JP7138963B2 - Adhesive for non-woven fabrics - Google Patents

Description

The present technology relates to adhesives for nonwoven fabrics.

In recent years, nonwoven fabrics have been widely used in various applications such as civil engineering materials, building materials, agricultural materials, automobile materials, aircraft materials, electronic device materials, and electrical device materials.
For example, moisture-permeable and waterproof nonwoven fabrics are used as civil engineering materials or building materials in order to cover earthen structures such as embankments and embankments, or building structures. Patent Document 1 proposes to provide an excellent waterproof sheet that has high strength to withstand wind pressure and can maintain good waterproof performance over a long period of time, and a sheet waterproofing construction method using the same.

Japanese Patent Application Laid-Open No. 2001-241118

The inventors of the present invention have investigated an adhesive to be applied to a nonwoven fabric, which has good workability before hardening, and has good followability and adhesiveness of the hardened product to the nonwoven fabric after hardening.
That is, the main object of the present invention is to provide an adhesive that is excellent in workability when applied to a nonwoven fabric, and that the cured product after curing has excellent conformability and adhesiveness to the nonwoven fabric.

As a result of intensive studies, the present inventors found that a specific adhesive has excellent workability when applied to a nonwoven fabric and can form a cured product having excellent followability and adhesion to the nonwoven fabric. rice field.

That is, the present invention contains a castor oil-based polyester polyol and an isocyanate compound, the viscosity of the adhesive before curing is 200 mPa s or more and 1200 mPa s or less when measured at 23 ° C., and after curing can provide a nonwoven fabric adhesive having a cured product hardness of A50 to A80 when measured at 23°C.
The isocyanate compound may be an aromatic polyisocyanate compound .
The form of use of the adhesive may be a two-component curing type.
Further, the present invention comprises a main agent containing a component (A) castor oil-based polyester polyol and a curing agent containing a component (B) an isocyanate compound. The viscosity of the adhesive is 200 mPa s or more and 1200 mPa s or less when measured at 23 ° C., and the hardness of the cured product after curing is A50 to A80 when measured at 23 ° C. A two-part nonwoven adhesive kit can be provided for use in formulating certain nonwoven adhesives.

ADVANTAGE OF THE INVENTION According to this invention, while being excellent in workability|operativity when applying to a nonwoven fabric, the hardened|cured material after hardening can provide the adhesive which has the excellent followability|trackability and adhesiveness with respect to a nonwoven fabric. Note that the effects of the present invention are not necessarily limited to the effects described herein, and may be any of the effects described herein.

FIG. 1 shows an example of bonding of sheets formed by bonding with the adhesive of the present invention. FIG. 1A is bonding by overlapping joints, and FIG. 1B is bonding by joints on one side. is shown. FIG. 2 is a diagram showing a production example of a planar bonded test piece 10 for a simple water stoppage test. FIG. 3 is a side view of a simple water cutoff test using a bonding test piece 20 having a substantially square pyramid shape. FIG. 4 is an upper view of a simple water cutoff test using a bonding test piece 20 having a substantially square pyramidal truncated shape. FIG. 5 is a perspective view from above of a simple water cutoff test using a folded bonding test piece 20 having a substantially square pyramid shape. FIG. 6 is a photograph of an upward observation of a simple water cutoff test using the bonding test piece 20 having a substantially square pyramid shape.

EMBODIMENT OF THE INVENTION Hereinafter, the form for implementing this invention is demonstrated in detail. It should be noted that the embodiments described below are examples of representative embodiments of the present invention, and the present invention is not limited to these embodiments. Also, the upper limit and lower limit of each numerical range can be arbitrarily combined as desired.

1. Description of the adhesive of the invention

The adhesive of the present invention has a viscosity of 1200 mPa·s or less when measured at 23°C before curing, and a hardness of the cured product after curing when measured at 23°C. , A50 to A80. The adhesive of the present invention may be for nonwoven fabrics or may be used for bonding nonwoven fabrics.
Also, the adhesive of the present invention may contain a polyol and an isocyanate compound.
The adhesive of the present invention is excellent in workability when applied to a nonwoven fabric by coating or the like, and the cured product after curing has excellent conformability and adhesiveness to a substrate.

2. Adhesive properties

In a preferred embodiment of the present invention, the viscosity of the adhesive before curing is preferably 1200 mPa·s or less, more preferably 1000 mPa·s or less, and still more preferably 1000 mPa·s or less as an upper limit value when measured at 23°C. 900 mPa s or less, and the lower limit is not particularly limited, but is preferably 300 mPa s or more, more preferably 400 mPa s or more, still more preferably 500 mPa s or more, and even more preferably 600 mPa s or more, Even more preferably, it is 700 mPa·s or more. The preferred numerical range is more preferably 300 to 1200 mPa·s, still more preferably 500 to 1000 mPa·s, still more preferably 600 to 900 mPa·s.
By setting the adhesive to a specific and moderate viscosity before curing, the impregnation property of the adhesive when applied to the nonwoven fabric can be moderated, and the adhesiveness of the cured product after curing can be improved. Furthermore, it is possible to improve the watertightness of the bonded portion of the nonwoven fabric after it is applied to the nonwoven fabric and cured. Furthermore, by setting the adhesive to a specific viscosity, it is possible to easily apply the adhesive to the non-woven fabric. Workability can be improved when the agent is applied to the nonwoven fabric.

<Method for Measuring Viscosity of Adhesive Before Curing>
The viscosity of the adhesive before curing can be measured according to JIS K 7117-1, K 7117-2 and JIS K 1557-5. JIS K 1557-5 is a standard for testing methods for polyurethane raw material polyols (methods for determining viscosity, etc.). Method for measuring viscosity at shear rate JIS K 7117-2 is cited. Specifically, immediately after adjusting the temperature of the adhesive to 23° C., it is measured with a BM type viscometer. In the case of a two-component adhesive, after adjusting the temperature of each of the liquids A and B to 23° C., the two liquids are mixed and immediately measured with a BM type viscometer.
Measurement conditions: Viscometer B-type series BM-type viscometer, 12 rotations, No. 3 rotor, measurement time of 1 minute, measurement temperature of 23°C

In a preferred embodiment of the present invention, the hardness of the cured product after curing in the adhesive of the present invention is preferably A80 or less, more preferably A75 or less, and even more preferably A75 or less as an upper limit when measured at 23°C. It is A70 or less, and the lower limit is preferably A50 or more, more preferably A55 or more, further preferably A60 or more. The preferred numerical range is preferably A55 to A80, more preferably A60 to A70.
By setting the hardness of the cured product after curing to a specific moderate hardness, it is possible to improve the followability and adhesiveness of the cured product existing inside the nonwoven fabric and on the adhesive surface, and to the nonwoven fabric. The watertightness of the nonwoven joint after application and curing can also be better.

<Method for Measuring Hardness of Cured Adhesive>
The hardness (Shore hardness) of the adhesive after curing can be measured according to JIS K 7215. Specifically, the adhesive is placed in a mold (depth/thickness: 8 mm x diameter: 60 mm) and cured at 23°C for one day. - Measured with an A hardness tester. The range of measurement of the hardness of the cured product by the Shore-A hardness tester is A10 to 90, and when it exceeds A90, it is measured by the Shore-D hardness tester.
Measurement conditions: Shore-A hardness meter instantaneous value, measurement temperature 23° C., shape of cured product: thickness 8 mm×diameter 60 mm.

In a preferred embodiment of the present invention, the tensile strength of the cured product in the normal state after curing in the adhesive of the present invention is not particularly limited, but the lower limit is preferably 2.0 MPa or more, more preferably 3.0 MPa or more, More preferably 3.5 MPa or more, still more preferably 4.0 MPa or more, still more preferably 4.5 MPa or more, more preferably 5.0 MPa or more, and the upper limit is preferably 15 MPa or less, more preferably 13 MPa or less. , more preferably 10 MPa or less, still more preferably 8.0 MPa or less, more preferably 7.5 MPa or less, more preferably 7.0 MPa or less, still more preferably 6.5 MPa or less, more preferably 6.0 MPa or less. The preferred numerical range is preferably 2.0 to 15 MPa, more preferably 4.0 to 7.5 MPa, still more preferably 5.0 to 6.5 MPa.
By making the cured product after curing have a specific moderate tensile strength, it is possible to improve the followability and adhesiveness of the cured product existing inside the nonwoven fabric and on the bonding surface, and also to improve the watertightness to the nonwoven fabric. can do better.

<Method for Measuring Tensile Strength of Cured Adhesive in Normal State>
A tensile strength test in a normal state of the cured product of the adhesive can be performed at 23° C. according to JIS K7113. Autograph ASG-X (Shimadzu Corporation) is used as the test machine, and the test can be performed at a test speed of 200 mm/min and N=2 to 5 (average value of these values).

In a preferred embodiment of the present invention, the gel time of the adhesive of the present invention is not particularly limited, but is preferably 30 to 120 minutes, more preferably 50 to 90 minutes, and still more preferably 60 to 80 minutes. It is possible to secure the pot life, and furthermore, it is possible to secure both the work time when bonding the base material and the shortening of the curing time, and the workability when applying the adhesive to the nonwoven fabric can be improved. can.
This gel time can be determined by taking 100 g of the adhesive in a cylindrical cup (5 cm in diameter x 9 cm in height), allowing it to stand at 23°C, and measuring the gel time until it loses fluidity due to the effects of curing. . In the case of measuring the gel time of a two-component adhesive, it can be carried out according to <Method for measuring gel time> in the following examples.

In the present invention, it is preferable to contain an adhesive component so as to have a specific viscosity and a specific hardness as described above. It can be adopted as appropriate.

3. Adhesive Composition In a preferred embodiment of the present invention, the adhesive comprises Component (A) a polyol and Component (B) an isocyanate compound. The adhesive of the present invention is preferably a urethane-based adhesive, and the urethane-based adhesive is cured by, for example, reacting a hydroxyl group (OH group) of a polyol with an isocyanate group (NCO group) of an isocyanate compound. It is possible to form resins of urethane polymers, which are materials.
As a result, it is possible to provide an adhesive that is excellent in workability when applied to a nonwoven fabric, and that is excellent in followability and adhesiveness of the cured product after curing to the nonwoven fabric. Examples of the composition of the adhesive of the present invention are described below.

<Component (A) polyol>
The polyol of component (A) used in the present invention is not particularly limited, and examples thereof include, but are not limited to, polyester polyols and polyether polyols. You may use 1 type(s) or 2 or more types selected from these. These polyols may be commercially available products or those obtained by known production methods.
Examples of polyols include polyols derived from vegetable oils and fats, and the polyols may be either natural or synthetic. Natural types include vegetable oils and fats such as castor oil, and synthetic types include vegetable oils and fats. and those obtained by condensation of polyhydric alcohols and the like with carboxylic acids (preferably fatty acids) contained in, but not limited to. Among these, castor oil-derived polyols including castor oil and the like are preferable.

The viscosity of the polyol is not particularly limited. The value is preferably 200 mPa·s or more, more preferably 500 mPa·s or more, and still more preferably 600 mPa·s or more.

<Method for measuring viscosity of polyol, etc.>
The viscosity in this specification can be measured according to JIS K 7117-1, K 7117-2 and JIS K 1557-5 in the same manner as in <Method for Measuring Viscosity of Adhesive Before Curing>. Specifically, after the temperature of the sample is adjusted to 23°C, it is measured at 23°C with a BM type viscometer.
Measurement conditions: Viscometer B-type series BM-type viscometer, 12 rotations, No. 3 rotor, measurement time of 1 minute, measurement temperature of 23°C

The hydroxyl value of the polyol is not particularly limited. The value is preferably 100 mgKOH/g or more, more preferably 110 mgKOH/g or more, still more preferably 120 mgKOH/g or more.
The hydroxyl value (mgKOH/g) used herein can be measured according to JIS K 0070 and JIS K 1557-5.

The number of functional groups (terminal hydroxyl groups) of the polyol is not particularly limited, but the upper limit is preferably 4 or less, more preferably 3 or less, and still more preferably 2.5 or less, and the lower limit is preferably 1 or more and more It is preferably 1.5 or more, more preferably 2 or more.
The number of functional groups (terminal hydroxyl group) in the present specification can be calculated by Formula 1 from the hydroxyl value and the number average molecular weight by GPC. Functional group number (terminal hydroxyl group)=hydroxyl value (mgKOH/g)×number average molecular weight/(1000×56.1) (Formula 1).

The mass content ratio of the polyol in the adhesive is not particularly limited, but the lower limit is preferably 60% by mass or more, more preferably 65% by mass or more, and still more preferably 70% by mass or more with respect to the mass of the adhesive. and the upper limit is preferably 85% by mass or less, more preferably 80% by mass or less, and even more preferably 75% by mass or less.
The volume content of the polyol in the adhesive is not particularly limited, but the lower limit of the volume of the adhesive is preferably 65% by volume or more, more preferably 68% by volume or more, and still more preferably 70% by volume or more. , Still more preferably 73% by volume or more, and the upper limit is preferably 90% by volume or less, more preferably 85% by volume or less, and even more preferably 80% by volume or less.

<Component (A) polyester polyol>
The polyester polyol is not particularly limited, and may be natural or synthetic. Commercially available polyester polyols may be used, or those obtained by known production methods may be used.

Examples of natural polyester polyols include, but are not limited to, vegetable oil polyols. Examples of the vegetable oil polyols include, but are not limited to, sunflower oil, rapeseed oil, linseed oil, cottonseed oil, paulownia oil, and coconut oil. , poppy oil, corn oil, castor oil and peanut oil, and one or more selected from these can be used. These vegetable oils and fats may include, for example, polyester polyols of polyglycerin fatty acid esters.

Synthetic polyester polyols include, but are not limited to, those obtained by condensation of carboxylic acids (preferably fatty acids) contained in these vegetable oils and polyhydric alcohols. For example, a hydrogenated vegetable oil, a reaction product of a vegetable oil or a hydrogenated vegetable oil and a polyhydric alcohol, an esterification reaction product of a vegetable oil-derived or hydrogenated vegetable oil-derived fatty acid and a polyhydric alcohol, and an alkylene oxide to these and the like, and one or more selected from these can be used.

The viscosity of the polyester polyol is not particularly limited, but the upper limit is preferably 1200 mPa s or less, more preferably 1000 mPa s or less, and still more preferably 900 mPa s or less when measured at 23°C. The lower limit is preferably 200 mPa·s or more, more preferably 500 mPa·s or more, and still more preferably 600 mPa·s or more.

The hydroxyl value of the polyester polyol is not particularly limited, but the upper limit is preferably 160 mgKOH/g or less, more preferably 150 mgKOH/g or less, still more preferably 145 mgKOH/g or less, still more preferably 140 mgKOH/g or less, The lower limit is preferably 100 mgKOH/g or more, more preferably 110 mgKOH/g or more, still more preferably 120 mgKOH/g or more.

The number of functional groups (terminal hydroxyl groups) of the polyester polyol is not particularly limited, but the upper limit is preferably 4 or less, more preferably 3 or less, and still more preferably 2.5 or less, and the lower limit is preferably 1 or more, It is more preferably 1.5 or more, and still more preferably 2 or more.

The content of the polyester polyol in the adhesive is not particularly limited, but the lower limit is preferably 60% by mass or more, more preferably 65% by mass or more, and still more preferably 70% by mass with respect to the mass of the adhesive. Above, the upper limit is preferably 85% by mass or less, more preferably 80% by mass or less, still more preferably 75% by mass or less, and a more preferable numerical range is preferably 60 to 80% by mass, more preferably is 65 to 75% by mass.

The volume content of the polyester polyol in the adhesive is not particularly limited, but the lower limit is preferably 65% by volume or more, more preferably 68% by volume or more, and still more preferably 70% by volume with respect to the volume of the adhesive. Above, even more preferably 73% by volume or more, the upper limit is preferably 90% by volume or less, more preferably 85% by volume or less, and even more preferably 80% by volume or less. is 68-85% by volume, more preferably 70-80% by volume.

Among polyester polyols, castor oil-based polyester polyols are preferred. As the castor oil-based polyester polyol, a commercially available product may be used, or one obtained by a known production method may be used.
The castor oil-based polyester polyol is not particularly limited, but for example, natural polyester polyol of castor oil, castor oil fatty acid, hydrogenated castor oil, hydrogenated castor oil fatty acid, etc., and synthetic systems such as those produced using these Polyester polyols and mixtures thereof can be mentioned, and one or more selected from these can be used.

Commercially available products may be used as castor oil-based polyester polyols, for example, castor oil (hydroxyl value 160 mgKOH/g, functional group number 2.7), H-81 (hydroxyl value 330 to 350 mgKOH/g, functional group number 3, 1000 to 1400 mPa.s (25 ° C.), manufactured by Ito Oil Co., Ltd.), H-1824 (hydroxyl value 55 to 77 mg KOH / g, functional group number 2.3, 700 to 1600 mPa.s (25 ° C.), manufactured by Ito Oil Co., Ltd.), HF-2009 (hydroxyl value 44 mgKOH/g, functional group number 2.2, 1500 mPa.s (25° C.), manufactured by Ito Seiyu Co., Ltd.), HF-1300 (hydroxyl value 75 to 105 mgKOH/g, functional group number 2, 170 to 250 mPa.s). s (25° C.), manufactured by Ito Seiso Co., Ltd.), but not limited thereto. One or more selected from these can be used.

The castor oil-based polyester polyol is preferably a mixture in which two or more types having different properties are combined. The mixture of castor oil-based polyester polyols is preferably a combination of two or more so that the viscosity falls within the specific viscosity range described in the above "Viscosity of polyol", and a suitable upper limit when measured at 23 ° C. , preferably 1200 mPa·s or less. In addition, the mixture may contain one or more selected from polyester polyols other than castor oil-based polyester polyols, polyether polyols such as polypropylene glycol, and the like, as long as the effects of the present invention are not impaired. .
Moreover, the mixture of castor oil-based polyester polyols may be a combination of two or more polyester polyols having different hydroxyl values. At this time, it may be a mixture of a high hydroxyl value castor oil-based polyester polyol and a low hydroxyl value castor oil-based polyester polyol. is intended to show the relative relationship that the hydroxyl value of This "high" is also intended to indicate the relative relationship that the hydroxyl value of a certain polyol is higher than the hydroxyl value of that certain polyol. The "low" preferably has a hydroxyl value of 10 to 150 mgKOH/g, more preferably a hydroxyl value of 50 to 100 mgKOH/g, which may be a combination of two or more polyester polyols having different hydroxyl values. . The "high" preferably has a hydroxyl value of 170 to 380 mgKOH/g, more preferably a hydroxyl value of 250 to 350 mgKOH/g, which may be a combination of two or more polyester polyols having different hydroxyl values. .

The hydroxyl value of the mixture of castor oil-based polyester polyols is preferably a combination of two or more so that the hydroxyl value falls within the specific hydroxyl value range described in the above "Hydroxyl value of polyol", and this preferred upper limit is preferred. is 160 mgKOH/g or less. Also, the number of functional groups in the mixture is preferably 2-3.

As a mixture of castor oil-based polyester polyols, for example, a mixture of castor oil and a castor oil-based polyester polyol having a hydroxyl value of 330 to 350 mgKOH/g, a castor oil-based polyester polyol having a hydroxyl value of 330 to 350 mgKOH/g and a hydroxyl value of 55 to 77 mgKOH. /g, more preferably a mixture of a castor oil-based polyester polyol having a hydroxyl value of 330 to 350 mgKOH/g and a castor oil-based polyester polyol having a hydroxyl value of 55 to 77 mgKOH/g. The functionality of the castor oil-based polyester polyol used in the mixture is preferably 2-3. The mixture may contain a polyol other than the castor oil-based polyester polyol as long as the effects of the present invention are not impaired.

The mass content ratio of the low hydroxyl value castor oil-based polyester polyol and the high hydroxyl value castor oil-based polyester polyol in the mixture of castor oil-based polyester polyols is not particularly limited, but is preferably 30 each in the adhesive. ~80:70-20, more preferably 65-75:35-25.
The mass content ratio of the low hydroxyl value castor oil-based polyester polyol in the castor oil-based polyester polyol mixture is not particularly limited, but is preferably 10 to 80 parts by mass with respect to 100 parts by mass of the castor oil-based polyester polyol mixture. , more preferably 20 to 70 parts by mass, still more preferably 20 to 50 parts by mass, and even more preferably 20 to 30 parts by mass.
The mass content ratio of the castor oil-based polyester polyol having a high hydroxyl value in the castor oil-based polyester polyol mixture is not particularly limited, but is preferably 20 to 90 parts by mass with respect to 100 parts by mass of the castor oil-based polyester polyol mixture. , more preferably 30 to 80 parts by mass, still more preferably 50 to 80 parts by mass, and even more preferably 70 to 80 parts by mass.

The viscosity of the castor oil-based polyester polyol is not particularly limited, but the upper limit is preferably 1200 mPa·s or less, more preferably 1000 mPa·s or less, and still more preferably 900 mPa·s or less when measured at 23°C. Also, the lower limit is preferably 200 mPa·s or more, more preferably 500 mPa·s or more, and still more preferably 600 mPa·s or more.

The hydroxyl value of the castor oil-based polyester polyol is not particularly limited, but the upper limit is preferably 160 mgKOH/g or less, more preferably 150 mgKOH/g or less, still more preferably 145 mgKOH/g or less, and even more preferably 140 mgKOH/g or less. and the lower limit is preferably 100 mgKOH/g or more, more preferably 110 mgKOH/g or more, and still more preferably 120 mgKOH/g or more.

The number of functional groups (terminal hydroxyl groups) of the castor oil-based polyester polyol is not particularly limited, but the upper limit is preferably 4 or less, more preferably 3 or less, and still more preferably 2.5 or less, and the lower limit is preferably It is 1 or more, more preferably 1.5 or more, and still more preferably 2 or more.

The mass content ratio of the castor oil-based polyester polyol in the adhesive is not particularly limited, but the lower limit is preferably 60% by mass or more, more preferably 65% by mass or more, and still more preferably 65% by mass or more, based on the mass of the adhesive. 70% by mass or more, the upper limit is preferably 85% by mass or less, more preferably 80% by mass or less, and even more preferably 75% by mass or less, and a more preferable numerical range is preferably 60 to 80% by mass. , more preferably 65 to 75% by mass.

The volume content of the castor oil-based polyester polyol in the adhesive is not particularly limited. 70% by volume or more, still more preferably 73% by volume or more, and the upper limit is preferably 90% by volume or less, more preferably 85% by volume or less, and even more preferably 80% by volume or less. , preferably 68 to 85% by volume, more preferably 70 to 80% by volume.

<Component (A) polyether polyol>
The polyether polyol is not particularly limited, but may be, for example, monools, diols, polyols, or a mixture of two or more selected from active hydrogen-containing compounds other than these, ethylene oxide, propylene oxide, butylene oxide, styrene oxide, and the like. 1 or 2 or more selected from the alkylene oxides are used, and those obtained by addition polymerization by a known method can be mentioned. One or two or more selected from these can be used.
Examples of monools of polyether polyols include, but are not particularly limited to, methanol, ethanol, propanol, butanol, octanol, lauryl alcohol, and the like.
Examples of diols for polyether polyols include, but are not limited to, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, butylene glycol, 1,3-butanediol, 1,4-butanediol, 1,6 - hexanediol and the like.
Examples of polyols of polyether polyols include, but are not particularly limited to, glycerin, trimethylolpropane, pentaerythritol, and the like.
Examples of active hydrogen-containing compounds other than these include, but are not particularly limited to, monoethanolamine, diethanolamine, triethanolamine, diglycerin, sorbitol, sucrose and the like.
As the polyether polyol, a commercially available product may be used, or one obtained by a known production method may be used. Commercially available products include, but are not limited to, polypropylene glycols such as P-2000 (hydroxyl value: 56 mgKOH/g, functional group number: 2, manufactured by Adeka). One or more selected from these can be used.

The mass content of the polyether polyol in the adhesive is not particularly limited, but is preferably 60-80% by mass, more preferably 65-75% by mass, based on the mass of the adhesive.
The volume content of the polyether polyol in the adhesive is not particularly limited, but is preferably 68 to 85% by volume, more preferably 70 to 80% by volume, based on the volume of the adhesive.

<Component (B) isocyanate compound>
The component (B) isocyanate compound used in the present invention is not particularly limited, but may include, for example, aromatic isocyanates, aliphatic isocyanates, and alicyclic isocyanates, and one or two selected from these. More can be used. As the isocyanate compound, a commercially available product may be used, or one obtained by a known production method may be used.
As the isocyanate compound, a polyisocyanate compound having two or more isocyanate groups in the molecule is preferred. As the polyisocyanate compound, organic polyisocyanate, modified polyisocyanate, isocyanate-based prepolymer, or a mixture thereof may be used.

Examples of aromatic polyisocyanate compounds include, but are not limited to, MDI (e.g., methylenebis(4,1-phenylene)=diisocyanate (also known as 4,4'-diphenylmethane diisocyanate (4,4'-MDI)), 2,4 diphenylmethane diisocyanate such as '-diphenylmethane diisocyanate (2,4'-MDI) and mixtures thereof, polymethylene-polyphenylene polyisocyanate (PMDI)), TDI (e.g. 2,4-toluenediisocyanate (2,4-TDI), 2 ,6-toluene diisocyanate (2,6-TDI) and mixtures thereof), 1,4-phenylene diisocyanate, diphenyl diisocyanate, tolidine diisocyanate (TODI), 1,5-naphthalene diisocyanate (1,5-NDI ), diphenyl ether diisocyanate, triphenylmethane triisocyanate, xylylene diisocyanate (XDI), phenylene diisocyanate (PDI) and the like, and one or more selected from these can be used.
Among these aromatic polyisocyanate compounds, MDI is preferred, and among MDIs, polymethylene=polyphenylene polyisocyanate (PMDI) is preferred.

"MDI" can be generally used as a generic term for diphenylmethane diisocyanate and polymethylene=polyphenylene polyisocyanate. The term "diphenylmethane diisocyanate" includes 2,2'-diphenylmethane diisocyanate (2,2'-MDI), 2,4'-diphenylmethane diisocyanate (2,4'-MDI) and 4,4'-diphenylmethane diisocyanate (4 , 4′-MDI) isomers. These isomers are collectively referred to as "monomeric MDI" or "MMDI". Also, the term "polymethylene-polyphenylene polyisocyanate (PMDI)" means "polymeric MDI" or "PMDI." These may include higher homologues of monomeric MDI and optionally also monomeric MDI.

Aliphatic polyisocyanate compounds include 1,6-hexaethylene diisocyanate (HDI), L-leucine diisocyanate (LDI), 1,6,11-undecane triisocyanate and the like, one or more selected from these can be used.

Examples of the alicyclic polyisocyanate compound include 4-4′-methylenebiscyclohexyl diisocyanate (hydrogenated MDI), isophorone diisocyanate (IPDI), cyclohexane diisocyanate (hydrogenated XDI) and the like, and one selected from these. Or 2 or more types can be used.

Among polyisocyanate compounds, bifunctional aromatic polyisocyanate compounds are preferred. Furthermore, among these polyisocyanate compounds, PMDI is preferable from the viewpoint of conformability to nonwoven fabric, adhesiveness, workability and environmental standards.

The NCO content (%) of the isocyanate compound is not particularly limited, but is, for example, 20 to 30%, preferably 25 to 30%, more preferably 26 to 29%, still more preferably 27 to 28%. The amount of NCO in this specification can be measured in accordance with "JIS K 1603-2007 Plastics-Polyurethane raw material aromatic isocyanate test method".
The viscosity of the isocyanate compound is not particularly limited, but is preferably 10 to 500 mPa·s, more preferably 50 to 300 mPa·s, still more preferably 100 to 200 mPa·s when measured at 23°C. The viscosity of the isocyanate compound can be measured according to the above <Method for measuring viscosity of polyol, etc.>.

The mass content of the isocyanate compound in the adhesive is not particularly limited, but the lower limit is preferably 15% by mass or more, more preferably 20% by mass or more, and still more preferably 25% by mass with respect to the mass of the adhesive. The upper limit is preferably 40% by mass or less, more preferably 35% by mass or less, and even more preferably 30% by mass or less.
The volume content of the isocyanate compound in the adhesive is not particularly limited, but the lower limit is preferably 10% by volume or more, more preferably 15% by volume or more, and still more preferably 20% by volume with respect to the volume of the adhesive. The upper limit is preferably 35% by volume or less, more preferably 32% by volume or less, even more preferably 30% by volume or less, and even more preferably 25% by volume or less.

The NCO amount (%) of the bifunctional aromatic polyisocyanate compound is not particularly limited, but is, for example, 20 to 30%, preferably 25 to 30%, more preferably 26 to 29%, still more preferably 27 to 28%. .
The viscosity of the bifunctional aromatic polyisocyanate compound is not particularly limited, but is preferably 10 to 500 mPa·s, more preferably 50 to 300 mPa·s, still more preferably 100 to 200 mPa·s.

The mass content ratio of the bifunctional aromatic polyisocyanate compound in the adhesive is not particularly limited, but the lower limit is preferably 15 mass% or more, more preferably 20 mass% or more, and further It is preferably 25% by mass or more, and the upper limit is preferably 40% by mass or less, more preferably 35% by mass or less, and still more preferably 30% by mass or less, and a more preferable numerical range is preferably 20 to 40. % by mass, more preferably 25 to 35% by mass.
The volume content of the bifunctional aromatic polyisocyanate compound in the adhesive is not particularly limited, but the lower limit is preferably 10% by volume or more, more preferably 15% by volume or more and It is preferably 20% by volume or more, and the upper limit is preferably 35% by volume or less, more preferably 32% by volume or less, even more preferably 30% by volume or less, and even more preferably 25% by volume or less, and is more preferable. The numerical range is preferably 15 to 32% by volume, more preferably 20 to 30% by volume.

<Mass content ratio and volume content ratio of component (A) and component (B)>
The mass content ratio of the component (A) polyol and the component (B) isocyanate compound (preferably a bifunctional aromatic polyisocyanate compound) in the adhesive is not particularly limited. On the other hand, the component (B) isocyanate compound (preferably a bifunctional aromatic polyisocyanate compound) is preferably 10 to 60 parts by mass, more preferably 20 to 50 parts by mass, and still more preferably 30 to 40 parts by mass. .
The mass content ratio of component (A) polyester polyol and component (B) isocyanate compound (preferably bifunctional aromatic polyisocyanate compound) in the adhesive is not particularly limited, but component (A) polyester polyol 100 mass part, the component (B) isocyanate compound (preferably a bifunctional aromatic polyisocyanate compound) is preferably 10 to 60 parts by mass, more preferably 20 to 50 parts by mass, and still more preferably 30 to 40 parts by mass. is.
The mass content ratio of component (A) castor oil-based polyester polyol and component (B) isocyanate compound (preferably bifunctional aromatic polyisocyanate compound) in the adhesive is not particularly limited, but component (A) castor The component (B) isocyanate compound (preferably a bifunctional aromatic polyisocyanate compound) is preferably 10 to 60 parts by mass, more preferably 20 to 50 parts by mass, and still more preferably 100 parts by mass of the oil-based polyester polyol. is 30 to 40 parts by mass.

Also, the volume content ratio of component (A) polyol and component (B) isocyanate compound (preferably bifunctional aromatic polyisocyanate compound) in the adhesive is not particularly limited, but component (A) polyol 100 volume parts, the component (B) isocyanate compound (preferably a bifunctional aromatic polyisocyanate compound) is preferably 10 to 50 parts by volume, more preferably 15 to 40 parts by volume, and still more preferably 25 to 35 parts by volume. is.
Also, the volume content ratio of component (A) polyester polyol and component (B) isocyanate compound (preferably bifunctional aromatic polyisocyanate compound) in the adhesive is not particularly limited, but component (A) polyester polyol With respect to 100 parts by volume, the component (B) isocyanate compound (preferably a bifunctional aromatic polyisocyanate compound) is preferably 10 to 50 parts by volume, more preferably 15 to 40 parts by volume, still more preferably 25 to 35 parts by volume. volume part.
In addition, the volume content ratio of component (A) castor oil-based polyester polyol and component (B) isocyanate compound (preferably bifunctional aromatic polyisocyanate compound) in the adhesive is not particularly limited, but component (A ) Per 100 parts by volume of castor oil-based polyester polyol, component (B) isocyanate compound (preferably bifunctional aromatic polyisocyanate compound) is preferably 10 to 50 parts by volume, more preferably 15 to 40 parts by volume, More preferably 25 to 35 parts by volume.

<Optional component>
The adhesive of the present invention can appropriately contain various additives other than the above components as optional components within a range that does not impair the effects of the present invention. As the optional component, for example, a solvent, a curable component, a curing accelerator, a photocuring agent, a filler, a plasticizer, an anti-aging agent, an antioxidant, a pigment, a dye, an ultraviolet absorber, a flame retardant, a surfactant, Dispersants, dehydrating agents, tackifiers, antistatic agents and the like can be mentioned, and one or more selected from these can be used.

The method for producing the adhesive of the present invention is not particularly limited, and for example, it can be prepared by simultaneously or separately mixing one or more adhesive components to be contained in the adhesive.

In the present invention, in the case of a two-component adhesive composed of a component (A) as a main agent and a component (B) as a curing agent, the component (A) and the component (B) are placed in separate containers. It may be filled and stored, and the inside of one or both of the containers may be replaced with an inert gas such as nitrogen gas. The mass usage ratio and volume usage ratio of component (A) and component (B) are the mass content ratio and volume content ratio described in the above <mass content ratio and volume content ratio of component (A) and component (B)>. The volume content ratio can be appropriately adopted. A two-component adhesive can be prepared by sufficiently mixing the main agent and the curing agent at the time of use. For example, using an adhesive tool such as a cartridge gun, component (A) and component ( The two components of B) may be applied while being mixed.

In the present invention, as described above, it is preferable that the adhesive containing the polyol and the isocyanate compound has specific properties, and the more preferable properties of the adhesive are appropriately selected from the above "2. Properties of the adhesive". can be adopted.

The form of use of the adhesive of the present invention is not particularly limited. and UV curable type. The form of use of the adhesive of the present invention is preferably a non-solvent system. Moreover, the form of use of the adhesive of the present invention is preferably a two-component curing type and/or a normal temperature curing type, since the work of applying the adhesive to a substrate can be easily performed.

The adhesive or adhesive component of the present invention is preferably used for bonding nonwoven fabrics that can be used for applications such as civil engineering, construction, agriculture, automobiles, aircraft, electronic devices, and electrical devices. Specifically, for example, civil engineering materials, building materials, agricultural materials, automobile materials, aircraft materials, electronic device materials, electrical device materials, etc., and one or two selected from these Species or more are more preferred.
Among these, the adhesive or adhesive component of the present invention is preferably used for bonding nonwoven fabrics that can be used for civil engineering materials, building materials, or agricultural materials. It is preferable to use it for bonding nonwoven fabrics that can be used for covering. It is more preferably used for bonding waterproof nonwoven fabrics.

In the present invention, an adhesive component or a urethane-based adhesive component configured so that the adhesive has a specific viscosity and a cured product with a specific hardness may be used to produce the adhesive. . The adhesive may be of a one-component type or a two-component type, and may be an adhesive kit comprising a container containing a main agent and a container containing a curing agent.
The invention can also provide a bonding method for bonding substrates using an adhesive or adhesive component to the substrate.

The adhesive of the present invention can form a cured product having excellent conformability and adhesiveness to substrates because the hardness of the cured product after curing is within a specific range.
Furthermore, since the adhesive of the present invention has an appropriate viscosity before hardening, it can harden while being well impregnated into the nonwoven fabric and also present on the adhesive surface of the nonwoven fabric. For this reason, after curing, the cured product of the adhesive satisfactorily exists inside the nonwoven fabric and also on the adhesive surface, so that the cured product has excellent adhesion to the nonwoven fabric. This cured product has excellent water resistance, and also has excellent conformability and adhesiveness to nonwoven fabrics, and thus has excellent watertightness.
In addition, the adhesive of the present invention does not harden for a predetermined period of time, so that it can be used for an appropriate amount of time. It is possible to improve work efficiency when giving. Further, the adhesive of the present invention has an appropriate viscosity, so that it can be easily applied to the nonwoven fabric. Furthermore, with the adhesive of the present invention, it is possible to perform the bonding work while securing the usable time by curing at room temperature without performing the heat-sealing bonding work, so the bonding work of the nonwoven fabric is simplified. can be easily performed. Thus, the adhesive of the present invention is excellent in workability when applying the adhesive to the nonwoven fabric.

As described above, the adhesive of the present invention has excellent workability when applied to a nonwoven fabric by coating or the like, and can form a cured product having excellent conformability and adhesiveness to the nonwoven fabric. Furthermore, the cured product obtained by applying the adhesive of the present invention to a nonwoven fabric and curing it has excellent watertightness and water resistance.

4. Method of using the adhesive of the present invention

The method of applying the adhesive of the present invention to a substrate is not particularly limited, and known methods can be used. For example, the method of using the adhesive of the present invention is to apply the adhesive to the base material by coating or the like, bring the base materials into contact with each other at the adhesive surface, and cure the adhesive to bond a plurality of base materials. can be made

The base material is not particularly limited, but includes, for example, base fabrics such as woven fabrics or non-woven fabrics, metal materials, synthetic resin materials, etc., and one or more selected from these can be used. , It is preferable to use an adhesive at least to bond the base fabrics. is preferred.

Among the substrates, the adhesive of the present invention can sufficiently impregnate the interior of the nonwoven fabric while partially remaining on the surface of the nonwoven fabric when applied, so that after curing, this cured product can be formed on the interior and on the surface. Non-woven fabrics are more preferable because they can exhibit excellent adhesiveness. It is more preferable to use

Although the nonwoven fabric is not particularly limited, it is preferably a long-fiber nonwoven fabric. Also, the nonwoven fabric may have a single layer or laminated structure.
The thickness of the non-woven fabric is not particularly limited, but it is preferably a thickness that can be used for civil engineering materials, building materials or agricultural materials. 1 to 5 mm.

The nonwoven fabric is not particularly limited, but examples thereof include natural fibers such as cellulose, synthetic fibers such as polyester, and the like. As materials for synthetic fibers, for example, thermoplastic resins such as polyolefins such as polyethylene and polypropylene, polyesters such as polyethylene terephthalate, polybutylene terephthalate, and polymethylene terephthalate, and polyamides such as nylon 6, nylon 66, and nylon 46 are used. It is possible.
Among these, polyester nonwoven fabric (for example, polyethylene terephthalate nonwoven fabric) and polyolefin (polyethylene etc.) nonwoven fabric are preferable.
Furthermore, the nonwoven fabric is more preferably a moisture-permeable waterproof nonwoven fabric, which is a nonwoven fabric added with a moisture-permeable and waterproof function. .

Examples of methods for forming a fleece in a nonwoven fabric include a dry method, a wet method, a spunbond method, a meltblown method, a thermal bond method, a chemical bond method (impregnation method, spray method, etc.), and the like, and any method can be used. may Examples of the method for binding fibers of the nonwoven fabric include a needle punch method, a water jet entanglement method, an adhesive method, and the like, and any method may be used. It is possible to provide a dry-laid nonwoven fabric or the like manufactured by a manufacturing method such as a dry method.

The adhesive of the present invention can be used outdoors or indoors, is preferably room temperature curing type, can be cured by moisture such as humidity, and can be cured without irradiation with light such as ultraviolet rays. It is possible. More specifically, the adhesive of the present invention can be cured under conditions of, for example, 5 to 90° C. and relative humidity (RH) of 5 to 95%.
The curing temperature of the adhesive of the present invention is, for example, -20 to +90°C, preferably 5 to 90°C, more preferably 4 to 50°C, still more preferably 10 to 40°C.
Although the curing time of the adhesive of the present invention is not particularly limited, it is preferably about 0.1 to 3 hours, more preferably about 0.5 to 2 hours, from the viewpoint of improving workability and securing working time. , more preferably 1 to 2 hours.
The coating amount of the adhesive of the present invention is not particularly limited, but is preferably 250 to 550 g, more preferably 300 to 500 g, and even more preferably 350 to 450 g with respect to a bonding area of 1000 cm ² .

The present technology will be described in further detail below based on test examples and the like. It should be noted that the test examples and the like described below are examples of typical examples and the like of the present technology, and the scope of the present technology should not be interpreted narrowly.

Weigh the volume (mL) of liquid A and liquid B so that the composition is as shown in the table below, and also measure the mass (g) at this time, mix liquid A and liquid B A liquid adhesive was obtained. When liquid A has multiple components, the mass (g) of each component is weighed, these components (castor oil-derived polyol liquid 1 and liquid 2) are mixed, and this mixed liquid is used as liquid A. . A two-component adhesive was applied to the adhesive surface of the test piece, another test piece was adhered to the applied adhesive surface, the two-component adhesive was cured, and then cured for a predetermined period of time. The work was done in the lab at room temperature (23°C). As a result, it was possible to obtain a bonded test piece in which a plurality of test pieces were bonded with a cured product obtained by curing the adhesive.

<Each material>
The compound names of the test pieces and materials shown in this test example are as follows. Commercially available products were used for these test pieces and materials.
[Test piece, joint]
Moisture-permeable and waterproof nonwoven fabric (compliant with JIS A 6111) (thickness 6 mm): Materials include a protective polyester nonwoven fabric and a waterproof polyethylene porous film. The moisture-permeable and waterproof nonwoven fabric is manufactured by the spunbond manufacturing method.
[Liquid A]
Castor oil-based polyester polyol (castor oil-derived polyol)
(1) Castor oil; hydroxyl value 160 mgKOH/g, functional group number 2.7, viscosity 670 mPa s (measurement temperature 23°C)
(2) Castor oil-based polyester polyol U1; hydroxyl value 55 to 77 mgKOH/g, functional group number 2.3, viscosity 700 to 1600 mPa s (measurement temperature 23° C.))
(3) Castor oil-based polyester polyol U8; hydroxyl value 330 to 350 mgKOH/g, number of functional groups 3, viscosity 1000 to 1400 mPa s (measurement temperature 23° C.)
[Liquid B]
Bifunctional aromatic isocyanate compound (1) Cosmonate PM-35 (manufactured by Mitsui Chemicals Polyurethane Co., Ltd.): polyisocyanate compound (modified isocyanate); polymethylene polyphenyl = polyisocyanate (PMDI) (methylenebis(4,1-phenylene) = diisocyanate), NCO%: 27.0 to 28.0%, viscosity 100 to 200 mPa s (23 ° C.)

Various measurements and various tests were performed according to the following methods. These results are shown in Table 1.

<Method for calculating hydroxyl value>
When liquid A is a single polyol, the hydroxyl value can be measured according to JIS K 0070 and JIS K 1557-1. When the liquid A contains multiple polyols, the hydroxyl value is (parts by mass of liquid A1 x hydroxyl value + parts by mass of A2 x hydroxyl value + ... parts by mass of liquid Ax x hydroxyl value) / mass of liquid A1 parts + parts by mass of liquid A2 + parts by mass of liquid Ax (total amount of parts by mass)). For example, in the case of Test Example 1, (U1: 75 x OHV 66 + U8: 25 x OHV 340) / 100 (total amount) = OHV 134.5 can be obtained.

<Method for measuring the viscosity of each material before curing>
Each viscosity measurement of the polyol and the polyisocyanate compound can be performed according to the above <Method for measuring viscosity of polyol, etc.>. Measurement conditions: JIS K 7117-1, K 7117-2 and JIS K 1557-5, B-type viscometer BM-type viscometer, 12 rotations, No. 3 rotor, measurement time of 1 minute, measurement temperature of 23°C.
The viscosity of the mixture after mixing the polyol and the polyisocyanate compound can be measured according to the above <Method for measuring the viscosity of the adhesive before curing>. Specifically, after adjusting the temperature of each liquid of A liquid and B liquid to 23 ° C., after stirring these two liquids, this mixed liquid was immediately measured with a BM viscometer at 23 ° C. for 1 minute. , can be measured. Measurement conditions: JIS K 7117-1, K 7117-2 and JIS K 1557-5, B-type viscometer BM-type viscometer, 12 rotations, No. 3 rotor, measurement time of 1 minute, measurement temperature of 23°C.

<Method for Measuring Hardness of Cured Product of Adhesive After Curing>
The hardness (Shore hardness) of the adhesive after curing can be measured according to the above <Method for measuring hardness of cured adhesive>. Measurement conditions: JIS K 7215, Shore-A hardness meter instantaneous value, measurement temperature 23° C. Shape of cured product: thickness 8 mm×diameter 60 mm.

<Adhesion strength test of bonding test piece>
Method for manufacturing a lap-bonded test piece: Using two strip-shaped test pieces (width 2.5 cm x length 15 cm x thickness 6 mm) 1 and 1, the adhesive surface at the end of one strip-shaped test piece 1 4 (2.5 cm wide by 5 cm long) at room temperature 23° C. with 5 g of adhesive/(2.5 cm by 5 cm). The bonding surface 4 (width 2.5 cm×length 5 cm) of the other strip-shaped test piece 1 was overlaid on the bonding surface 4 coated with the adhesive and cured at room temperature of 23°C. After curing, it was cured at 23° C. for 1 week to obtain a “lap joint test piece” 10a (width 2.5 cm×length 25 cm, joint thickness 12 mm) (see FIG. 1A).
The adhesives of Test Examples 1 to 5 were applied according to this manufacturing method of the lap joint test pieces to obtain the lap joint test pieces of Test Examples 1 to 5, and these were used for the adhesion strength test of the joint test pieces.

The adhesive strength test was conducted at 23° C. according to JIS 7214 using the lapped bonded test piece manufactured in the above <Adhesive Strength Test of Bonded Test Piece>. Autograph AGS-X (Shimadzu Corporation) was used as the test machine, and the test speed was 100 mm/min, N=2 (average value of these values).

The elongation test and tensile strength test can be performed at 23° C. according to JIS K7113 using a 5B type test piece prepared according to JIS K7161-2. The 5B type test piece is a cured resin cured only with an adhesive. Autograph AGS-X (Shimadzu Corporation) was used as the test machine, and the test speed was 200 mm/min, N=3 (mean value of these values).

The unit for the elongation test is %, the unit for the tensile strength test is MPa, and the unit for the adhesion strength test is N/5 cm.
Normally, the test is conducted in an environment of 23±2° C. and 50±5% RH.
In water immersion, the test is performed after the bonded test piece is immersed in water for 30 days under an environment of 23±2° C. and 50±5% RH.

<Evaluation of broken state>
After the <adhesive strength test (normal state)>, the bonding test piece was observed for fractured state, and visually evaluated for base material failure (SF), interfacial peeling (AF), and cohesive failure (CF). When the moisture-permeable and waterproof nonwoven fabric as the substrate is destroyed, the substrate is destroyed, and when the moisture-permeable and waterproof nonwoven fabric and the adhesive are destroyed at the bonding interface between the hardened layer, the interface Cohesive failure was evaluated when the inside of the cured product (resin) layer in which the adhesive was cured was destroyed without destroying the non-woven fabric as the base material.

<Method for measuring gel time>

<Simple water stoppage test>
A method for manufacturing a bonding test piece used in a simple water stoppage test will be described with reference to FIG. Using the two-component adhesives of Test Examples 1 to 5 obtained by mixing Liquids A and B before coating, bonded test pieces of Test Examples 1 to 5 were produced. More specific description will be given below.
Two test pieces (30 cm x 30 cm x 6 mm thick) were used, and the ends of these test pieces 1, 1 were butted (Fig. 2A). An adhesive surface 4 (adhesive area 30 cm × 10 cm) for applying an adhesive is provided at 10 cm each of 5 cm in the left and right direction from the butt ends of the two test pieces 1, 1, and 30 cm from the top end to the bottom end in the vertical direction, An adhesive was applied to the entire adhesive surface 4 at a room temperature of 23° C. at a rate of 120 g/(30 cm×10 cm) so that the adhesive layer would have a uniform thickness. A test piece 3 (30×10 cm×6 mm in thickness) to be a joint was placed on the adhesive surface 4 coated with the adhesive (FIG. 2B).
At this time, a cartridge gun for applying the two-component adhesive may be used, and the cartridge gun for applying the two-component adhesive consists of a container containing liquid A and a container containing liquid B. A specific amount (mL) of liquid A and liquid B are simultaneously extruded from the nozzle, and the extruded liquids A and B are mixed at the nozzle, and the adhesive of this mixed liquid can be applied to the test piece.

After the joint 3 was placed on the adhesive surface 4 and pressed, the adhesive was cured at room temperature of 23°C. After curing, the cured product of the adhesive was cured for 7 days. As a result, a bonded test piece 10 (30 cm x 60 cm, thickness of 12 mm at the bonded portion) having a bonded portion 21 in which the bonded surface 4 of the test pieces 1, 1 and the bonded surface of the joint 3 were bonded with a cured adhesive was prepared. manufactured. This was used as a bonding test piece 10 for a simple water stoppage test.

As shown in FIGS. 3 to 6, the obtained planar joint test piece 10 (30 cm×60 cm, joint thickness 12 mm) was placed near both ends in the lateral direction (10 cm) of the joint 3 so that the ends of the pleats came inward. A substantially truncated quadrangular pyramid shape was formed by folding four portions in the same manner as above to obtain a bonding test piece 20 having a substantially truncated quadrangular pyramid shape.

A 30 cm × 60 cm joint test piece 20 for a simple water stoppage test is set as shown in Figs. The presence or absence of water leakage from the joint portion 21 of the subsequent joint test piece was confirmed.
Furthermore, the bonded test piece 20 after the test was cut in the longitudinal direction (60 cm), and the state of the cross section of the bonded portion 21 was observed.
In the cross-sectional observation of the joint 21, the state of the cured product (resin) in which the adhesive in the nonwoven fabric is cured is assumed to be the state in which the adhesive is impregnated, and the adhesive surface 4 of the test piece coated with the adhesive is taken as the starting point (0 mm), The distance (mm) of the tip of the impregnated cured product from the adhesive surface is measured, and the impregnation rate is obtained by [distance from the adhesive surface to the tip of the cured product (mm) / thickness of the test piece (mm)] x 100 (%). be able to. When a plurality of test pieces are used, the impregnation rates of these can be obtained, and the average value of the impregnation rates can be obtained.

<Evaluation of impregnability>
Visually confirm up to which layer the test piece is impregnated.
× (improper): 50% or more impregnation with no resin remaining on the adhesive surface, or not impregnated by 50% or more △ (good to slightly poor): 50% or more resin partially on the adhesive surface Impregnated 〇 (excellent): Resin is present on the adhesive surface, but the resin is impregnated by 50% or more. △ (good to somewhat poor) is regarded as acceptable. However, in the cross section of the joint portion 21, it is preferable that there are as many portions in the joined state as possible. The bonding ratio can be obtained and evaluated at ×100, and a bonding ratio of 50% or more is desirable.

3 to 6 are schematic diagrams and observation photographs of a simple water cutoff test using a bonding test piece 20 folded into a substantially quadrangular truncated pyramid shape. Specifically, FIG. 3 is a side view of the simple water stoppage test, FIG. 4 is a top observation view of the simple water stoppage test, and FIG. 5 is a perspective view from above of the simple water stoppage test. be. FIG. 6 is a photograph of the simple water stopping test when viewed from above.
A 5 L plastic container (26 cm in height×20 cm in diameter) with a handle was used as the supporting container 30 for placing the test piece.
FIG. 3 shows a side view of a bonding test piece 20 having a substantially truncated pyramidal shape inserted up to about 12 cm into a support container 30 for setting the test piece, and water 25 being poured into the inserted bonding test piece 20 . It is a schematic diagram when
FIGS. 4 and 6 show approximately four specimens in which the test specimens 1, 1 are arranged so that the butted portions pass through the center of the support container 30 for installing the specimen (on the line between the spout and the handle), and the pleats are folded inward. FIG. 2 is a schematic view and a photograph of a state in which water 25 is poured into a truncated pyramid-shaped bonding test piece 20 as viewed from above.

<Test results of Test Examples 1 to 5>
Table 1 shows the test results of Test Examples 1 to 5.
From the results of the <simple water stoppage test>, the bonded test pieces 20 of Test Examples 2 to 4 had no water leakage, and when this cross section was visually observed, the resin, which is the cured adhesive, accounts for 50% or more of the nonwoven fabric. The adhesive surface 4 of the test pieces 1, 1 and the adhesive surface of the joint 3 were adhered to form a joint 21 that does not cause water leakage. Since these adhesives had appropriate thixotropy and viscosity, it was confirmed that these adhesives adhered to the joints after hardening even though they impregnated the nonwoven fabric.
Even when the joint test pieces of Test Examples 2 to 4 were bent near the joint, no gaps that could cause water leakage were formed in the joint test pieces, and it was considered that the hardness of the resin after curing was moderate. .
On the other hand, in the bonded test piece 10 of Test Example 1, when the vicinity of the bonded portion was folded, the cured resin was hard and could not follow the nonwoven fabric, and it was confirmed that a gap was formed in the bonded test piece.
From this, it was confirmed that the adhesives of Test Examples 2 to 4 had excellent conformability and adhesiveness to the nonwoven fabric after curing. Furthermore, it was confirmed that the adhesives of Test Examples 2 to 4 were excellent in watertightness after curing.

Furthermore, from the results of <Method for measuring gel time>, the gel time of the adhesives of Test Examples 2 to 4 was 65 to 75 minutes, so positioning between base materials, application to base materials, and adhesion between base materials It was confirmed that an appropriate working time (pot life) can be secured when performing such as.

The adhesives of Test Examples 2 to 4 had a viscosity of 1000 mPa·s or less when measured at 23° C. before curing, and the hardness of the cured resin after curing was It was A50-A80 when measured at 23°C.

Furthermore, a polyol other than castor oil is used as A liquid, and the adhesive is added so that the viscosity of the mixed liquid containing this A liquid and B liquid (PMDI) is about 1500 mPa s when measured at 23 ° C. made. A planar bonding test piece 10 was obtained by applying and curing this adhesive, and a bonding test piece 20 having a substantially truncated pyramid shape was produced. As a result of conducting a simple water stoppage test using this bonding test piece 20, it was confirmed that water leakage occurred from the bonding portion 21 and that the watertightness of the cured resin after curing was poor. Observation of the cross section of this joint 21 confirmed that the adhesive was impregnated only to less than 50% of the thickness of the nonwoven fabric. Since it was high, it was thought that the impregnation of the adhesive was not sufficient.

In addition, in the case of the solvent product of Test Example 5, a bonding test piece 20 having a substantially truncated pyramid shape was obtained using this solvent product, and the cross section of the bonding portion 21 was observed. It was impregnated, but there was no adhesive left on the surface of the non-woven fabric due to excessive impregnation, so after curing, there was no cured resin on the bonding surface of the joint, creating gaps, and it was confirmed that watertightness was poor. .

Furthermore, from the results of the <tensile strength test> and the results of <evaluation of fracture state> shown in Table 1, the resin strength when the adhesives of Test Examples 1 to 5 were cured was examined. In addition, the adhesiveness of the cured product of the adhesive to the nonwoven fabric was evaluated comprehensively by the following evaluations, taking into account the above <evaluation of impregnation> and the above <evaluation of fracture state>.
<Evaluation of adhesion of cured product>
Very good adhesion (◎): excellent impregnation (○), and the breaking state is SF Good adhesion (○): excellent impregnation (○), and the breaking state is CF or SF Slightly poor adhesion (△): Good to slightly poor impregnation (△), and part of the fracture state is CF Poor adhesion (×): Impregnation is not possible (×) , or the fracture state is AF

When the adhesive of Test Example 1 was applied to the non-woven fabric, the fracture state was evaluated as SF.
When the adhesive of Test Example 2 was applied to the nonwoven fabric, the adhesive slightly impregnated the nonwoven fabric and the evaluation of the fracture state was somewhat unfavorable. Met.
When the adhesive of Test Example 3 was applied to a non-woven fabric, the tensile strength (normal state) was slightly weak, so the evaluation of the fracture state was SF and CF, and the resin strength was slightly weak. Followability and adhesion were good.
When the adhesive of Test Example 4 was applied to a non-woven fabric, the evaluation of the state of breakage was good as SF, and the followability and adhesiveness of this cured product were also good according to the results of a simple water stoppage test. Regarding <evaluation of adhesion of cured product>, △ in Test Example 2, ○ in Test Example 3, and ⊚ in Test Example 4, and the adhesiveness of the cured product obtained by curing the adhesive of Test Example 4 is the highest. It was good. Furthermore, the cured products obtained by curing Test Examples 2 to 4 have water resistance such that the cured products are less likely to be hydrolyzed by contact with water, and the properties of the resin can be easily maintained. Among them, the water resistance of the cured product of Test Example 4 was the best, and it was considered that the type and combination of polyols were involved in this water resistance.
In addition, the tensile strength (normal state) of the resin, which is the cured product when the adhesive is cured, is 4.0 MPa or more, so that it is possible to provide an adhesive that can form a cured product having better resin strength. It could be confirmed.

For this reason, among the adhesives of Test Examples 1 to 5, the adhesives of Test Examples 2 to 4 are preferable from the viewpoint of workability, resin strength, conformability, adhesiveness, watertightness, and water resistance. and more preferably the adhesives of Test Examples 3 and 4. A particularly preferable adhesive is the adhesive of Test Example 4, which is excellent in all of workability, resin strength, followability, adhesiveness, watertightness, and water resistance, and has a very good balance of these properties. It was confirmed that it was good.
In the adhesive of Test Example 4, liquid A contains a mixture of two types of castor oil-based polyester polyols with different properties, liquid B contains a bifunctional aromatic isocyanate compound of PMDI, and liquid A and liquid B are mixed. Since it was a mixture, it was confirmed that such an adhesive component, volume content ratio, etc. can provide an adhesive that is excellent in workability, resin strength, conformability, adhesiveness, watertightness, and water resistance. did it. Furthermore, it has also been confirmed that such adhesive components, volume content ratios, and the like are suitable for producing an adhesive with specific properties.

From this example, in order to provide an adhesive that has excellent workability when applied to a nonwoven fabric and that the cured product after curing has excellent followability and adhesiveness to the nonwoven fabric, adhesion before curing The specific property that the viscosity of the agent is 1200 mPa s or less when measured at 23 ° C., and the hardness of the cured product after curing is A50 to A80 when measured at 23 ° C. It has been confirmed that the adhesive used is good.
From this example, in order to provide an adhesive that has excellent workability when applied to a nonwoven fabric and that the cured product after curing has excellent conformability and adhesiveness to the nonwoven fabric, polyol and an isocyanate compound and the polyol is more preferably a polyester polyol, more preferably a castor oil-based polyester polyol.
Furthermore, from the viewpoint of workability, conformability and adhesiveness, it was confirmed that a specific adhesive having both of these properties and composition is more preferable.

That is, from this example, by using the above-mentioned specific adhesive, this specific adhesive has excellent workability before curing when applying the adhesive to the base material by coating, etc. It was confirmed that a cured product having excellent conformability and adhesiveness could be formed. Furthermore, the cured product obtained by applying this specific adhesive to a nonwoven fabric and curing it has a moderate hardness and satisfactorily exists inside and on the adhesive surface of the nonwoven fabric, and has excellent watertightness and water resistance. It could be confirmed. Thus, the inventors were able to provide an adhesive suitable for nonwovens.

<Investigation of water pollutants contained in adhesives>
The adhesives of Test Examples 2 to 4 were immersed in water and eluted, and then tested according to the Ministry of the Environment uniform wastewater standards (www.env.go.jp/water/impure/haisui.html).

All of the adhesives of Test Examples 2 to 4 gave analysis results below the standard value, and these adhesives or their hardened products are safe and have little effect on the surrounding water quality even after long-term use in rivers, etc. It was confirmed that the

When a moisture-permeable waterproof nonwoven fabric is laid on embankments or embankments of rivers, lakes, etc., water leakage from the joints of the moisture-permeable waterproof nonwoven fabric should be suppressed in order to maintain the state of the embankments and embankments. Since it was necessary to maintain the strength of the joint portion, a professional operator used a heat-sealing sheet and a heat-sealing machine to heat-seal the joint surfaces.

On the other hand, with the specific adhesive of the present invention, even ordinary workers can easily and simply bond nonwoven fabrics together, and the cured product and the cured product having excellent watertightness and water resistance after curing It is possible to obtain a moisture-permeable and waterproof nonwoven fabric containing a material. As described above, the adhesive of the present invention is excellent in bonding workability when applying the adhesive to the moisture-permeable waterproof nonwoven fabric installed on the embankment as described above and when curing the base material with the adhesive. Furthermore, it is possible to provide a cured product with excellent watertightness and water resistance, and a moisture-permeable and waterproof nonwoven fabric containing the cured product. It can also be used for bonding a moisture-permeable and waterproof nonwoven fabric to be laid on a structure.

REFERENCE SIGNS LIST 1 nonwoven fabric, 3 joint, 4 adhesive surface, 10 bonded nonwoven fabric, 20 substantially truncated cone-shaped bonded nonwoven fabric, 21 joint, 25 water, 30 support container

Claims (4)

including a castor oil-based polyester polyol and an isocyanate compound,
The viscosity of the adhesive before curing is 200 mPa s or more and 1200 mPa s or less when measured at 23 ° C., and the hardness of the cured product after curing is A50 or more when measured at 23 ° C. A non-woven fabric adhesive that is A80. The adhesive according to Claim 1, wherein the isocyanate compound is an aromatic polyisocyanate compound. The adhesive according to claim 1 or 2 , wherein the adhesive is used in a two-component curing type. Consists of component (A) a main agent containing a castor oil-based polyester polyol and component (B) a curing agent containing an isocyanate compound,
The main agent and the curing agent are mixed at the time of use, and the viscosity of the adhesive before curing is 200 mPa s or more and 1200 mPa s or less when measured at 23 ° C., and the cured product after curing. used to prepare nonwoven fabric adhesives having a hardness of A50 to A80 when measured at 23°C;
Two-component adhesive kit for non-woven fabrics.

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