JP2007161991A - Moisture-curable polyurethane hot-melt adhesive for wet veneer and decorative fixture member produced by using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a moisture-curable polyurethane hot-melt adhesive for wet veneer, exhibiting excellent initial adhesion strength and normal adhesion strength to both of a wet veneer and a substrate and forming an adhesive layer having excellent water resistance. <P>SOLUTION: The moisture-curable polyurethane hot-melt adhesive for wet veneer contains a urethane prepolymer obtained by reacting a polyol containing (A) a long-chain aliphatic polyester polyol expressed by general formula (I) and (B) an aliphatic polyether polyol having a number-average molecular weight of 2,000-10,000 with a polyisocyanate, wherein the aliphatic polyether polyol (B) contains a structure unit derived from ethylene oxide in an amount of 10-60 mass% based on the total aliphatic polyether polyol (B). <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a moisture-curable polyurethane hot melt adhesive for wet veneer that can be used in various fields including the construction field.

  In recent years, in the construction field, for the purpose of protecting base materials and improving aesthetics, base materials such as wood, plywood, particle board, medium density fiber board (MDF), makeup paper, vinyl chloride sheet, veneer, etc. In many cases, a decorative member obtained by bonding materials is used for a flooring material, a wall material, a ceiling material or the like. In particular, the demand for a decorative product obtained by bonding a veneer such as a veneer to a base material has a high-quality wood grain appearance derived from the veneer.

As the single plate, generally, a wood base material sliced to a thickness of about 0.1 mm to 0.5 mm is used.
However, the veneer described above is easily affected by the temperature and humidity in the atmosphere, and depending on the working environment conditions when the veneer is bonded to the base material, There was a problem of causing wrinkles and cracks derived from a single plate.

  A method for producing a decorative product having a good appearance without causing the above problems has been studied conventionally. For example, an adhesive is applied to the surface of a base material, and the moisture content is 15 on the coated surface. % Or more of single plates, so-called wet single plates, and then press-clamping are known (for example, see Patent Document 1). The wet veneer is a generic term for a veneer having a water content of approximately 15 to 50% by mass, and a veneer coated with various additives such as a metal contamination inhibitor. A wet veneer has good flexibility and strength as compared to a dry veneer, and thus hardly causes cracking or the like when the veneer is bonded to a substrate.

On the other hand, as an adhesive that can be used when the wet veneer and the substrate are bonded together, an aqueous adhesive having a good affinity with the wet veneer has been generally used.
However, with conventional aqueous adhesives, it is difficult to develop a practically sufficient level of initial and normal adhesive strength at high temperatures. In some cases, partial peeling of the veneer was caused.
As a method of solving such a problem, there is a method of depositing and curing the obtained cosmetic product for a certain period. However, such a method has a problem of significantly reducing the production efficiency of the cosmetic product.

  Moreover, when the said base material is a wooden base material, a wooden base material may absorb and expand a part of water contained in a water-based adhesive. The expanded wood base material returns to its original size as the water evaporates over time, but at that time, the surface of the wood base material is distorted, resulting in poor appearance of the resulting decorative product. There was a problem of causing.

  In addition, since the water-based adhesive generally does not have good water resistance, it is difficult to use it when manufacturing a cosmetic product that can be used for applications requiring high water resistance and hot water resistance. there were.

JP-A-6-190802

  The problem to be solved by the present invention is that an excellent initial bond strength and normal bond strength can be expressed on both a wet veneer and a base material, and an adhesive layer excellent in water resistance can be formed. Furthermore, it is to provide a moisture-curable polyurethane hot melt adhesive for wet veneer that can improve the production efficiency of a decorative product or the like.

  As the present inventors proceeded with studies to solve the above-mentioned problems, a so-called solvent-free moisture-curable hot melt adhesive that does not contain an organic solvent or an aqueous medium is effective for environmental protection and improvement of the working environment. We paid attention to that it is used in the field of building materials from the viewpoint. Among them, the moisture-curable polyurethane hot melt adhesive has characteristics such as good adhesion and flexibility inherent to polyurethane resins, so even when it is used for adhesion between a substrate and a wet veneer. Therefore, we considered that it would be possible to develop excellent adhesive strength and water resistance.

However, in a cosmetic product obtained by applying a moisture curable polyurethane hot melt adhesive to a substrate and then placing the wet veneer on the coated surface and pressing it, the wet veneer is dried. As a result, partial peeling of the veneer was caused.
The above problem can be solved to some extent by continuing the pressing until the wet veneer is sufficiently dried. However, the above method has a problem that the production efficiency of the decorative product is significantly reduced.

  The inventors of the present invention considered that the above-described peeling may be caused by insufficient affinity with water of the moisture-curable polyurethane hot-melt adhesive to be used in the course of further study. The use of a moisture curable polyurethane hot melt adhesive containing a surfactant was studied. As a result, although it became possible to express good adhesive strength by using the adhesive, there was a problem that a significant decrease in water resistance was caused.

  In addition, the present inventors have improved the affinity of the adhesive for water by introducing various hydrophilic groups into the urethane resin contained in the adhesive. We thought that it would be possible to express this, and proceeded with intensive studies. As a result, in particular, a long-chain aliphatic polyester polyol generally having crystallinity, and a polyol containing an aliphatic polyether polyol having a number average molecular weight of 2000 to 10,000 and having a structural unit derived from a specific range of ethylene oxide, Moisture-curable polyurethane hot melt adhesive containing urethane prepolymer obtained by reacting with polyisocyanate can exhibit practically sufficient level of adhesive strength and unexpectedly lowers water resistance. Therefore, the present inventors have found that it is suitable for use in producing a decorative member by exclusively bonding a wet veneer and a base material.

  That is, the present invention reacts a polyol containing a long-chain aliphatic polyester polyol (A) represented by the general formula (I) and an aliphatic polyether polyol (B) having a number average molecular weight of 2000 to 10,000 with a polyisocyanate. A structural unit derived from ethylene oxide in a range of 10 to 60% by mass with respect to the total of the aliphatic polyether polyol (B). It is related with the moisture hardening type polyurethane hot-melt-adhesive agent for wet single boards characterized by having.

（一般式（I）中、Ｒ^１及びＲ^２は、それぞれ独立して、炭素原子数が偶数である直鎖のアルキレン基を示し、かつＲ^１及びＲ^２の有する炭素原子数の合計は１２以上である。ｎは３〜４０を示す。）

(In general formula (I), R ¹ and R ² each independently represent 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 (N is 3 to 40)

Moreover, this invention has the layer (X) formed with the moisture-curable polyurethane hot-melt-adhesive adhesive agent for wet single boards on a base material, and has a layer which consists of a single board on the said layer (X). The present invention relates to a decorative product and a manufacturing method thereof.
The present invention also applies the wet-cured wet-cured polyurethane hot melt adhesive for wet veneer on a substrate, and then presses the wet veneer placed on the coated surface. It is related with the manufacturing method of the decorative member which adhere | attaches the said base material and the said wet veneer by this.
The present invention also applies the moisture-curable polyurethane hot melt adhesive for wet veneer heated and melted on a substrate, and then places the wet veneer on the coated surface, and then the wet veneer The present invention relates to a method for manufacturing a decorative member, in which a non-woven fabric is placed thereon and then the base material and the wet veneer are bonded by pressing.
The present invention also applies a wet-pressing wet-curing polyurethane hot melt adhesive for wet veneer on a substrate and then placing the wet veneer on the coated surface by a hot press method. The present invention relates to a method for manufacturing a decorative member, in which the substrate and the wet veneer are bonded by pressing and then pressing by a cold press method.
In addition, the present invention applies a wet-pressed wet curable polyurethane hot melt adhesive for wet veneer on a base material, and then placed the wet veneer on the coated surface by a cold press method. The present invention relates to a method for manufacturing a decorative member, in which the base material and the wet veneer are bonded by pressing.

  The “normal adhesive strength” as used in the present invention refers to a moisture curing reaction after bonding a substrate and a wet veneer, which will be described later, using a moisture-curable polyurethane hot melt adhesive in a heat-melted state. It refers to the bond strength that develops by almost complete progression. “Normal adhesive strength” varies depending on the moisture-curing polyurethane hot-melt adhesive used, but generally after bonding the substrate and the wet veneer, under an environment of a temperature of approximately 23 ° C. and a relative humidity of 65%. It is expressed by curing for about 24 hours.

The moisture-curable polyurethane hot melt adhesive for wet veneer of the present invention can exhibit a sufficient level of initial bond strength and normal bond strength for bonding a substrate and a wet veneer.
And the decorative product obtained by bonding the base material and the wet veneer using the moisture-curable polyurethane hot melt adhesive for wet veneer of the present invention causes wrinkles or cracks of the veneer. It has no external appearance.
Because of the excellent characteristics as described above, the moisture-curable polyurethane hot melt adhesive for wet veneer of the present invention can be used in a wide range of fields including the construction field and has a very high utility value. It is.

  The moisture-curable polyurethane hot melt adhesive for wet veneer of the present invention contains a urethane prepolymer obtained by reacting a specific polyol and polyisocyanate described below as a main component, and optionally contains other additives. It is made.

  The urethane prepolymer contained in the moisture-curable polyurethane hot-melt adhesive for wet veneer of the present invention can form a cross-linked structure by reacting with moisture present in the air or in the substrate to which it is applied. 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. Also, urethane prepolymers having a number average molecular weight of tens of thousands can 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 in the above range, a moisture-curable polyurethane hot melt adhesive for wet single plate having excellent fluidity and workability can be obtained.

The urethane prepolymer used in the present invention has both properties of 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 with 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 selected urethane prepolymer, which is solid at room temperature but can be melted and applied by heating, applied in a molten state, and cooled. It is a property that solidifies and develops adhesiveness.

  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, such as hot melt typified by ethylene vinyl acetate. 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 comes out 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. Generally, the lower the softening point of the urethane prepolymer used, the better the workability. Conversely, the higher the softening point, the better the adhesive strength.
The softening point of the urethane prepolymer used in the present invention is preferably in the range of 40 to 120 ° C. If the softening point of the urethane prepolymer is within such a range, the workability is good and the adhesive strength is excellent. A moisture curable polyurethane hot melt adhesive is obtained. 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.

  Examples of methods for adjusting the softening point of the urethane prepolymer include (1) a method for adjusting the molecular weight of the urethane prepolymer, and (2) crystallinity of the polyalkylene chain of the polyester polyol when the polyester polyol is used as a raw material. (3) Adjustment method by introduction of aromatic cyclic structure using polyol or polyisocyanate, (4) Adjustment method by urethane bond content, etc. Multiple combinations can be used.

  In the method (1) for adjusting the softening point of the urethane prepolymer, generally the softening point tends to increase with the increase in the molecular weight of the urethane prepolymer. 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 the method (2) for adjusting the softening point of the urethane prepolymer, generally, the greater the number of carbon atoms in the polyalkylene chain of the crystalline polyester polyol, the more the crystallinity of the resulting urethane prepolymer is improved. 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.
In the method (4) for adjusting the softening point of the urethane prepolymer, generally, the softening point tends to increase as the content of urethane bonds increases.

  The urethane prepolymer used in the present invention is produced by reacting various polyols and polyisocyanates described below under the condition that the isocyanate group of the polyisocyanate is excessive with respect to the hydroxyl group of the polyol. be able to.

  As the polyol, a long-chain aliphatic polyester polyol (A) represented by the following general formula (I) and an aliphatic polyether polyol (B) having a number average molecular weight of 2000 to 10,000 are used in combination. This is important in solving the problems of the present invention.

First, the long chain aliphatic polyester polyol (A) will be described.
The long-chain aliphatic polyester polyol (A) used for producing the urethane prepolymer has a structure represented by the general formula (I).

(In general formula (I), 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 3 to 40.)

R ¹ in the general formula (I) is a linear alkylene group having an even number of carbon atoms, and is 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 preferably a linear alkylene group having an even number of 4 or more carbon atoms.

R ² in the general formula (I), wherein a linear alkylene group having the number of carbon atoms independently is an even number and R ^1, the 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.
By using a long-chain aliphatic polyester polyol in which R ¹ and R ² are linear alkylene groups each having the number of carbon atoms in the above range, the crystallinity of the resulting urethane prepolymer is increased, It is possible to obtain a moisture-curable polyurethane hot-melt adhesive for wet veneer that can exhibit a level of initial adhesive strength that can prevent peeling from the veneer.

  N in the said general formula (I) is 3-40, it is preferable to exist in the range of 9-25, and the range of 9-15 is more preferable. By using a long-chain aliphatic polyester polyol having n within the above range, it has an appropriate melt viscosity and excellent coating workability, and normal adhesion strength is manifested after bonding the substrate and the veneer. In the meantime, it is possible to obtain a moisture-curable polyurethane hot melt adhesive for wet veneer capable of expressing a level of initial adhesive strength that can prevent the substrate and veneer from peeling off.

  The long-chain aliphatic polyester polyol (A) can be produced, for example, by subjecting a linear aliphatic diol having an even number of carbon atoms and a linear aliphatic dicarboxylic acid having an even number of carbon atoms to a condensation reaction. it can. 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. 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. be able to.

In addition, the combination of the linear aliphatic diol and the linear aliphatic dicarboxylic acid used when the long-chain aliphatic polyester polyol (A) is produced is R ^{1 represented} by the general formula (I) and The total number of carbon atoms contained in R ² 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 the linear aliphatic diol and 1,12-dodecanedicarboxylic acid or sebacic acid as the linear aliphatic dicarboxylic acid is used. It is preferable to do.

  The long-chain aliphatic polyester polyol (A) preferably has a number average molecular weight of 10,000 or less, and more preferably in the range of 3000 to 5000.

  The long-chain aliphatic polyester polyol (A) is preferably used in the range of 20 to 60 parts by mass with respect to 100 parts by mass of the total amount of polyol and polyisocyanate used when the urethane prepolymer is produced. It is more preferable to use in the range of ˜40 parts by mass. By using the long-chain aliphatic polyester polyol (A) within the above range in combination with various polyols described later, it has an appropriate melt viscosity and excellent coating workability, and prevents peeling between the substrate and the veneer. It is possible to obtain a moisture-curable polyurethane hot-melt adhesive for wet veneer capable of expressing a possible initial adhesive strength.

Next, the aliphatic polyether polyol (B) used in the present invention will be described.
The aliphatic polyether polyol (B) has a number average molecular weight in the range of 2000 to 10,000 and is derived from ethylene oxide in the range of 10 to 60% by mass with respect to the total of the aliphatic polyether polyol (B). Those having a structural unit can be used. Specifically, the aliphatic polyether polyol (B) is prepared by adding ethylene oxide to both ends of a general aliphatic polyether polyol such as polypropylene glycol or polybutylene glycol to thereby add hydroxyl groups present at both ends of the molecule. Modified to primary hydroxyl group.

  The moisture-curable polyurethane hot melt adhesive for wet veneer of the present invention obtained by using the aliphatic polyether polyol (B) has an initial adhesive strength at a level that can prevent peeling between the substrate and veneer. It can be expressed.

  On the other hand, the moisture-curable polyurethane hot melt adhesive obtained by using an aliphatic polyether polyol having a number average molecular weight of less than 2000 instead of the aliphatic polyether polyol (B) has good water resistance. It is not preferable because it is difficult to form an adhesive layer. In addition, when an aliphatic polyether polyol having a number average molecular weight greater than 10,000 is used instead of the aliphatic polyether polyol (B), the urethane prepolymer having a structural unit derived from the aliphatic polyether polyol (B). Dispersibility of the polymer with respect to the urethane prepolymer having a structural unit derived from the long-chain aliphatic polyester polyol (A) is decreased, and as a result, a moisture-curable urethane hot melt that is substantially solid at room temperature can be obtained. It becomes difficult.

  The aliphatic polyether polyol (B) has a number average molecular weight in the range of 2000 to 10,000, and it is more preferable to use one having a number average molecular weight in the range of 3000 to 5000. By using an aliphatic polyether polyol (B) having a number average molecular weight within such a range in combination with the long-chain aliphatic polyester polyol (A), it is excellent when bonding a substrate and a wet veneer. It is possible to develop initial bond strength and normal bond strength.

  Further, a moisture-curable polyurethane hot melt adhesive for wet veneer obtained by using an aliphatic polyether polyol having a structural unit derived from ethylene oxide of less than 10% by mass instead of the aliphatic polyether polyol (B). Since the agent does not have a level of hydrophilicity that can be used for laminating wet veneers, it is difficult to use the agent in such applications. The hydrophilicity of the adhesive can be improved by using an excessive amount of an aliphatic polyether polyol having a structural unit derived from ethylene oxide of less than 10% by mass. Since the initial adhesive strength of the resulting moisture curable polyurethane hot melt adhesive tends to decrease, it is not preferable.

On the other hand, the moisture-curable polyurethane hot melt adhesive for wet veneer obtained by using an aliphatic polyether polyol having a structural unit derived from ethylene oxide exceeding 60% by mass exhibits a sufficient level of water resistance. However, it is difficult to use in applications that require water resistance.
As the aliphatic polyether polyol (B), it is preferable to use an aliphatic polyether polyol having a structural unit derived from ethylene oxide of 10 to 40% by weight. By using an aliphatic polyether polyol having a structural unit derived from ethylene oxide in the above range, a moisture-curable polyurethane hot melt adhesive for wet veneer having excellent water resistance and initial adhesive strength can be obtained.

  The aliphatic polyether polyol (B) can be produced by adding ethylene oxide to a known aliphatic polyether polyol (b1) such as polypropylene glycol or polybutylene glycol.

  The aliphatic polyether polyol (b1) can be produced, for example, by ring-opening polymerization of an alkylene oxide such as propylene oxide or 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 the polymer obtained by ring-opening polymerization.

  Examples of the low molecular weight polyol that can be used as an initiator in producing the aliphatic polyether polyol (b1) include ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, and 1,3-butylene glycol. 1,4-butylene glycol, 2,2-dimethyl-1,3-propanediol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, 1,8-octanediol, diethylene glycol, triethylene Examples include glycol, dipropylene glycol, and tripropylene glycol.

  Examples of the aliphatic polyether polyol (B) include ethylene oxide-modified polypropylene glycol in which ethylene oxide is added to both ends of polypropylene glycol, ethylene oxide-modified polypropylene glycol obtained by random copolymerization of propylene oxide and ethylene oxide, and polybutylene glycol. It is preferable to use an ethylene oxide-modified polybutylene glycol in which ethylene oxide is added to both ends thereof because it can exhibit excellent initial adhesive strength and excellent water resistance to a wet veneer.

  The aliphatic polyether polyol (B) is preferably used in the range of 1 to 30 parts by mass with respect to 100 parts by mass of the total amount of polyol and polyisocyanate used when the urethane prepolymer is produced. It is more preferable to use in the range of 20 parts by mass. By using the aliphatic polyether polyol (B) within the above range, it is possible to obtain a moisture-curable polyurethane hot melt adhesive for wet single plate capable of expressing excellent normal adhesive strength.

  In the present invention, in addition to the long-chain aliphatic polyester polyol (A) and the aliphatic polyether polyol (B), other polyols can be used in combination as necessary.

  Examples of other polyols that can be used in combination with the polyol include aromatic polyester polyols (CI) having a number average molecular weight of 2000 to 5000 and a glass transition temperature of 30 ° C. or higher.

  Examples of the aromatic polyester polyol (CI) include a method of condensing an aromatic polycarboxylic acid and a low molecular weight aliphatic polyol, a method of condensing an aliphatic polycarboxylic acid and a low molecular weight aromatic polyol, and the like. Can be manufactured by.

  Examples of the aromatic polycarboxylic acid that can be used in the production of the aromatic polyester polyol (CI) include phthalic acid, isophthalic acid, terephthalic acid, hexahydroisophthalic acid, and the like. More than one species can be used in combination. Examples of the aliphatic polycarboxylic acid include adipic acid, sebacic acid, azelaic acid, decamethylene dicarboxylic acid, and the like.

  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, 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 can be used.

  As the low molecular weight aromatic polyol, for example, an aromatic polyol obtained by subjecting bisphenol A, bisphenol F, or the like to ring-opening addition reaction of ethylene oxide, propylene oxide, γ-butyrolactone, ε-caprolactone, or the like can be used. .

  As the aromatic polyester polyol (CI), ethylene glycol or neopentyl glycol is used as the low molecular weight aliphatic polyol, isophthalic acid or terephthalic acid is used as the aromatic polycarboxylic acid, and the glass transition temperature is 30 ° C. or higher. It is preferable to use an aromatic polyester polyol obtained by a suitable combination and a condensation reaction by a known method.

  The aromatic polyester polyol (CI) has a glass transition temperature of 30 ° C. or higher, and more preferably has a glass transition temperature in the range of 30 to 70 ° C. Moisture for wet veneer that can exhibit excellent normal adhesive strength by using an aromatic polyester polyol (CI) having a glass transition temperature within the above range in combination with the long-chain aliphatic polyester polyol (A) or the like. A curable polyurethane hot melt adhesive can be obtained.

  The aromatic polyester polyol (CI) is preferably used in the range of 5 to 25 parts by mass with respect to 100 parts by mass of the total amount of polyol and polyisocyanate used in producing the urethane prepolymer, and 10 to 20 parts by mass. It is more preferable to use within the range of parts.

  Moreover, as another polyol which can be used together with the polyol, for example, an aromatic polyester polyol (CII) having a number average molecular weight of 400 to 3500 and a glass transition temperature of 20 ° C. or less can be used.

  Examples of the aromatic polyester polyol (CII) include a low molecular weight polyol having a side chain such as diethylene glycol, neopentyl glycol, hydroxypivalic acid-2,2-dimethyl-3-hydroxypropyl, and the like, and the aromatic polyester polyol. The aromatic polyester polyol obtained by making it react with the thing similar to the aromatic polycarboxylic acid illustrated as what can be used when manufacturing (CI) can be used.

  The aromatic polyester polyol (CII) has a glass transition temperature of 20 ° C. or lower, and more preferably has a glass transition temperature in the range of −30 to 20 ° C. If it is in this range, it is possible to obtain a moisture-curable polyurethane hot melt adhesive for wet veneer that can exhibit further excellent normal adhesive strength.

  The aromatic polyester polyol (CII) is preferably used in a range of 5 to 20 parts by mass with respect to 100 parts by mass of the total amount of polyol and polyisocyanate used when the urethane prepolymer is produced. It is more preferable to use in the range of 20 parts by mass, and it is more preferable that the total of the aromatic polyester polyol (CI) and the aromatic polyester polyol (CII) is in the range of 10 to 35 parts by mass. If the usage-amount of the said aromatic polyester polyol is in the said range, the moisture hardening type polyurethane hot-melt-adhesive agent for wet single plates which can express the outstanding normal-state adhesive strength can be obtained.

Moreover, as another polyol that can be used in combination with the polyol, for example, an aliphatic polyester polyol (D) having a 2,2-dimethyl-1,3-propylene group and having a melting point of 30 ° C. or lower may be used. it can.

  The aliphatic polyester polyol (D) can be prepared by a condensation reaction between neopentyl glycol or hexamethylpivalic acid diol and polycarboxylic acid, or by using neopentyl glycol or hexamethylpivalic acid diol as an initiator for caprolactone or γ-butyl. It can be produced by a ring-opening polymerization method such as lactone.

  When the aliphatic polyester polyol (D) is produced, a low molecular weight aliphatic polyol or aliphatic polycarboxylic acid other than those described above can be used in combination as necessary.

  Examples of the other low molecular weight aliphatic polyols 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, etc. it can. Among them, it is possible to use a low molecular weight aliphatic polyol having an ether bond such as diethylene glycol, triethylene glycol, dipropylene glycol, tripropylene glycol, and the like, and the obtained aliphatic polyester polyol (D) and the aliphatic polyether. It is preferable for improving the compatibility with the polyol (B), and as a result, a moisture-curable polyurethane hot melt adhesive for wet veneer having excellent heat melting stability can be obtained.

  As said aliphatic polycarboxylic acid, adipic acid, sebacic acid, azelaic acid, decamethylene dicarboxylic acid etc. can be used together, for example.

  As said aliphatic polyester polyol (D), it is preferable to use what has 10-20 mass% of said 2, 2- dimethyl- 1, 3- propylene groups with respect to the whole aliphatic polyester polyol (D), It is more preferable to use what has 12-18 mass%. By using the aliphatic polyester polyol having the 2,2-dimethyl-1,3-propylene group within the above range in combination with the long-chain aliphatic polyester polyol (A) or the aliphatic polyether polyol (B). It is possible to obtain a moisture-curable polyurethane hot melt adhesive for wet veneer that has high permeability to the base material and high adhesiveness in the heat-melted state.

  The aliphatic polyester polyol (D) is preferably used in the range of 1 to 50 parts by mass with respect to 100 parts by mass of the total amount of polyol and polyisocyanate used when producing the urethane prepolymer. It is more preferable to use in the range of 20 parts by mass, and it is even more preferable to use in the range of 5 to 15 parts by mass. The moisture-curable polyurethane hot melt adhesive for wet veneer obtained by using the aliphatic polyester polyol (D) within the above range can exhibit high tackiness immediately after the start of pressing, and as a result Even if the pressing time between the material and the veneer is shorter than usual, it is possible to prevent the veneer from peeling off, and as a result, it is possible to improve the production efficiency of the decorative product member described later.

  Further, as the polyol used in the present invention, in addition to the above-described ones, polyester polyols, aromatic polyether polyols other than those described above, acrylic polyols, polycarbonate polyols, polyolefin polyols, and the like, as long as the effects of the present invention are not impaired. Castor oil-based polyols and the like can be used.

  Next, the polyisocyanate used when manufacturing the said urethane prepolymer is demonstrated.

  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, and naphthalene diisocyanate, Aliphatic polyisocyanates such as hexamethylene diisocyanate, lysine diisocyanate, cyclohexane diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, xylylene diisocyanate, tetramethylxylylene diisocyanate, or polyisocyanates having an alicyclic structure can be used. Among these, since the moisture-curable polyurethane hot melt adhesive of the present invention is used after being melted by heating, it is preferable to use diphenylmethane diisocyanate having a low vapor pressure during heating and melting.

  Next, the manufacturing method of the urethane prepolymer used by this invention is demonstrated in detail.

  The urethane prepolymer used in the present invention can be produced by a known and usual method. For example, for the polyisocyanate in the reaction vessel, a polyol from which water has been removed, that is, a long-chain aliphatic polyester polyol (A) and an aliphatic polyether polyol (B), and other polyols as described above, if necessary, are separately provided. It can be manufactured by a method in which the reaction is carried out by dripping or adding a mixture of the mixture and the reaction until the hydroxyl group of the polyol is substantially eliminated. The urethane prepolymer can be usually produced without a solvent, but may be produced by reacting in an organic solvent. When reacting in an organic solvent, an organic solvent such as ethyl acetate, n-butyl acetate, methyl ethyl ketone, and toluene that does not hinder the reaction can be used, but by a method such as heating under reduced pressure during or after the reaction. It is necessary to remove the organic solvent.

  When manufacturing the said urethane prepolymer, a urethanization catalyst can be used as needed. The urethanization catalyst can be appropriately added at any stage of the 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; and organometallic compounds such as dibutyltin dilaurate. Can do.

  The ratio of the polyol and polyisocyanate used in producing the urethane prepolymer is the equivalent ratio of the isocyanate group of the polyisocyanate to the hydroxyl group of the polyol (hereinafter referred to as the equivalent ratio of [isocyanate group / hydroxyl group]. Is preferably in the range of 1.1 to 5.0, and more preferably in the range of 1.5 to 3.0. By adjusting the equivalent ratio within such a range, it is possible to obtain a moisture-curable polyurethane hot melt adhesive for wet veneer with good coatability.

In the urethane prepolymer used in the present invention, a urethane prepolymer having a structural unit derived mainly from a long-chain aliphatic polyester polyol (A) forms a matrix, and an aliphatic polyether polyol (B ) Urethane prepolymers having structural units derived from, urethane prepolymers having structural units mainly derived from aromatic polyester polyols (CI), and urethane prepolymers having structural units mainly derived from aromatic polyester polyols (CII) It is preferable to have a so-called sea-island type phase separation structure in which domains composed of The wet-cure polyurethane hot-melt adhesive for wet veneer having a sea-island type phase separation structure is a wet veneer after bonding a base material and a wet veneer until normal adhesive strength is developed. It is possible to prevent peeling and opening due to shrinkage caused by drying, and to exhibit excellent normal adhesive strength, water resistance and boiling resistance.
The average domain diameter of the domains formed in the matrix is preferably in the range of 1 to 1000 μm, more preferably in the range of 1 to 100 μm. The average domain diameter referred to in the present invention is a value obtained by measuring the diameters of 200 domains with an optical microscope and averaging them.

  The moisture curable polyurethane hot melt adhesive for wet veneer of the present invention preferably has a melt viscosity at 125 ° C. in the range of 2000 to 50,000 mPa · s. By using a moisture-curable polyurethane hot melt adhesive for wet veneer having a melt viscosity within the above range, a known coating device such as a roll coater can be used when applying the adhesive to a substrate. It becomes.

  In addition, the moisture curable polyurethane hot melt adhesive for wet veneer of the present invention includes, if necessary, a tackifier, a curing catalyst, a plasticizer, a stabilizer, a filler, a dye, a pigment, a fluorescent whitening agent, Silane coupling agents, additives such as wax, thermoplastic resins, and the like can be appropriately selected and used within a range that does not impair the object of the present invention.

Examples of the tackifier 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 Esters, castor oil, and the like can be used.

  As the stabilizer, for example, hindered phenol compounds, benzotriazole compounds, hindered amine compounds and the like can be used.

  As the filler, for example, silicic acid derivatives, talc, metal powder, calcium carbonate, clay, carbon black and the like can be used. By adding a filler, it is possible to prevent the adhesive from seeping out from the surface of the veneer, which is preferable.

  Next, the makeup | decoration structure member of this invention is demonstrated.

  The decorative member of the present invention has a layer (X) formed by a moisture-curable polyurethane hot melt adhesive for wet veneer on a substrate, and a layer made of a veneer on the layer (X). It can be used for, for example, stair treads, door frames, window frames, sills, handrails, 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 said base material may have site | parts of complicated shapes, such as a groove part, R part, and reverse R part.

  The wet veneer is a slice having a moisture content higher than the humidity in the atmosphere, and the veneer includes conifers such as cedar, broad-leaved trees such as cocoons, firewood, and cocoons, and southern materials such as ebony. Can be used. Moreover, what sliced the wooden base material which has a laminated structure which consists of several different types of wood generally called a flitch can also be used. As the wet single plate, it is preferable to use one having a water content of approximately 15 to 40% by mass.

  As a method of bonding the base material and the wet veneer using the moisture curable polyurethane hot melt adhesive for wet veneer of the present invention, for example, the moisture for wet veneer heated and melted at 60 to 150 ° C. A method of applying a curable polyurethane hot melt adhesive on a substrate using a roll coater, spray coater, T-die coater, knife coater, etc., and bonding and pressing the wet single plate on the application surface, There is a method in which the adhesive heated and melted using the roll coater or the like is applied onto a wet veneer, and the substrate is bonded to the coated surface and pressed. The pressing can be appropriately performed according to the shape of the substrate using, for example, a roll press, a flat press, a belt press, or the like. As a pressing method, it is preferable to apply a flat press method from the viewpoint of maintaining good surface smoothness of the resulting decorative product.

Moreover, when the base material and the wet veneer are bonded together using the moisture-curable polyurethane hot melt adhesive for wet veneer of the present invention, it is preferable to adjust the temperature appropriately as necessary.
Specifically, the hot press method etc. which adhere | attach a base material and a wet veneer under heating conditions are applicable. In addition, when using an adhesive with an extremely short open time for the purpose of suppressing shrinkage during the drying process of the wet veneer, a so-called hot and cold method combining the hot press method and the cold press method is used. It is preferable to apply a cold press method or the like.

The hot and cold press method generally uses a pair of dies, male and female, and activates the hot melt adhesive by pressing with the hot press method, and then presses with the cold press method. This is a method of bonding substrates together.
Specifically, the substrate is placed on one mold, and then the moisture-curable polyurethane hot-melt adhesive for wet veneer of the present invention which is heated and melted is applied onto the substrate, and then the application surface is applied. A wet veneer is placed on the other, and the other die is placed on the wet veneer at a temperature of about 60 to 100 ° C. and a relatively low pressure of about 0.2 to 5 kg / cm ^2. The wet curable polyurethane hot melt adhesive for wet veneer of the present invention is infiltrated into the substrate by pressing (hot pressing method), and then at a relatively low temperature of about 20 to 50 ° C., And it is the method of manufacturing a cosmetics production member by pressing (cold press method) by the comparatively low pressure of about 0.2-5 kg / cm < ² >.

The hot press method can be performed using a roll press, a flat press, or the like as described above provided with a roll whose temperature can be adjusted.
The cold press method can be performed by using a normal roll press or flat press as described above at room temperature.

  The decorative product obtained by the hot and cold press method is excellent in terms of surface smoothness and adhesive strength. Moreover, it is more preferable from the viewpoint that the initial adhesive strength and the pot life are not easily changed by the working environment temperature.

  When producing a decorative member by the various methods described above, from the viewpoint of promoting the drying of moisture contained in the wet veneer, a moisture-curable polyurethane hot melt adhesive for wet veneer heated and melted on a substrate is used. It is preferable to apply and then press the wet veneer on the coated surface and then press the wet veneer on the wet veneer by the same method as described above.

  As the nonwoven fabric, it is preferable to use a material having heat resistance at a level capable of withstanding the temperature at the time of pressing, for example, natural fibers made of cotton, hemp, etc., chemical fibers made of rayon, etc., nylon, polyester, etc. Synthetic fibers, inorganic fibers made of glass, carbon, or the like can be used.

  Since the decorative product of the present invention thus obtained is free from wrinkles or cracks on a single plate and has an excellent appearance, it is a floor member, a wall covering material, a ceiling material, a window frame, a staircase member, and a storage. It can be used for doors, interior doors, storage shelves, furniture, and the like.

  Hereinafter, the present invention will be described more specifically with reference to examples.

Synthesis Example 1 <Preparation Example of Long-Chain Aliphatic Polyester Polyol (A-1)>
In a 2-liter flask, 1160 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 tetraisopropoxytitanium as an esterification catalyst 0.007 parts by mass were added and melted at 120 ° C. Next, the temperature was raised to 220 ° C. over 3 to 4 hours with stirring and held for 4 hours, and then cooled to 100 ° C. to thereby obtain the long-chain aliphatic polyester polyol (A-1) (number average molecular weight 3800, acid value). 0.1, hydroxyl value 31.8).

Synthesis Example 2 <Preparation Example of Aliphatic Polyester Polyol (A′-2)>
Aliphatic polyester polyol (A′-2) (A′-2) by reacting in the same manner as in Synthesis Example 1 except that 720 parts by mass of adipic acid is used instead of 1,12-dodecanedicarboxylic acid described in Synthesis Example 1. A number average molecular weight of 4,500, an acid value of 0.1, and a hydroxyl value of 24.4) were prepared.

Synthesis Example 3 <Preparation Example of Aromatic Polyester Polyol (CI-1)>
In a 2 liter four-necked flask, 125 parts by mass of ethylene glycol, 210 parts by mass of neopentyl glycol, 350 parts by mass of isophthalic acid, 200 parts by mass of terephthalic acid, 60 parts by mass of adipic acid, and tin butyrate An aromatic polyester polyol (CI-1) was prepared by adding 0.03 parts by mass and reacting at 220 ° C.

Synthesis Example 4 <Preparation Example of Aromatic Polyester Polyol (CII-1)>
In a 2 liter four-necked flask, 450 parts by mass of neopentyl glycol and 500 parts by mass of isophthalic acid, 0.03 parts by mass of tin butyrate are added and reacted at 220 ° C. to react with an aromatic polyester polyol ( CII-1) was prepared.

Synthesis Example 5 <Preparation example of aliphatic polyester polyol (D-1)>
In a 2-liter four-necked flask, 100 parts by mass of diethylene glycol, 200 parts by mass of neopentyl glycol, 300 parts by mass of 1,6-hexanediol, 500 parts by mass of adipic acid, and 0.03 mass of tin butyrate Aliphatic polyester polyol (D-1) (number average molecular weight 2500, acid value 0.2, hydroxyl value 44.5) having an ether bond was prepared by adding part thereof and reacting at 220 ° C.

  As the aliphatic polyether polyol, various polyether polyols (B-1), (B-2), (B′-3), (B′-4), (B′-5) described in Table 4 below. , (B′-6) were used. In Table 4, PPG represents polypropylene glycol, EO-PPG represents ethylene oxide-modified polypropylene glycol obtained by ring-opening addition of ethylene oxide to both ends of polypropylene glycol, and PEG represents polyethylene glycol.

Example 1
In a 2-liter four-necked flask, 220 parts by mass of long-chain aliphatic polyester polyol (A-1), 220 parts by mass of aliphatic polyester polyol (A′-2), and 110 parts by mass of aliphatic polyether polyol (B-1) Parts, aromatic polyester polyol (CI-1) 165 parts by mass, aliphatic polyester polyol (D-1) 110 parts by mass, and then heated at 100 ° C. under reduced pressure, moisture relative to the total amount in the four-necked flask It dehydrated until it became 0.05 mass%.

  Next, 130 parts by mass of 4,4′-diphenylmethane diisocyanate (4,4′-MDI) is added to the four-necked flask cooled to 70 ° C., and about 100 ° C. until the isocyanate group content becomes constant. Urethane prepolymer 1 was prepared by reacting for 3 hours.

  Next, 50 parts by mass of super ester A100 (rosin ester, manufactured by Arakawa Chemical Industries, Ltd.) and 1.5 mass of U-CAT660M (2,2′-dimorpholinodiethyl ether, manufactured by San Apro Co., Ltd.) as tackifiers. Moisture curable polyurethane hot melt adhesive 1 was prepared by adding part and stirring until uniform. When the obtained moisture-curable polyurethane hot melt adhesive 1 was heated and melted at 125 ° C., the melt viscosity was ICI type cone plate viscometer (ICI, cone diameter: 19.5 mm, cone angle: 2.0 °). ) Was 19,000 mPa · s. Moreover, isocyanate group content was 2.1 mass%.

Example 2
280 parts by mass of long-chain aliphatic polyester polyol (A-1), 280 parts by mass of aliphatic polyester polyol (A′-2), 140 parts by mass of aliphatic polyether polyol (B-1) in a 2 liter four-necked flask , 140 parts by mass of aromatic polyester polyol (CII-1), and ethylene-vinyl acetate copolymer (F-1) having a structural unit derived from vinyl acetate of 45% by mass (trade name EVAFLEX EV45X, Mitsui DuPont Polychemical Co., Ltd.) After mixing 50 parts by mass (made by company), it was dehydrated by heating at 100 ° C. under reduced pressure until the water content in the four-necked flask was 0.05 mass%.

  Next, 120 parts by mass of 4,4′-diphenylmethane diisocyanate and 35 parts by mass of carbodiimide-modified diphenylmethane diisocyanate (Isonate 143LJ, manufactured by Mitsubishi Chemical Corporation) are added to the four-necked flask cooled to 70 ° C. and contains an isocyanate group. Urethane prepolymer 2 was prepared by reacting at 100 ° C. for about 3 hours until the amount was constant.

  Next, 1.5 parts by mass of U-CAT660M (2,2′-dimorpholinodiethyl ether, manufactured by San Apro Co., Ltd.) was added and stirred until uniform to prepare moisture-curable polyurethane hot melt adhesive 2. When the obtained moisture-curable polyurethane hot melt adhesive 2 was melted by heating at 125 ° C., the melt viscosity was ICI type cone plate viscometer (ICI, cone diameter: 19.5 mm, cone angle: 2.0 °). ) Was 22,000 mPa · s. Moreover, isocyanate group content was 1.9 mass%.

Example 3
In a 2 liter four-necked flask, 305 parts by mass of long-chain aliphatic polyester polyol (A-1), 305 parts by mass of aliphatic polyester polyol (A′-2), and 60 parts by mass of aliphatic polyether polyol (B-1) Part, aliphatic polyester polyol (D-1) 185 parts by mass, and ethylene-vinyl acetate copolymer (F-1) having a structural unit derived from vinyl acetate 45% by mass (trade name EVAFLEX EV45X, Mitsui DuPont Polychemical Co., Ltd.) 100 parts by mass and Superester A100 (rosin ester, manufactured by Arakawa Chemical Co., Ltd.) are mixed with 100 parts by mass. It dehydrated until it became 0.05 mass%.

  Next, 1.5 parts by mass of U-CAT660M (2,2′-dimorpholinodiethyl ether, manufactured by San Apro Co., Ltd.) was added to the four-necked flask cooled to 70 ° C. and mixed for 10 minutes. 130 parts by weight of '-diphenylmethane diisocyanate and 15 parts by weight of polymethylene polyphenyl polyisocyanate (PAPI-135, manufactured by Mitsubishi Chemical Corporation) are added and reacted at 100 ° C for about 3 hours until the isocyanate group content becomes constant. Thus, a moisture curable polyurethane hot melt adhesive 3 was prepared.

When the obtained moisture-curable polyurethane hot melt adhesive 3 was melted by heating at 125 ° C., the melt viscosity was ICI type cone plate viscometer (ICI, cone diameter: 19.5 mm, cone angle: 2.0 °). ) Was 18,000 mPa · s. Moreover, isocyanate group content was 2.2 mass%.

Example 4
345 parts by mass of long-chain aliphatic polyester polyol (A-1), 345 parts by mass of aliphatic polyester polyol (A′-2), 170 parts by mass of aliphatic polyether polyol (B-1) in a 2-liter four-necked flask And 100 parts by mass of ethylene-vinyl acetate copolymer (F-1) having a structural unit derived from vinyl acetate of 45% by mass (trade name Evaflex EV45X, manufactured by Mitsui DuPont Polychemical Co., Ltd.) and super ester A100 (rosin) After mixing 75 parts by mass of ester (produced by Arakawa Chemical Co., Ltd.), it was dehydrated by heating at 100 ° C. under reduced pressure until the water content in the four-necked flask was 0.05% by mass.

  Next, 100 parts by mass of 4,4′-diphenylmethane diisocyanate and 30 parts by mass of polymethylene polyphenyl polyisocyanate (trade name PAPI-135, manufactured by Mitsubishi Chemical Corporation) are added to the four-necked flask cooled to 70 ° C. The urethane prepolymer 4 was prepared by reacting at 100 ° C. for about 3 hours until the isocyanate group content was constant.

  Next, 1.5 parts by mass of U-CAT660M (2,2′-dimorpholinodiethyl ether, manufactured by San Apro Co., Ltd.) was added and stirred until uniform to prepare moisture-curable polyurethane hot melt adhesive 4. The resulting moisture-curing polyurethane hot melt adhesive 4 was melted by heating at 125 ° C., and the melt viscosity was determined to be an ICI type cone plate viscometer (ICI, cone diameter: 19.5 mm, cone angle: 2.0). It was 20,000 mPa · s. Moreover, isocyanate group content was 2.1 mass%.

Example 5
190 parts by mass of long-chain aliphatic polyester polyol (A-1), 190 parts by mass of aliphatic polyester polyol (A′-2), 60 parts by mass of aliphatic polyether polyol (B-1) in a 2-liter four-necked flask , 140 parts by mass of aromatic polyester polyol (CI-1), 90 parts by mass of aromatic polyester polyol (CII-1), 100 parts by mass of aliphatic polyester polyol (D-1), and 45 parts by mass of a structural unit derived from vinyl acetate. % Ethylene-vinyl acetate copolymer (F-1) (trade name Evaflex EV45X, manufactured by Mitsui DuPont Polychemical Co., Ltd.) 30 parts by mass, and then heated at 100 ° C. under reduced pressure to heat in a four-necked flask It dehydrated until the water | moisture content with respect to the whole quantity became 0.05 mass%.

  Next, 140 parts by mass of 4,4′-diphenylmethane diisocyanate and 10 parts by mass of polymethylene polyphenyl polyisocyanate (trade name PAPI-135, manufactured by Mitsubishi Chemical Corporation) are added to the four-necked flask cooled to 70 ° C. The urethane prepolymer 5 was prepared by reacting at 100 ° C. for about 3 hours until the isocyanate group content was constant.

  Subsequently, 1.5 mass parts of U-CAT660M (2,2'-dimorpholinodiethyl ether, manufactured by San Apro Co., Ltd.) was added and stirred until uniform to prepare a moisture-curable polyurethane hot melt adhesive 5. The resulting moisture-curing polyurethane hot melt adhesive 5 was melted by heating at 125 ° C., and the melt viscosity was determined to be an ICI type cone plate viscometer (made by ICI, cone diameter: 19.5 mm, cone angle: 2.0). It was 18,000 mPa · s. Moreover, isocyanate group content was 2.5 mass%.

Example 6
In a 2-liter four-necked flask, 90 parts by mass of aliphatic polyether polyol (B-1), 100 parts by mass of aliphatic polyester polyol (D-1), and surface-treated calcined kaolin having an average particle diameter of 0.8 microns After mixing 100 parts by weight, 185 parts by mass of the long-chain aliphatic polyester polyol (A-1), 185 parts by mass of the aliphatic polyester polyol (A′-2), 140 parts by mass of the aromatic polyester polyol (CI-1), Ethylene-vinyl acetate copolymer (F-1) having 60 mass parts of aromatic polyester polyol (CII-1) and 45 mass% of a structural unit derived from vinyl acetate (trade name: EVAFLEX EV45X, Mitsui DuPont Polychemical Co., Ltd. (Made) After mixing 30 parts by mass, the water in the four-necked flask can be heated to 100 ° C under reduced pressure. It was dehydrated until .05 wt%.

  Next, 140 parts by mass of 4,4′-diphenylmethane diisocyanate and 15 parts by mass of polymethylene polyphenyl polyisocyanate (trade name PAPI-135, manufactured by Mitsubishi Chemical Corporation) are added to the four-necked flask cooled to 70 ° C. Urethane prepolymer 6 was prepared by reacting at 100 ° C. for about 3 hours until the isocyanate group content was constant.

  Next, 1.5 parts by mass of U-CAT660M (2,2′-dimorpholinodiethyl ether, manufactured by San Apro Co., Ltd.) was added and stirred until uniform to prepare moisture-curable polyurethane hot melt adhesive 6. The resulting moisture-curing polyurethane hot melt adhesive 5 was melted by heating at 125 ° C., and the melt viscosity was determined to be an ICI type cone plate viscometer (made by ICI, cone diameter: 19.5 mm, cone angle: 2.0). It was 24,000 mPa · s. The isocyanate group content was 2.4% by mass.

Example 7
100 parts by mass of long-chain aliphatic polyester polyol (A-1), 350 parts by mass of aliphatic polyester polyol (A′-2), 110 parts by mass of aliphatic polyether polyol (B-2) in a 2-liter four-necked flask , 150 parts by mass of aromatic polyester polyol (CI-1), 60 parts by mass of aromatic polyester polyol (CII-1), 100 parts by mass of aliphatic polyester polyol (D-1), and 45 parts by mass of a structural unit derived from vinyl acetate. % Ethylene-vinyl acetate copolymer (F-1) (trade name: Evaflex EV45X, manufactured by Mitsui DuPont Polychemical Co., Ltd.) 50 parts by mass, and then heated at 100 ° C. under reduced pressure to heat in a four-necked flask It dehydrated until the water | moisture content with respect to the whole quantity became 0.05 mass%.

  Next, 140 parts by mass of 4,4′-diphenylmethane diisocyanate and 15 parts by mass of polymethylene polyphenyl polyisocyanate (trade name PAPI-135, manufactured by Mitsubishi Chemical Corporation) are added to the four-necked flask cooled to 70 ° C. Urethane prepolymer 7 was prepared by reacting at 100 ° C. for about 3 hours until the isocyanate group content was constant.

  Next, 25 parts by mass of Superester A100 (rosin ester, manufactured by Arakawa Chemical Co., Ltd.) and 1.5 parts by mass of U-CAT660M (2,2′-dimorpholinodiethyl ether, manufactured by San Apro Co., Ltd.) are added to be uniform. The moisture-curing polyurethane hot melt adhesive 7 was prepared by stirring until. The resulting moisture-curing polyurethane hot melt adhesive 7 was melted by heating at 125 ° C., and the melt viscosity was ICI type cone plate viscometer (ICI, cone diameter: 19.5 mm, cone angle: 2.0). It was 30,000 mPa · s. Moreover, isocyanate group content was 2.5 mass%.

<< Comparative Example 1 >>
300 parts by mass of long-chain aliphatic polyester polyol (A-1), 500 parts by mass of long-chain aliphatic polyester polyol (A′-2), 200 parts by mass of aliphatic polyester polyol (D-1) in a 2-liter four-necked flask And 50 parts by mass of an ethylene-vinyl acetate copolymer (trade name EVAFLEX EV45X, manufactured by Mitsui DuPont Polychemical Co., Ltd.) having 45 mass% of a structural unit derived from vinyl acetate and heating at 100 ° C. under reduced pressure Thus, dehydration was performed until the water content in the four-necked flask became 0.05% by mass.

  Next, 110 parts by mass of 4,4′-diphenylmethane diisocyanate and 30 parts by mass of polymethylene polyphenyl polyisocyanate (trade name PAPI-135, manufactured by Mitsubishi Chemical Corporation) are added to the four-necked flask cooled to 70 ° C. In addition, urethane prepolymer 8 was prepared by reacting at 100 ° C. for about 3 hours until the isocyanate group content was constant.

  Next, 50 parts by mass of superester A100 (rosin ester, manufactured by Arakawa Chemical Co., Ltd.) and 1.0 mass of U-CAT660M (2,2′-dimorpholinodiethyl ether, manufactured by San Apro Co., Ltd.) as tackifiers. Moisture curable polyurethane hot melt adhesive 8 was prepared by adding part and stirring until uniform. The resulting moisture-curing polyurethane hot melt adhesive 8 was melted by heating at 125 ° C., and the melt viscosity was determined to be an ICI type cone plate viscometer (made by ICI, cone diameter: 19.5 mm, cone angle: 2.0). It was 20,000 mPa · s. The isocyanate group content was 1.7% by mass.

<< Comparative Example 2 >>
300 parts by mass of long-chain aliphatic polyester polyol (A-1), 500 parts by mass of long-chain aliphatic polyester polyol (A′-2), aliphatic polyether polyol (B′-6) in a 2 liter four-necked flask 200 parts by mass, 100 parts by mass of aliphatic polyester polyol (D-1), and ethylene-vinyl acetate copolymer having 45% by mass of structural units derived from vinyl acetate (trade name EVAFLEX EV45X, manufactured by Mitsui DuPont Polychemical Co., Ltd. ) After mixing 50 parts by mass, it was dehydrated by heating under reduced pressure at 100 ° C. until the water content in the four-necked flask was 0.05% by mass.

  Next, 140 parts by mass of 4,4′-diphenylmethane diisocyanate and 25 parts by mass of polymethylene polyphenyl polyisocyanate (trade name PAPI-135, manufactured by Mitsubishi Chemical Corporation) are added to the four-necked flask cooled to 70 ° C. In addition, urethane prepolymer 9 was prepared by reacting at 100 ° C. for about 3 hours until the isocyanate group content was constant.

  Next, 50 parts by mass of superester A100 (rosin ester, manufactured by Arakawa Chemical Co., Ltd.) and 1.0 mass of U-CAT660M (2,2′-dimorpholinodiethyl ether, manufactured by San Apro Co., Ltd.) as tackifiers. Moisture curable polyurethane hot melt adhesive 9 was prepared by stirring until part addition was uniform. The resulting moisture-curing polyurethane hot melt adhesive 9 was melted by heating at 125 ° C., and the melt viscosity was determined to be an ICI type cone plate viscometer (made by ICI, cone diameter: 19.5 mm, cone angle: 2.0). It was 20,000 mPa · s. Moreover, isocyanate group content was 2.1 mass%.

<< Comparative Example 3 >>
300 parts by mass of long-chain aliphatic polyester polyol (A-1), 500 parts by mass of long-chain aliphatic polyester polyol (A′-2), aliphatic polyether polyol (B′-5) in a 2 liter four-necked flask 300 parts by mass, 100 parts by mass of an aliphatic polyester polyol (D-1), and an ethylene-vinyl acetate copolymer having 45 mass% of a structural unit derived from vinyl acetate (trade name EVAFLEX EV45X, manufactured by Mitsui DuPont Polychemical Co., Ltd. ) After mixing 50 parts by mass, it was dehydrated by heating under reduced pressure at 100 ° C. until the water content in the four-necked flask was 0.05% by mass.

  Next, 200 parts by mass of 4,4′-diphenylmethane diisocyanate and 20 parts by mass of polymethylene polyphenyl polyisocyanate (trade name PAPI-135, manufactured by Mitsubishi Chemical Corporation) are added to the four-necked flask cooled to 70 ° C. In addition, urethane prepolymer 10 was prepared by reacting at 100 ° C. for about 3 hours until the isocyanate group content was constant.

  Next, 50 parts by mass of superester A100 (rosin ester, manufactured by Arakawa Chemical Co., Ltd.) and 1.0 mass of U-CAT660M (2,2′-dimorpholinodiethyl ether, manufactured by San Apro Co., Ltd.) as tackifiers. A moisture-curing polyurethane hot melt adhesive 10 was prepared by adding part and stirring until uniform. The resulting moisture-curing polyurethane hot melt adhesive 10 was melted by heating at 125 ° C., and the melt viscosity was ICI-type cone plate viscometer (ICI, cone diameter: 19.5 mm, cone angle: 2.0). It was 17,000 mPa · s. The isocyanate group content was 2.7% by mass.

<< Comparative Example 4 >>
300 parts by mass of long-chain aliphatic polyester polyol (A-1), 500 parts by mass of long-chain aliphatic polyester polyol (A′-2), aliphatic polyether polyol (B′-3) in a 2 liter four-necked flask 200 mass parts, 165 mass parts of aromatic polyester polyol (CI-1), 200 mass parts of aliphatic polyester polyol (D-1), and ethylene-vinyl acetate copolymer having 45 mass% of structural units derived from vinyl acetate ( Product name Evaflex EV45X, manufactured by Mitsui DuPont Polychemical Co., Ltd.) After mixing 50 parts by mass, dehydration is performed until the water content in the four-necked flask becomes 0.05% by mass by heating at 100 ° C. under reduced pressure. did.

  Next, 200 parts by mass of 4,4′-diphenylmethane diisocyanate and 20 parts by mass of polymethylene polyphenyl polyisocyanate (trade name PAPI-135, manufactured by Mitsubishi Chemical Corporation) are added to the four-necked flask cooled to 70 ° C. In addition, urethane prepolymer 11 was prepared by reacting at 100 ° C. for about 3 hours until the isocyanate group content was constant.

  Next, 50 parts by mass of superester A100 (rosin ester, manufactured by Arakawa Chemical Co., Ltd.) and 1.0 mass of U-CAT660M (2,2′-dimorpholinodiethyl ether, manufactured by San Apro Co., Ltd.) as tackifiers. Moisture-curable polyurethane hot melt adhesive 11 was prepared by stirring until part was added and uniform. The resulting moisture-curing polyurethane hot melt adhesive 11 was melted by heating at 125 ° C., and the melt viscosity was ICI-type cone plate viscometer (ICI, cone diameter: 19.5 mm, cone angle: 2.0). It was 20000 mPa · s. The isocyanate group content was 2.3% by mass.

<< Comparative Example 5 >>
300 parts by mass of long-chain aliphatic polyester polyol (A-1), 500 parts by mass of long-chain aliphatic polyester polyol (A′-2), aliphatic polyether polyol (B′-4) in a 2 liter four-necked flask 200 parts by mass, 200 parts by mass of an aliphatic polyester polyol (D-1), and an ethylene-vinyl acetate copolymer having a structural unit derived from vinyl acetate of 45% by mass (trade name EVAFLEX EV45X, manufactured by Mitsui DuPont Polychemical Co., Ltd.) ) After mixing 50 parts by mass, it was dehydrated by heating under reduced pressure at 100 ° C. until the water content in the four-necked flask was 0.05% by mass.

  Next, 200 parts by mass of 4,4′-diphenylmethane diisocyanate and 20 parts by mass of polymethylene polyphenyl polyisocyanate (trade name PAPI-135, manufactured by Mitsubishi Chemical Corporation) are added to the four-necked flask cooled to 70 ° C. In addition, urethane prepolymer 12 was prepared by reacting at 100 ° C. for about 3 hours until the isocyanate group content was constant.

  Next, 50 parts by mass of superester A100 (rosin ester, manufactured by Arakawa Chemical Co., Ltd.) and 1.0 mass of U-CAT660M (2,2′-dimorpholinodiethyl ether, manufactured by San Apro Co., Ltd.) as tackifiers. A moisture-curable polyurethane hot melt adhesive 12 was prepared by stirring until part addition was uniform. When the obtained moisture-curable polyurethane hot melt adhesive 12 was melted by heating at 125 ° C., the melt viscosity was ICI type cone plate viscometer (manufactured by ICI, cone diameter: 19.5 mm, cone angle: 2.0). It was 19,000 mPa · s. The isocyanate group content was 2.7% by mass.

<< Comparative Example 6 >>
In a 2 liter four-necked flask, 220 parts by mass of aliphatic polyester polyol (A′-2), 110 parts by mass of aliphatic polyether polyol (B-1), and 165 parts by mass of aliphatic polyester polyol (D-1) After mixing, it was dehydrated by heating at 100 ° C. under reduced pressure until the water content in the four-necked flask was 0.05 mass%.

  Next, 90 parts by mass of 4,4′-diphenylmethane diisocyanate (4,4′-MDI) is added to the four-necked flask cooled to 70 ° C., and about 100 ° C. until the isocyanate group content becomes constant. Urethane prepolymer 13 was prepared by reacting for 3 hours.

  Next, 50 parts by mass of super ester A100 (rosin ester, manufactured by Arakawa Chemical Industries, Ltd.) and 1.5 mass of U-CAT660M (2,2′-dimorpholinodiethyl ether, manufactured by San Apro Co., Ltd.) as tackifiers. Moisture curable polyurethane hot melt adhesive 13 was prepared by stirring until part addition was uniform. When the obtained moisture-curable polyurethane hot melt adhesive 13 was heated and melted at 125 ° C., the melt viscosity was ICI-type cone plate viscometer (manufactured by ICI, cone diameter: 19.5 mm, cone angle: 2.0 °). ) Was 8000 mPa · s. The isocyanate group content was 2.6% by mass.

  Various measurements were performed according to the following methods.

[Measurement method of isocyanate group content (mass%)]
The excess amine was added to each urethane prepolymer to react the isocyanate group of the urethane prepolymer with dibutylamine, and then the remaining amine was titrated with hydrochloric acid.

[Method for preparing Specimen I]
Using a hot melt roll coater, each moisture curable polyurethane hot melt adhesive heated and melted at 120 ° C. on a JAS type I plywood with a thickness of 12 mm and a surface sanded in an environment of 23 ° C. and 65% relative humidity. Then, after applying at an application speed of 20 m / min to an average of about 80 g / m ² , a veneer having a water content of 70% by mass and a thickness of 0.6 mm is immediately bonded to the application surface, and then the veneer A non-woven fabric (weighing 30 g / m ² ) made of polyethylene terephthalate was placed thereon, and a test piece was prepared by pressing for 10 seconds at a pressure of about 10 kg / cm ² using a flat press.

[Surface appearance evaluation method]
1. Evaluation of adhesive exudation from veneer surface After sanding the surface of each test piece I produced by the above method, an aqueous stain colorant (Mirazole Color V, manufactured by Dainippon Ink & Chemicals, Inc.) ) Was visually observed in accordance with the following evaluation criteria after applying 3 g / m ² and drying.

○: Adhesive does not ooze out from the veneer surface, and there is no coloring defect.
Δ: Some adhesive oozes out from the surface of the veneer, and there is no coloring defect.
X: Adhesive oozes out from the surface of the veneer and poor coloring.

2. Evaluation of the peeling of the protruding plate The presence or absence of peeling of the protruding plate on the surface of each test piece I produced by the above method was visually observed.

○: There is peeling of the veneer.
Δ: Slight peeling of the veneer.
X: There is peeling of the veneer.

3. Evaluation of cracks on the surface of the veneer The presence or absence of cracks derived from the veneer on the surface of each test piece I produced by the above method was visually observed.

○: No crack.
(Triangle | delta): There is a crack of a 1mm or less protruding plate.
X: There is a crack of the protruding plate of 1 mm or more.

[Evaluation method of initial bond strength]
Each test piece I produced by the above method was cured for 1 hour in an environment of a temperature of 23 ° C. and a relative humidity of 65%, and then peeled in the direction of 90 ° in the same environment. From this, the initial adhesive strength was evaluated. The initial adhesive strength required for the wet-curing moisture-curable polyurethane hot melt adhesive is preferably approximately 10 N / 25 mm or more. Furthermore, in order to perform secondary processing such as in-line cutting and drilling, it is preferable to be 20 N / 25 mm.

[Evaluation method of normal adhesive strength]
Each test piece I produced by the above method was cured for 72 hours in an environment of a temperature of 23 ° C. and a relative humidity of 65%, and then a plane tensile test was performed in the same environment to evaluate its tensile strength. The test was performed under the same conditions using a tensile tester (STD-201NA manufactured by Imada Manufacturing Co., Ltd.) under the conditions of a tensile speed of 2 mm / min and a peeling area of 4 cm ² . The normal adhesive strength required for the wet-curing moisture-curable polyurethane hot melt adhesive is approximately 0.4 N / mm ² or more in the case of a decorative member such as a wall or door, although it varies depending on the application used. It is preferable. Furthermore, if it is 1.0 N / 25mm or more, it is said that it is sufficient performance when using it for the building member use of a site | part with a load, such as a floor member and a window frame.

[Evaluation method of water resistance]
A portion (75 × 75 mm square) of each test piece I prepared by the above method was cured for 72 hours in an environment of a temperature of 23 ° C. and a relative humidity of 65%, and then placed in a water bath boiled to 100 ° C. It was immersed for a period of time, and then dried for 16 hours in a hot air circulating drier adjusted to 60 ° C. Next, a part of the test piece was dipped in a water bath boiled to 100 ° C. for 4 hours, and then dried in a hot air circulating dryer adjusted to 60 ° C. for 3 hours. The peeling of the protruding plate at some corners of each test piece after drying, specifically, each side part (75 mm), was visually observed.

○: No peeling.
(Triangle | delta): The length of the part which the protrusion board peeled is 25 mm or less on each side.
X: There is a side where the protruding plate is peeled off by 25 mm or more.

“4,4′-MDI” in Table 5, Table 6 and Table 7 represents 4,4′-diphenylmethane diisocyanate, “Isonate 143LJ” represents carbodiimide-modified diphenylmethane diisocyanate manufactured by Mitsubishi Chemical Corporation, “ “PAPI 135” represents polymethylene polyphenyl polyisocyanate manufactured by Mitsubishi Chemical Corporation. “Superester A100” represents a rosin ester manufactured by Arakawa Chemical Industries, Ltd., “Evaflex EV45X” represents an ethylene-vinyl acetate copolymer manufactured by Mitsui DuPont Polychemical Co., Ltd., and “U-CAT660M”. “Represents 2,2′-dimorpholinodiethyl ether manufactured by San Apro Co., Ltd., and“ surface-treated calcined kaolin ”represents surface-treated calcined kaolin having an average particle diameter of 0.8 μm.

  “4,4′-MDI” in Table 8, Table 9 and Table 10 represents 4,4′-diphenylmethane diisocyanate, “Isonate 143LJ” represents carbodiimide-modified diphenylmethane diisocyanate manufactured by Mitsubishi Chemical Corporation, “ “PAPI 135” represents polymethylene polyphenyl polyisocyanate manufactured by Mitsubishi Chemical Corporation. “Superester A100” represents a rosin ester manufactured by Arakawa Chemical Industries, Ltd., “Evaflex EV45X” represents an ethylene-vinyl acetate copolymer manufactured by Mitsui DuPont Polychemical Co., Ltd., and “U-CAT660M”. "Represents 2,2'-dimorpholino diethyl ether manufactured by San Apro Co., Ltd.

Claims (12)

Urethane pre-polymer obtained by reacting a polyol containing a long-chain aliphatic polyester polyol (A) represented by the general formula (I) and an aliphatic polyether polyol (B) having a number average molecular weight of 2000 to 10,000 with a polyisocyanate. It contains a polymer, and the aliphatic polyether polyol (B) has a structural unit derived from ethylene oxide in the range of 10 to 60% by mass with respect to the entire aliphatic polyether polyol (B). Moisture curable polyurethane hot melt adhesive for wet veneer.

(In general formula (I), R ¹ and R ² each independently represent 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 (N is 3 to 40) The aliphatic polyether polyol (B) is ethylene oxide-modified polypropylene glycol in which ethylene oxide is added to both ends of polypropylene glycol, or ethylene oxide-modified polybutylene glycol in which ethylene oxide is added to both ends of polybutylene glycol. The moisture-curing polyurethane hot melt adhesive for wet veneer as described. The moisture-curable polyurethane hot melt adhesive for wet veneer according to claim 1, wherein the aliphatic polyether polyol (B) is an ethylene oxide-modified polypropylene glycol obtained by random copolymerization of propylene oxide and ethylene oxide. The moisture-curable polyurethane hot melt adhesive for wet veneer according to claim 1, wherein the aliphatic polyether polyol (B) is contained in an amount of 1 to 30 parts by mass with respect to 100 parts by mass of the total amount of the polyol and the polyisocyanate. Agent. The wet according to any one of claims 1 to 4, wherein the polyol further comprises an aromatic polyester polyol (CI) having a number average molecular weight of 2000 to 5000 and a glass transition temperature of 30 ° C or higher. Moisture curable polyurethane hot melt adhesive for veneer. The wet according to any one of claims 1 to 5, wherein the polyol further comprises an aromatic polyester polyol (CII) 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 adhesive for veneer. The said polyol has an aliphatic polyester polyol (D) which has a 2, 2- dimethyl- 1, 3- propylene group, and melting | fusing point is 30 degrees C or less, In any one of Claims 1-6. Moisture curable polyurethane hot melt adhesive for wet veneer. It has the layer (X) formed with the moisture hardening type polyurethane hot-melt-adhesive agent for wet single boards in any one of Claims 1-7 on a base material, and from a single board on the said layer (X) A decorative member having a layer. What applied the moisture hardening type polyurethane hot-melt-adhesive agent for wet veneers in any one of Claims 1-7 melted | heated on the base material, and then mounted the wet veneer on this application surface. A method for producing a decorative member, wherein the base material and the wet veneer are bonded together by pressing. Applying the moisture-curable polyurethane hot melt adhesive for wet veneer according to any one of claims 1 to 7, which is heated and melted on a substrate, and then placing the wet veneer on the coated surface, Next, a method for producing a decorative member, in which a nonwoven fabric is placed on the wet veneer, and then the substrate and the wet veneer are bonded by pressing. What applied the moisture hardening type polyurethane hot-melt-adhesive agent for wet veneers in any one of Claims 1-7 melted | heated on the base material, and mounted the wet veneer on this application surface then A method for producing a decorative member, wherein the base material and the wet veneer are bonded by pressing with a hot press method and then with a cold press method. A wet veneer-type polyurethane hot melt adhesive for wet veneer according to any one of claims 1 to 7, which is heated and melted on a substrate, and then the wet veneer is placed on the coated surface A method for producing a decorative member, in which the base material and the wet veneer are bonded together by pressing them with a cold press method.