JP2008231151A - Moisture-curing hot melt adhesive, fabricated member and flash panel using the same - Google Patents

Abstract

[Problem] To provide a moisture-curable hot-melt adhesive having excellent mechanical strength and adhesive strength and capable of exhibiting excellent moisture resistance performance with an adhesive alone, and a construction member and a flash panel using the same. To do.
SOLUTION: A urethane prepolymer obtained by reacting a polyol component (A) and a polyisocyanate component (B) is contained, and the polyol component (A) contains a polyol (a) having a cycloolefin structure in the molecule. It is related with the moisture hardening type hot-melt-adhesive which contains and content of the cycloolefin structure in a urethane prepolymer exists in the range of 10-30 mass%. The content of the polyol (a) in the polyol component (A) is preferably in the range of 50 to 100% by mass.
[Selection] Figure 1

Description

  The present invention relates to a moisture-curable hot-melt adhesive that can be used for forming a moisture-permeable layer in, for example, a building member, and a construction member and a flash panel using the same.

  Conventionally, in the field of building materials such as doors, substrates such as plywood, MDF (medium density fiberboard) and particle board, and surface materials such as decorative sheets are pasted in order to improve aesthetics and impart durability. The combined decorative member is widely used, and such a decorative member is generally used as a building member by sticking it on both sides of the core material.

  From the viewpoints of weight reduction and heat insulation, the core material is often hollow. Therefore, a temperature difference is likely to occur between the inside (particularly the hollow portion) and the outside of the building member, and condensation may occur in summer or winter. And when dew condensation is absorbed by the cosmetic work member, deformation such as warpage or swelling of the cosmetic work member may occur due to a difference in moisture absorption between members constituting the cosmetic work member. In view of this, for the purpose of suppressing the warpage and swelling of the decorative member and improving the durability, it has been studied to provide a moisture-permeable layer inside the decorative member.

  In Patent Document 1, as a decorative board that can suppress warping and swelling and has sufficient heat resistance performance, for example, a polyurethane-based adhesive is used as a reactive hot melt adhesive on both the front and back surfaces of a wooden substrate. A decorative board to which decorative paper is attached is disclosed. However, in the technique of Patent Document 1, it is difficult to obtain sufficient moisture permeation resistance only by using a hot melt adhesive that does not contain water or a solvent as the adhesive.

  Patent Document 2 proposes a technology for waterproofing the entire inner surface of each of the front surface material and the back surface material with a waterproofing agent that essentially does not contain water as a flash panel that can effectively reduce warpage. As the waterproofing agent, there has been proposed a hot-melt type moisture-curing urethane waterproofing agent containing 0.5 to 5% by weight of isocyanate in the molecule and having physical properties of a solidification time at room temperature of 30 minutes or less. . However, the waterproofing agent proposed in Patent Document 2 does not necessarily have mechanical strength and final adhesive strength as an adhesive, and it is necessary to use a separate adhesive to bond the member formed with the waterproofing agent to other members. Therefore, it is not preferable in terms of production efficiency and manufacturing cost of the flash panel.

  Patent Document 3 discloses an isocyanate compound, a polyfunctional carboxylic acid compound, and an aliphatic or alicyclic diol or triol as a reactive hot melt urethane adhesive composition having excellent life stability, bonding thermal stability and strength. A urethane prepolymer composition containing a reaction product with a polyester-polyol obtained by reacting a compound has been proposed.

  In Patent Document 4, as a reactive hot melt adhesive composition excellent in creep resistance and adhesion to a substrate, (a) one or more polymers having a weight average molecular weight of 30,000 to 100,000, b) one or more polyfunctional polyols, (c) one or more organic compounds having at least two hydroxy groups, and (d) one or more polyisocyanates, the ratio of isocyanate groups to hydroxyl groups (NCO / OH) Reactive hot melt adhesive compositions have been proposed in which is between 2.1 and 6.0 and the amount of free isocyanate groups is greater than 3.5 weight percent based on the total weight of the composition .

  Patent Document 5 discloses a specific long-chain polyester polyol, an aliphatic polyether polyol having a number average molecular weight of 3000 to 15000, and 1000 as a moisture-curable polyurethane hot melt adhesive that exhibits excellent final adhesive strength. An aromatic polyester polyol having a number average molecular weight of ˜5000 and a glass transition temperature of 40 ° C. or higher, and an aromatic polyester having a number average molecular weight of 400 to 3500 and a glass transition temperature of 20 ° C. or lower. Moisture curable polyurethane hot melt adhesives containing polyols have been proposed. However, Patent Documents 3 to 5 do not consider providing moisture resistance to the adhesive composition.

That is, for example, it has not yet been obtained an adhesive having good mechanical strength, adhesive strength, and moisture permeation performance that can be used alone as a moisture permeation layer for various structural members such as building materials. It is.
JP 2006-15505 A JP-A-10-193491 JP-A-1-54087 JP 2006-104468 A JP 2005-320520 A

  The present invention solves the above-described problems, and has a moisture curable hot melt adhesive having excellent mechanical strength and adhesive strength, and capable of exhibiting excellent moisture permeation resistance with an adhesive alone. An object of the present invention is to provide a structure member and a flash panel using the above-mentioned.

  The present inventor has made various studies on polyols and polyisocyanates that can form urethane prepolymers for the purpose of imparting excellent moisture permeation resistance. Although it was considered that moisture permeation resistance could be imparted from the viewpoint of structure, the moisture permeation resistance could still not be improved to a practically sufficient level. As a result of further investigation, when a specific amount of cycloolefin structure was introduced into the urethane prepolymer, it was unexpectedly found that excellent moisture permeation performance was exhibited, and the present invention was completed. .

  That is, this invention contains the urethane prepolymer obtained by making a polyol component (A) and a polyisocyanate component (B) react, and a polyol component (A) is a polyol (a) which has a cycloolefin structure in a molecule | numerator. It is related with the moisture hardening type hot-melt-adhesive containing content of the cycloolefin structure in urethane prepolymer in the range of 10-30 mass%.

  In the moisture curable hot melt adhesive of the present invention, the content of the polyol (a) in the polyol component (A) is preferably in the range of 50 to 100% by mass.

  In the moisture curable hot melt adhesive of the present invention, the number average molecular weight of the polyol (a) is preferably in the range of 500 to 3,000.

  In the moisture curable hot melt adhesive of the present invention, the cycloolefin structure is preferably a cyclohexane structure.

  In the moisture curable hot melt adhesive of the present invention, the polyol component (A) preferably contains a polycarbonate polyol having a cycloolefin structure in the molecule in the range of 50 to 90% by mass.

  In the moisture curable hot melt adhesive of the present invention, the polyol component (A) preferably contains a crystalline polyester polyol having a melting point in the range of 60 to 80 ° C.

  In the moisture-curable hot melt adhesive of the present invention, the crystalline polyester polyol has the following general formula (1),

(In General Formula (1), R ¹ and R ² each independently represents a linear alkylene group having an even number of carbon atoms, and the total number of carbon atoms of R ¹ and R ² is 12 or more. N represents an integer of 3 to 40.)
It is preferable to be represented by

The moisture curable hot melt adhesive of the present invention preferably further contains a filler.
The filler is preferably mainly composed of layered silicate.

  The present invention also includes a base material, a sheet-like or film-like surface member, and an adhesive layer that adheres the base material and the surface member. The present invention relates to a fabricated member formed by curing a hot melt adhesive.

  In the structure member of the present invention, the base material is a wood base material, and the surface member is selected from a film and sheet made of polyvinyl chloride, a film and sheet made of polyolefin, a film and sheet made of polyethylene terephthalate, and paper. It is preferable that it is at least either.

  The present invention also relates to a flash panel formed by adhering the above-described structure member on both surfaces of a core material.

  In the flash panel of the present invention, the core material preferably has a honeycomb structure.

  The moisture curable hot melt adhesive of the present invention has excellent mechanical strength and adhesive strength after curing, and exhibits excellent moisture permeation resistance alone. Therefore, by using the moisture curable hot melt adhesive of the present invention, a moisture permeable layer having excellent durability and moisture resistance can be formed with high production efficiency.

[Moisture-curing hot melt adhesive]
The moisture curable hot melt adhesive of the present invention contains a urethane prepolymer obtained by reacting a polyol component (A) and a polyisocyanate component (B). The polyol component (A) contains a polyol (a) having a cycloolefin structure in the molecule. Moreover, content of the cycloolefin structure in a urethane prepolymer exists in the range of 10-30 mass%.

  The urethane prepolymer contained in the moisture-curable hot melt adhesive of the present invention can typically react with moisture present in the air or in the substrate to which the adhesive is applied to form a crosslinked structure. A compound having an isocyanate group in the molecule and having a solid or viscous property at room temperature. In general, what is called a urethane prepolymer has a relatively low molecular weight, but those skilled in the art also have a number average molecular weight (Mn) of several tens of thousands, which is also called a urethane prepolymer. For example, urethane prepolymers having a number average molecular weight of tens of thousands can also be used.

  The number average molecular weight of the urethane prepolymer is preferably in the range of 1000 to 30000, and more preferably in the range of 4000 to 10,000. When the number average molecular weight of the urethane prepolymer is 1000 or more, the mechanical strength, final adhesion strength and moisture permeation resistance after curing of the moisture curable hot melt adhesive are particularly good. Especially good in workability and workability.

  The number average molecular weight in the present invention is determined by reacting an excess amount of an amino compound with a urethane prepolymer and measuring the concentration of the isocyanate group by back titrating the remaining amine concentration with hydrochloric acid. It is a value calculated based on this.

  The urethane prepolymer contained in the moisture curable hot melt adhesive of the present invention has both of two characteristics, moisture crosslinking reactivity and hot melt property. The moisture cross-linking reactivity of the urethane prepolymer is derived from the cross-linking reaction initiated by the reaction of the isocyanate group of the urethane prepolymer and moisture (water), and is a property resulting from the isocyanate group of the urethane prepolymer. It is.

  On the other hand, the hot melt property of the urethane prepolymer is a property resulting from the molecular structure of the urethane prepolymer to be selected, and it is solid at room temperature but can be melted and applied by heating. It is a property that can solidify and develop adhesiveness when cooled.

  Hot melt is a general term for properties or substances that are solid or viscous at room temperature, but melt and become fluid or liquid when heated. For example, hot melts typified by ethylene vinyl acetate are generally used. Are known. Hot melt is a solvent-free type and is a solid or viscous property at room temperature, but when heated, it melts and can be applied, and it has the property that cohesive force is produced again by cooling. For example, it is useful as a solventless adhesive or coating material.

  Hot melt properties are closely related to the softening point. In general, the lower the softening point of the urethane prepolymer, the better the workability, and conversely, the higher the softening point, the better the final adhesive strength.

  The softening point of the urethane prepolymer contained in the moisture-curable hot melt adhesive of the present invention is preferably in the range of 40 to 120 ° C. When the softening point of the urethane prepolymer is 40 ° C. or higher, the final adhesive strength is good, and when it is 120 ° C. or lower, workability is good. The softening point of the urethane prepolymer is more preferably 60 ° C. or higher, and further preferably 100 ° C. or lower. In addition, the softening point as used in the field of this invention means the temperature which begins to heat-flow and lose cohesive force, when the temperature of a urethane prepolymer is raised in steps. In addition, the softening point in this invention is the value calculated | required by the ring and ball method based on JISK5902.

  As a method for adjusting the softening point of the urethane prepolymer, for example, (1) an adjustment method based on the molecular weight of the urethane prepolymer, and (2) depending on the crystallinity of the polyalkylene chain of the polyester polyol when a polyester polyol is used as a raw material. An adjustment method, (3) an adjustment method by introducing an aromatic cyclic structure using a polyol or polyisocyanate, (4) an adjustment method by the content of urethane bonds, and the like can be employed. Can be used in combination.

  In the method (1) for adjusting the softening point of the urethane prepolymer, generally, the softening point tends to increase as the molecular weight of the urethane prepolymer increases. In addition, adjustment of the molecular weight of a urethane prepolymer can employ | adopt methods, such as adjustment by the molar ratio of polyisocyanate and a polyol, use of high molecular weight polyol, for example, and there is no restriction | limiting in particular.

  In addition, in the above-mentioned method (2) for adjusting the softening point of the urethane prepolymer, as the number of carbon atoms in the polyalkylene chain of the crystalline polyester polyol increases, the crystallinity of the resulting urethane prepolymer improves and softens. The point tends to increase, and the softening point tends to increase as the amount of the crystalline polyester polyol used increases.

  In the method (3) for adjusting the softening point of the urethane prepolymer, generally, the softening point tends to increase as the content of the aromatic cyclic structure in the urethane prepolymer increases.

  Moreover, in (4) of the adjustment method of the softening point of said urethane prepolymer, there exists a tendency for a softening point to raise normally, so that there is much content of a urethane bond.

  The urethane prepolymer contained in the moisture-curable hot melt adhesive of the present invention has a polyol component (A) and a polyisocyanate component (B) described below, and the isocyanate group of the polyisocyanate component (B) is a polyol. It can manufacture by making it react on the conditions which become excess with respect to the hydroxyl group which a component (A) has.

  The melting point and glass transition temperature in the present invention are values obtained from an endothermic peak measured and detected using a differential scanning calorimeter at a heating rate of 10 ° C./min.

  In addition, the “final bond strength” in the present invention means that, unless otherwise specified, a moisture-curable hot melt adhesive is applied to an adherend in a molten state, and the desired adherend is bonded to each other. It shall mean the adhesive strength expressed by the almost complete progress of the curing reaction. The conditions for developing the adhesive strength differ depending on the moisture-curing hot melt adhesive used, but in general, after bonding the objects to be bonded together, the temperature is 23 ° C. and the relative humidity is 65%. If it is cured for about an hour, "final bond strength" will be manifested.

<Polyol component (A)>
(Polyol (a))
In the present invention, the polyol component (A) contains a polyol (a) having a cycloolefin structure in the molecule. In a urethane-based adhesive, generally, a urethane prepolymer obtained by a reaction between a polyol component and an isocyanate component is formed at an application site of the adhesive, and cured by crosslinking of the urethane prepolymer to exhibit adhesiveness. Polyurethane mainly forms soft segments derived from polyol-derived parts and hard segments mainly composed of urethane-bonded parts, and moisture permeation in urethane adhesives occurs predominantly at the soft segment sites where the degree of molecular freedom is relatively high. it is conceivable that.

  A polyol having a cycloolefin structure in the molecule has a relatively strong molecular structure due to the presence of a cyclic structure, but is not as rigid as a molecule composed of only an aromatic structure, for example. Therefore, by using the polyol component (A) containing the polyol (a) having a cycloolefin structure in the molecule, the moisture curable hot melt adhesive is given good mechanical strength, and the moisture curable hot melt adhesive. In particular, moisture permeation from the soft segment portion can be suppressed to impart good moisture permeation resistance to the adhesive, and the final adhesive strength can be exhibited well. That is, according to the present invention, it is possible to obtain a moisture curable hot melt adhesive having good mechanical strength, final adhesive strength and moisture permeation resistance.

  The polyol (a) may be a polyol having a cycloolefin structure in the molecule, but it is particularly preferable to have a cycloolefin structure in the main chain. In this case, the mechanical strength and moisture permeation resistance after curing of the moisture curable hot melt adhesive can be obtained better.

  In this invention, content of the cycloolefin structure in a urethane prepolymer exists in the range of 10-30 mass%. When the content of the cycloolefin structure in the urethane prepolymer is less than 10% by mass, the mechanical strength and moisture permeation resistance after curing of the moisture-curable hot melt adhesive cannot be sufficiently improved, and 30% by mass. When the content exceeds 50%, the urethane prepolymer is insufficiently cured and the moisture curable hot melt adhesive cannot be provided with good mechanical strength and final adhesive strength, and sufficient moisture permeation resistance is obtained. I can't. The content of the cycloolefin structure in the urethane prepolymer is more preferably 15% by mass or more, and more preferably 26% by mass or less.

  The cycloolefin structure possessed by the polyol (a) is preferably a cycloolefin structure having, for example, 5 to 10 carbon atoms in view of availability. Among these, a cyclohexane structure having 6 carbon atoms is particularly preferable in that there are various derivatives and the degree of freedom in designing the urethane prepolymer obtained is high. As the polyol (a), polyester polyol, polyether polyol, polycarbonate polyol and the like can also be used.

  Specific preferred examples of the polyol (a) include low molecular polyols such as cyclohexanedimethanol, cyclohexanediethanol, adamantane di-methanol, adamantane di-ethanol, cyclopentane dimethanol, cyclopentane diethanol, and the like. Above all, the resulting moisture curable hot melt adhesive has a good balance of mechanical strength after curing, final adhesive strength, moisture permeation resistance, workability, workability, and reaction with polyisocyanate component (B). Cyclohexanedimethanol is particularly preferable because of its excellent properties.

  Moreover, as a polyester polyol which can be used as a polyol (a), the polyester polyol obtained by making a polyol and polycarboxylic acid react can be illustrated. In this case, examples of the polyol include low molecular polyols as described above, and examples of the polycarboxylic acid include cyclohexane dicarboxylic acid, adamantane dicarboxylic acid, and cyclopentane dicarboxylic acid.

  Examples of combinations of polyols and polycarboxylic acids in obtaining the above polyester polyol include combinations of polyols having a cycloolefin structure and polycarboxylic acids not having a cycloolefin structure, and those having no cycloolefin structure. A combination of a polyol and a polycarboxylic acid having a cycloolefin structure can be exemplified.

  In the moisture curable hot melt adhesive of the present invention, the content of the polyol (a) in the polyol component (A) is preferably in the range of 50 to 100% by mass. When the content of the polyol (a) is 50% by mass or more, the effect of improving the adhesive strength and moisture permeation resistance can be obtained better. The content of the polyol (a) is more preferably 70% by mass or more. The content of the polyol (a) may be 100% by mass, for example, 90% by mass or less, and further 80% by mass or less, and the balance is further improved in characteristics such as mechanical strength and final adhesive strength. From the viewpoint of preventing peeling of the bonded portion when the bonded portion is subjected to secondary processing such as cutting immediately after processing, it is also preferable to contain another polyol.

  In addition, content of the cycloolefin structure in this invention is the value calculated | required by calculation based on the mass of the raw material component which contributes to introduction | transduction of the cycloolefin structure in a urethane prepolymer.

  In the moisture curable hot melt adhesive of the present invention, the number average molecular weight of the polyol (a) is preferably in the range of 500 to 3,000. When the number average molecular weight of the polyol (a) is 500 or more, the mechanical strength and moisture permeation resistance after curing of the moisture curable hot melt adhesive are better, and when it is 3000 or less, the final adhesive strength is good. In addition, painting workability and workability are not easily impaired. The number average molecular weight of the polyol (a) is more preferably 800 or more, and more preferably 2000 or less.

  The polyol component (A) preferably contains a polycarbonate polyol having a cycloolefin structure in the molecule as the polyol (a). In the present invention, the polycarbonate polyol means a linear polymer having a carbonate bond in the main chain and having two or more hydroxyl groups in the molecule. Due to the presence of polycarbonate polyol having a cycloolefin structure in the molecule, moisture-curable hot melt adhesives have better mechanical strength, superior durability such as solvent resistance, water resistance, heat resistance, and hydrolysis resistance. Is granted.

  The content of the polycarbonate polyol having a cycloolefin structure in the molecule in the polyol component (A) is preferably in the range of 50 to 90% by mass. When the content of the polycarbonate polyol in the polyol component (A) is 50% by mass or more, the effect of improving the mechanical strength is obtained more favorably. When the content is 90% by mass or less, the balance includes, for example, mechanical strength, final From the viewpoint of further improving the properties such as adhesive strength, and preventing peeling of the bonded portion when secondary processing such as cutting is performed on the bonded portion immediately after bonding processing, other polyols are included. Can do. As for content of this polycarbonate polyol in a polyol component (A), it is more preferable that it is 70 mass% or more, and it is more preferable that it is 80 mass% or less.

  As the polycarbonate polyol, for example, those obtained by esterification of carbonic acid and aliphatic polyhydric alcohol can be used. Specifically, 1,3-propanediol, 1,4-butanediol, 1, Diols such as 6-hexanediol, diethylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol (PTMG) and the like, and dialkyl carbonates typified by dimethyl carbonate and the like and cyclic carbonates typified by ethylene carbonate and the like The reaction product etc. are mentioned.

  As the polycarbonate polyol, those having a number average molecular weight in the range of 500 to 3000 are particularly preferably used. When the number average molecular weight of the polycarbonate polyol is 500 or more, the effect of improving the mechanical strength after curing of the moisture curable hot melt adhesive is better obtained. When the number average molecular weight is 3000 or less, the moisture curable hot melt adhesive is The final adhesive strength after curing can be maintained well. The number average molecular weight of the polycarbonate polyol is more preferably 800 or more, and more preferably 2000 or less.

(Crystalline polyester polyol)
In the moisture curable hot melt adhesive of the present invention, the polyol component (A) preferably contains a crystalline polyester polyol. When the polyol component (A) contains a crystalline polyester polyol, the mechanical strength and moisture permeation resistance after curing of the moisture curable hot melt adhesive are improved. As the crystalline polyester polyol, typically, a crystalline polyester polyol having a melting point in the range of 60 to 80 ° C. can be used. When the melting point of the crystalline polyester polyol is 60 ° C. or higher, the mechanical strength and moisture permeation resistance after curing of the moisture-curable hot melt adhesive are particularly good. On the other hand, when the melting point of the crystalline polyester polyol is 80 ° C. or lower, the fluidity and workability of the moisture-curing hot melt adhesive can be kept good. The melting point of the crystalline polyester polyol is more preferably 65 ° C. or higher, and more preferably 70 ° C. or higher.

  The proportion of the crystalline polyester polyol in the polyol component (A) is preferably in the range of 5 to 50% by mass. When the proportion of the crystalline polyester polyol in the polyol component (A) is 5% by mass or more, the mechanical strength and moisture permeation resistance after curing of the moisture curable hot melt adhesive can be further improved, When the ratio is 50% by mass or less, it is advantageous in that it is possible to prevent an excessive increase in the melt viscosity of the moisture-curable hot melt adhesive and to maintain good fluidity and workability.

  Preferable specific examples of the crystalline polyester polyol include, for example, 1,6-hexanediol and adipic acid, 1,6-hexanediol and sebacic acid, 1,4-butanediol and 1,12-dodecanedicarboxylic acid, 1 , 6-hexanediol and 1,12-dodecanedicarboxylic acid, 1,10-nonanediol and succinic acid, 1,10-nonanediol and adipic acid, 1,8-octanediol and adipic acid, respectively. And polyester polyols that can be used.

  In particular, the crystalline polyester polyol has the following general formula (1),

(In General Formula (1), R ¹ and R ² each independently represents a linear alkylene group having an even number of carbon atoms, and the total number of carbon atoms of R ¹ and R ² is 12 or more. N represents an integer of 3 to 40.)
It is preferable to be represented by

R ¹ in the general formula (1) is a linear alkylene group having an even number of carbon atoms, and may be appropriately selected within a range where the total number of carbon atoms of R ¹ and R ² is 12 or more. However, it is particularly preferably a linear alkylene group having an even number of 4 or more carbon atoms.

R ² in the general formula (1) is an alkylene group of straight chain carbon atoms independently of R ¹ is an even number, the range of total number of carbon atoms possessed by R ¹ and R ² is 12 or more However, it is preferably a linear alkylene group having an even number of 10 or more carbon atoms.

When a long-chain aliphatic polyester polyol in which R ¹ and R ² are each a linear alkylene group having the number of carbon atoms within the above range is used, the crystallinity of the resulting urethane prepolymer increases, and the moisture-curing type The mechanical strength and moisture permeation resistance after curing of the hot melt adhesive become better.

  N in the general formula (1) is an integer of 3 to 40, more preferably in the range of 9 to 25, and still more preferably in the range of 9 to 15. When n is 3 or more, the mechanical strength and moisture permeation resistance after curing of the moisture curable hot melt adhesive are particularly good. Moreover, when n is 40 or less, the melt viscosity of the moisture-curable hot melt adhesive does not become too high, and workability and workability are particularly good.

  The long-chain aliphatic polyester polyol as described above is produced, for example, by a condensation reaction of a linear aliphatic diol having an even number of carbon atoms and a linear aliphatic dicarboxylic acid having an even number of carbon atoms. Can do. As the linear aliphatic diol, for example, ethylene glycol, 1,4-butanediol, 1,6-hexanediol, 1,8-octanediol, 10-decanediol and the like can be used, and preferably 1,6 -Hexanediol, 1,8-octanediol, 1,10-decanediol can be used.

  As the linear aliphatic dicarboxylic acid, for example, succinic acid, adipic acid, sebacic acid, 1,12-dodecanedicarboxylic acid and the like can be used, and preferably sebacic acid and 1,12-dodecanedicarboxylic acid are used. Can do.

Moreover, the combination of the linear aliphatic diol and the linear aliphatic dicarboxylic acid used when producing the long-chain aliphatic polyester polyol is included in R ¹ and R ^{2 represented} by the general formula (1). The total number of carbon atoms can be appropriately selected within a range of 12 or more, preferably 12-20. Among them, a long-chain aliphatic polyester polyol obtained by reacting 1,6-hexanediol as a linear aliphatic diol and 1,12-dodecanedicarboxylic acid or sebacic acid as a linear aliphatic dicarboxylic acid is used. Is preferred.

  The number average molecular weight of the crystalline polyester polyol is preferably 10,000 or less, and more preferably in the range of 3000 to 5000. When the number average molecular weight is 10,000 or less, workability, workability, and final adhesion strength of the moisture curable hot melt adhesive are particularly good. When the number average molecular weight is 3000 or more, the mechanical strength and moisture permeation resistance after curing of the moisture curable hot melt adhesive are particularly good.

(Other polyols)
The polyol component (A) may contain a polyol other than those described above. For example, when the polyol component (A) contains an aromatic polyester polyol, the mechanical strength after curing of the moisture-curable hot melt adhesive becomes better. Aromatic polyester polyols are produced by, for example, a method in which an aromatic polycarboxylic acid and a low molecular weight aliphatic polyol are subjected to a condensation reaction, a method in which an aliphatic polycarboxylic acid and a low molecular weight aromatic polyol are subjected to a condensation reaction, or the like. Can do.

  Examples of the aromatic polycarboxylic acid include phthalic acid, isophthalic acid, terephthalic acid, and hexahydroisophthalic acid. These can be used alone or in combination of two or more. Examples of the aliphatic polycarboxylic acid include adipic acid, sebacic acid, azelaic acid, decamethylene dicarboxylic acid, and the like.

  Preferred examples of the low molecular weight aliphatic polyol include ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,3-butylene glycol, 1,4-butylene glycol, and 2,2-dimethyl. -1,3-propanediol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, 1,8-octanediol, diethylene glycol, triethylene glycol, dipropylene glycol, tripropylene glycol and the like. .

  In the production of the aromatic polyester polyol, ethylene glycol or neopentyl glycol is selected as the low molecular weight aliphatic polyol, and isophthalic acid or terephthalic acid is selected as the aromatic polycarboxylic acid. A combination of the aliphatic polyol and the aromatic polycarboxylic acid can be appropriately designed so that the glass transition temperature is, for example, 30 ° C. or higher, more typically 30 to 80 ° C. By subjecting the aliphatic polyol and the aromatic polycarboxylic acid to a condensation reaction by a known method, the desired aromatic polyester polyol can be obtained. When the polyol component (A) contains such an aromatic polyester polyol having a high glass transition temperature, good mechanical strength is imparted by the moisture-curable hot melt adhesive.

  The number average molecular weight of the aromatic polyester polyol in this case can be, for example, in the range of 400 to 6000, more preferably in the range of 800 to 4000.

  Also, for example, low molecular weight polyols having side chains such as diethylene glycol, neopentyl glycol, hydroxypivalic acid-2,2-dimethyl-3-hydroxypropyl, and the like, for example, phthalic acid, isophthalic acid, terephthalic acid, hexahydroisophthalic acid An aromatic polyester polyol having a glass transition temperature of, for example, −30 ° C. to 60 ° C. is obtained by appropriately combining the aromatic polycarboxylic acid and the like, and subjecting the polyol and the aromatic polycarboxylic acid to a condensation reaction by a known method. Obtainable. When the polyol component (A) contains an aromatic polyester polyol having such a low glass transition temperature, a good final adhesion strength is imparted by the moisture-curable hot melt adhesive.

  The number average molecular weight of the aromatic polyester polyol in this case can be, for example, in the range of 400 to 6000, more preferably in the range of 800 to 4000.

  In addition, it is preferable that it is in the range of 0.1-20 mass% among polyol components (A), and, as for content of aromatic polyester polyol, it is more preferable that it exists in the range of 1-10 mass%. When the content of the aromatic polyester polyol is 0.1% by mass or more of the polyol component (A), the mechanical strength after curing of the moisture-curable hot melt adhesive is good, and is 20% by mass or less. In addition, the final adhesive strength of the moisture curable hot melt adhesive is kept good.

  Moreover, as an aromatic polyol, the aromatic polyol obtained by carrying out ring-opening addition reaction of ethylene oxide, propylene oxide, (gamma) -butyrolactone, (epsilon) -caprolactone, etc. may be contained in bisphenol A, bisphenol F, etc., for example.

  Furthermore, in the present invention, the polyol component (A) may contain a polyether polyol. In this case, the polyether polyol contained in the polyol component (A) has an action to disperse stress to the adhesive layer made of the moisture-curable hot melt adhesive of the present invention. It has the effect of improving the final bond strength after curing.

  As the polyether polyol, for example, an aliphatic polyether polyol is preferably used. The number average molecular weight of the polyether polyol is preferably in the range of 300 to 10,000. When the number average molecular weight is 300 or more, the effect of improving the final adhesive strength is good, and when it is 10,000 or less, the reactivity with the polyisocyanate is good.

  Examples of preferred polyether polyols include polyethylene glycol, polypropylene glycol, polybutylene glycol and the like.

  The polyether polyol can be produced, for example, by ring-opening polymerization of an alkylene oxide such as ethylene oxide, propylene oxide, butylene oxide using a low molecular weight polyol described later as an initiator. It can also be produced by ring-opening addition of γ-butyrolactone, ε-caprolactone or the like to a polymer obtained by ring-opening polymerization.

  Examples of the low molecular weight polyol that can be used as an initiator when producing a polyether polyol include ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,3-butylene glycol, and 1,4-butylene. Glycol, 2,2-dimethyl-1,3-propanediol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, 1,8-octanediol, diethylene glycol, triethylene glycol, dipropylene glycol, Examples include tripropylene glycol.

  Here, for example, a polyether polyol having a secondary hydroxyl group at the molecular end generally has a tendency that the reactivity with the polyisocyanate decreases as the molecular weight increases. As a method for improving the reactivity between a polyether polyol having a secondary hydroxyl group at the molecular end and a relatively large molecular weight, and polyisocyanate, an alkylene oxide such as ethylene oxide is added to both ends of the polyether. A method of modifying so that both ends are primary hydroxyl groups is effective. When such an alkylene oxide-modified polyether polyol is used, it is advantageous in that a moisture-curable hot melt adhesive having good reactivity with isocyanate and good final adhesive strength can be obtained.

  Preferable specific examples of such an alkylene oxide-modified polyether polyol include, for example, an alkylene oxide-modified polyether polyol in which both ends of a polyether polyol of polypropylene glycol or polybutylene glycol are modified with an alkylene oxide such as ethylene oxide. .

  In addition, the content of the alkylene oxide-derived structural unit in the alkylene oxide-modified polyether polyol is preferably 20% by mass or less, more preferably 10% by mass or less, based on the entire polyether polyol. When the content of the structural unit derived from the alkylene oxide is 20% by mass or less of the entire polyether polyol, the final adhesive strength after curing of the moisture-curable hot melt adhesive is good, and the polyether polyol and the poly This is advantageous in that the reactivity with isocyanate is good.

  The content of the polyether polyol is preferably in the range of 0.1 to 20% by mass and more preferably in the range of 1 to 10% by mass in the polyol component (A). When the content of the polyether polyol is 0.1% by mass or more, it is advantageous in that the effect of improving the final adhesive strength is favorable. When the content is 20% by mass or less, the content in the polyol component (A) For example, the content of the polyol (a) or the like is not excessively decreased, and the moisture-curable hot melt adhesive is advantageous in that the mechanical strength and moisture permeation resistance after curing are good.

  Furthermore, the polyol (A) can contain other polyols as long as the object of the present invention is not impaired, in addition to the above-described polyols. Examples of other polyols include polyolefin polyols, polyester polyols, polyether polyols other than those described above, acrylic polyols, castor oil-based polyols, and the like.

<Polyisocyanate component (B)>
The polyisocyanate component (B) used in the present invention is an isocyanate compound having two or more isocyanate groups in the molecule.

  Examples of the polyisocyanate include aromatic polyisocyanates such as 4,4′-diphenylmethane diisocyanate, 2,4′-diphenylmethane diisocyanate, carbodiimide-modified diphenylmethane diisocyanate, crude diphenylmethane diisocyanate, phenylene diisocyanate, tolylene diisocyanate, naphthalene diisocyanate, hexa Aliphatic polyisocyanates such as methylene diisocyanate, lysine diisocyanate, cyclohexane diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, xylylene diisocyanate, and tetramethylxylylene diisocyanate, or polyisocyanates having an alicyclic structure can be used. Of these, the moisture-curable hot melt adhesive of the present invention is used after being melted by heating, and therefore diphenylmethane diisocyanate having a low vapor pressure during heating and melting is particularly preferred.

<Manufacture of urethane prepolymer>
Next, the manufacturing method of a urethane prepolymer is demonstrated in detail. In this invention, a urethane prepolymer is obtained by reaction of a polyol component (A) and a polyisocyanate component (B). Production of the urethane prepolymer can be carried out by a known and usual method. For example, after the polyol component (A) from which water has been removed is dropped into the polyisocyanate component (B) in the reaction vessel, the polyol component (A) The method of making it react until the hydroxyl group which has has disappeared substantially is used. When the polyol component (A) is composed of a plurality of types of polyols, the above dropping may be performed by a method of dropping each polyol separately or by a method of dropping a mixture of each polyol.

  The urethane prepolymer can be usually produced without a solvent, but may be produced by reacting in an organic solvent. When the polyol component (A) and the polyisocyanate component (B) are reacted in an organic solvent, an organic solvent such as ethyl acetate, n-butyl acetate, methyl ethyl ketone, and toluene that does not inhibit the reaction can be used. In the middle of the reaction or after the completion of the reaction, the organic solvent is preferably removed by a method such as heating under reduced pressure.

  When manufacturing a urethane prepolymer, a urethanization catalyst can be used as needed. The urethanization catalyst can be appropriately added at any stage of the above reaction.

  Examples of the urethanization catalyst include nitrogen-containing compounds such as triethylamine, triethylenediamine and N-methylmorpholine; metal salts such as potassium acetate, zinc stearate and tin octylate; organometallic compounds such as dibutyltin dilaurate and the like. Can do.

  The amount ratio of the polyol component (A) and the polyisocyanate component (B) when producing the urethane prepolymer is equivalent to the isocyanate group of the polyisocyanate component (B) and the hydroxyl group of the polyol component (A). (Hereinafter also referred to as “isocyanate group / hydroxyl group (equivalent ratio)”) is preferably in the range of 1.1 to 7.0, and more preferably in the range of 1.5 to 5.0. . By adjusting the isocyanate group / hydroxyl group (equivalent ratio) within such a range, a moisture-curable hot melt adhesive having good coatability can be obtained.

  The moisture curable hot melt adhesive of the present invention preferably has a melt viscosity at 120 ° C. in the range of 2000 to 9000 mPa · s. When the melt viscosity at 120 ° C. is within the above range, for example, the base material and the sheet-like or film-like surface member that are generally used in construction materials for building materials are bonded to the moisture-curable hot melt adhesive of the present invention. When pasting together using an agent, it is advantageous in that the surface member can be easily peeled off without damaging the surface of the base material within a certain period of time after bonding and within 5 minutes as a guide.

<Structure of urethane prepolymer>
The urethane prepolymer contained in the moisture curable hot melt adhesive of the present invention typically has the following general formula (2),

(In General Formula (2), A1 represents a divalent organic group having a cycloolefin structure in the main chain, B1 represents a divalent organic group, and o represents an integer of 1 or more.)
The repeating unit represented by

  When a polycarbonate polyol is used in the preparation of the urethane prepolymer of the present invention, the urethane prepolymer is typically represented by the following general formula (3),

(In general formula (3), A2 is a divalent organic group having a carbonate ester bond and an aromatic group in the main chain, B1 is a divalent organic group as in general formula (2), and p is 1. Each of the above integers)
The repeating unit represented by these is further included.

  In the present invention, when a crystalline polyester polyol is used in preparing the urethane prepolymer, the urethane prepolymer is typically represented by the following general formula (4),

(In the general formula (4), A3 is a divalent organic group including an aliphatic divalent hydrocarbon group having a sum of 12 or more carbon atoms and a substantially straight chain in the main chain; (B1 represents a divalent organic group as in the general formula (2), and q represents an integer of 1 or more)
The repeating unit represented by these is further included.

  In this invention, it can confirm that the urethane prepolymer contains said repeating unit by the analysis etc. which used NMR (each magnetic resonance apparatus), for example.

<Ingredients other than urethane prepolymer>
The moisture-curing hot melt adhesive of the present invention may be composed only of a urethane prepolymer, but may contain other components. The content of the urethane prepolymer in the moisture curable hot melt adhesive can be in the range of 50 to 100% by mass, more preferably in the range of 70 to 99% by mass. When the content of the urethane prepolymer in the moisture curable hot melt adhesive is 50% by mass or more, the mechanical strength, the adhesive strength, and the moisture permeation resistance are good. In addition, when this content is less than 100 mass% and also 99 mass% or less, the various additives for further modifying a moisture hardening type hot-melt-adhesive can be contained.

(Filler)
It is preferable that the moisture curable hot melt adhesive further contains a filler. When the filler is contained, it is advantageous in that the mechanical strength and moisture permeation resistance of the moisture-curable hot melt adhesive are improved. It is particularly preferable that the filler is mainly composed of layered silicate. A main component means the component contained in the quantity exceeding 50 mass% of the whole here. When the filler is mainly composed of layered silicate, it is advantageous in that the effect of improving the mechanical strength and moisture permeation resistance of the moisture-curable hot melt adhesive can be obtained more favorably.

  Preferable specific examples of the layered silicate include mica, talc, kaolin, smectite and the like. As the mica, organically treated mica and thin film mica are preferable.

  As the filler, for example, metal powder, calcium carbonate, clay, carbon black and the like may be further used in addition to the layered silicate.

(Other ingredients)
Further, the moisture curable hot melt adhesive of the present invention includes a tackifier, a curing catalyst, a plasticizer, a stabilizer, a dye, a pigment, a fluorescent whitening agent, a silane coupling agent, a wax and the like as necessary. Additives, thermoplastic resins, and the like can be appropriately selected and used within a range not impairing the object of the present invention.

Examples of tackifiers include rosin resins, rosin ester resins, hydrogenated rosin ester resins, terpene resins, terpene phenol resins, hydrogenated terpene resins, and C ₅ aliphatic resins as petroleum resins. C ₉ -based aromatic resins, C ₅ -based and C ₉ -based copolymer resins, and the like can be used.

  Examples of the plasticizer include dibutyl phthalate, dioctyl phthalate, dicyclohexyl phthalate, diisooctyl phthalate, diisodecyl phthalate, dibenzyl phthalate, butyl benzyl phthalate, trioctyl phosphate, epoxy plasticizer, toluene-sulfoamide, chloroparaffin, adipic acid ester , Castor oil and the like can be used.

  As the stabilizer, for example, a hindered phenol compound, a benzotriazole compound, a hindered amine compound, or the like can be used.

[Artificial materials]
The present invention also includes a base material, a sheet-like or film-like surface member, and an adhesive layer that adheres the base material and the surface member. The present invention relates to a fabricated member formed by curing a hot melt adhesive.

  FIG. 1 is a cross-sectional view showing an example of the structure of a feature member according to the present invention. The structure member 1 includes a base material 11 and sheet or film surface members 14 and 15 bonded together with adhesive layers 12 and 13 formed by curing the moisture curable hot melt adhesive of the present invention. Is formed. Although FIG. 1 shows the case where the surface member of the present invention is formed on both surfaces of the substrate, the surface member of the present invention may be formed only on one surface of the substrate.

  The feature member of the present invention can be manufactured by laminating a substrate and a sheet-like or film-like surface member as described later, using the moisture-curable hot melt adhesive of the present invention, for example, It can be used for door materials, wall panels, ceiling panels, closet doors, partitions, desks, shelves, storage furniture, and the like.

  As the base material, for example, a wood base material such as plywood, MDF (medium density fiber board), particle board, or a metal base material such as aluminum or iron can be used. The base material may have a part with a complicated shape such as a groove part, an R part, or an inverted R part.

  As the surface member, for example, a sheet or film made of a resin such as polyester, nylon, polystyrene, polycarbonate, vinyl chloride, ethylene-vinyl acetate copolymer, polyvinyl alcohol, polyethylene, polypropylene, paper, a veneer, a metal foil, etc. Can be used. Among them, at least one selected from films and sheets made of polyvinyl chloride, films and sheets made of polyolefin, films and sheets made of polyethylene terephthalate, and paper is particularly preferably used.

  The surface member may be generally called decorative paper, base paper for decorative board, decorative sheet, or the like, which is decorated with plain or various colors, patterns, and the like. Further, a primer treatment with a resin or the like may be performed on the back surface of the surface member, that is, the surface on the base material side.

  As a method of bonding the base material and the surface member to form the fabricated member of the present invention, for example, a moisture curable hot melt adhesive is melted by heating within a range of 60 to 150 ° C., a roll coater, Applying the moisture-curing hot melt adhesive on the substrate using a spray coater, T-die coater, knife coater, etc., and bonding the surface member to the coated surface, or moisture curing melted as described above A hot-melt adhesive is applied onto the surface member using a roll coater, etc., and the substrate is bonded to the coated surface, and matched to the shape of the substrate by methods such as roll press, flat press, and belt press. For example, a method of pressure bonding may be used.

[Flash panel]
The present invention also relates to a flash panel formed by adhering the above-described structure member on both surfaces of a core material. The flash panel of the present invention can be used for door materials, wall panels, ceiling panels, closet doors, partitions, desks, shelves, storage furniture, and the like.

  FIG. 2 is a cross-sectional view showing an example of the configuration of the flash panel according to the present invention. In the flash panel 200, the structure member 1 in which the surface members 14 and 15 are bonded to both surfaces of the base material 11 through the adhesive layers 12 and 13, and both surfaces of the base material 21 through the adhesive layers 22 and 23. Further, the structuring member 2 formed by bonding the film-like or sheet-like surface members 24 and 25 to each other is bonded to both surfaces of the core material 3. Note that FIG. 2 shows the case where the structure member of the present invention is formed on both surfaces of the core material, but the structure member of the present invention may be formed only on one surface of the core material.

  Examples of the core material include wood materials such as LVL (single plate laminate), plywood, OSB (oriented strand board), particle board, and MDF (medium density fiberboard), and metal materials such as aluminum, magnesium, steel plate, and SUS. , Paper materials, etc. can be used. It is particularly preferable that the core material has a honeycomb structure in that the flash panel can be reduced in weight and heat insulation can be improved.

  As a method for forming the flash panel of the present invention by bonding the core material and the crafting member, for example, the moisture-curing hot melt adhesive of the present invention is applied with a roll coater, knife coater, bar coater, die coater or the like. For example, a method of applying the core material and adhering the core material and the manufactured member by a method such as a flat press, a roll press, or a belt press can be used.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated in detail, this invention is not limited to these.

<Polyol component (A)>
Polyols (a-1), (a-2), (a-3), (a-4), (a-5), which are polyols (a) having a cycloolefin structure, in the formulation of Table 2 and Table 3. The details of polyols (a′-6), (a′-7), and (a′-8), which are polyols having no cycloolefin structure, are as shown in Table 1 and below.

(Synthesis Example 1: Preparation Example of Polyol (a-5))
In a 2-liter four-necked flask, 100 parts by mass of cyclohexanedimethanol, 125 parts by mass of ethylene glycol, 210 parts by mass of neopentyl glycol, 350 parts by mass of isophthalic acid, 280 parts by mass of terephthalic acid and adipic acid Polyester (a-5), which is a polyester polyol having a cyclo ring structure (“CHPES” in Tables 2 and 3), by adding 50 parts by mass and 0.03 parts by mass of tin butyrate and reacting at 220 ° C. (Also described).

(Synthesis Example 2: Preparation Example of Polyol (a′-7))
In a 4 liter flask, 1150 parts by mass of 1,12-dodecanedicarboxylic acid (molecular weight 230.30), 615 parts by mass of 1,6-hexanediol (molecular weight 118.17), and tetraisopropoxy as an esterification catalyst 0.007 parts by mass of titanium was added and melted at 120 ° C. Next, the mixture was heated to 220 ° C. over 3 to 4 hours with stirring and held for 4 hours, and then cooled to 100 ° C., whereby a polyol (a′-7) which is a long-chain aliphatic polyester polyol (Table 2). , 3, also described as “HG / DDA”) (number average molecular weight 3500, acid value 0.4, hydroxyl value 31.6).

(Synthesis Example 3: Preparation Example of Polyol (a′-8))
720 parts by weight of adipic acid, 615 parts by weight of 1,6-hexanediol (molecular weight 118.17), and 0.007 parts by weight of tetraisopropoxytitanium as an esterification catalyst were added to a 2 liter flask, at 120 ° C. They were melted. Next, the mixture was sublimed at 220 ° C. over 3 to 4 hours with stirring and held for 4 hours, and then cooled to 100 ° C., whereby a polyol (a′-8) which is a long chain fatty acid polyester polyol (Tables 2 and 3 (Also referred to as “HG / AA”) (number average molecular weight 4500, acid value 0.1, hydroxyl value 24.8).

  Moreover, the commercial item shown in Table 1 was used as polyol (a-1), (a-2), (a-3), (a-4), (a'-6).

Note 1: (a-1) is represented by the following general formula (5),

(In general formula (5), r is 2-16)
It is a polyol (a-1) which consists of a structure represented by these.
Note 2: (a-2) represents the number X of the structure represented by the above general formula (5), the following general formula (6),

(In general formula (6), r is 2-21)
It is a polyol (a-2) whose ratio (X / Y) with the number Y of the structure represented by is 3/1.
Note 3: (a-3) is a polyol (a-3) in which the ratio (X / Y) is 1/1.
Note 4: (a-4) is a polyol (a-4) having the above ratio (X / Y) of 1/3. Note 5: (a′-6) is a polyol (a′-6) derived from hexanediol and polycarbonate.

<Preparation of filler>
The details of the organically treated mica and thin film mica in the formulation of Table 2 and Table 3 described below are as follows.

(Preparation of organically treated mica)
100 parts by mass of Clarite Mica 300-D (manufactured by Kuraray Co., Ltd.) was dispersed in 150 parts by mass of isopropyl alcohol, then 2 parts by mass of acrylpropylsilane (manufactured by Shin-Etsu Chemical Co., Ltd., KBM503) was added and stirred for 30 minutes. . Then, said isopropyl alcohol was removed using the rotary evaporator, and also organic processing mica was obtained by performing 80 degreeC vacuum drying for 8 hours.

(Thin film mica)
As the thin film mica, a trade name “Yodogawa Mica Z20” (manufactured by Yodogawa Industries, cleaved sericite, maximum particle size 20 μm, thickness 0.01 to 0.1 μm) was used.

<Example 1>
(Preparation of moisture-curing hot melt adhesive)
A moisture-curable polyurethane hot melt adhesive was prepared according to the formulation shown in Table 2. In a 2 liter four-necked flask, 604 parts by mass of a polyol (a-3) having a cycloolefin structure and 67 parts by mass of a polyol (a′-7) which is a long-chain aliphatic polyester are mixed, and at 100 ° C. By depressurizing heating, dehydration was performed until the water content in the four-necked flask was 0.05% by mass.

  After the inside of the above four-necked flask was cooled to 70 ° C., 328 parts by mass of 4,4′-diphenylmethane diisocyanate (manufactured by Nippon Polyurethane Co., Ltd., Millionate MT) melted at 70 ° C. was added, and the isocyanate group content was constant. By making it react at 110 degreeC for about 3 hours until it became, urethane prepolymer (I) was obtained.

  Next, the urethane prepolymer (I), 150 parts by mass of the organically treated mica, and 0.02 parts by mass of SH5500 (manufactured by Toray Dow Corning Silicone Co., Ltd.) as an antifoaming agent are mixed, and 2 at 110 ° C. A moisture curable polyurethane hot melt adhesive was prepared by stirring for a period of time.

(Preparation of test piece)
FIG. 3 is a diagram for explaining a method for producing a test piece used for evaluating the normal adhesive strength of the fabricated member. Prepare a structure member in which an olefin decorative sheet as a surface member (not shown) is bonded to one surface of a medium density fiber board (MDF: length 300 mm, width 300 mm, thickness 2.4 mm) as a base material 31; Using a roll coater (speed 5 m / min), a coating amount of 120 g / min is applied to the moisture-curable polyurethane hot-melt adhesive heated and melted at 120 ° C. on the surface of the construction member on which the olefin decorative sheet is not bonded. It was applied as a m ^2.

  Next, 10 single-layer laminated materials (LVL (Laminated Veneer Number) plywood: 300 mm long, 30 mm wide, 25 mm thick) are used as the base material 33 on the application surface 32 of the moisture-curable polyurethane hot melt adhesive formed as described above. As shown in FIG.

Then, on the LVL plywood placed on the coating surface 32, the same construction member as described above coated with a moisture-curable hot melt adhesive was placed by the same method as described above, and 1 minute from the placement. After that, a test piece for evaluating normal bond strength was obtained by pressing a cube with a side of 50 mm by pressing with a flat press at 30 kgf / cm ² for 30 seconds.

(Production of flash panel)
A flash panel was produced using the moisture curable polyurethane hot melt adhesive obtained above. FIG. 4 is a diagram for explaining the frame material used for manufacturing the flash panel, and FIG. 5 is a diagram for explaining a method for evaluating the warpage of the flash panel. Prepare a structure member 51 in which an olefin decorative sheet is bonded to one surface of a medium density fiber board (MDF: length 300 mm, width 300 mm, thickness 2.4 mm), and the olefin decorative sheet of the structure member is not bonded. A moisture curable hot melt adhesive was applied to the surface using a roll coater (speed 5 m / min) so that the coating amount was 120 g / m ² . Next, the frame member 400 shown in FIG. 4 is placed on the application surface of the moisture curable polyurethane hot melt adhesive formed as described above, and the moisture curable hot melt adhesive is applied onto the frame member 400 in the same manner as described above. The applied construction member 51 similar to the above was placed.

One minute after placing, the flash panel 500 was obtained by pressing with a flat press at 2 kgf / cm ² for 30 seconds.

<Comparative Example 1>
(Production of fabricated parts)
Fabricated members were prepared using commercially available adhesives and moisture-proof paper. A tie-force H-845 (Dainippon Ink Chemical Co., Ltd.) is attached to the surface of the MDF, which is 300mm wide, 1820mm long, 2.4mm thick and has an olefin decorative sheet bonded to one surface. Kogyo Co., Ltd.) was applied using a roll coater adjusted to a speed of 20 m / min and a temperature of 120 ° C. so that the coating amount was 40 g / m ^2, and then continuously moisture-proof on the coated surface. Moisture proof performance by pasting paper (manufactured by Toppan Printing Co., Ltd., VS sheet), then pressing with a roll coater consisting of a rubber backup roll and a metal roll, and curing for 2 days The fabricated member having

  When sticking moisture-proof paper to a member made of MDF and an olefin decorative sheet, some of the defective products such as deterioration of moisture permeability due to generation of wrinkles of moisture-proof paper and poor appearance were seen in part ( Yield 90%). In addition, it took 3 days from the start of bonding of the moisture-proof paper to the end of curing.

(Production of flash panel)
A moisture-curing polyurethane hot-melt adhesive having no moisture-proofing function (trade name: Tyforce FH-420, manufactured by Dainippon Ink & Chemicals, Inc.) Was applied using a roll coater similar to the above at a rate of 5 m / min so as to give a coating amount of 120 g / m ² to produce a flash panel.

<Examples 2-6, Comparative Examples 2-5>
Examples 2 to 6 and Comparative Examples 2 to 5 are the same as Example 1 except that the formulation of each example shown in Table 2 and Table 3 was followed instead of the formulation of Example 1 shown in Table 2. Preparation of urethane prepolymers (II), (III), (IV), (V), (VI), (VIII), (IX), (X), (XI), moisture-curing polyurethane hot melt adhesive Preparation of the crafting member and the flash panel.

[Performance evaluation]
(Melt viscosity)
The melt viscosity when the obtained moisture-curable polyurethane hot melt adhesive was heated and melted at 125 ° C. was determined to be the ICI type cone plate viscometer (made by ICI, cone diameter: 19.5 mm, cone angle: 2.0 °). It measured using.

(Moisture permeability)
A release film made of polyethylene terephthalate was placed on a glass plate adjusted to a surface temperature of 100 ° C. On the release film, a moisture-curable polyurethane hot-melt adhesive heated and melted at 120 ° C. was applied using an applicator so as to have a film thickness of 100 μm to prepare a coated product. The coated material was cured for 1 week in an atmosphere at a temperature of 23 ° C. and a relative humidity of 65%, and then the film formed from the moisture-curable polyurethane hot melt adhesive was peeled off from the release film, did. The moisture permeability of the measurement sample was measured based on a moisture permeability cup method (JIS-Z-0208-B method) (unit: g / m ² · 24 hr). The moisture permeability is generally good if it is 35 or less, and more preferably if it is 20 or less.

  In addition, about the comparative example 1, it replaced with said film and measured the water vapor transmission rate of the VS sheet. Further, the moisture permeability of the cured film composed of the tie-force FH-420 was measured by the same method as described above, and was 100.

(Evaluation method for normal adhesion strength of fabricated parts)
Using the above-described test piece prepared by the method shown in FIG. 3, the normal state adhesive strength was evaluated. The evaluation was performed according to the plane tensile test method of JAS (enforced in October 1969). Specifically, after fixing the test piece prepared above so that the surface made of the olefin decorative sheet faces up, a square groove (one side is 20 mm) with a depth reaching the LVL plywood is formed on the surface. Produced. Next, after polishing the square surface with # 120 sandpaper, an adhesive (No. 3 for Aron Alpha Pro) manufactured by Toa Gosei Co., Ltd. was applied to the surface to adhere the same shape metal member. .

The adhesion strength between the fabricated member and the LVL plywood when the bonded metal member was pulled upward was measured. The evaluation was performed on 10 test pieces, and the average value (unit: kg / cm ² ) was calculated.

(Evaluation method of flash panel warpage)
One cycle of the above-prepared flash panel, curing for 8 hours in an atmosphere at a temperature of 40 ° C. and a relative humidity of 30%, and curing for 16 hours in an atmosphere at a temperature of 40 ° C. and a relative humidity of 90% The warpage of the flash panel after 5 cycles was measured.

  The warpage of the flash panel is evaluated as ○ when the warpage amount H in the longitudinal direction of the flash panel shown in FIG. 5 is less than 5 mm when the pre-curing flash panel is used as a reference. It was evaluated.

  As shown in the results of Tables 2 and 3, the moisture permeability of the film of each example formed from the moisture curable hot melt adhesive is in the range of 15 to 32 with respect to 30 of Comparative Example 1, and is good. Excellent moisture permeation resistance. In addition, the period until the end of curing was significantly reduced to 1 day in each example compared to 4 days in Comparative Example 1. In addition, the yield was remarkably improved to almost 100% in each example as compared to 90% in Comparative Example 1. From these results, it was confirmed that according to the present invention, a moisture-curable polyurethane hot melt adhesive having excellent moisture permeability can be obtained, and a flash panel using the adhesive can be efficiently produced.

  On the other hand, in Comparative Examples 2 and 4 in which the content of the cycloolefin structure in the urethane prepolymer is too small, and in Comparative Example 3 in which the urethane prepolymer does not contain a cycloolefin structure, it is formed from a moisture-curable polyurethane hot melt adhesive. The film had a high water vapor transmission rate and caused flash panel warpage. Moreover, also in Comparative Example 5 in which the content of the cycloolefin structure in the urethane prepolymer was too large, the moisture permeability of the film formed from the moisture-curable polyurethane hot melt adhesive was high. Therefore, it was confirmed that by setting the content of the cycloolefin structure in the urethane prepolymer within a predetermined range, it is possible to obtain a moisture-curable polyurethane hot melt adhesive that provides excellent moisture permeation resistance.

  Further, in Examples 1 and 2 using a moisture-curable polyurethane hot melt adhesive that further contains organically treated mica or thin film mica, which is a layered silicate, as a filler, compared with the case where no filler is contained, It has been confirmed that the moisture permeation resistance can be further improved by including a filler with a lower humidity value.

  It should be understood that the embodiments and examples disclosed herein are illustrative and non-restrictive in every respect. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  The moisture-curing hot melt adhesive of the present invention is, for example, a door material, a wall panel, a ceiling panel, a closet door, a partition, a desk, a shelf, storage furniture, a window frame, a skirting board, a floor member, a moisture permeable resistance of building members It is suitably applied as a layer, and the construction member and the flash panel of the present invention are suitably applied as a building member as described above, for example.

It is sectional drawing which shows the example of a structure of the structure member which concerns on this invention. It is sectional drawing which shows the example of a structure of the flash panel which concerns on this invention. It is a figure explaining the preparation methods of the test piece used for evaluation of the normal state adhesive strength of a structure member. It is a figure explaining the frame material used for preparation of a flash panel. It is a figure explaining the method of curvature evaluation of a flash panel.

Explanation of symbols

  1,2,51 Structure member, 11,21,31,33 Base material, 12,13,22,23 Adhesive layer, 14,15,24,25 Surface member, 3 core material, 32 Application surface, 200,500 Flash panel, 400 frame material.

Claims (13)

Containing a urethane prepolymer obtained by reacting the polyol component (A) and the polyisocyanate component (B),
The polyol component (A) contains a polyol (a) having a cycloolefin structure in the molecule,
A moisture-curable hot melt adhesive, wherein the content of the cycloolefin structure in the urethane prepolymer is in the range of 10 to 30% by mass.   The moisture-curable hot melt adhesive according to claim 1, wherein the content of the polyol (a) in the polyol component (A) is in the range of 50 to 100% by mass.   The moisture-curable hot melt adhesive according to claim 1, wherein the polyol (a) has a number average molecular weight in the range of 500 to 3,000.   The moisture-curable hot melt adhesive according to claim 1, wherein the cycloolefin structure is a cyclohexane structure.   The moisture-curable hot melt adhesive according to claim 1, wherein the polyol component (A) contains a polycarbonate polyol having a cycloolefin structure in the molecule within a range of 50 to 90% by mass.   The moisture-curable hot melt adhesive according to claim 1, wherein the polyol component (A) contains a crystalline polyester polyol having a melting point in the range of 60 to 80 ° C. The crystalline polyester polyol has the following general formula (1):

(In General Formula (1), R ¹ and R ² each independently represents a linear alkylene group having an even number of carbon atoms, and the total number of carbon atoms of R ¹ and R ² is 12 or more. N represents an integer of 3 to 40.)
The moisture curable hot melt adhesive according to claim 6, represented by:   The moisture-curable hot melt adhesive according to claim 1, further comprising a filler.   The moisture curable hot melt adhesive according to claim 8, wherein the filler is mainly composed of layered silicate.   It has a base material, a sheet-like or film-like surface member, and an adhesive layer that adheres the base material and the surface member, and the adhesive layer is moisture according to any one of claims 1 to 9. A fabricated member formed by curing a curable hot melt adhesive.   The base material is a wood base material, and the surface member is at least one selected from films and sheets made of polyvinyl chloride, films and sheets made of polyolefin, films and sheets made of polyethylene terephthalate, and paper. The structure member according to claim 10.   The flash panel formed by adhere | attaching the structure member of Claim 10 on both surfaces of a core material.   The flash panel according to claim 12, wherein the core material has a honeycomb structure.

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