阅读说明：本技术 层叠体和车辆用内饰材料的表皮材料 (Laminate and skin material for vehicle interior material ) 是由 长野祐也 大田英生 井上贵博 东海真平 于 2018-12-21 设计创作，主要内容包括：一种层叠体(10),在由发泡聚氨酯树脂组合物得到的发泡聚氨酯层(11)上通过包含聚氨酯预聚物(I)和催化剂(II)的聚氨酯热熔胶粘剂(13)胶粘有覆盖层(15),所述发泡聚氨酯树脂组合物包含含活性氢基团的蓖麻油酸锡和含磷固体阻燃剂,所述聚氨酯预聚物(I)以多元醇成分(A)和多异氰酸酯成分(B)为原料。(A laminate (10) wherein a covering layer (15) is bonded to a foamed polyurethane layer (11) obtained from a foamed polyurethane resin composition containing active hydrogen group-containing tin ricinoleate and a phosphorus-containing solid flame retardant by means of a polyurethane hot-melt adhesive (13) containing a polyurethane prepolymer (I) and a catalyst (II), the polyurethane prepolymer (I) being produced from a polyol component (A) and a polyisocyanate component (B).)

1. A laminate comprising a covering layer and a foamed polyurethane layer obtained from a foamed polyurethane resin composition comprising a polyol, a polyisocyanate, a blowing agent, a catalyst and a flame retardant,

the foamed polyurethane resin composition includes: tin ricinoleate containing an active hydrogen group as the catalyst and a phosphorus-containing solid flame retardant as the flame retardant,

the foamed polyurethane layer and the cover layer are adhered by a polyurethane hot-melt adhesive comprising a polyurethane prepolymer (I) and a catalyst (II), the polyurethane prepolymer (I) being prepared 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 relative to the entire polyisocyanate component (B),

the catalyst (II) comprises a reactive catalyst having a functional group that reacts with an isocyanate group.

2. The laminate of claim 1, wherein said reactive catalyst is a catalyst having one functional group reactive with said isocyanate group and having a tertiary amine structure.

3. The laminate according to claim 1 or 2, wherein the polyol component (A) comprises a crystalline polyester polyol (a-1) and a polyether polyol (a-2), the crystalline polyester polyol (a-1) comprises a condensation product of an aliphatic dicarboxylic acid having 10 to 12 carbon atoms and an aliphatic diol having 4 to 6 carbon atoms,

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).

4. The laminate according to claim 3, wherein the crystalline polyester polyol (a-1) has a number average molecular weight of 1000 to 5000, and the polyether polyol (a-2) has a number average molecular weight of 1000 to 4000.

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

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

7. The laminate according to any one of claims 1 to 6, wherein the polyol component (A) of the polyurethane prepolymer (I) in the polyurethane hot-melt adhesive comprises, as the other polyol (a-3), one or more polyols selected from the group consisting of amorphous polyester polyols, polycarbonate polyols, and low-molecular-weight diols having a number-average molecular weight of 500 or less.

8. The laminate according to any one of claims 1 to 7, wherein a surface layer is bonded to a surface of the foamed polyurethane layer opposite to a surface on which the covering layer is placed, with the polyurethane hot-melt adhesive.

9. A skin material for a vehicle interior material, wherein the skin material for a vehicle interior material is formed using the laminate according to claim 8.

Technical Field

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

Background

For example, as a skin material for covering a surface of a seat cushion of a vehicle, there is a skin material obtained by forming a laminate by applying a coating layer to one surface of a foamed polyurethane layer and applying a surface layer to the other surface of the laminate. The cover material is cut and sewn into a shape to cover the seat cushion.

The cover layer is provided to improve slidability for performing a sewing operation and a covering operation of the seat cushion with a 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 including genuine leather, synthetic leather, or woven fabric, depending on the decorative property, tactile property, and the like required for the seat of the vehicle.

Further, since a skin material to be coated on the surface of a seat cushion of a vehicle requires heat resistance, a polyurethane reaction type hot melt adhesive is used for adhesion of a foamed polyurethane layer, a coating layer and a surface layer (patent document 1). The polyurethane reaction type hot melt adhesive contains a polyurethane prepolymer obtained by reacting a polyester polyol with a polyisocyanate as a main component.

As the adhesive used for the seat cushion of the vehicle, it is preferable that the amount of organic volatile matter affecting the human body is small. As such a low outgassing hot melt adhesive, patent document 2 discloses an olefin-based hot melt adhesive having low outgassing properties.

Disclosure of Invention

Problems to be solved by the invention

The skin material itself to be coated on the surface of the seat cushion of the vehicle is also required to have a small amount of VOC (volatile organic compound) which adversely affects the human body. The amount of VOC of the skin material covering the surface of the seat cushion of the vehicle varies depending on the material of the surface layer, and the amount of VOC varies depending on the portion used even with the same kind of genuine leather or the like. Further, although the olefin-based hot melt adhesives can achieve low VOC, their use is limited from the viewpoint of heat resistance and the like, and they are difficult to use in vehicles and the like.

The present invention has been made in view of the above-described circumstances, and an object thereof is to reduce the VOC amount of a laminate including a polyurethane foam layer and a cover layer, to which a surface layer is not adhered, the VOC amount of which is likely to fluctuate depending on the material quality or the like, thereby reducing the VOC amount of a skin material to which a vehicle interior material including a surface layer of a predetermined material is adhered.

Furthermore, in consideration of the case of a vehicle fire, etc., the skin material of the interior material for a vehicle is required to have flame retardancy. In addition, good thermal characteristics (particularly, heat resistance and thermal stability) are required for use in vehicles. The purpose of the present invention is to provide a laminate and a skin material for a vehicle interior material, which have low VOC, good flame retardancy, and good thermal properties.

Means for solving the problems

In the laminate of the present invention capable of solving the above problems,

(1) the laminate comprises a covering layer placed on a foamed polyurethane layer obtained from a foamed polyurethane resin composition comprising a polyol, a polyisocyanate, a blowing agent, a catalyst and a flame retardant,

the aforementioned foamable polyurethane resin composition comprises: tin ricinoleate containing an active hydrogen group as the aforementioned catalyst and a phosphorus-containing solid flame retardant as the aforementioned flame retardant,

the foamed polyurethane layer and the cover layer are bonded by a polyurethane hot-melt adhesive comprising a polyurethane prepolymer (I) which is prepared from a polyol component (A) and a polyisocyanate component (B) and a catalyst (II),

the polyisocyanate component (B) in the polyurethane hot-melt adhesive contains more than 0.5 mass% and not more than 10 mass% of carbodiimide-modified diphenylmethane diisocyanate based on the entire polyisocyanate component (B),

the aforementioned catalyst (II) contains a reactive catalyst having a functional group that reacts with an isocyanate group.

(2) In the laminate of the above (1), it is preferable that:

the aforementioned reactive catalyst is a catalyst having one functional group that reacts with the aforementioned isocyanate group and having a tertiary amine structure.

(3) In the laminate according to the above (1) or (2), it is preferable that:

the polyol component (A) comprises a crystalline polyester polyol (a-1) and a polyether polyol (a-2), the crystalline polyester polyol (a-1) comprising a condensation product of an aliphatic dicarboxylic acid having 10 to 12 carbon atoms and an aliphatic diol having 4 to 6 carbon atoms,

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).

(4) In the laminate of the above (3), it is preferable that:

the number average molecular weight of the crystalline polyester polyol (a-1) is 1000 to 5000, and the number average molecular weight of the polyether polyol (a-2) is 1000 to 4000.

(5) In the laminate according to any one of the above (1) to (4), it is preferable that:

the foamed polyurethane resin composition comprises the phosphorus-containing solid flame retardant as the flame retardant and melamine powder having an average particle diameter of 0.1 to 0.5. mu.m.

(6) In the laminate according to any one of the above (1) to (5), it is preferable that:

the phosphorus-containing solid flame retardant in the foamed polyurethane resin composition is a phosphate ester compound.

(7) In the laminate according to any one of the above (1) to (6), it is preferable that:

the polyol component (a) of the polyurethane prepolymer (I) in the hot melt adhesive contains, as the other polyol (a-3), one or more polyols selected from the group consisting of amorphous polyester polyols, polycarbonate polyols, and low molecular weight diols having a number average molecular weight of 500 or less.

(8) In the laminate according to any one of the above (1) to (7), it is preferable that:

a surface layer is bonded to the surface of the foamed polyurethane layer opposite to the surface on which the cover layer is placed, with the polyurethane hot-melt adhesive.

The skin material of the interior material for a vehicle according to the present invention is capable of solving the above problems

(9) The laminate of (8) above.

Effects of the invention

The present invention can provide a laminate and a skin material for a vehicle interior material, which have a low VOC, good flame retardancy, and good thermal characteristics (particularly, moist heat resistance and thermal stability).

Drawings

Fig. 1 is a sectional view showing a laminate according to an embodiment of the present invention.

Fig. 2 is a sectional view showing a laminate according to another embodiment of the present invention.

Fig. 3 is a table showing the composition, thermal characteristics, combustibility, VOC, and the like of examples and comparative examples of the present invention.

Detailed Description

A laminate 10 according to an embodiment of the present invention shown in fig. 1 includes: a laminate in which a coating layer 15 is placed on one surface of the foamed polyurethane layer 11.

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, polyether polyol or polyester polyol is used. The polyether polyol includes, in addition to compounds obtained by addition polymerization of an alkylene oxide to a polyol, polypropylene glycol, polybutylene glycol, and the like. As the polyhydric alcohol, glycerin, dipropylene glycol, trimethylolpropane, or the like is used. As the alkylene oxide, ethylene oxide, propylene oxide, and the like are used.

Examples of the polyether polyol include a triol obtained by addition polymerization of propylene oxide to glycerin, a triol obtained by addition polymerization of ethylene oxide to the triol, and a diol obtained by addition polymerization of propylene oxide to dipropylene glycol.

The polyether polyol may be a polyether polyol obtained by reacting a polyoxyalkylene polyol with a polyvalent carboxylic acid anhydride and a compound having a cyclic ether group. Examples of the polyoxyalkylene polyol include polyethylene glycol, polypropylene glycol, and propylene oxide adducts of glycerin. Examples of the polyvalent carboxylic acid anhydride include anhydrides of succinic acid, adipic acid, phthalic acid and the like. Examples of the compound having a cyclic ether group (alkylene oxide) include ethylene oxide and propylene oxide. Polyether polyols are preferable to polyester polyols in terms of excellent reactivity with polyisocyanates and in terms of no hydrolysis.

As the polyester polyol, in addition to a condensation polyester polyol obtained by reacting a polycarboxylic acid such as adipic acid or phthalic acid with a polyol such as ethylene glycol, propylene glycol or glycerin, a lactone polyester polyol and a polycarbonate polyester polyol can be used.

As the polyisocyanate, an aliphatic polyisocyanate or an aromatic polyisocyanate having 2 or more isocyanate groups, a mixture thereof, a modified polyisocyanate obtained by modifying the above, and the like can be used. Examples thereof include: toluene Diisocyanate (TDI), 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, tetramethylxylylene diisocyanate (TMXDI), 1,3, 6-hexamethylene triisocyanate, 1,6, 11-undecane triisocyanate, bicycloheptane triisocyanate, and modifications and derivatives thereof. In addition, other prepolymers may also be used. The polyisocyanate may be used alone or in combination of two or more.

The isocyanate index is preferably 80-110. When the isocyanate index is less than 80, it is difficult to obtain the foamed polyurethane layer 11 having good mechanical properties such as tensile strength and elongation, while when it exceeds 110, flexibility of the foamed polyurethane layer 11 is lowered. The isocyanate INDEX (INDEX) is a value obtained by multiplying the number of moles of an isocyanate group contained in a polyurethane raw material to 1 mole of an active hydrogen group by 100 times, and is calculated from [ (isocyanate equivalent in the foamed polyurethane resin composition/equivalent of active hydrogen in the foamed polyurethane resin composition) × 100 ].

As the blowing agent, water, a fluorocarbon substitute, or a hydrocarbon such as pentane may be used alone or in combination. In the case of water, carbon dioxide is generated when the polyol reacts with the polyisocyanate, and foaming is performed using the carbon dioxide. The amount of water as the blowing agent is preferably about 2 parts by mass to about 5 parts by mass with respect to 100 parts by mass of the polyol. In addition, in the case of using other foaming agents together with water, the amount of the other foaming agents may be determined as appropriate.

The catalyst is preferably tin ricinoleate containing an active hydrogen group, and more preferably used in combination with an amine catalyst. By including tin ricinoleate in the catalyst, the amount of VOC of the foamed polyurethane layer 11 and the laminate 10 can be reduced. As the amine catalyst, there may be mentioned: triethylamine, triethylenediamine, diethanolamine, dimethylaminomeorpholine, N-ethylmorpholine, tetramethylguanidine, and the like.

As the flame retardant, a phosphorus-containing solid flame retardant was used. The phosphorus-containing solid flame retardant is a compound having low volatility, and may be used in the form of a halogen-free or halogen-containing compound. Specifically, triphenyl phosphate (white, flaky), aromatic condensed phosphate (white powder to granular), tris (tribromoneopentyl) phosphate (white, crystalline, powder), and the like can be used. The content of the phosphorus-containing solid flame retardant is preferably 3 to 15 parts by mass per 100 parts by mass of the polyol. When the content is less than 3 parts by mass, the low combustibility of the foamed polyurethane layer 11 cannot be sufficiently improved. On the other hand, when the amount is more than 15 parts by mass, the balance of foaming tends to be lost, and it tends to be difficult to obtain a good foamed polyurethane layer 11.

The phosphorus-containing flame retardant includes a phosphorus-containing liquid flame retardant in addition to the phosphorus-containing solid flame retardant used in the present embodiment. However, since the phosphorus-containing liquid flame retardant has higher volatility than the phosphorus-containing solid flame retardant, the VOC amounts of the foamed polyurethane layer 11 and the laminate 10 increase.

For the flame retardant of the present embodiment, it is preferable to use melamine powder together with the phosphorus-containing solid flame retardant. Melamine [ C ]₃N₃(NH₂)₃]Since oxygen is not contained, the progress of combustion can be suppressed. The melamine powder preferably has an average particle size of 0.1 to 0.5. mu.m. The "average particle size" of the melamine is a particle size calculated by a particle size distribution measuring apparatus (for example, SALD-7000H (manufactured by Shimadzu corporation)). Specifically, the weight average (average of weight (volume) based distribution) particle diameter of a dispersion in which a sample is dispersed in a solvent (for example, ethyl acetate) is evaluated as "average particle diameter" using this apparatus. Supposing that the average particle diameterFine melamine powder of 0.1 to 0.5 μm is dispersed in the foamed polyurethane layer 11, and is melted to form a coating film at the time of combustion of the foamed polyurethane layer 11, and blocks oxygen to suppress combustion. When the average particle size 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 is lowered, and the effect of improving the low combustibility cannot be sufficiently exhibited.

The content of the melamine powder is preferably 3 to 13 parts by mass per 100 parts by mass of the polyol. When the content is less than 3 parts by mass, the action of promoting the low combustibility of the foamed polyurethane layer 11 cannot be sufficiently exerted. On the other hand, if the amount exceeds 13 parts by mass, the balance of foaming tends to be lost, and a satisfactory foamed polyurethane layer 11 may not be obtained.

The density and thickness of the foamed polyurethane layer 11 may be appropriately determined, and when the laminate 10 is used for a skin material of a vehicle interior material such as a seat cushion of a vehicle, the density is preferably 20kg/m, for example, so that the laminate can be bent along the surface of the vehicle interior material³～35kg/m³And a thickness of about 3mm to about 10 mm.

It is preferable to include, for example, a foam stabilizer as other additive in the foamed polyurethane resin composition. Examples of the foam stabilizer include: polysiloxane compounds, anionic surfactants such as sodium dodecylbenzenesulfonate and sodium laurate, polyether siloxanes, and phenolic compounds. The content of the foam stabilizer is exemplified by 0.5 to 2.5 parts by mass per 100 parts by mass of the polyol.

Further, as examples of other additives, known additives such as a filler, a stabilizer, a colorant, a plasticizer, and an antibacterial agent may be mentioned as necessary.

The foamed polyurethane layer 11 is produced by a known method for producing a polyurethane foam. As known methods for producing a polyurethane foam, there are mold foaming and plate foaming (スラブ foaming). Mold foaming is a method of filling a foaming polyurethane resin composition in a mold and foaming the composition in the mold. On the other hand, the plate foaming is a method of mixing and discharging a foamed polyurethane resin composition onto a belt conveyor, and foaming the composition at atmospheric pressure and normal temperature. As the foamed polyurethane layer of the present embodiment, a plate-type foam obtained by cutting foamed polyurethane produced by plate-type foaming into a predetermined thickness is more preferable.

The cover layer 15 is preferably a nonwoven fabric, a woven fabric, or a knitted fabric. In particular, since the warp knitted fabric of the knitted fabric has elasticity and stretchability, when the layered body 11 is used as a skin material of a vehicle interior material when used as the cover layer 15, the warp knitted fabric is likely to deform along the surface of the vehicle interior material, and the skin material is less likely to wrinkle. Further, as a material of the cover layer 15, nylon, polyester, or the like can be cited.

The foamed polyurethane layer 11 and the cover layer 15 are bonded by a polyurethane hot melt adhesive 13, and the polyurethane hot melt adhesive 13 contains a polyurethane prepolymer (I) and a catalyst (II) that are made of a polyol component (a) and a polyisocyanate component (B). The polyurethane prepolymer (I) is obtained by reacting a polyol component (a) and a polyisocyanate (B) as raw materials with the polyol component (a) by stoichiometrically excess amount of the polyisocyanate (B), and has an isocyanate group (NCO) at the terminal.

Here, a hot melt adhesive composition usable as the polyurethane hot melt adhesive 13 of the present embodiment will be specifically described in the following order. However, the present invention is not limited to the specific examples described herein.

1 component (A)

2 method of manufacture

3 physical Properties

4 use

5 application method

< ingredient > > <

The hot melt adhesive composition according to the present embodiment is a reactive polyurethane hot melt adhesive with low outgassing. The hot melt adhesive composition according to the present embodiment includes an isocyanate-terminated polyurethane prepolymer (I) as a base resin and a catalyst (II). In addition, other components may be contained in the adhesive composition as necessary.

When such a hot melt adhesive composition is used, adhesiveness is exhibited when the polyurethane prepolymer which is heated to be in a molten state is cooled and solidified. Further, a more firm adhesiveness is exhibited by the formation of a crosslinked structure by the reaction of the uncured isocyanate end with moisture in the air. Such hot melt adhesive compositions may be referred to as moisture-curable hot melt adhesive compositions, reactive hot melt adhesive compositions, or the like.

< polyurethane prepolymer (I) >

The polyurethane prepolymer (I) is obtained by using a polyol component (a) and a polyisocyanate component (B) as raw materials, and usually reacting the polyol component (a) with a stoichiometric excess of the polyisocyanate component (B).

< polyol component (A) >

The polyol component (a) is not particularly limited as long as it is a polyol generally used for producing a polyurethane prepolymer, but preferably includes a polyester polyol and a polyether polyol. More specifically, the polyester polyol (a-1) preferably contains a crystalline polyester polyol (a-1) and a polyether polyol (a-2), and the crystalline polyester polyol (a-1) contains 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.

As the aliphatic dicarboxylic acid having 10 to 12 carbon atoms, there may be mentioned: sebacic acid (sebacylic acid, C10), undecanedioic acid (C11) and dodecanedioic acid (C12). Further, examples of the aliphatic diol 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, 6-hexanediol, etc.).

In the present embodiment, "crystalline polyester polyol" means a polyester polyol having a melting point of 30 ℃ or higher, and "amorphous polyester polyol" means a polyester polyol having a melting point of less than 30 ℃ or a polyester polyol having no melting point. Such crystallization can be controlled by appropriately selecting the carboxylic acid/alcohol constituting the polyester polyol. Melting point is determined using differential scanning calorimetry at temperatureDegree program(rate of temperature rise 5 ℃/min)Within the temperature range at which the melting peak occurs.

The number average molecular weight of the crystalline polyester polyol (a-1) is preferably in the range of 1000 to 5000, more preferably in the range of 2000 to 4500. Here, the "number average molecular weight" is a value calculated from the hydroxyl value of the raw material. The other "number average molecular weight" described in the present specification is also a value calculated in the same manner as the number average molecular weight described herein.

Examples of the polyether polyol (a-2) include: polyethylene glycol, polypropylene glycol, polytetramethylene ether glycol, and the like obtained by polymerizing cyclic ethers such as ethylene oxide, propylene oxide, and tetrahydrofuran, and copolyethers thereof. The cyclic ether may be obtained by polymerizing the above-mentioned cyclic ether with a polyhydric alcohol such as glycerin or trimethylolethane.

The number average molecular weight of the polyether polyol (a-2) is preferably in the range of 1000 to 4000, more preferably 1500 to 3000.

Examples of the polyol other than the crystalline polyester polyol (a-1) and the polyether polyol (a-2) include at least one polyol (a-3) selected from the group consisting of amorphous polyester polyols, polycarbonate polyols, and low-molecular diols having a number-average molecular weight of 500 or less. The polyol component (A) may contain only the other polyol (a-3), but preferably contains the crystalline polyester polyol (a-1) and the polyether polyol (a-2) and further contains the polyol (a-3).

Examples of the amorphous polyester polyol include polyester polyols prepared from an aliphatic dicarboxylic acid (e.g., succinic acid, adipic acid, sebacic acid, azelaic acid, etc.), an aromatic dicarboxylic acid (e.g., phthalic acid, terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid, etc.), an alicyclic dicarboxylic acid (e.g., hexahydrophthalic acid, hexahydroterephthalic acid, hexahydroisophthalic acid, etc.) or an ester or anhydride thereof, and ethylene glycol, 1, 3-propanediol, 1, 2-propanediol, 1, 3-butanediol, 1, 4-butanediol, 1, 5-pentanediol, 1, 6-hexanediol, 3-methyl-1, 5-pentanediol, neopentyl glycol, 1, 8-octanediol, 1, 9-nonanediol, or the like, or a mixture thereof by a dehydration condensation reaction; and polylactone diols obtained by ring-opening polymerization of lactone monomers such as caprolactone and methylvalerolactone.

Examples of the polycarbonate polyol include those obtained by reacting at least one of polyhydric alcohols such as ethylene glycol, 1, 2-propanediol, 1, 3-butanediol, 1, 4-butanediol, 1, 5-pentanediol, 1, 6-hexanediol, 3-methyl-1, 5-pentanediol, neopentyl glycol, 1, 8-octanediol, 1, 9-nonanediol, diethylene glycol, and alicyclic dihydroxy compounds with ethylene carbonate, dimethyl carbonate, diethyl carbonate, and the like.

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

The 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 the above-mentioned polyols may be contained.

< polyisocyanate component (B) >

A polyisocyanate (an isocyanate having a plurality of isocyanate groups) contained as the polyisocyanate component (B) will be described.

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

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

Other polyisocyanates (b-2) are not particularly limited, and include, for example: toluene Diisocyanate (TDI), 4' -diphenylmethane diisocyanate (MDI), polymethylene polyphenyl polyisocyanate (polymeric MDI), hydrogenated MDI, 1, 5-naphthalene diisocyanate, 1, 6-Hexamethylene Diisocyanate (HDI), isophorone diisocyanate, Xylylene Diisocyanate (XDI), hydrogenated XDI, tetramethylxylylene diisocyanate (TMXDI), 1, 8-diisocyanatomethyloctane, lysine ester triisocyanate, 1,3, 6-hexamethylene triisocyanate, 1,6, 11-undecane triisocyanate, bicycloheptane triisocyanate, and modifications, derivatives, and the like thereof.

The other polyisocyanate (b-2) preferably comprises 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, still more preferably 2.0 to 2.5, still more preferably 2.0 to 2.3, and particularly preferably 2.0 to 2.1.

The average number of functional groups of all polyisocyanates contained in the polyisocyanate component (B) can be calculated by the method disclosed in Japanese patent laid-open No. 10-231347 or the like. For example, when modified diphenylmethane diisocyanate and diphenylmethane diisocyanate (purified p-MDI, 4' -MDI) are contained, the NCO group content can be calculated from the following formula 1 based on the measurement result of the NCO group content when the modified diphenylmethane diisocyanate and the diphenylmethane diisocyanate are weighed so as to have the same ratio.

The NCO group content of the polyurethane prepolymer (I) is not particularly limited, but is preferably 1.0% to 2.5%. By setting the range as described above, curing due to moisture can be promoted while suppressing foaming or the like during work. The NCO group content was measured in accordance with 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 reactive with an isocyanate group in the reactive catalyst is, for example, an active hydrogen group reactive with a polyisocyanate, and is preferably at least one of a hydroxyl group and an amino group.

The reactive catalyst is preferably a catalyst having one functional group reactive with an isocyanate group and having a tertiary amine structure.

Examples of the reactive catalyst include: (1) amine catalysts having a hydroxyl group as a functional group (e.g., N-dimethylaminohexanol, N-dimethylaminoethoxyethanol, N-dimethylaminoethoxyethanol, diethanolamine, triethanolamine) and (2) amine catalysts having an amino group as a functional group (e.g., N "-tetramethyldiethylenetriamine), and the like.

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

The catalyst (II) may contain a catalyst other than the reaction type catalyst (for example, a metal-based catalyst, an amine-based catalyst having no functional group, or the like) within a range not to impair the effect of the present invention.

< other ingredients >

As other components, known additives used in hot melt adhesives, for example, oil components (plasticizers), tackifier resins, antioxidants, waxes, and the like, may be blended in a range of preferably 150ppm or less of VOC. In addition, a heat stabilizer, a filler, or the like may be added.

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

Examples of the tackifier resin include at least one tackifier resin selected from the group consisting of 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 of the antioxidant include: phenol type antioxidants (e.g., Irganox1010 (manufactured by BASF corporation)), sulfur type antioxidants (e.g., SUMILIZER TP-D (manufactured by Sumitomo chemical Co., Ltd)), and phosphorus type antioxidants (e.g., Irgafos168 (manufactured by BASF corporation), JP-650 (manufactured by North City chemical Co., Ltd.)).

Examples of the wax include: natural waxes (e.g., animal waxes (e.g., beeswax and spermaceti wax), vegetable waxes (e.g., wood wax), petroleum waxes (e.g., paraffin wax), and the like), and synthetic waxes { e.g., synthetic hydrocarbons (e.g., low molecular weight polyethylene), fatty acid esters (e.g., polyethylene glycol), and the like }.

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

< contents of ingredients >)

The content of the polyurethane prepolymer (I) is preferably 80 to 99.99 mass% (more preferably 95 to 99.99 mass%) with respect to the entire composition.

The content of the catalyst (II) may vary depending on the type of the polyurethane prepolymer (I), but is preferably 0.01 to 0.1 mass% (more preferably 0.01 to 0.05 mass%) of the entire composition.

When the polyol component (a) contains the crystalline polyester polyol (a-1) and the 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 the range as described above, an appropriate curing time and a high peel strength can be maintained.

The content of the polyether polyol (a-2) in the polyol component (a) is preferably 30 to 80% by mass, more preferably 40 to 60% by mass, based on the entire polyol component (a). By setting in such a range, both high flexibility and peel strength can be achieved.

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

the content of the other polyol (a-3) in the polyol component (a) is preferably 30% by mass or less with respect to the entire polyol component (a). By setting the content in such a range, physical properties such as resistance to wet heat aging and peel strength can be satisfied. The lower limit is not particularly limited, and is, for example, 5 mass% or more with respect to the entire polyol component (a).

In the polyisocyanate component (B), the content of the carbodiimide-modified diphenylmethane diisocyanate (B-1) is more than 0.5% by mass and 10% by mass or less with respect to the entire polyisocyanate component (B). 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, further preferably 0.8% by mass or more and 10% by mass or less, further 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, based on the entire polyisocyanate component (B). By setting the blending amount of the carbodiimide-modified diphenylmethane diisocyanate (b-1) within this range, the wet heat resistance and the heat stability of the adhesive can be improved by the modified group while suppressing an increase in the viscosity of the composition. Among these, the content of the carbodiimide-modified diphenylmethane diisocyanate (B-1) is preferably 1 mass% or more and 10 mass% or less with respect to the entire polyisocyanate component (B).

It is preferable that 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 other polyisocyanate (b-2) is MDI (pure MDI) as a whole.

< manufacturing method > >)

The method for producing the polyurethane hot-melt adhesive composition according to the present embodiment is not particularly limited as long as it is a known method, and the produced polyurethane hot-melt adhesive composition does not impair the object of the present invention. For example, it can be manufactured as follows. The following methods can be enumerated: (1) a predetermined amount of polyisocyanate is dropped into a reaction vessel containing a predetermined amount of polyol, and then heated to react under such conditions that the isocyanate group of the polyisocyanate is stoichiometrically excessive relative to the hydroxyl group of the polyol, thereby producing a polyurethane prepolymer (I). (2) The desired polyurethane hot melt adhesive composition is produced by dropping a predetermined amount of other components including the catalyst (II) into the polyurethane prepolymer (I) and stirring.

The reaction is carried out at a temperature of, for example, 50 to 120 ℃ and preferably 60 to 100 ℃. The reaction time is, for example, 1 to 15 hours.

< Property > > <

Next, the physical properties of the hot melt adhesive composition according to the present embodiment will be described.

<<VOC>>

The amount of organic volatile components generated when the hot melt adhesive composition according to the present embodiment is heated at 90 ℃ is preferably 150ppm or less in terms of toluene. By setting the VOC to this range, the specified value can be satisfied for the entire product of the vehicle seat.

< Wet Heat resistance >

The moist heat resistance of the hot melt adhesive composition according to the present embodiment is preferably 400 hours or more, and the moist heat resistance is evaluated as a time period for which a peel strength of 80% or more can be maintained with respect to a normal peel strength when the composition is left to stand in a moist heat environment (80 ℃ C. 95%).

< thermal stability 1 (storage stability): intermediate temperature/Long term thermal stability >

The hot melt adhesive composition according to the present embodiment preferably has a storage stability of 80% or more, which is evaluated as a residual ratio of NCO% in a state of being left standing at 50 ℃ for 3 months in a state of being sealed in an aluminum bag (NCO% after standing/NCO% before standing x 100).

< thermal stability 2: high temperature/short term thermal stability >)

The thermal stability of the hot melt adhesive composition according to the present embodiment, which is evaluated as the rate of increase in viscosity of the hot melt adhesive composition after heating at 140 ℃ for 4 hours under a nitrogen atmosphere (viscosity after test/viscosity before test × 100), is preferably 200% or less.

< measuring method >

A rotor No. 4 connected to a Brookfield digital viscometer LVDV-I + from Brookfield corporation may be placed in a cylindrical glass vessel to melt the sample to 140 ℃ by heating to 150. + -.15 g, and the viscosity may be measured. The viscosity before the test was the viscosity after 0 hour, and the viscosity after the test was 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 3N/25mm or more, which is evaluated as a peel strength after the polyurethane foam and the skin material are bonded for 1 day.

< < use > >)

The hot melt adhesive composition according to the present embodiment is a reactive hot melt adhesive composition capable of laminating and adhering a skin material and a substrate. In particular, when the adhesive is formed into a specific fibrous form described later, an adhesive layer (a layer containing the cured hot melt adhesive composition) having excellent quality and texture, air permeability, and penetration resistance is formed. Therefore, the present invention can be applied to cases where the skin material and the base material are a resin foam, a resin film, synthetic leather, natural leather, woven fabric, nonwoven fabric, or the like, regardless of the type. Further, since the present invention can be applied to a case where the base material is a polyurethane resin foam, the present invention can also be applied to a long product obtained by laminating and adhering a base material made of a continuous sheet and a skin material, and to a member for a vehicle (particularly, a vehicle interior) to which a general thermoplastic hot-melt adhesive is difficult to apply.

< application method > >)

Next, an example of a method of applying the hot melt adhesive composition according to the present embodiment will be described. In the present example, a case has been described in which the hot melt adhesive composition is applied by a non-contact method (for example, a spray method) so as to form a predetermined adhesive layer, but the method of applying the hot melt adhesive composition according to the present embodiment is not limited thereto, and the hot melt adhesive composition may be applied to the surface to be adhered 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). In general, it is necessary to set an atmosphere containing no moisture in the melting step.

< coating Process >)

Next, the hot melt adhesive composition in a molten state is applied to the surface to be adhered (preferably, the surface of the foam) of the object to be adhered by an appropriate application method (preferably, a non-contact application method). The shape of the coating is not particularly limited, and may be, for example, a linear, dot, or fiber shape, as long as an adhesive layer is formed. Alternatively, the adhesive layer may be formed in a sheet form. The coating amount of the adhesive composition of the adhesive layer may be preferably set to 5g/m²～50g/m²(more preferably 10 g/m)²～30g/m²) And the like. The adhesive composition may be applied to both surfaces to be adhered.

The specific coating conditions are not particularly limited, and for example, when the non-contact coating method is used as described above, the coating can be performed under a pressure of 0.01 to 0.4MPa and a temperature of 100 to 160 ℃.

Here, the non-contact type coating method is a method of coating the adhesive composition without bringing the coating apparatus into contact with the member to be adhered, and examples thereof include coating by a spray method.

The surface to be adhered may be subjected to a known pretreatment (for example, primer treatment, corona treatment, plasma treatment, or the like) before the coating step.

< contact step and curing step >)

After the coating step, another member is brought into contact with the surface to be adhered (coated surface) on which the adhesive layer is provided, and the hot melt adhesive composition is cooled and solidified. Generally, as described above, after cooling and curing, the uncured isocyanate end reacts with moisture in the air to form a crosslinked structure, thereby exhibiting stronger adhesiveness.

When the hot-melt adhesive composition according to the present embodiment is applied by the method described in the above-mentioned application step, the adhesive composition can be adhered without separating the object to be adhered. Specifically, the resin foam, resin film, synthetic leather, natural leather, woven fabric, or nonwoven fabric is excellent in quality and texture, air permeability, and adhesiveness, and is prevented from penetrating into an object to be adhered. In particular, such an effect can be obtained even when the object to be adhered is a polyurethane resin foam.

As described above, a laminate having an adhesive layer, which is a cured product of the hot melt adhesive composition according to the present embodiment, and particularly a laminate having a foam and an adhesive layer provided on a surface of the foam, can be obtained. The laminate is preferably a laminate comprising a polyurethane foam as a base material and a skin material or a back fabric as a specific configuration. Such a laminate can be preferably used as an interior material for a vehicle, that is, a laminate (laminate sheet) in which a skin-like layer is bonded to the surface of a laminate sheet in which a back base layer is formed on the back surface of a cushion layer including a foam as a base material.

Here, referring again to fig. 1, a laminate 10 of the present embodiment will be described. The laminate 10 was produced as follows: a predetermined amount of the polyurethane hot melt adhesive 13 is applied to either one or both of the one surface of the foamed polyurethane layer 11 and the cover layer 15, and then the one surface of the foamed polyurethane layer 11 is overlapped with the cover layer 15, in which state the polyurethane hot melt adhesive 13 is cooled and solidified.

The method of applying the polyurethane hot melt adhesive 13 may be any of a non-contact method such as spray coating and a contact method such as roll coater coating. The coating weight of the polyurethane hot melt adhesive 13 is preferably 5g/m²～50g/m²More preferably 10g/m²～30g/m². As the conditions in the case of the non-contact system, a pressure of 0.01MPa to 0.4MP can be exemplifieda. The temperature is 100-160 ℃.

The polyurethane hot-melt adhesive 13 exhibits stronger adhesive strength by forming a crosslinked structure by reacting uncured terminal isocyanate in the polyurethane prepolymer (I) with moisture in the air after cooling and curing.

The laminate 20 of the other embodiment shown in fig. 2 is composed of a laminate in which the covering layer 15 is placed on one surface of the foamed urethane layer 11 and the surface layer 19 is placed on the surface of the foamed urethane layer 11 opposite to the surface on which the covering layer 15 is placed. The cover layer 15 and the foamed polyurethane layer 11 are glued by means of a polyurethane hot melt adhesive 13, and the surface layer 19 and the foamed polyurethane layer 11 are glued by means of a polyurethane hot melt adhesive 17. The polyurethane hot melt adhesives 13 and 17 are the same as the hot melt adhesive 13 illustrated in the laminate 10 of figure 1.

The surface layer 19 is made of a suitable material such as natural leather, synthetic leather, and fabric (plastic film lining).

The laminate 20 is produced by the following method. First, one surface of the foamed polyurethane layer 11 and the cover layer 15 are bonded by the polyurethane hot melt adhesive 13 in the same manner as the laminate 10 of fig. 1. Then, a predetermined amount of polyurethane hot melt adhesive 17 is applied to either or both of the other face of the foamed polyurethane layer 11 and the surface layer 19. Then, the surface of the foamed polyurethane layer 11 is overlapped with the surface layer 19, and the polyurethane hot melt adhesive 17 is cooled and solidified in this state. This can yield a laminate 20. The polyurethane hot melt adhesive 17 exhibits stronger adhesive strength by forming a crosslinked structure by reacting uncured terminal isocyanate in the polyurethane prepolymer with moisture in the air after cooling and curing. The surface layer 19 and one side of the foamed polyurethane layer 11 may be first bonded by the polyurethane hot melt adhesive 17, and then the cover layer 15 and the opposite side of the foamed polyurethane layer 11 may be bonded by the polyurethane hot melt adhesive 13.

The laminate 20 is suitable as a skin material for a vehicle interior material such as a seat cushion, a headrest, or an instrument panel of a vehicle. The interior material for a vehicle has a cushion material made of foamed polyurethane or the like as a main constituent material, and a surface of the cushion material is covered with a skin material. In the case where the laminate 20 is used as a skin material of an interior material for a vehicle, the laminate 20 is cut into a predetermined size to obtain a plurality of laminate pieces, and the plurality of laminate pieces are sewn so that the surface layer 19 is on the front side, thereby forming a shape to be covered on the interior material for a vehicle.