JP7455250B2 - Surface material for laminates and vehicle interior materials - Google Patents

Description

The present invention relates to a laminate and a skin material for a vehicle interior material using the same.

For example, as a skin material that covers the surface of a vehicle seat cushion, there is a laminate in which a covering layer is adhered to one surface of a foamed polyurethane layer, and a surface layer is adhered to the other surface of the laminate. The skin material is cut and sewn into a shape that covers the seat cushion.

The covering layer is provided for the purpose of improving slipperiness in order to improve the work during sewing and the work when covering the seat cushion with the skin material, and to protect the back surface of the foamed polyurethane layer.
On the other hand, the surface layer is made of an appropriate material such as genuine leather, synthetic leather, fabric, etc. depending on the decorativeness and tactility required of the vehicle seat.

Furthermore, since the skin material that covers the surface of vehicle seat cushions is required to have heat resistance, some use polyurethane-reactive hot-melt adhesives to bond the foamed polyurethane layer to the covering layer and surface layer (Patent Document 1) ). A polyurethane-reactive hot melt adhesive has a polyurethane prepolymer obtained by reacting a polyester polyol and a polyisocyanate as a main component.

Adhesives used for vehicle seat cushions are desired to have low organic volatile content that affects the human body. As such a low outgassing hot melt adhesive, Patent Document 2 discloses a low outgassing olefin hot melt adhesive.

Japanese Patent Application Publication No. 2017-136735 Japanese Patent Application Publication No. 2017-031273

The skin material itself that covers the surface of the seat cushion of a vehicle is required to have a low amount of VOC (volatile organic compounds) that have an adverse effect on the human body. In addition, the amount of VOCs in the surface material that covers the surface of vehicle seat cushions varies depending on the material of the surface layer, and furthermore, even if the material is the same type of genuine leather, the amount of VOCs will vary depending on the part where it is used. . Furthermore, although it is possible to achieve low VOC with olefin-based hot melt adhesives, their uses are limited from the viewpoint of heat resistance, etc., and it has been difficult to use them for vehicles.

The present invention has been made in view of the above points, and it is possible to reduce the amount of VOC in a laminate consisting of a foamed polyurethane layer and a covering layer to which the surface layer, which tends to vary depending on the material, etc., is not bonded. The purpose is to reduce the amount of VOC in a skin material of a vehicle interior material to which a surface layer made of a predetermined material is bonded.
Furthermore, the skin material of vehicle interior materials is required to have flame retardancy in consideration of the possibility of a vehicle fire. In addition, good thermal properties (especially heat resistance and thermal stability) are required for use in vehicles. An object of the present invention is to provide a laminate and a skin material for vehicle interior materials that have low VOC, good flame retardancy, and good thermal properties.

The invention of claim 1 provides a laminate in which a coating layer is placed on a foamed polyurethane layer obtained from a foamed polyurethane resin composition containing a polyol, a polyisocyanate, a blowing agent, a catalyst, and a flame retardant. The composition contains tin ricinoleate containing an active hydrogen group as the catalyst, and a phosphorus-containing solid flame retardant as the flame retardant, and the foamed polyurethane layer and the coating layer contain a polyol component (A) and a polyisocyanate. The polyisocyanate component (B) in the polyurethane hot melt adhesive is bonded by a polyurethane hot melt adhesive containing a polyurethane prepolymer (I) made from component (B) and a catalyst (II), Contains more than 0.5% by mass and 10% by mass or less of carbodiimide-modified diphenylmethane diisocyanate based on the entire polyisocyanate component (B), and the catalyst (II) includes a reactive catalyst having a functional group that reacts with an isocyanate group. It is characterized by

The invention according to claim 2 is characterized in that in claim 1, the reactive catalyst has one functional group that reacts with the isocyanate group and has a tertiary amine structure.

The invention according to claim 3 is characterized in that in claim 1 or 2, the polyol component (A) is a crystalline polyol component consisting of a condensation reaction product of an aliphatic dicarboxylic acid having 10 to 12 carbon atoms and an aliphatic diol having 4 to 6 carbon atoms. Contains a polyester polyol (a-1) and a polyether polyol (a-2), and the content of the polyether polyol (a-2) in the polyol component (A) is 100% by mass of the polyol component (A). % to 30 to 80% by mass.

According to a fourth aspect of the invention, in the third aspect, the crystalline polyester polyol (a-1) has a number average molecular weight of 1,000 to 5,000, and the polyether polyol (a-2) has a number average molecular weight of 1,000. ~4000.

The invention according to claim 5 is the invention according to any one of claims 1 to 4, wherein the foamed polyurethane resin composition comprises, as the flame retardant, the phosphorus-containing solid flame retardant and an average particle size of 0.1 to 0.5 μm. melamine powder.

The invention according to claim 6 is characterized in that, in any one of claims 1 to 5, the phosphorus-containing solid flame retardant in the foamed polyurethane resin composition is a phosphate ester compound.

The invention according to claim 7 is the invention according to any one of claims 1 to 6, wherein the polyol component (A) of the polyurethane prepolymer (I) in the hot melt adhesive is other polyol (a-3). , an amorphous polyester polyol, a polycarbonate polyol, and a low molecular weight diol having a number average molecular weight of 500 or less.

According to an eighth aspect of the invention, in any one of claims 1 to 7, a surface layer is formed using the polyurethane hot melt adhesive on a surface of the foamed polyurethane layer opposite to the surface on which the coating layer is placed. It is characterized by being glued.

The invention according to claim 9 is a skin material for a vehicle interior material using the laminate according to claim 8.

According to the present invention, it is possible to provide a laminate and a skin material for a vehicle interior material that have low VOC, good flame retardancy, and good thermal properties (especially moisture and heat resistance and thermal stability).

FIG. 1 is a sectional view showing a laminate according to an embodiment of the present invention. It is a sectional view showing the layered product of other embodiments of the present invention. It is a table showing the configuration, thermal characteristics, flammability, VOC, etc. of Examples and Comparative Examples of the present invention.

A laminate 10 according to one embodiment of the present invention shown in FIG. 1 comprises a foamed polyurethane layer 11 having a covering layer 15 placed on one surface thereof.
The foamed polyurethane layer 11 is obtained by foaming a foamed polyurethane resin composition containing a polyol, a polyisocyanate, a foaming agent, a catalyst, and a flame retardant.
As the polyol, a polyether polyol or a polyester polyol is used. As the polyether polyol, in addition to a compound obtained by addition polymerization of an alkylene oxide to a polyhydric alcohol, polypropylene glycol, polytetramethylene glycol, etc. are listed. As the polyhydric alcohol, glycerin, dipropylene glycol, trimethylolpropane, etc. are used. As the alkylene oxide, ethylene oxide, propylene oxide, etc. are used.

Examples of polyether polyols include triols obtained by addition-polymerizing propylene oxide to glycerin, triols obtained by addition-polymerizing ethylene oxide thereto, diols obtained by addition-polymerizing propylene oxide to dipropylene glycol, and the like.

The polyether polyol may be a polyether ester polyol obtained by reacting a polyoxyalkylene polyol with a polycarboxylic acid anhydride and a compound having a cyclic ether group. Examples of polyoxyalkylene polyols include polyethylene glycol, polypropylene glycol, and propylene oxide adducts of glycerin. Examples of polycarboxylic anhydrides include anhydrides such as succinic acid, adipic acid, and phthalic acid. Examples of the compound having a cyclic ether group (alkylene oxide) include ethylene oxide and propylene oxide. Polyether polyols are preferable than polyester polyols because they have excellent reactivity with polyisocyanates and do not undergo hydrolysis.

Examples of polyester polyols include condensed polyester polyols obtained by reacting polycarboxylic acids such as adipic acid and phthalic acid with polyols such as ethylene glycol, propylene glycol, and glycerin, as well as lactone-based polyester polyols and polycarbonate-based polyester polyols. is used.

As the polyisocyanate, aliphatic or aromatic polyisocyanates having two or more isocyanate groups, mixtures thereof, modified polyisocyanates obtained by modifying them, and the like can be used. For example, tolylene diisocyanate (TDI), 4,4'-diphenylmethane diisocyanate (MDI), polymethylene polyphenyl polyisocyanate, hydrogenated MDI, 1,5-naphthalene diisocyanate, 1,6-hexamethylene diisocyanate (HDI), Isophorone diisocyanate, xylylene diisocyanate (XDI), hydrogenated XDI, tetramethylxylene diisocyanate (TMXDI), 1,3,6-hexamethylene triisocyanate, 1,6,11-undecane triisocyanate, bicycloheptane triisocyanate, and modified products and derivatives thereof. Other prepolymers can also be used. The polyisocyanate may be used alone or in combination of two or more.

The isocyanate index is preferably 80 to 110. If the isocyanate index is less than 80, it will be difficult to obtain a foamed polyurethane layer 11 with good mechanical properties such as tensile strength and elongation, while if it exceeds 110, the flexibility of the foamed polyurethane layer 11 will decrease. The isocyanate index (INDEX) is a value obtained by multiplying by 100 the number of moles of isocyanate groups per mole of active hydrogen groups contained in the urethane raw material, [(Isocyanate equivalent in the foamed polyurethane resin composition/foamed polyurethane resin composition)] (equivalent amount of active hydrogen in the substance) x 100].

As the blowing agent, water, a chlorofluorocarbon substitute, or a hydrocarbon such as pentane can be used alone or in combination. In the case of water, carbon dioxide gas is generated during the reaction between polyol and polyisocyanate, and the carbon dioxide gas causes foaming. The amount of water as a blowing agent is preferably about 2 to 5 parts by weight per 100 parts by weight of polyol. Moreover, when using other foaming agents together with water, the amount of the other foaming agents is determined as appropriate.

As the catalyst, tin ricinoleate containing an active hydrogen group is suitable, and it is more suitable to use it in combination with an amine catalyst. By including tin ricinoleate in the catalyst, the amount of VOC in the foamed polyurethane layer 11 and the laminate 10 can be reduced. Examples of the amine catalyst include triethylamine, triethylenediamine, diethanolamine, dimethylaminomorpholine, N-ethylmorpholine, and tetramethylguanidine.

As the flame retardant, a phosphorus-containing solid flame retardant is used. The phosphorus-containing solid flame retardant is a compound with low volatility, and either non-halogen or halogen-containing one can be used, and a phosphoric ester compound is used. Specifically, triphenyl phosphate (white, flake-like), aromatic condensed phosphate ester (white powder to granules), tris (tribromoneopentyl) phosphate (white, crystalline, powder), etc. are used. be able to. The content of the phosphorus-containing solid flame retardant is preferably 3 to 15 parts by weight per 100 parts by weight of the polyol. If this content is less than 3 parts by mass, the low flammability of the polyurethane foam layer 11 cannot be sufficiently improved. On the other hand, if it exceeds 15 parts by mass, the balance of foaming tends to be disrupted, making it difficult to obtain a good foamed polyurethane layer 11.

In addition to the phosphorus-containing solid flame retardant used in this embodiment, the phosphorus-containing flame retardant includes a phosphorus-containing liquid flame retardant. However, since the phosphorus-containing liquid flame retardant has higher volatility than the phosphorus-containing solid flame retardant, the amount of VOC in the polyurethane foam layer 11 and the laminate 10 increases.

As the flame retardant of this embodiment, it is preferable to use melamine powder together with the phosphorus-containing solid flame retardant. Since melamine [C ₃ N ₃ (NH ₂ ) ₃ ] does not contain oxygen, the progress of combustion can be suppressed. The average particle diameter of the melamine powder is preferably 0.1 to 0.5 μm. Here, the "average particle size" of melamine is calculated using a particle size distribution measuring device (for example, SALD-7000H (manufactured by Shimadzu Corporation)). Specifically, using this device, the weight average (average of weight (volume) based distribution) particle diameter obtained by evaluating a dispersion in which a sample is dispersed in a solvent (for example, ethyl acetate) is average particle diameter. Fine melamine powder with an average particle diameter of 0.1 to 0.5 μm is dispersed in the polyurethane foam layer 11, and when the polyurethane foam layer 11 burns, it melts to form a film, blocking oxygen and suppressing combustion. Guessed. When the average particle diameter of the melamine powder is less than 0.1 μm, the production of the melamine powder becomes complicated and the production cost increases. On the other hand, if it exceeds 0.5 μm, the dispersibility of the melamine powder in the foamed polyurethane layer 11 decreases, making it impossible to sufficiently improve the low flammability.

The content of melamine powder is preferably 3 to 13 parts by weight per 100 parts by weight of polyol. If the content is less than 3 parts by mass, the effect of promoting low flammability of the foamed polyurethane layer 11 cannot be sufficiently achieved. On the other hand, if it exceeds 13 parts by mass, the balance of foaming tends to collapse, and there is a possibility that a good foamed polyurethane layer 11 cannot be obtained.

The density and thickness of the foamed polyurethane layer 11 are determined as appropriate, but when the laminate 10 is used as a skin material for a vehicle interior material such as a vehicle seat cushion, it should be bent along the surface of the vehicle interior material. For example, the density is preferably about 20 to 35 kg/m ³ and the thickness is about 3 to 10 mm.

The foamed polyurethane resin composition preferably contains other additives, such as a foam stabilizer. Examples of the foam stabilizer include silicone compounds, anionic surfactants such as sodium dodecylbenzenesulfonate and sodium laurate, polyether siloxanes, and phenolic compounds. The content of the foam stabilizer is exemplified as 0.5 to 2.5 parts by weight per 100 parts by weight of the polyol.
Furthermore, examples of other additives include known additives such as fillers, stabilizers, colorants, plasticizers, antibacterial agents, and the like, if necessary.

The polyurethane foam layer 11 is manufactured by a known method for manufacturing polyurethane foam. Known methods for producing polyurethane foam include mold foaming and slab foaming. Mold foaming is a method in which a mold is filled with a foamed polyurethane resin composition and foamed within the mold. On the other hand, slab foaming is a method in which a foamed polyurethane resin composition is mixed, discharged onto a belt conveyor, and foamed at room temperature under atmospheric pressure. As the foamed polyurethane layer of this embodiment, a slab foam obtained by cutting foamed polyurethane produced by slab foaming into a predetermined thickness is more preferable.

As the covering layer 15, a nonwoven fabric, a woven fabric, or a knitted fabric is preferable. In particular, among knitted materials, tricot has elasticity and stretchability, so when used as the covering layer 15, when the laminate 11 is used as the skin material of the vehicle interior material, it deforms along the surface of the vehicle interior material. It is easy to clean and the skin material is less prone to wrinkles. Further, examples of the material of the covering layer 15 include nylon, polyester, and the like.

The foamed polyurethane layer 11 and the coating layer 15 are made of a polyurethane hot melt adhesive 13 containing a polyurethane prepolymer (I) made from a polyol component (A) and a polyisocyanate component (B) and a catalyst (II). It is glued. Polyurethane prepolymer (I) is obtained by using polyol component (A) and polyisocyanate (B) as raw materials and reacting polyisocyanate (B) in a stoichiometrically excessive amount with polyol component (A). , a polyurethane prepolymer having isocyanate groups (NCO) at the ends.

Here, the hot melt adhesive composition that can be employed as the polyurethane hot melt adhesive 13 of this embodiment will be specifically described in the following order. However, the present invention is not limited to the specific examples described herein.
1 Ingredients 2 Manufacturing method 3 Physical properties 4 Application 5 Application method

<<<Ingredients>>>
The hot melt adhesive composition according to this embodiment is a reactive urethane hot melt with low outgas properties. The hot melt adhesive composition according to this embodiment includes an isocyanate-terminated polyurethane prepolymer (I) as a base resin and a catalyst (II). Furthermore, other components may be included in the adhesive composition as required.

When such a hot melt adhesive composition is used, adhesive properties are developed when the polyurethane prepolymer heated to a molten state is cooled and solidified. Furthermore, the uncured isocyanate terminals react with moisture in the air to form a crosslinked structure, resulting in stronger adhesiveness. Such a hot melt adhesive composition may be referred to as a moisture-curable hot melt adhesive composition, a reactive hot melt adhesive composition, or the like.

<<Polyurethane prepolymer (I)>>
Polyurethane prepolymer (I) uses a polyol component (A) and a polyisocyanate component (B) as raw materials, and usually the polyisocyanate component (B) is reacted with the polyol component (A) in a stoichiometrically excessive amount. You can get it by doing that.

<Polyol component (A)>
The polyol component (A) is not particularly limited as long as it is commonly used in the production of polyurethane prepolymers, but preferably includes polyester polyols and polyether polyols. More specifically, a crystalline polyester polyol (a-1) consisting of a condensation reaction product of an aliphatic dicarboxylic acid having 10 to 12 carbon atoms and an aliphatic diol having 4 to 6 carbon atoms, and a polyether polyol (a-2) ).

Examples of aliphatic dicarboxylic acids having 10 to 12 carbon atoms include decanedioic acid (sebacic acid, C10), undecanedioic acid (C11), and dodecanedioic acid (C12). In addition, aliphatic diols having 4 to 6 carbon atoms include butanediol (e.g., 1,3-butanediol, 1,4-butanediol, etc.), pentanediol (e.g., 1,5-pentanediol, etc.), and hexanediol (e.g., 1,5-pentanediol, etc.). Examples include diols (eg, 1,6-hexanediol, etc.).

In the present embodiment, "crystalline polyester polyol" refers to a polyester polyol with a melting point of 30°C or higher, and "amorphous polyester polyol" refers to a polyester polyol with a melting point of less than 30°C or a polyester polyol with no melting point. shows. Note that such crystallinity can be adjusted by appropriately selecting the carboxylic acid/alcohol constituting the polyester polyol. The melting point is the temperature at which a melting peak appears in the range of -80°C to 100°C under a temperature program of 25°C to -80°C to 100°C (heating rate of 5°C/min) using a differential scanning calorimeter.

The number average molecular weight of the crystalline polyester polyol (a-1) is preferably within the range of 1000 to 5000, more preferably within the range of 2000 to 4500. Here, the "number average molecular weight" is a value calculated from the hydroxyl value of the raw material. Other "number average molecular weights" described in this specification are also values calculated in the same manner as explained here.

Examples of the polyether polyol (a-2) include polyethylene glycol, polypropylene glycol, polytetramethylene ether glycol, etc. obtained by polymerizing cyclic ethers such as ethylene oxide, propylene oxide, and tetrahydrofuran, and copolyethers thereof. Can be mentioned. Moreover, it can also be obtained by polymerizing the above-mentioned cyclic ether using a polyhydric alcohol such as glycerin or trimethylolethane.

The number average molecular weight of the polyether polyol (a-2) is preferably within the range of 1,000 to 4,000, more preferably within the range of 1,500 to 3,000.

Further, the polyol other than the crystalline polyester polyol (a-1) and the polyether polyol (a-2) is selected from the group consisting of an amorphous polyester polyol, a polycarbonate polyol, and a low molecular diol having a number average molecular weight of 500 or less. One or more polyols (a-3) are exemplified. The polyol component (A) may contain only the other polyol (a-3), but it contains the crystalline polyester polyol (a-1) and the polyether polyol (a-2), and contains the polyol ( It is preferable to further contain a-3).

Examples of amorphous polyester polyols include aliphatic dicarboxylic acids (such as succinic acid, adipic acid, sebacic acid, and azelaic acid), and aromatic dicarboxylic acids (such as phthalic acid, terephthalic acid, isophthalic acid, and naphthalene dicarboxylic acid). , alicyclic dicarboxylic acids (such as hexahydrophthalic acid, hexahydroterephthalic acid, and hexahydroisophthalic acid), or esters or acid anhydrides thereof, and ethylene glycol, 1,3-propylene glycol, 1,2- Propylene glycol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, neopentyl glycol, 1, Polyester polyol obtained by dehydration condensation reaction with 8-octanediol, 1,9-nonanediol, etc., or a mixture thereof; polylactone diol obtained by ring-opening polymerization of lactone monomers such as ε-caprolactone, methylvalerolactone, etc. etc.

Examples of polycarbonate polyols include ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6- At least one polyhydric alcohol such as hexanediol, 3-methyl-1,5-pentanediol, neopentyl glycol, 1,8-octanediol, 1,9-nonanediol, diethylene glycol, alicyclic dihydroxy compound, etc. , diethylene carbonate, dimethyl carbonate, diethyl carbonate and the like.

The low molecular weight diol is not particularly limited as long as it has a molecular weight of 500 or less, but examples include ethylene glycol, propanediol, 2-methyl-1,3-propanediol, and 2-butyl-2-ethyl-1,3-propanediol. Examples include diol, 2,4-diethyl-1,5-pentanediol, and 2-ethyl-1,3-hexanediol.

Other polyols (a-3) may be used alone or in combination of two or more. Further, as the other polyol (a-3), polyols other than those mentioned above may be included.

<Polyisocyanate component (B)>
The polyisocyanate (having a plurality of isocyanate groups) included as the polyisocyanate component (B) will be explained.

The polyisocyanate component (B) contains at least carbodiimide-modified diphenylmethane diisocyanate (b-1) and a polyisocyanate other than the carbodiimide-modified diphenylmethane diisocyanate (other polyisocyanate (b-2)).

Carbodiimide-modified diphenylmethane diisocyanate (b-1) is a compound represented by the following formula.

Other polyisocyanates (b-2) are not particularly limited, but examples include tolylene diisocyanate (TDI), 4,4'-diphenylmethane diisocyanate (MDI), polymethylene polyphenyl polyisocyanate (polymeric MDI), and hydrogenated MDI. , 1,5-naphthalene diisocyanate, 1,6-hexamethylene diisocyanate (HDI), isophorone diisocyanate, xylylene diisocyanate (XDI), hydrogenated XDI, tetramethylxylylene diisocyanate (TMXDI), 1,8-diisocyanatomethyl Examples include octane, lysine ester triisocyanate, 1,3,6-hexamethylene triisocyanate, 1,6,11-undecane triisocyanate, bicycloheptane triisocyanate, and modified products and derivatives thereof.

The other polyisocyanate (b-2) preferably includes MDI (pure MDI).

The average number of functional groups (average number of isocyanate groups) of all polyisocyanates contained in the polyisocyanate component (B) is preferably 2.0 to 4.0, more preferably 2.0 to 3.0, It is more preferably 2.0 to 2.5, even more preferably 2.0 to 2.3, and particularly preferably 2.0 to 2.1.

Note that the average number of functional groups of all polyisocyanates contained in the polyisocyanate component (B) can be calculated based on the method disclosed in JP-A-10-231347 and the like. For example, when containing modified diphenylmethane diisocyanate and diphenylmethane diisocyanate (purified p-MDI, 4,4'-MDI), the NCO group content when the modified diphenylmethane diisocyanate and diphenylmethane diisocyanate are weighed in the same ratio. Based on the measurement results of the ratio, it can be calculated from the following equation 1.

The NCO group content of the polyurethane prepolymer (I) is not particularly limited, but is preferably 1.0 to 2.5%. By setting it in such a range, it becomes possible to promote curing due to moisture while suppressing foaming during work. Note that the NCO group content is measured according to JIS K1603-1.

<Catalyst (II)>
The catalyst (II) includes a reactive catalyst having a functional group that reacts with an isocyanate group.

The functional group that reacts with an isocyanate group in the reactive catalyst is, for example, an active hydrogen group that reacts with a polyisocyanate, and is preferably at least one functional group selected from a hydroxyl group and an amino group.

The reactive catalyst preferably has one functional group that reacts with an isocyanate group and has a tertiary amine structure.

As a reactive catalyst, for example, (1) an amine catalyst having a hydroxyl group as a functional group (for example, N,N-dimethylaminohexanol, N,N-dimethylaminoethoxyethoxyethanol, N,N-dimethylaminoethoxyethanol); , diethanolamine, triethanolamine), and (2) amine catalysts having an amino group as a functional group (for example, N,N,N'',N''-tetramethyldiethylenetriamine).

These reactive catalysts may be used alone or in combination of two or more.

Further, the catalyst (II) may contain a catalyst other than the reactive catalyst (for example, a metal catalyst, an amine catalyst without the above-mentioned functional group, etc.) as long as the effects of the present invention are not impaired.

<Other ingredients>
Other components include known additives used in hot melt adhesives, such as oil components (plasticizers), tackifier resins, antioxidants, waxes, etc., preferably within a range where the VOC is 150 ppm or less. Can be blended. Further, heat stabilizers, fillers, etc. may be added.

Examples of the oil component include paraffinic oil, naphthenic oil, and aromatic oil. Note that vegetable oil or the like may be used as the oil component.

Tackifier resins include aliphatic petroleum resins, aromatic petroleum resins, hydrogenated aliphatic petroleum resins, hydrogenated aromatic petroleum resins, terpene resins, styrene resins, rosin resins, and modified resins thereof. Examples include one or more tackifying resins selected from the group consisting of:

Examples of antioxidants include phenolic antioxidants (for example, Irganox 1010 (manufactured by BASF)), sulfur-based antioxidants (for example, SUMILIZER TP-D (manufactured by Sumitomo Chemical)), and phosphorus antioxidants (for example, , Irgafos168 (manufactured by BASF), and JP-650 (manufactured by Johoku Kagaku).

Waxes include natural waxes (e.g., animal waxes (beeswax, spermaceti wax, etc.), vegetable waxes (wood wax, etc.), petroleum waxes (paraffin wax, etc.), etc.), and synthetic waxes (e.g., synthetic hydrocarbons). (low-molecular polyethylene, etc.), fatty acid engineered esters (polyethylene glycol, etc.), etc.).

These additives may be used alone or in combination of two or more.

<<Content of each component>>
The content of polyurethane prepolymer (I) is preferably 80 to 99.99% by mass (more preferably 95 to 99.99% by mass) based on the entire composition.

The content of catalyst (II) varies depending on the type of polyurethane prepolymer (I), but is preferably 0.01 to 0.1% by mass (more preferably 0.01 to 0.1% by mass) based on the entire composition. 05% by mass).

When the polyol component (A) contains a crystalline polyester polyol (a-1) and a polyether polyol (a-2), the content of the crystalline polyester polyol (a-1) in the polyol component (A) is preferably 10 to 60% by mass, more preferably 20 to 40% by mass, based on the entire polyol component (A). By setting it as such a range, it becomes possible to maintain an appropriate solidification time and high peel strength.

Further, the content of the polyether polyol (a-2) in the polyol component (A) is preferably 30 to 80% by mass, and 40 to 60% by mass, based on the entire polyol component (A). It is more preferable to do so. By setting it as such a range, it becomes possible to achieve both high flexibility and peel strength.

Note that the ratio of the content of crystalline polyester polyol (a-1) to the content of polyether polyol (a-2) in the polyol component (A) is preferably 20:80 to 70:30. The ratio is more preferably 30:70 to 50:50.

Further, the content of the other polyol (a-3) in the polyol component (A) is preferably 30% by mass or less based on the entire polyol component (A). By setting it in such a range, it becomes possible to satisfy physical properties such as moisture heat aging resistance and peel strength. Note that the lower limit is not particularly limited, but is, for example, 5% by mass or more based on the entire polyol component (A).

In the polyisocyanate component (B), the content of carbodiimide-modified diphenylmethane diisocyanate (b-1) is more than 0.5% by mass and 10% by mass or less based on the entire polyisocyanate component (B). Furthermore, the content is preferably 0.6% by mass or more and 10% by mass or less, more preferably 0.7% by mass or more and 10% by mass or less, based on the entire polyisocyanate component (B), and It is more preferably 0.8% by mass or more and 10% by mass or less, even more preferably 0.9% by mass or more and 10% by mass or less, and particularly preferably 1% by mass or more and 10% by mass or less. By setting the blending amount of carbodiimide-modified diphenylmethane diisocyanate (b-1) within this range, it is possible to suppress an increase in the viscosity of the composition while improving the moist heat resistance and thermal stability of the adhesive due to the modified base group. . Among these, the content of carbodiimide-modified diphenylmethane diisocyanate (b-1) is preferably 1% by mass or more and 10% by mass or less based on the entire polyisocyanate component (B).

50% by mass or more, 80% by mass or more, 90% by mass or more, 95% by mass or more, 99% by mass or more, or 100% by mass of the entire other polyisocyanate (b-2) is MDI (pure MDI). It is preferable.

<<<Manufacturing method>>>
The method for producing the urethane hot melt adhesive composition according to the present embodiment may be any known method, and is not particularly limited as long as the produced urethane hot melt adhesive composition does not impair the purpose of the present invention. For example, it can be manufactured as follows. (1) A predetermined amount of polyisocyanate is dropped into a reaction container containing a predetermined amount of polyol, and then heated, so that the isocyanate groups of the polyisocyanate are stoichiometrically excessive with respect to the hydroxyl groups of the polyol. The reaction is carried out under the following conditions to prepare polyurethane prepolymer (I). (2) A method of producing a desired urethane hot melt adhesive composition by dropping a predetermined amount of other components including the catalyst (II) onto the polyurethane prepolymer (I) and stirring the mixture.
The reaction is carried out at a temperature of, for example, 50 to 120°C, preferably 60 to 100°C. The reaction time is, for example, 1 to 15 hours.

<<<Physical properties>>>
Next, each physical property of the hot melt adhesive composition according to this embodiment will be explained.

<<VOC>>
In the hot melt adhesive composition according to the present embodiment, it is preferable that the amount of organic volatile components generated when heated at 90° C. is 150 ppm or less in terms of toluene. By keeping the VOC within this range, all vehicle seat products can meet the regulatory values.

<<Moist heat resistance>>
The hot-melt adhesive composition according to the present embodiment has heat-and-moisture resistance as a time period during which it can maintain a peel strength of 80% or more of the normal peel strength when left standing in a heat-and-moisture environment (80° C., 95%). It is preferable that the evaluated moisture and heat resistance is 400 hours or more.

<<Thermal stability 1 (storage stability): medium temperature/long-term thermal stability>>
The hot melt adhesive composition according to the present embodiment was sealed in an aluminum bag and allowed to stand at 50°C for 3 months, and the residual rate of NCO% (NCO% after standing/NCO% before standing) It is preferable that the storage stability evaluated as NCO%×100) is 80% or more.

<<Thermal Stability 2: High Temperature/Short-term Thermal Stability>>
The hot melt adhesive composition according to the present embodiment was evaluated as the viscosity increase rate (viscosity after test/viscosity before test x 100) of the hot melt adhesive composition heated at 140° C. for 4 hours in a nitrogen atmosphere. It is preferable that the thermal stability is 200% or less.

<Measurement method>
Rotor No. connected to Brookfield Digital Viscometer LVDV-I+. The viscosity can be measured by placing 15 g of sample No. 4 heated and melted at 140° C. in a cylindrical glass container. The viscosity before the test is the viscosity after 0 hours, and the viscosity after the test is the viscosity after 4 hours.

<<Normal peel strength>>
The hot melt adhesive composition according to the present embodiment preferably has a normal peel strength of 3 N/25 mm or more, which is evaluated as peel strength one day after bonding the urethane foam and the skin material.

<<<Applications>>>
The hot melt adhesive composition according to this embodiment is a reactive hot melt adhesive composition capable of laminating and bonding a skin material and a base material. In particular, when formed into a specific fibrous form as described below, it forms an adhesive layer (a layer made of a cured hot melt adhesive composition) that is excellent in texture, air permeability, and seepage prevention properties. Therefore, any type of skin material and base material can be used, such as resin foam, resin film, synthetic leather, natural leather, woven fabric, or non-woven fabric. In addition, since the base material can be applied to urethane resin foam, it can be applied to long products in which a base material consisting of a continuous sheet and a skin material are laminated and bonded, and ordinary thermoplastic hot melt adhesives can be used. It can also be used for vehicle parts (particularly for vehicle interiors), which are difficult to apply.

<<<How to apply>>>
Next, an example of a method for applying the hot melt adhesive composition according to the present embodiment will be described. Note that in this example, a case will be described in which a hot melt adhesive composition is applied using a non-contact method (for example, a spray method) to form a predetermined adhesive layer. The method of applying the agent composition is not limited to this, and it may be applied to the surface to be bonded by a known method.

<<Melting process>>
First, the hot melt adhesive composition according to the present embodiment is heated and held in a molten state (melting step). Usually, the melting process requires a moisture-free atmosphere.

<<Coating process>>
Next, the hot melt adhesive composition in a molten state is applied to the surface of the object to be bonded (preferably the surface of the foam) using an appropriate coating method (preferably a non-contact coating method). do. The specific shape during application is not particularly limited, but for example, it may be applied in a linear shape, dot shape, fiber shape, etc. to form an adhesive layer. Alternatively, the adhesive layer may be formed in the form of a sheet. In the adhesive layer, the adhesive composition may be applied in an amount of preferably 5 to 50 g/m ² (more preferably 10 to 30 g/m ² ). Note that the adhesive composition may be applied to both surfaces to be bonded.

The specific coating conditions are not particularly limited; for example, when using a non-contact coating method as described above, the coating may be carried out at a pressure of 0.01 to 0.4 MPa and a temperature of 100 to 160°C. good.

Here, the non-contact coating method is a method of coating the adhesive composition without the coating equipment coming into contact with the member to be bonded, and includes, for example, coating by a spray method.

Note that prior to the coating step, the surface to be bonded may be subjected to known pretreatment (for example, primer treatment, corona treatment, plasma treatment, etc.).

<<Contact process, curing process>>
After the coating step, another member is brought into contact with the surface to be bonded (coated surface) provided with the adhesive layer, and the hot melt adhesive composition is cooled and hardened. Usually, as described above, after cooling and curing, uncured isocyanate terminals react with moisture in the air to form a crosslinked structure, thereby developing stronger adhesiveness.

When applying the hot-melt adhesive composition according to the present embodiment by the method described in the above-mentioned application step, adhesion is possible regardless of the object to be adhered. Specifically, even if it is a resin foam, a resin film, a synthetic leather, a natural leather, a woven fabric, or a nonwoven fabric, it has excellent texture, air permeability, and adhesiveness, and can be prevented from seeping into the object to be bonded. Particularly, such effects can be achieved even when the object to be bonded is a urethane resin foam.

As described above, a laminate having an adhesive layer that is a cured product of the hot melt adhesive composition according to the present embodiment, in particular, a foam and an adhesive layer provided on the surface of the foam, is manufactured. A laminate having the following properties is obtained. In addition, as for the specific structure of the laminate, it is preferable that the laminate is composed of urethane foam as a base material and a skin material or back fabric. Such a laminate is preferably a vehicle interior material, that is, a base material (a skin layer is attached to the surface of a laminate sheet with a backing fabric layer formed on the back side of a cushioning layer made of foam). It can be used as a laminated material (laminated sheet).

Here, referring again to FIG. 1, the laminate 10 of this embodiment will be described. The laminate 10 is manufactured by applying a predetermined amount of polyurethane hot melt adhesive 13 to one or both of one side of the foamed polyurethane layer 11 and the covering layer 15, and then applying the polyurethane hot melt adhesive 13 to one side of the foamed polyurethane layer 11 and the covering layer 15. This is done by superimposing them and cooling and curing the polyurethane hot melt adhesive 13 in that state.

The method for applying the polyurethane hot melt adhesive 13 may be either a non-contact method such as spray coating, or a contact method such as roll coater coating. The coating amount of the polyurethane hot melt adhesive 13 is preferably 5 to 50 g/m ² , more preferably 10 to 30 g/m ² . As conditions for the non-contact method, a pressure of 0.01 to 0.4 MPa and a temperature of 100 to 160°C are exemplified.

After cooling and curing, the polyurethane hot melt adhesive 13 exhibits stronger adhesive strength because the uncured terminal isocyanate in the polyurethane prepolymer (I) reacts with moisture in the air to form a crosslinked structure. .

In a laminate 20 according to another embodiment shown in FIG. 2, a covering layer 15 is placed on one surface of the foamed polyurethane layer 11, and the covering layer 15 is placed on one surface of the foamed polyurethane layer 11 on the opposite side to the surface on which the covering layer 15 is placed. It consists of a surface layer 19 placed on the surface. The covering layer 15 and the foamed polyurethane layer 11 are bonded together by a polyurethane hot melt adhesive 13, and the surface layer 19 and the foamed polyurethane layer 11 are bonded together by a polyurethane hot melt adhesive 17. The polyurethane hot melt adhesives 13 and 17 are the same as the hot melt adhesive 13 described in connection with the laminate 10 of FIG.

The surface layer 19 is made of an appropriate material such as natural leather, synthetic leather, or fabric (plastic film lined product).

The laminate 20 can be manufactured by the following method. First, one side of the polyurethane foam layer 11 and the covering layer 15 are bonded together using a polyurethane hot melt adhesive 13 in the same manner as the laminate 10 in FIG. Thereafter, a predetermined amount of polyurethane hot melt adhesive 17 is applied to either or both of the other surface of the foamed polyurethane layer 11 and the surface layer 19. Thereafter, the surface of the foamed polyurethane layer 11 and the surface layer 19 are overlapped, and in this state, the polyurethane hot melt adhesive 17 is cooled and hardened. Thereby, a laminate 20 can be obtained. After cooling and curing, the polyurethane hot melt adhesive 17 exhibits stronger adhesive strength because the uncured terminal isocyanate in the polyurethane prepolymer reacts with moisture in the air to form a crosslinked structure. Note that it is also possible to first adhere the surface layer 19 to one side of the foamed polyurethane layer 11 with the polyurethane hot melt adhesive 17 and then adhere the cover layer 15 to the opposite side of the foamed polyurethane layer 11 with the polyurethane hot melt adhesive 13. good.

The laminate 20 is suitable as a skin material for a vehicle interior material such as a vehicle seat cushion, headrest, or instrument panel. The main component of vehicle interior materials is a cushioning material made of foamed polyurethane or the like, and the surface of the cushioning material is covered with a skin material. When the laminate 20 is used as a skin material for a vehicle interior material, the laminate 20 is cut into a predetermined size and a plurality of laminate pieces are sewn together with the surface layer 19 on the front side. Create a shape that covers the interior material.

Next, the present invention will be explained in more detail with reference to Examples and Comparative Examples, but the present invention is not limited thereto.

[Example A related to urethane hot melt adhesive composition]
<<<Manufacture of urethane hot melt adhesive composition>>>
Hereinafter, a method for producing a polyurethane hot melt adhesive composition according to each Example and each Comparative Example will be described.

<<Example A1>>
The polyol component (A) was charged into a reactor, the polyisocyanate component (B-1) was added, and the reaction was carried out at 100°C for 3 to 4 hours, followed by the addition of an OH group-containing tertiary amine catalyst and further 1 A polyurethane hot melt adhesive composition containing a urethane prepolymer having an NCO group content of 2.0% was obtained by reacting for a time. The blending amounts of each component are 80 parts by mass of the polyol component (A), 20 parts by mass of the polyisocyanate component (B-1), and 0.03 parts by mass of the amine catalyst.

<Polyol component (A)>
Crystalline polyester polyol (sebacic acid/butanediol) melting point 60°C, number average molecular weight 4000, 40 parts by mass Polypropylene glycol Addition form PO alone, number average molecular weight 2000, 50 parts by mass Polycarbonate diol, number average molecular weight 1000, 10 parts by mass

<Polyisocyanate component (B-1)>
Diphenylmethane diisocyanate (MDI), 99 parts by mass Carbodiimide-modified MDI, 1 part by mass

<<Example A2>>
A polyurethane hot melt adhesive composition according to Example A2 was produced in the same manner as Example A1 except that the polyisocyanate component (B-1) was changed to the polyisocyanate component (B-2).

<Polyisocyanate component (B-2)>
Diphenylmethane diisocyanate (MDI), 90 parts by mass Carbodiimide-modified MDI, 10 parts by mass

<<Comparative Example A1>>
A polyurethane hot melt adhesive composition according to Comparative Example A1 was produced in the same manner as Example A1 except that the polyisocyanate component (B-1) was changed to the polyisocyanate component (B-3).

<Polyisocyanate component (B-3)>
Diphenylmethane diisocyanate (MDI), 100 parts by mass

<<Comparative Example A2>>
Polyurethane hot melt adhesive according to Comparative Example A2 in the same manner as Example A1 except that the OH group-containing tertiary amine catalyst was changed to a high molecular weight tertiary amine catalyst (main component: N,N'-dimethyldodecylamine). A drug composition was prepared.

<<Comparative Example A3>>
A polyurethane hot melt adhesive composition according to Comparative Example A3 was produced in the same manner as Example A1 except that the polyisocyanate component (B-1) was changed to the polyisocyanate component (B-4).

<Polyisocyanate component (B-4)>
Diphenylmethane diisocyanate (MDI), 99.5 parts by mass Carbodiimide-modified MDI, 0.5 parts by mass

<<Comparative Example A4>>
A polyurethane hot melt adhesive composition according to Comparative Example A4 was produced in the same manner as Example A1 except that the polyisocyanate component (B-1) was changed to the polyisocyanate component (B-5).

<Polyisocyanate component (B-5)>
Diphenylmethane diisocyanate (MDI), 89 parts by mass Carbodiimide-modified MDI, 11 parts by mass

＜＜＜Evaluation＞＞
Next, each of the hot melt adhesive compositions obtained above was specifically evaluated by the following method. The evaluation results are shown in Table 1.

<<VOC>>
The hot melt adhesive was directly put into a glass tube of a thermal desorption device (TD-100, manufactured by Markes), and the outgas was measured by GC/MS (GC/MS (6890/5973), manufactured by Agilent). The sample was heated at 90°C for 30 minutes, and the toluene equivalent value was calculated up to C20. When the measurement result was 150 ppm or less, it was determined to be passed.

<<Moist heat resistance>>
A urethane foam (150 x 25 x 5 mm) was spray-coated with 20 g/m ² of hot melt adhesive melted at 140° C. using a hand gun (manufactured by REKA), and the skin material was pressure-bonded. After 3 days, it was allowed to stand in an environment of 80°C and 95%, and the peel strength was measured every 100 hours. The time from the normal peel strength to the time when 80% was maintained was measured. When the measurement result was 400 hours or more, it was determined that the test was passed. Normal peel strength was measured by the following method.

<Normal peel strength>
A urethane foam (150 x 25 x 5 mm) was spray-coated with a hot melt adhesive melted at 140° C. at 20 g/m ² using a hand gun (manufactured by REKA), and the skin material was pressure-bonded. One day later, the peel strength was measured using an autograph (AG-Xplus, manufactured by Shimadzu Corporation) at a tensile speed of 200 mm/min. The average value of the peel strengths at three points, each of the maximum and minimum values, was calculated using the median value of N=3.

<<Storage stability>>
A hot melt adhesive (12.5 g) was placed in an aluminum bag (volume 110 cc), and the bag was allowed to stand at 50° C. for 3 months in a sealed state, and the rate of decrease in NCO% was measured. When the measurement result was 80% or more, it was judged as passing.

<<Thermal stability>>
The viscosity increase rate of the hot melt adhesive after heating at 140° C. for 4 hours in a nitrogen atmosphere was measured. When the measurement result was 200% or less, it was determined to have passed.

[Example B related to laminate]
Using the following raw materials, foamed polyurethane resin compositions having the formulations of each example and each comparative example shown in FIG. Foamed polyurethane layers of Comparative Examples B1 to B12 were produced. Note that the numerical values of raw materials in the foamed polyurethane resin composition column of FIG. 3 are parts by mass.

Polyol: polyether polyol, number of functional groups 3, molecular weight 3000, hydroxyl value 56 mgKOH/g, product name: GP3050NS, manufactured by Sanyo Chemical Industries, Ltd. Flame retardant 1: melamine powder, average particle size 0.3 μm, product name: melamine, Mitsui Chemicals Co., Ltd. Flame retardant 2: Phosphorus-containing solid flame retardant, aliphatic phosphoric acid amidate, Product name: DAIGURD-850, Daihachi Chemical Industry Co., Ltd. Flame retardant 3: Phosphorus-containing liquid flame retardant, condensed phosphate ester, Product name: DAIGURD -880, manufactured by Daihachi Chemical Industry Co., Ltd. Foaming agent: Water Foam stabilizer: Silicone foam stabilizer, Product name: B-8244, manufactured by Evonik Amine catalyst: N,N-dimethylaminohexanol, Product name: No. 25, manufactured by Kao Corporation Metal catalyst 1: tin ricinoleate containing active hydrogen groups, product name: KOSMOSEF, manufactured by Evonik Metal catalyst 2: stannous octylate, manufactured by Johoku Kagaku Kogyo Co., Ltd. Polyisocyanate: TDI (2, Mixture of 4-TDI 80% and 2,6-TDI 20%), product name: Coronate T-80, manufactured by Tosoh Corporation

Density (apparent density, based on JIS K 7222), tensile strength (based on JIS K 6700-5 3), and elongation (based on JIS K 6400-5 3) were measured for the foamed polyurethane layers of each Example and each Comparative Example.

Further, a coating layer was adhered to one side of the foamed polyurethane layer of Example B1 using hot melt adhesive 6 to produce a laminate of Example B1. The coating layer was Nylon Tricot 15d manufactured by Kiryu Tricot Co., Ltd., and hot melt adhesive 6 was spray-coated at a coating amount of 20 g/m ² .

As the polyurethane hot melt adhesive 6, the polyurethane hot melt adhesive composition produced in Example A1 above was used.

Further, a coating layer was adhered to one side of the foamed polyurethane layer of Example B2 using hot melt adhesive 7 to produce a laminate of Example B2. The coating layer was Nylon Tricot 15d manufactured by Kiryu Tricot Co., Ltd., and hot melt adhesive 7 was spray-coated at a coating amount of 20 g/m ² .

As polyurethane hot melt adhesive 7, the polyurethane hot melt adhesive composition produced in Example A2 above was used.

Further, a coating layer was adhered to one side of the foamed polyurethane layer of Comparative Examples B1 to B3 and Comparative Examples B7 to B10 using polyurethane hot melt adhesive 1, and Comparative Examples B1 to B3 and Comparative Examples B7 to A laminate of Comparative Example B10 was manufactured. The coating layer was Nylon Tricot 15d manufactured by Kiryu Tricot Co., Ltd., and polyurethane hot melt adhesive 1 was spray-coated at a coating amount of 20 g/m ² .

Polyurethane hot melt adhesive 1 was prepared by putting the following polyol component (A) into a reaction container, adding polyisocyanate and an amine catalyst, and reacting at 100°C for 3 to 4 hours to obtain NCO%=2.0. % polyurethane prepolymer was prepared and designated as polyurethane hot melt adhesive 1.

(Polyurethane hot melt adhesive 1)
・Polyol component (A)
Crystalline polyester polyol (a-1): Sebacic acid/butanediol, melting point 60°C, number average molecular weight 4000, 35 parts by mass Polyether polyol (a-2): Polypropylene glycol (addition form PO alone), number average molecular weight 2000 , 50 parts by mass Other polyol (a-3): Amorphous polyester polyol, phthalic acid/neopentyl glycol, number average molecular weight 1000, 15 parts by mass - Polyisocyanate (B)
Diphenylmethane diisocyanate, NCO% = 33%, 24 parts by mass - Amine catalyst: N,N-dimethyldodecylamine, 0.05 parts by mass

Regarding the foamed polyurethane layer of Comparative Example B4, a coating layer was adhered to one side thereof using polyurethane hot melt adhesive 2 to produce a laminate of Comparative Example B4. The coating layer was Nylon Tricot 15d manufactured by Kiryu Tricot Co., Ltd., and polyurethane hot melt adhesive 2 was spray-coated at a coating amount of 20 g/m ² .

Polyurethane hot melt adhesive 2 was prepared by putting the following polyol component (A) into a reaction container, adding polyisocyanate and an amine catalyst, and reacting at 100°C for 3 to 4 hours to obtain an NCO% of 2.0. % polyurethane prepolymer was produced and designated as polyurethane hot melt adhesive 2.

(Polyurethane hot melt adhesive 2)
・Polyol component (A)
Crystalline polyester polyol (a-1): dodecanedioic acid/hexanediol, melting point 70°C, number average molecular weight 4000, 35 parts by mass Polyether polyol (a-2): polypropylene glycol (addition form PO alone), number average Molecular weight 2000, 50 parts by mass Other polyol (a-3): polycarbonate diol (addition form PO alone), melting point 50°C, number average molecular weight 1000, 15 parts by mass - Polyisocyanate (B)
Diphenylmethane diisocyanate, NCO% = 33%, 24 parts by mass - Amine catalyst: N,N-dimethyldodecylamine, 0.05 parts by mass

Regarding the foamed polyurethane layer of Comparative Example B5, a coating layer was adhered to one side thereof using polyurethane hot melt adhesive 3 to produce a laminate of Comparative Example B5. The coating layer was made of Nylon Tricot 15d manufactured by Kiryu Tricot Co., Ltd., and polyurethane hot melt adhesive 3 was spray-coated at a coating amount of 20 g/m ² .

Polyurethane hot melt adhesive 3 was prepared by putting the following polyol component (A) into a reaction container, adding polyisocyanate and an amine catalyst, and reacting at 100°C for 3 to 4 hours to obtain NCO%=2.0. % polyurethane prepolymer was prepared and designated as polyurethane hot melt adhesive 3.

(Polyurethane hot melt adhesive 3)
・Polyol component (A)
Crystalline polyester polyol (a-1): dodecanedioic acid/hexanediol, melting point 70°C, number average molecular weight 4000, 35 parts by mass Polyether polyol (a-2): polypropylene glycol (addition form PO alone), number average Molecular weight: 2000, 50 parts by mass Other polyol (a-3): Butylethylpropanediol (addition form PO alone), melting point: 43°C, 15 parts by mass - Polyisocyanate (B)
Diphenylmethane diisocyanate, NCO% = 33%, 40 parts by mass - Amine catalyst: N,N-dimethyldodecylamine, 0.05 parts by mass

Regarding the foamed polyurethane layer of Comparative Example B6, a coating layer was adhered to one side thereof using polyurethane hot melt adhesive 4 to produce a laminate of Comparative Example B6. The coating layer was Nylon Tricot 15d manufactured by Kiryu Tricot Co., Ltd., and polyurethane hot melt adhesive 4 was spray-coated at a coating amount of 20 g/m ² .

Polyurethane hot melt adhesive 4 was prepared by putting the following polyol component (A) into a reaction container, adding polyisocyanate and an amine catalyst, and reacting at 100°C for 3 to 4 hours to obtain NCO%=2.0. % polyurethane prepolymer was prepared and designated as polyurethane hot melt adhesive 4.

(Polyurethane hot melt adhesive 4)
・Polyol component (A)
Crystalline polyester polyol (a-1): Sebacic acid/hexanediol, melting point 65°C, number average molecular weight 4000, 20 parts by mass Polyether polyol (a-2): Polypropylene glycol (addition form PO alone), number average molecular weight 2000, 80 parts by mass ・Polyisocyanate (B)
Diphenylmethane diisocyanate, NCO% = 33%, 18 parts by mass - Amine catalyst: N,N-dimethyldodecylamine, 0.05 parts by mass

Regarding the foamed polyurethane layer of Comparative Example B11, a coating layer (Nylon Tricot 15d, manufactured by Kiryu Tricot Co., Ltd.) was adhered by flame lamination to produce a laminate of Comparative Example B11.

Regarding the foamed polyurethane layer of Comparative Example B12, the covering layer was adhered with polyurethane hot melt adhesive 5 to produce a laminate of Comparative Example B12. The coating layer was Nylon Tricot 15d manufactured by Kiryu Tricot Co., Ltd., and polyurethane hot melt adhesive 5 was spray-coated at a coating amount of 20 g/m ² .

The polyurethane hot melt adhesive 5 contains, as polyol components, crystalline polyester polyol (adipic acid/butanediol), melting point 58° C., number average molecular weight 2000, 30 parts by mass, and polypropylene glycol, number average molecular weight 1000, 70 parts by mass. 20 parts by mass of diphenylmethane diisocyanate (NCO%=33%) as a polyisocyanate and 0.05 parts by mass of an amine catalyst (N,N-dimethyldodecylamine) were added, and the mixture was heated at 100°C for 3 hours. A polyurethane prepolymer with an NCO% of 2.0% was produced by reacting for ~4 hours, and was used as polyurethane hot melt adhesive 5.

The laminates of Example B1, Example B2, and Comparative Examples B1 to B12 were evaluated for flammability, VOC value, FOG value, TVOC value, moist heat resistance, storage stability, and thermal stability.
The flammability was measured based on FMVSS302. Flammability is judged as "self-extinguishing" if the flame goes out within 60 seconds at a combustion distance of 51 mm, "non-flammable" if the test piece does not ignite or the flame goes out before marked line A, and "non-flammable" if the flame goes out within 60 seconds at a combustion distance of 51 mm. If it is less than min, it is "passed", and the flame retardance increases in the order of "pass" → "self-extinguishing" → "non-flammable", and "non-flammable" is the most excellent flame retardant.

To measure the VOC value, a 7 mg test piece (with a coating layer) was prepared from the laminates of Example B1, Example B2, and Comparative Examples B1 to B12, and the test piece was placed in a glass tube and placed in a thermal desorption device. (Product name: TDSA (including KAS, KAS-3+, KAS-4); manufactured by Gestel) was used to carry out the VOC measurement method specified in "German Automobile Industry Association VDA278". Specifically, each test piece was heated at a temperature of 90°C for 30 minutes, and the gas generated during the heating was collected using a gas chromatograph mass spectrometer (product name: gas chromatograph mass spectrometer (product number: 6890-5973N)). ; manufactured by Agilent) and the VOC value was calculated. In addition, in accordance with the regulations of "German Automobile Industry Association VDA 278", following the VOC value measurement, heating is performed at a temperature of 120°C for 1 hour, and the gas generated during the heating is similarly analyzed using a gas chromatograph mass spectrometer. The FOG value was also calculated. FOG is a phenomenon in which volatile substances adhere to glass, causing it to become cloudy.

The TVOC value is the total amount of volatile organic compounds emitted and was measured based on PV-3341. Specifically, it is calculated based on the peak area obtained by heating at a temperature of 120° C. for 5 hours and analyzing the gas generated during the heating using a gas chromatograph.
In addition, evaluations of VOC, etc. were conducted. The evaluation criteria were "○" when all of VOC<100ppm, FOG<250ppm, and TVOC<30μgC/g were satisfied, and "x" when any one was not satisfied.

The heat and humidity resistance of the polyurethane hot melt adhesive used in each Example and each Comparative Example was evaluated according to the following method. Three days after creating the laminate, the laminate was allowed to stand in an environment of 80° C. and 95%, and the peel strength was measured every 100 hours. The time from the normal peel strength to the time when 80% was maintained was measured. When the measurement result was 400 hours or more, it was determined that the test was passed. Normal peel strength was measured by the following procedure. One day after creating the laminate, the peel strength was measured using an autograph (AG-Xplus, manufactured by Shimadzu Corporation) at a tensile speed of 200 mm/min. The numerical value obtained by averaging the peel strengths at three points each of the maximum value and minimum value was calculated as the median value of N=3, and was defined as the normal peel strength.

The storage stability of the polyurethane hot melt adhesive used in each Example and each Comparative Example was evaluated according to the following method. A hot melt adhesive (12.5 g) was placed in an aluminum bag (volume 110 cc), and the bag was allowed to stand at 50° C. for 3 months in a sealed state, and the rate of decrease in NCO% was measured. When the measurement result was 80% or more, it was judged as passing.

The thermal stability of the polyurethane hot melt adhesive used in each Example and each Comparative Example was evaluated according to the following method. The viscosity increase rate of the hot melt adhesive after heating at 140° C. for 4 hours in a nitrogen atmosphere was measured. When the measurement result was 200% or less, it was determined to have passed.

In addition, a comprehensive evaluation was performed on the laminates of Example B1, Example B2, and Comparative Examples B1 to B12. The criteria for the overall evaluation is that if the flammability judgment is nonflammable, the VOC etc. evaluation is “〇”, and the moisture heat resistance etc. evaluation is “〇”, the overall evaluation is “〇”, the flammability judgment is nonflammable, and the VOC etc. If the evaluation is "〇" but the evaluation of heat and humidity resistance etc. is "x", the overall evaluation will be "△", and if the flammability judgment is not nonflammable or the VOC evaluation is "x", the overall evaluation will be "x". ”.
Note that "-" in the FOG and TVOC result columns in FIG. 3 means not measured.

(Example B1)
The foamed polyurethane layer of Example B1 contained 100 parts by mass of polyol, 4 parts by mass of flame retardant 1 (melamine powder), 4 parts by mass of flame retardant 2 (phosphorus-containing solid flame retardant), 3.95 parts by mass of blowing agent (water), Obtained from a foamed polyurethane resin composition consisting of 1.1 parts by mass of foam stabilizer, 0.18 parts by mass of amine catalyst, 1.3 parts by mass of metal catalyst 1 (tin ricinoleate containing active hydrogen groups), and isocyanate index 103. It is something. The foamed polyurethane layer of Comparative Example B1 has a density of 25.7 kg/m ³ , a tensile strength of 90 kPa, and an elongation of 216%.

The laminate of Example B1 has a covering layer adhered to one side of a foamed polyurethane layer with a polyurethane hot melt adhesive 6, and has a combustible distance of 0 mm, a flammability rating of "nonflammable", a VOC value of 70 ppm, and an FOG value of 31 ppm. , TVOC value of 13 μgC/g, evaluation of VOC etc. as “〇”, evaluation of heat and humidity resistance as “〇”, evaluation of storage stability as “〇”, evaluation of thermal stability as “〇”, and overall evaluation as “〇”. The laminate of Example B1 has low VOC, good flame retardancy and good thermal properties.

(Example B2)
The foamed polyurethane layer of Example B2 was obtained from the same foamed polyurethane resin composition as Example B1, and had the same physical property values as the foamed polyurethane layer of Example B1. The laminate of Example B2 has a covering layer adhered to one side of a foamed polyurethane layer with a polyurethane hot melt adhesive 7, and has a combustible distance of 0 mm, a flammability rating of "nonflammable", a VOC value of 72 ppm, and an FOG value of 30 ppm. , TVOC value of 13 μgC/g, evaluation of VOC etc. as “〇”, evaluation of heat and humidity resistance as “〇”, evaluation of storage stability as “〇”, evaluation of thermal stability as “〇”, and overall evaluation as “〇”. The laminate of Example B2 has low VOC, good flame retardancy and good thermal properties.

(Comparative example B1)
The foamed polyurethane layer of Comparative Example B1 contained 100 parts by mass of polyol, 5 parts by mass of flame retardant 2 (phosphorus-containing solid flame retardant), 3.9 parts by mass of blowing agent (water), 1.1 parts by mass of foam stabilizer, and amine catalyst. It was obtained from a foamed polyurethane resin composition consisting of 0.18 parts by mass, 0.8 parts by mass of Metal Catalyst 1 (tin ricinoleate containing active hydrogen groups), and Isocyanate Index 103. The foamed polyurethane layer of Comparative Example B1 has a density of 25.0 kg/m ³ , a tensile strength of 97 kPa, and an elongation of 198%.

The laminate of Comparative Example B1 has a covering layer adhered to one side of a foamed polyurethane layer using polyurethane hot melt adhesive 1, and has a flammability distance of 0 mm, a combustibility rating of "nonflammable", a VOC value of 79 ppm, and a FOG value. 30 ppm, TVOC value 18 μgC/g, evaluation of VOC etc. as “〇”, evaluation of humidity and heat resistance as “×”, evaluation of storage stability as “〇”, evaluation of thermal stability as “〇”, and overall evaluation as “△”. The laminate of Comparative Example B1 has good flame retardancy and low VOC.

(Comparative example B2)
The foamed polyurethane layer of Comparative Example B2 was obtained from the same foamed polyurethane resin composition as Example B1, and had the same physical property values as the foamed polyurethane layer of Example B1. The laminate of Comparative Example B2 has a coating layer adhered to one side of the foamed polyurethane layer with polyurethane hot melt adhesive 1, and has a combustible distance of 0 mm, a flammability rating of "nonflammable", a VOC value of 74 ppm, and an FOG value of 42 ppm. , TVOC value of 15 μgC/g, evaluation of VOC etc. as “〇”, evaluation of heat and humidity resistance as “×”, evaluation of storage stability as “〇”, evaluation of thermal stability as “〇”, and overall evaluation as “△”. The laminate of Comparative Example B2 has good flame retardancy and low VOC

(Comparative Example B3)
The foamed polyurethane layer of Comparative Example B3 was obtained from a foamed polyurethane resin composition consisting of 100 parts by mass of polyol, 4 parts by mass of flame retardant 1 (melamine powder), 4 parts by mass of flame retardant 2 (phosphorus-containing solid flame retardant), 3 parts by mass of blowing agent (water), 1.5 parts by mass of foam stabilizer, 0.1 parts by mass of amine catalyst, 2.75 parts by mass of metal catalyst 1 (tin ricinoleate containing an active hydrogen group), and an isocyanate index of 110. The foamed polyurethane layer of Comparative Example B3 had a density of 34.9 kg/m ³ , a tensile strength of 132 kPa, and an elongation of 204%.

The laminate of Comparative Example B3 has a coating layer adhered to one side of the foamed polyurethane layer with polyurethane hot melt adhesive 1, and has a combustible distance of 0 mm, a flammability rating of "nonflammable", a VOC value of 86 ppm, and an FOG value of 59 ppm. , TVOC value of 3 μgC/g, evaluation of VOC etc. as “〇”, evaluation of heat and humidity resistance as “×”, evaluation of storage stability as “〇”, evaluation of thermal stability as “〇”, and overall evaluation as “△”. The laminate of Comparative Example B3 has good flame retardancy and low VOC.

(Comparative example B4)
The foamed polyurethane layer of Comparative Example B4 was obtained from the same foamed polyurethane resin composition as Example B1, and had the same physical property values as the foamed polyurethane layer of Example B1.
The laminate of Comparative Example B4 has a covering layer adhered to one side of the foamed polyurethane layer with polyurethane hot melt adhesive 2, and has a combustible distance of 0 mm, a combustibility rating of "nonflammable", a VOC value of 70 ppm, and an FOG value of 34 ppm. , TVOC value of 14 μgC/g, evaluation of VOC etc. as “〇”, evaluation of heat and humidity resistance as “×”, evaluation of storage stability as “〇”, evaluation of thermal stability as “〇”, and overall evaluation as “△”. The laminate of Comparative Example B4 has good flame retardancy and low VOC.

(Comparative example B5)
The foamed polyurethane layer of Comparative Example B5 is obtained from the same foamed polyurethane resin composition as Example B1, and has the same physical property values as the foamed polyurethane layer of Example B1.
The laminate of Comparative Example B5 has a coating layer adhered to one side of the foamed polyurethane layer with polyurethane hot melt adhesive 3, and has a combustible distance of 0 mm, a flammability rating of "nonflammable", a VOC value of 69 ppm, and an FOG value of 41 ppm. , TVOC value of 8 μgC/g, evaluation of VOC etc. as “〇”, evaluation of heat and humidity resistance as “×”, evaluation of storage stability as “〇”, evaluation of thermal stability as “〇”, and overall evaluation as “△”. The laminate of Comparative Example B5 has good flame retardancy and low VOC.

(Comparative example B6)
The foamed polyurethane layer of Comparative Example B6 was obtained from the same foamed polyurethane resin composition as Example B1, and had the same physical property values as the foamed polyurethane layer of Example B1.
The laminate of Comparative Example B6 has a coating layer adhered to one side of the foamed polyurethane layer with polyurethane hot melt adhesive 4, and has a combustible distance of 0 mm, a flammability rating of "nonflammable", a VOC value of 88 ppm, and a FOG value of 53 ppm. , TVOC value of 10 μgC/g, evaluation of VOC etc. as “〇”, evaluation of heat and humidity resistance as “×”, evaluation of storage stability as “〇”, evaluation of thermal stability as “〇”, and overall evaluation as “△”. The laminate of Comparative Example B6 has good flame retardancy and low VOC.

(Comparative example B7)
The foamed polyurethane layer of Comparative Example B7 contained 100 parts by mass of polyol, 15 parts by mass of flame retardant 1 (melamine powder), 4.3 parts by mass of blowing agent (water), 1.1 parts by mass of foam stabilizer, and 0.18 parts by mass of amine catalyst. It was obtained from a foamed polyurethane resin composition consisting of 0.31 parts by mass of metal catalyst 2 (stannous octylate) and 103 parts by mass of isocyanate index. The foamed polyurethane layer of Comparative Example B7 has a density of 24.6 kg/m ³ , a tensile strength of 70 kPa, and an elongation of 97%.

The laminate of Comparative Example B7 has a covering layer adhered to one side of the foamed polyurethane layer with polyurethane hot melt adhesive 1, and has a flammability distance of 10 mm, a flammability rating of "self-extinguishing", a VOC value of 446 ppm, and a FOG value. 43 ppm, evaluation of VOC etc. is "x", evaluation of heat and humidity resistance is "x", evaluation of storage stability is "○", evaluation of thermal stability is "○", and overall evaluation is "x". Comparative Example B7 has poor flame retardancy and high VOC because the flame retardant does not contain a phosphorus-containing solid flame retardant and the metal catalyst does not contain tin ricinoleate containing an active hydrogen group.

(Comparative example B8)
The foamed polyurethane layer of Comparative Example B8 contained 100 parts by mass of polyol, 20 parts by mass of flame retardant 1 (melamine powder), 4.7 parts by mass of blowing agent (water), 1.1 parts by mass of foam stabilizer, and 0.18 parts by mass of amine catalyst. It was obtained from a foamed polyurethane resin composition consisting of 0.31 parts by mass of metal catalyst 2 (stannous octylate) and 103 parts by mass of isocyanate index. The foamed polyurethane layer of Comparative Example B8 has a density of 25.5 kg/m ³ , a tensile strength of 56 kPa, and an elongation of 64%.

The laminate of Comparative Example B8 has a coating layer adhered to one side of the foamed polyurethane layer with polyurethane hot melt adhesive 1, and has a combustible distance of 0 mm, a combustibility rating of "nonflammable", a V0C value of 434 ppm, and an F0G value of 61 ppm. , evaluation of V0C etc. is "x", evaluation of heat and humidity resistance is "x", evaluation of storage stability is "○", evaluation of thermal stability is "○", and overall evaluation is "x". Comparative Example B8 has a higher content of melamine powder than Comparative Example B7, so the flammability was judged as "non-flammable", but since the metal catalyst does not contain tin ricinoleate containing active hydrogen groups, it has a high VOC It is.

(Comparative example B9)
The foamed polyurethane layer of Comparative Example B9 used 0.31 parts by mass of Metal Catalyst 2 (stannous octylate) in place of Metal Catalyst 1 (tin ricinoleate containing active hydrogen groups) in Comparative Example B1, and compared the others. This is an example that is the same as Example B1. The foamed polyurethane layer of Comparative Example B9 has a density of 25.6 kg/m ³ , a tensile strength of 114 kPa, and an elongation of 206%.

The laminate of Comparative Example B9 has a coating layer adhered to one side of the foamed polyurethane layer with polyurethane hot melt adhesive 1, and has a combustible distance of 0 mm, a flammability rating of "nonflammable", a V0C value of 639 ppm, and an F0G value of 78 ppm. , evaluation of V0C etc. is "x", evaluation of heat and humidity resistance is "x", evaluation of storage stability is "○", evaluation of thermal stability is "○", and overall evaluation is "x". Compared to Comparative Example B1, Comparative Example B9 did not contain Metal Catalyst 1 (tin ricinoleate containing active hydrogen groups), and therefore had an extremely high VOC value.

(Comparative example B10)
In the foamed polyurethane layer of Comparative Example B10, 4 parts by mass of flame retardant 3 (phosphorus-containing liquid flame retardant) was used in place of 4 parts by mass of flame retardant 2 (phosphorus-containing solid flame retardant) in Comparative Example B2, and the others were the same as in Comparative Example. This is an example similar to B2. The foamed polyurethane layer of Comparative Example B10 has a density of 24.8 kg/m ³ , a tensile strength of 105 kPa, and an elongation of 201%.

The laminate of Comparative Example B10 has a coating layer adhered to one side of a polyurethane foam layer with polyurethane hot melt adhesive 1, and has a combustible distance of 0 mm, a flammability rating of "non-combustible", a V0C value of 219 ppm, and an F0G value of 1242 ppm. , evaluation of V0C etc. is "x", evaluation of heat and humidity resistance is "x", evaluation of storage stability is "○", evaluation of thermal stability is "○", and overall evaluation is "x". Compared to Comparative Example B2, Comparative Example B10 used flame retardant 3 (phosphorus-containing liquid flame retardant) instead of flame retardant 2 (phosphorus-containing solid flame retardant), so the VOC value and FOG value were extremely large. Ta.

(Comparative example B11)
The foamed polyurethane layer of Comparative Example B11 is obtained from the same foamed polyurethane resin composition as Comparative Example B3, and has the same physical property values as the foamed polyurethane layer of Comparative Example B3.

The laminate of Comparative Example B11 had a coating layer adhered to one side of the foamed polyurethane layer by flame lamination, had a combustible distance of 0 mm, and was judged to be "non-combustible" in terms of flammability, but the V0C value was 260. Evaluation of V0C etc. is "x", evaluation of heat and humidity resistance is "x", evaluation of storage stability is "○", evaluation of thermal stability is "○", and overall evaluation is "x". In Comparative Example B11, the VOC value was much higher than that in Comparative Example B3 because the adhesion was performed by frame lamination.

(Comparative example B12)
The foamed polyurethane layer of Comparative Example B12 is obtained from the same foamed polyurethane resin composition as Comparative Example B3, and has the same physical property values as the foamed polyurethane layer of Comparative Example B3.

The laminate of Comparative Example B12 had a coating layer adhered to one side of the foamed polyurethane layer with polyurethane hot melt adhesive 5, and had a flammability distance of 0 mm and a combustibility rating of "nonflammable," but a V0C value of 128 ppm. , F0G value 219 ppm, TV0C value 16 μgC/g, V0C etc. evaluation “×”, heat and humidity resistance evaluation “×”, storage stability evaluation “〇”, thermal stability evaluation “〇”, overall evaluation “×” It is. Compared to Comparative Example B3, Comparative Example B12 does not contain a crystalline polyester polyol (a-1) consisting of a condensation reaction product of an aliphatic dicarboxylic acid having 10 to 12 carbon atoms and an aliphatic diol having 4 to 6 carbon atoms. Since a hot melt adhesive made from polyol component (A) was used, the V0C value and F0G value were extremely large.

As described above, the laminates of Example B1 and Example B2, in which the covering layer was adhered to one side of the foamed polyurethane layer of the present invention with the polyurethane hot melt adhesive of the present invention, had low VOC, good flame retardancy, and good flame retardancy. Since it has excellent thermal properties, it is suitable as a member constituting the skin material of a vehicle interior material.
Furthermore, since the laminates of Example B1 and Example B2 have low V0C, good flame retardancy, and good thermal properties, the surface layer made of genuine leather, synthetic leather, fabric, etc. is the polyurethane hot melt of the present invention. A laminate bonded with an adhesive also has lower V0C, better flame retardancy, and better thermal properties than a frame laminate with a surface layer bonded, and is suitable as a skin material for vehicle interior materials. .

Although the invention has been described in detail with reference to specific embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the invention.

10, 20 Laminate 11 Foamed polyurethane layer 13, 17 Polyurethane hot melt adhesive 15 Covering layer 19 Surface layer

Claims (5)

In a laminate with a VOC of less than 100 ppm, in which a coating layer is placed on a foamed polyurethane layer containing a flame retardant,
The foamed polyurethane layer and the coating layer are adhered by a polyurethane hot melt adhesive containing a polyurethane prepolymer (I) made from a polyol component (A) and a polyisocyanate component (B),
The polyisocyanate component (B) in the polyurethane hot melt adhesive contains more than 0.5% by mass and 10% by mass or less of carbodiimide-modified diphenylmethane diisocyanate based on the entire polyisocyanate component (B). body. In a laminate with a VOC of less than 100 ppm, in which a coating layer is placed on a foamed polyurethane layer containing a flame retardant,
The foamed polyurethane layer and the coating layer are adhered by a polyurethane hot melt adhesive containing a polyurethane prepolymer (I) made from a polyol component (A) and a polyisocyanate component (B),
The polyisocyanate component (B) in the polyurethane hot melt adhesive includes carbodiimide-modified diphenylmethane diisocyanate,
A laminate, wherein the polyurethane hot melt adhesive has a thermal stability of 200% or less.
<Thermal stability>
A value evaluated as the viscosity increase rate (viscosity after test/viscosity before test x 100) of a hot melt adhesive composition heated at 140° C. for 4 hours in a nitrogen atmosphere. The laminate according to claim 1 or 2, wherein the laminate has a burning rate of 102 mm/min or less in a flammability test according to FMVSS302. The polyol component (A) consists of a crystalline polyester polyol (a-1) consisting of a condensation reaction product of an aliphatic dicarboxylic acid having 10 to 12 carbon atoms and an aliphatic diol having 4 to 6 carbon atoms, and a polyether polyol (a). -2),
From claim 1, wherein the content of the polyether polyol (a-2) in the polyol component (A) is 30 to 80% by mass based on 100% by mass of the polyol component (A). 3. The laminate according to any one of 3. A skin material for a vehicle interior material, comprising the laminate according to any one of claims 1 to 4.