JP2011032305A - One-component moisture-curable urethane resin-based adhesive - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a low VOC-type moisture-curable urethane resin-based adhesive capable of providing suitable workability, adhesion and creak tightness while using a component which does not correspond to a volatile organic compound (VOC) in a test using [the small chamber method] defined in JIS A1901: 2003. <P>SOLUTION: This one component moisture-curable urethane resin-based adhesive includes: an isocyanate group containing urethane prepolymer (A) obtained by reacting a polyol compound having at least two active hydrogen in the molecule with a polyisocyanate compound having at least two isocyanate group in the molecule; and a viscosity controlling agent (B) which does not correspond to VOC in the test using the small chamber method defined in JIS A1901: 2003. The adhesive has a TVOC emission amount of ≤150 μg/m<SP>3</SP>7 at days after the test using the small chamber method and an emission rate of ≤150 μg/m<SP>2</SP>×h. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

The present invention relates to a volatile organic compound (Volatile) that is considered to be highly harmful to the human body.
Organic compounds (hereinafter referred to as “VOC”). More specifically, it is a one-component moisture-curing urethane that has good application workability, adhesion, floor restraint, and floor noise prevention properties when used in floor construction applications including floor heating applications, and has low VOC generation. The present invention relates to a resin adhesive.

  In recent years, the so-called “sick house” problem, in which the organic solvent or the like used for viscosity adjustment is released into the living space and remains in the living space as well as the air density of the house is increased, has been highlighted.

  One-pack type moisture-curing urethane resin adhesives are mainly used when constructing residential floors, and their demand is increasing in recent years. Conventionally, urethane resin adhesives used for floor construction have different desired viscosities depending on the application, and therefore, the viscosity is adjusted with an organic solvent or the like to obtain good workability. However, since the floor occupies a large area in the living space, there has been a strong demand for reducing organic solvents and the like particularly for building materials and adhesives for floor construction due to the above-mentioned problems.

JP 2005-89504 A JP 2006-22298 A

In January 2002, the Ministry of Health, Labor and Welfare gave 400 μg / m ³ as a provisional target value for the total concentration of volatile organic compounds (TVOC) in living spaces. Here, this numerical value is a numerical value for the entire living space. In the living space, various building materials, adhesives, and the like are also used for parts other than the floor (for example, walls and ceilings). For this reason, the above-mentioned target value cannot be cleared unless the adhesive for floor construction, which is one element constituting the living space, is far below this value.

  In order to solve such a problem, it is conceivable to add a non-VOC component as a viscosity modifier. However, when a non-VOC component is simply blended as a viscosity modifier, the performance of the adhesive may be adversely affected. That is, since the non-VOC component remains in the film even after the adhesive is cured, the cured film is plasticized and softened, and as a result, the restraint property of the flooring is lowered. In particular, in floor heating applications, the expansion and contraction of the flooring material is large, so that using such an adhesive does not sufficiently restrain the flooring material, which may cause problems such as gaps in the flooring material sunk portion or pushing up. In urethane resin adhesives, dibutylhydroxytoluene (hereinafter referred to as “BHT”) is blended as an anti-aging agent into a polyol compound or an isocyanate compound used as a raw material when a urethane prepolymer is synthesized, and this is a VOC. There is also a problem that it is difficult to reduce the VOC because it corresponds to a component.

  The problem to be solved by the present invention is that, when used in floor construction applications, it has good coating workability, adhesiveness, floor restraint and anti-flooring properties that are equal to or better than conventional ones, and VOC emissions are extremely high. It is to provide a low one-component moisture-curing urethane resin adhesive.

  As a result of diligent research by the present inventors to solve the above-mentioned problems, while using a non-VOC component as a viscosity modifier, it is equivalent to or more than a conventional one-component moisture-curable urethane resin adhesive for floor construction. While maintaining the performance of the present invention, the inventors have found a technique for obtaining an adhesive having an extremely low VOC emission, and have completed the present invention. The present invention is composed of the following first to fifth inventions.

The first invention includes an isocyanate group obtained by reacting a polyol compound (a1) having two or more active hydrogens in the molecule with a polyisocyanate compound (a2) having two or more isocyanate groups in the molecule. It contains a urethane prepolymer (A) and a viscosity modifier (B) that does not fall under VOC in the small chamber method test defined by JIS A 1901: 2003, and the TVOC emission after 7 days in the test is 150 μ / The present invention relates to a one-component moisture-curing urethane resin adhesive having a m ³ or less and a diffusion rate of 150 μg / m ² · h or less. In the present invention, the isocyanate group-containing urethane prepolymer (A) is simply referred to as “urethane prepolymer (A)” and a viscosity modifier (B that does not fall under VOC in the small chamber method test defined in JIS A 1901: 2003) (B ) May be simply referred to as “viscosity modifier (B)”.

  The second invention relates to a one-part moisture curable urethane resin adhesive according to the first invention, characterized in that dibutylhydroxytoluene is not blended in the urethane prepolymer (A).

  A third invention is characterized in that the viscosity modifier (B) is a dialkyl ester of adipic acid and / or a dialkyl ester of sebacic acid, and the one-component moisture-curable urethane according to the first or second invention The present invention relates to a resin adhesive.

  The fourth invention further relates to a one-component moisture-curable urethane resin adhesive according to any one of the first to third inventions, characterized in that crude MDI (C) is contained as an additive. Is.

  5th invention is 8-20 mass parts of compounding quantities of a viscosity modifier (B) with respect to 100 mass parts of urethane prepolymers (A), and the compounding quantity of crude MDI (C) is 2-2. The present invention relates to a one-part moisture-curing urethane resin adhesive according to the fourth invention, which is 10 parts by mass.

  The one-part moisture-curing urethane resin adhesive according to the present invention is equivalent to or better than conventional one-part moisture-curing urethane resin adhesives for floor construction (workability, adhesiveness, floor restraint, floor noise prevention) It is an extremely useful adhesive that can sufficiently cope with the “sick house” problem.

  Hereinafter, the best mode for carrying out the present invention will be described in detail. In addition, this invention is not limited only to these illustrations, Of course, a various change can be added in the range which does not deviate from the summary of this invention.

[Urethane prepolymer (A)]
The urethane prepolymer (A) in the present invention reacts a polyol compound (a1) having two or more active hydrogens in the molecule described later with a polyisocyanate compound (a2) having two or more isocyanate groups in the molecule. This is a urethane prepolymer containing an active isocyanate group in the molecule.

  The synthesis method of the urethane prepolymer may be a conventionally known method. For example, in a closed reaction kettle equipped with a stirrer, condenser, vacuum dehydration device, and nitrogen stream device, a compound having two or more active hydrogens at the end, such as polyols, is charged and dehydrated under reduced pressure, and then an isocyanate compound is blended into nitrogen. It is made to react at 70-100 degreeC under airflow for 3 to 8 hours, and the urethane resin type composition containing a urethane prepolymer is obtained. At this time, the molar ratio of isocyanate group (NCO) to active hydrogen group (OH) is NCO / OH = 1.2 or more, and NCO mass% in the urethane prepolymer is NCO mass% = 1 to 20%. It is preferable to be in the range of (most preferably 2 to 15%). When NCO mass% is high, the adhesive strength is also improved, but foaming during curing increases, and the cured film tends to become brittle. On the other hand, when the NCO mass% is low, foaming is reduced, but the viscosity of the prepolymer is high and it tends to be difficult to ensure the workability of the adhesive.

  Moreover, since the unreacted polyisocyanate compound exists, so that the ratio of NCO / OH exceeds 2.0, the viscosity of a urethane prepolymer will become low by these dilution effects. Moreover, in order to obtain desired performance, two or more types of urethane prepolymers may be mixed and used, or a polyisocyanate compound may be added to the urethane prepolymer by post-addition.

[About the polyol compound (a1)]
As a polyol compound having two or more active hydrogens in the molecule (hereinafter sometimes simply referred to as “polyol compound (a1)”), a bifunctional or more functional polyol compound having a molecular weight of about 100 to 20,000 is used. They can be used according to the purpose and performance. As the polyol compound (a1), polyether type polyols, polyester type polyols, polyolefin polyols and the like can be used alone or in combination of two or more. Moreover, it does not prevent using monool together.

  Examples of polyether type polyols include diols such as ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, 1,3-butanediol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, and bisphenol A. , Triols such as trimethylolethane, trimethylolpropane, glycerin, sorbitol, and the like, and ethylene oxide in the presence of one or more amines such as ammonia, ethylenediamine, urea, monomethyldiethanolamine, monoethyldiethanolamine, Examples thereof include random or block copolymers obtained by ring-opening polymerization of propylene oxide, butylene oxide, styrene oxide, etc., and mixtures thereof.

  Polyester type polyols include, for example, polymers obtained by polycondensation of dicarboxylic acids such as maleic acid, fumaric acid, adipic acid, sebacic acid, phthalic acid or the like and the above diols alone or mixtures, ε-caprolactone, valero. Examples thereof include ring-opening polymers such as lactones, and active hydrogen compounds having two or more active hydrogens such as castor oil.

  Examples of the polyolefin type polyol include polybutadiene polyol, polyisoprene polyol and hydrogenated products thereof.

  The polyol compound (a1) preferably does not contain dibutylhydroxytoluene (BHT) which is an anti-aging agent. As a polyol compound not containing BHT, Asahi Glass Co., Ltd. “Preminol 5001F” (polyether type polyol / number average molecular weight 4000) or the like can be used.

[About Polyisocyanate Compound (a2)]
Examples of the polyisocyanate compound having two or more isocyanate groups in the molecule (hereinafter sometimes simply referred to as “polyisocyanate compound (a2)”) include aliphatic, alicyclic, araliphatic, and aromatic diisocyanate compounds. And other polyisocyanate compounds. Specific examples thereof will be given below.

  Aliphatic diisocyanate compounds: trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, pentamethylene diisocyanate, 1,2-propylene diisocyanate, 1,2-butylene diisocyanate, 2,3-butylene diisocyanate, 1,3-butylene diisocyanate, 2, 4,4- or 2,2,4-trimethylhexamethylene diisocyanate, 2,6-diisocyanate methyl caproate, and the like.

  Alicyclic diisocyanate compound: 1,3-cyclopentene diisocyanate, 1,4-cyclohexane diisocyanate, 1,3-cyclohexane diisocyanate, 3-isocyanate methyl-3,5,5-trimethylcyclohexyl isocyanate, 4,4'-methylenebis (cyclohexyl) Isocyanate), methyl-2,4-cyclohexane diisocyanate, methyl-2,6-cyclohexane diisocyanate, 1,3-bis (isocyanatomethyl) cyclohexane, 1,4-bis (isocyanatomethyl) cyclohexane, isophorone diisocyanate and the like.

  Aroaliphatic diisocyanate compounds: 1,3- or 1,4-xylylene diisocyanate or mixtures thereof, ω, ω'-diisocyanate-1,4-diethylbenzene, 1,3- or 1,4-bis (1-isocyanate) -1-methylethyl) benzene or a mixture thereof.

  Aromatic diisocyanate compounds: m-phenylene diisocyanate, p-phenylene diisocyanate, 4,4'-diphenyl diisocyanate, 1,5-naphthalene diisocyanate, 4,4'-diphenylmethane diisocyanate, 2,4- or 2,6-tolylene diisocyanate 4,4'-toluidine diisocyanate, 4,4'-diphenyl ether diisocyanate, and the like.

  Examples of the polyisocyanate compound excluding the diisocyanate compound include aliphatic, alicyclic, araliphatic, and aromatic polyisocyanate compounds. Specific examples thereof will be given below.

  Aliphatic polyisocyanate compounds: lysine ester triisocyanate, 1,4,8-triisocyanate octane, 1,6,11-triisocyanate undecane, 1,8-diisocyanate-4-isocyanate methyloctane, 1,3,6-tri Isocyanate hexane, 2,5,7-trimethyl-1,8-diisocyanate-5-isocyanate methyloctane, and the like.

  Alicyclic polyisocyanate compounds: 1,3,5-triisocyanatecyclohexane, 1,3,5-trimethylisocyanatecyclohexane, 3-isocyanatemethyl-3,3,5-trimethylcyclohexylisocyanate, 2- (3-isocyanatepropyl) -2,5-di (isocyanatomethyl) -bicyclo [2,2,1] heptane, 2- (3-isocyanatopropyl) -2,6-di (isocyanatomethyl) -bicyclo [2,2,1] heptane, 3- (3-Isocyanatopropyl) -2,5-di (isocyanatemethyl) -bicyclo [2,2,1] heptane, 5- (2-isocyanatoethyl) -2-isocyanatomethyl-3- (3-isocyanatopropyl) ) -Bicyclo [2,2,1] heptane, 6- (2-isocyanate) Nateethyl) -2-isocyanatomethyl-3- (3-isocyanatopropyl) -bicyclo [2,2,1] heptane, 5- (2-isocyanatoethyl) -2-isocyanatomethyl-2- (3-isocyanatopropyl)- Bicyclo [2,2,1] heptane, 6- (2-isocyanatoethyl) -2-isocyanatomethyl-2- (3-isocyanatopropyl) -bicyclo [2,2,1] heptane, and the like.

  Aro-aliphatic polyisocyanate compound: 1,3,5-triisocyanate methylbenzene and the like.

  Aromatic polyisocyanate compounds: triphenylmethane-4,4 ′, 4 ″ -triisocyanate, 1,3,5-triisocyanatebenzene, 2,4,6-triisocyanatotoluene, 4,4′-diphenylmethane-2, 2 ', 5,5'-tetraisocyanate and the like.

  When using these polyisocyanate compounds, when yellowing becomes a problem, it is preferable to use aliphatic, alicyclic, and araliphatic polyisocyanate compounds. It is preferable that the polyisocyanate compound (a2) does not contain BHT which is an antiaging agent. As an isocyanate compound in which BHT is not blended, “MT-A965” (4,4′-diphenylmethane diisocyanate) manufactured by Nippon Polyurethane Industry Co., Ltd. can be used.

[Viscosity modifier (B)]
The viscosity modifier (B) in the present invention is a substance or compound that is liquid at room temperature and blended for the purpose of reducing its viscosity by a diluting action in the one-part moisture-curing urethane resin adhesive composition, And it does not correspond to VOC in the small chamber method test prescribed | regulated by JISA1901: 2003.

  Here, the “volatile organic compound (VOC), formaldehyde and other carbonyl compound emission measurement test for building materials—small chamber method” defined in JIS A 1901: 2003 will be described.

In this test method, an adhesive is applied on a stainless steel plate or glass plate in a standard state (23 ± 2 ° C.) and cured to obtain a test specimen. The conditions at that time are as follows.
Application amount of adhesive: 300 ± 15 g / m ² Application area: 80 cm ² Curing time: 60 ± 10 minutes Curing environment: 23 ± 2 ° C.
The specimen after curing is left in a small chamber with a chamber capacity of 20 L, and the test is started under the following conditions.
Test temperature: 28 ± 1 ° C. Relative humidity: 50 ± 5% Ventilation frequency: 0.5 ± 0.05 times / h Sample load factor: 0.4 m ² / m ³ . Under this condition, the air from the chamber is sampled twice after curing for 7 days, and the VOC emission amount and emission rate are determined. Conditions for collecting VOC, formaldehyde and other carbonyl compounds are as follows.
In the case of VOC Collection tube: TENAX-TA Air collection amount: 3.2L
Formaldehyde and other carbonyl compounds Collection tube: DNPH cartridge Air collection volume: 10L
The collected VOC is measured by using a gas chromatograph equipped with a mass spectrometer by attaching a collection tube to a heat desorption device, desorbing the VOC by heating.
In the case of formaldehyde and other carbonyl compounds, the carbonyl compound DNPH derivative in the DNPH cartridge is dissolved using acetonitrile and desorbed, and then measured using a high performance liquid chromatograph.
As a criterion for determining VOC, a substance detected in a range from n-hexane to n-hexadecane analyzed in a gas chromatograph is defined as VOC, and a value converted to toluene is obtained using the sum of peak areas.

  When the viscosity modifier (B) is a dialkyl ester of adipic acid and / or a dialkyl ester of sebacic acid, the compatibility with the urethane prepolymer is good, and an appropriate urethane resin adhesive is used. This is preferable because the viscosity can be adjusted. However, in the case of a dialkyl ester of adipic acid, the alkyl group has 8 or more carbon atoms, and in the case of a dialkyl ester of sebacic acid, the alkyl group has 4 or more carbon atoms. Of course, even if these are used alone, good workability can be obtained. However, it is preferable to use both in combination, because better workability can be obtained. Although the compounding quantity of a viscosity modifier (B) is not restrict | limited in particular, Preferably about 8-20 mass parts is used with respect to 100 mass parts of urethane prepolymers (A). When the blending amount of the viscosity modifier (B) is small, workability is not sufficiently imparted, and when the blending amount is large, the cured film is plasticized and it becomes difficult to obtain the binding force of the flooring.

  Commercially available products such as “DOA” (bis (2-ethylhexyl) adipate) manufactured by Daihachi Chemical Industry Co., Ltd. and “DINA” (diisononyl adipate) manufactured by Daihachi Chemical Industry Co., Ltd. can be used as the dialkyl ester of adipic acid. As the dialkyl ester of sebacic acid, commercially available products such as “DOS” (dioctyl sebacate) manufactured by Hogoku Seiyaku Co., Ltd. and “DBS” (dibutyl sebacate) manufactured by Hogoku Seiyaku Co., Ltd. can be used.

[About Crude MDI]
The urethane resin-based adhesive of the present invention preferably further contains crude MDI (C) as an additive. Here, crude MDI is a polyisocyanate mixture of diphenylmethane diisocyanate (MDI) and polyphenylmethane polyisocyanate (polymeric MDI). Since Crude MDI is liquid at room temperature, it can be combined with the viscosity modifier (B) during application work to provide workability. After the flooring is applied, it reacts with moisture in the air and hardens. Cohesive force can be imparted to the adhesive film, and further adhesiveness, floor restraint, and floor noise prevention performance can be imparted. Although the compounding quantity of crude MDI (C) is not restrict | limited in particular, Preferably about 2-10 mass parts is used with respect to 100 mass parts of urethane prepolymers (A). As the amount of Crude MDI increases, the cohesive strength of the cured film itself increases, while foaming due to reaction with moisture in the air increases during the curing of the adhesive, resulting in a significant improvement in total floor restraint. can not see.

  As the crude MDI (C), commercially available products such as “44V10”, “44V20”, “44V70”, “J243” manufactured by Sumika Bayer Urethane Co., Ltd. can be used.

  In the moisture curable urethane resin adhesive of the present invention, it is particularly preferable to use a viscosity modifier (B) and crude MDI (C) in combination. In this case, with respect to 100 parts by mass of the urethane prepolymer (A), the amount of the viscosity modifier (B) is 8 to 20 parts by mass, and the amount of the crude MDI (C) is 2 to 10 parts by mass. It is good to be.

[Other ingredients]
The urethane resin adhesive according to the present invention contains a urethane prepolymer (A) and a viscosity modifier (B). However, the urethane resin adhesive is used for VOC in the small chamber method test defined in JIS A 1901: 2003. If it is a component which does not correspond, other conventionally known arbitrary components may be contained. Examples of such components include heavy calcium carbonate, surface-treated calcium carbonate, kaolin, clay, talc, silica sand, silica and other fillers, titanium oxide, carbon black, other colorants such as dyes and pigments, and ketones. , Aromatic hydrocarbons, aliphatic hydrocarbons diluents, tackifiers, thickeners, silane coupling agents, pigment dispersants, antifoaming agents, titanium coupling agents, UV absorbers, etc. It is done. In addition, since the filler may contain moisture that reacts with the isocyanate compound, it is added after the dehydration treatment so that the water content is 0.2% or less, preferably 0.1% or less. It is preferable to do this.

  EXAMPLES Hereinafter, although this invention is demonstrated in detail based on an Example, this invention is not limited to an Example.

[Example 1]
2 L separable of 600 parts by mass of bifunctional polypropylene glycol (number average molecular weight 4000), 200 parts by mass of trifunctional polypropylene glycol (number average molecular weight 3000) and 214 parts by mass of 4,4′-diphenylmethane diisocyanate (MDI) The flask was charged and reacted at 90 ° C. for 3 hours under a nitrogen stream to obtain an isocyanate group-containing urethane prepolymer having an NCO mass% of 5%. The polypropylene glycol and 4,4'-diphenylmethane diisocyanate used here contained BHT as an anti-aging agent.
100 parts by mass of the reaction product (urethane resin composition) containing the urethane prepolymer obtained above, 60 parts by mass of calcium carbonate (“NS # 2300” manufactured by Nitto Flour & Chemical Co., Ltd.), surface-treated calcium carbonate (Maruo calcium) 40 parts by mass of “Shirets 200”, 0.4 parts by mass of dehydrating agent (“PTSI” by Nippon Soda Co., Ltd.) and 10 parts by mass of diisononyl adipate (“DINA” by Taoka Chemical Co., Ltd.) are added to a 2 L planetary mixer. The mixture was stirred and stirred for 40 minutes under reduced pressure to obtain a moisture curable urethane resin adhesive.

[Example 2]
The same method as in Example 1 except that diisononyl adipate of Example 1 (“DINA” manufactured by Taoka Chemical Co., Ltd.) was reduced to 8 parts by mass and 2 parts by mass of dibutyl sebacate (“DBS” manufactured by Hogoku Seiyaku Co., Ltd.) was added. A moisture curable urethane resin adhesive was obtained.

Example 3
A moisture-curing urethane resin adhesive was obtained in the same manner as in Example 1 except that two types of polypropylene glycol and 4,4'-diphenylmethane diisocyanate used did not contain BHT.

Example 4
A moisture-curing urethane resin adhesive was obtained in the same manner as in Example 3 except that 2 parts by mass of Crude MDI (“44V20” manufactured by Sumika Bayer Urethane Co., Ltd.) was further added at the time of stirring and mixing in the planetary mixer. It was.

Example 5
A moisture-curable urethane resin adhesive was obtained in the same manner as in Example 3 except that 5 parts by mass of crude MDI was further added at the time of stirring and mixing in the planetary mixer.

Example 6
A moisture-curing urethane resin adhesive was obtained in the same manner as in Example 3 except that 10 parts by mass of crude MDI was further added at the time of stirring and mixing in the planetary mixer.

Example 7
A moisture-curable urethane resin adhesive was obtained in the same manner as in Example 4 except that the amount of diisononyl adipate was increased to 16 parts by mass in Example 4.

[Comparative Example 1]
In place of diisononyl adipate as a viscosity modifier, a moisture curable urethane resin adhesive was prepared in the same manner as in Example 1 except that 10 parts by mass of an isoparaffin hydrocarbon (“Isopar H” manufactured by ExxonMobil) was used. Obtained.

[Comparative Example 2]
A moisture-curing urethane resin adhesive was obtained in the same manner as in Example 3 except that 15 parts by mass of Crude MDI (“44V20” manufactured by Sumika Bayer Urethane Co., Ltd.) was further added at the time of stirring and mixing in the planetary mixer. It was.

[Comparative Example 3]
A moisture curable urethane resin adhesive was obtained in the same manner as in Example 4 except that the amount of diisononyl adipate was increased to 24 parts by mass in Example 4.

  Regarding the moisture curable urethane resin adhesives obtained in Examples 1 to 7 and Comparative Examples 1 to 3, application workability, adhesiveness, compressive strength, splitting strength, floor squealing property, and VOC are obtained by the following methods. The amount of emission was measured.

[Coating workability]
The prepared urethane resin adhesive was filled into a paper tube jumbo cartridge (760 ml) and left at 5 ° C. for 24 hours. Thereafter, an adhesive was applied using a cartridge gun in an atmosphere of 5 ° C., and the resistance of the cartridge gun at that time was evaluated in the following four stages. If evaluation is (double-circle) or (circle), it can be judged that there is no problem practically.
A: The resistance of the cartridge gun when applying the adhesive is very small, and the application workability is very good.
○: The resistance of the cartridge gun during application of the adhesive is small, and it can be said that the application workability is good.
Δ: The resistance of the cartridge gun during application of the adhesive is slightly heavy, and it can be said that the application workability is insufficient.
×: The resistance of the cartridge gun when applying the adhesive is very heavy, and it can be said that the coating workability is poor.

[Adhesive strength]
The test was conducted by a method according to JIS A 5536. The evaluation at that time was as follows. If evaluation is (circle), it can be judged that practically sufficient adhesive strength is acquired.
○: Adhesive strength is 1 N / mm ² or more, or material destruction of the adherend.
X: Adhesive strength is 1 N / mm ² or less, and material destruction of the adherend is not observed.

[Compressive shear bond strength]
A urethane resin adhesive was applied to an asada material of 25 mm × 30 mm (thickness 10 mm), and an asada material of the same size was adhered so as to have an adhesion area of 625 mm ² to obtain a test specimen (FIG. 1). After curing for 7 days in an environment of 23 ° C. and 55% relative humidity, a compression shear test was performed. The evaluation at that time was as follows. If evaluation is (double-circle) or (circle), it can be judged that it has practically sufficient floor restraint property.
A: Compression shear bond strength is 6.0 N / mm ² or more. In this case, floor restraint that suppresses expansion and contraction of the flooring can be obtained.
◯: The compression shear adhesive strength is 4.5 N / mm ² or more. In this case, it is possible to obtain floor restraint that almost suppresses expansion and contraction of the flooring.
Δ: Compression shear bond strength is 3.0 N / mm ² or more. In this case, the floor restraint property can be obtained so that the expansion and contraction of the floor material can be substantially suppressed except for floor heating applications.
X: The compression shear adhesive strength is 3.0 N / mm ² or less. In this case, the expansion and contraction of the floor material cannot be suppressed.

[Split bond strength]
An asada material of 25 mm × 50 mm (thickness 5 mm) and an asada material of 25 mm × 40 mm (thickness 10 mm) were bonded together in advance for “bond woodworking” (manufactured by Konishi Co., Ltd.). Apply urethane resin adhesive to be evaluated to the adhesive surface (25mm x approx. 35mm) provided with spacers so that the thickness of the adhesive layer is about 0.3mm, and then add 25mm x 50mm (thickness 5mm) asada The materials were bonded together (FIG. 2). After curing for 7 days in an environment of 23 ° C. and 55% relative humidity, a splitting test was performed. The evaluation at that time was as follows. If evaluation is (double-circle) or (circle), it can be judged that it has cohesion force of the cured film sufficient practically.
A: Split adhesion strength is 20 N / mm or more B: Split adhesion strength is 15 N / mm or more Δ: Split adhesion strength is 10 N / mm or more ×: Split adhesion strength is 10 N / mm or less

[Flooding]
A specimen was prepared by a method according to JIS A 5536, and a floor squealing test was conducted. The evaluation at that time was as follows. If evaluation is (circle), it can be judged that a problem does not arise practically.
○: No sticky sound such as Necha
Δ: Tacking sound such as necha
X: A tack sound such as a necha sound is heard.

[VOC emission]
Tested according to JIS A 1901: 2003 “Measurement of Emission of Volatile Organic Compounds (VOC), Formaldehyde and Other Carbonyl Compounds of Building Materials—Small Chamber Method”, and TVOC Emission after 7 Days The emission rate was measured. The evaluation at that time was as follows.
A: Emission amount 50 μg / m ³ or less, and emission rate 50 μg / m ³ · h or less ○: Emission amount 150 μg / m ³ or less, and emission rate 150 μg / m ³ · h or less Δ: Emission amount 400 μg / m ³ Below, and a diffusion rate of 400 μg / m ³ · h or less ×: a diffusion amount of 400 μg / m ³ or more, or a diffusion rate of 400 μg / m ³ · h or more

  As is clear from the results shown in the table, the moisture-curing urethane resin adhesives (Examples 1 to 7) according to the present invention are equivalent to or more than the conventional urethane resin adhesives for floor construction (Comparative Example 1). It can be seen that it has performance (workability, adhesiveness, floor restraint, floor noise prevention) and extremely low VOC emission.

  The moisture-curing urethane resin adhesive according to the present invention has performances (workability, adhesiveness, floor restraint, floor noise prevention) equivalent to or better than conventional urethane resin adhesives for floor construction. , VOC emission is extremely low and industrially useful.

It is explanatory drawing which shows the test body shape of the compression shear bond strength in experiment. It is explanatory drawing which shows the test body shape of the split adhesive strength in experiment.

1: Asada material 2: Evaluation adhesive 3: Spacer

Claims (5)

Isocyanate group-containing urethane prepolymer (A) obtained by reacting a polyol compound (a1) having two or more active hydrogens in the molecule with a polyisocyanate compound (a2) having two or more isocyanate groups in the molecule When,
Viscosity modifier (B) that does not correspond to volatile organic substances (VOC) in the small chamber method test defined in JIS A 1901: 2003,
In this test, a one-component moisture-curing urethane resin adhesive having a TVOC emission amount of 150 μ / m ³ or less after 7 days in the test and a diffusion rate of 150 μg / m ² · h or less.   The one-component moisture-curable urethane resin adhesive according to claim 1, wherein dibutylhydroxytoluene is not blended with the urethane prepolymer (A).   The one-component moisture-curable urethane resin adhesive according to claim 1 or 2, wherein the viscosity modifier (B) is a dialkyl ester of adipic acid and / or a dialkyl ester of sebacic acid.   The one-component moisture-curable urethane resin adhesive according to any one of claims 1 to 3, further comprising crude MDI (C) as an additive. The blending amount of the viscosity modifier (B) is 8 to 20 parts by weight and the blending amount of crude MDI (C) is 2 to 10 parts by weight with respect to 100 parts by weight of the urethane prepolymer (A). The one-component moisture-curable urethane resin adhesive according to claim 4, wherein the one-component moisture-curable urethane resin adhesive is provided.