonded to the end of the polymer chain containing structural units derived from polyols, structural units derived from polyamines having a polysiloxane skeleton, and structural units derived from polyisocyanate. The obtained urethane prepolymer was used as it is as a reactive hot-melt adhesive.

Details of each component shown in Table 1 are as follows.
・Polyol (a)
a-1: Amorphous polyester polyol containing adipic acid and isophthalic acid, ethylene glycol and neopentyl glycol as main components (number of hydroxy groups: 2, number average molecular weight: 2000)
- Polyamine (b) having a polysiloxane skeleton
b-1: Double-ended amino-modified silicone oil (manufactured by Shin-Etsu Chemical Co., Ltd., trade name: X-22-161A, number of amino groups: 2)
・Polyisocyanate (c)
c-1: Diphenylmethane diisocyanate (manufactured by Tosoh Corporation, trade name: Millionate MT, number of isocyanate groups: 2)
・Catalyst (d)
d-1: Dimorpholinodiethyl ether (manufactured by San-Apro Co., Ltd., trade name: UCAT-660M)

<Viscosity before curing>
The viscosities of the reactive hot-melt adhesives before curing of Examples 1 and 2 and Comparative Example 1 were measured using a BH-HH small-volume rotational viscometer (manufactured by Toki Sangyo Co., Ltd.), rotor No. 4, sample amount 15 g, Measurement was performed at 120°C. Table 1 shows the results.

<Adhesive strength at initial stage and after curing>
The reactive hot-melt adhesives of Examples 1 and 2 and Comparative Example 1 were melted at 120° C. and applied onto a stretch fabric (spandex, manufactured by Toray Oprontex Co., Ltd., Lycra (registered trademark)), and a bar An adhesive layer was formed by coating with a coater to a thickness of 80 μm. The same stretchable fabric was placed on the formed adhesive layer and pressed at 120° C. to obtain a pressed body. The adhesive strength of the crimped body after 5 minutes from the time of crimping was measured using a force gauge (manufactured by Imada Co., Ltd., DS250N), and this was taken as the initial adhesive strength of the reactive hot-melt adhesive. Next, the pressure-bonded body was cured in a constant temperature bath at 23° C. and 50% RH for 1 day to cure the adhesive layer, thereby producing a bonded body. The adhesive strength of the adhesive body is measured by a T-type peel strength test using a tensile tester (EZ-Test EZ-SX, manufactured by Shimadzu Corporation) under the conditions of a measurement temperature of 25 ° C. and a tensile speed of 100 mm / min. This was taken as the adhesive strength of the reactive hot-melt adhesive after curing. Table 1 shows the results. In addition, "fabric failure" in the adhesive strength after curing means that the elastic fabric itself is destroyed (torn) beyond the measurable range. Since the measurable range is about 25 N/8 mm, it is estimated that "fabric failure" is 25 N/8 mm or more.

As shown in Table 1, the reactive hot-melt adhesives of Examples 1 and 2 containing urethane prepolymers containing structural units derived from polyamines having siloxane bonds are comparative example 1 which does not contain such urethane prepolymers. Compared to the reactive hot-melt adhesive of No. 2, the initial and post-curing adhesive strength was greater. From the above, it was confirmed that the reactive hot-melt adhesive of the present invention is excellent in adhesive strength at the initial stage and after curing.

1, 2... Stretch fabric, 4... Adhesive layer, 10... Jig.

Claims (3)

A urethane prepolymer having a polymer chain containing a structural unit derived from a polyol, a structural unit derived from a polyamine having a siloxane bond, and a structural unit derived from a polyisocyanate, and an isocyanate group bonded to the end of the polymer chain. contains
the polyol comprises a polyester polyol,
The content of the polyester polyol is 90% by mass or more based on the total amount of polyol,
Reactive hot melt adhesives used to bond fabric to fabric, paper to paper, or fabric to paper . a first adherend;
a second adherend;
A cured product of the reactive hot melt adhesive according to claim 1, which bonds the first adherend and the second adherend to each other;
with
The bonded body, wherein the first adherend and the second adherend are cloth and cloth, paper and paper, or cloth and paper . a step of melting the reactive hot melt adhesive according to claim 1 and applying it to a first adherend to form an adhesive layer;
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;
with
A method for producing an adhesive body, wherein the first adherend and the second adherend are cloth and cloth, paper and paper, or cloth and paper.

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