JP6725866B2 - Method for manufacturing laminated body - Google Patents

Description

The present invention relates to a method for producing a laminate in which a moisture-curable polyurethane hot melt resin composition is applied in a bead shape.

Since moisture-curable polyurethane hot melt adhesives are solvent-free, various researches have been made to date as environmentally friendly adhesives centering on fiber bonding and building material lamination, and are widely used in industry.

In addition, in recent years, in bonding optical components, etc., there is a growing need for weight reduction and thinning of optical components, and it has been considered to replace hot-melt adhesives with acrylic pressure-sensitive adhesives that have been the mainstream until now. Has been done.

Examples of the hot-melt adhesive that can be used for bonding the optical components include (a) 100 parts by weight of a polyurethane resin having a flow starting temperature of 55° C. or higher and 110° C. or lower, and (b) Tg of 0° C. or higher and 110. 5 to 150 parts by weight of a saturated polyester resin having a molecular weight of 10,000 to 25,000 or less, (c) 10 to 150 parts by weight of an epoxy resin having a softening point of 60 to 140° C. and a molecular weight of 700 to 3,000, and ( d) An adhesive using a moist-heat-resistant hot-melt adhesive composition characterized by containing 10 to 200 parts by weight of an inorganic filler surface-treated with a coupling agent is disclosed (for example, see Patent Document 1). reference.).

On the other hand, in bonding the optical components, there is an increasing need for applying an adhesive to the adherend by bead coating from the viewpoint of cost reduction and the like. However, when the wet heat resistant hot-melt adhesive composition is bead-coated with a bead coating device, there is a problem that the bead-coated product flows and a problem that a thread is pulled, and a desired adhesive layer is formed. It could be difficult to do.

JP, 2003-27030, A

The problem to be solved by the present invention is to provide an excellent bead coating product with a moisture-curable polyurethane hot melt resin composition when producing a laminate in which the moisture-curable polyurethane hot melt resin composition is applied in a bead form. It is an object of the present invention to provide a manufacturing method for obtaining moldability and thread-pulling resistance.

The present invention is a reaction product of a polyol (A) and a polyisocyanate (B), and a urethane prepolymer (i) having an isocyanate group having a melt viscosity at 120° C. of 6,000 to 50,000 mPa·s. And a moisture-curable polyurethane hot melt resin composition containing an inorganic filler (ii) is applied in a bead form on a substrate.

According to the production method of the present invention, it is possible to obtain excellent shape-retaining properties and beading resistance of a bead-coated article made of the moisture-curable polyurethane hot melt resin composition. Therefore, it is easy to form a cured product layer of the moisture-curable polyurethane hot melt resin composition into a desired shape. In addition to the above effects, when a moisture-curable polyurethane hot melt resin composition having a specific composition is used, excellent initial adhesive strength and impact resistance can be obtained.

Therefore, the manufacturing method of the present invention can be suitably used not only for fiber bonding/laminating of building materials but also for manufacturing optical members, and particularly for manufacturing vehicle headlights.

The method for producing a laminate of the present invention is a reaction product of a polyol (A) and a polyisocyanate (B), and has an isocyanate group having a melt viscosity at 120° C. of 6,000 to 50,000 mPa·s. It is essential to apply the moisture-curable polyurethane hot melt resin composition containing the urethane prepolymer (i) and the inorganic filler (ii) in a bead form on the substrate.

In the present invention, it is essential that the melt viscosity of the urethane prepolymer (i) at 120°C is in the range of 6,000 to 50,000 mPa·s. When the melt viscosity is less than 6,000 mPa·s, the bead-coated article flows, and when it exceeds 50,000 mPa·s, stringing occurs. The melt viscosity is preferably in the range of 7,000 to 40,000 mPa·s from the viewpoint that the bead coating property, the shape retention property of the bead coated product, and the yarn pulling resistance can be further improved. More preferably, it is in the range of 1,000 to 30,000 mPa·s. The melt viscosity of the urethane prepolymer (i) at 120° C. was measured by melting the urethane prepolymer (i) at 120° C. for 1 hour and then using a cone plate meter (40P cone, rotor speed: 50 rpm). The measured value is shown. In order to obtain the urethane prepolymer (i) satisfying the melt viscosity, it is most important to adjust the kind of the polyol (A) as a raw material.

As the polyol (A), for example, acrylpolyol (a1), crystalline polyester polyol (a2), polyether polyol (a3), amorphous polyester polyol, polycarbonate polyol, polybutadiene polyol and the like can be used. These polyols may be used alone or in combination of two or more. Among these, it is preferable to use the acrylic polyol (a1) from the viewpoint that the melt viscosity of the urethane prepolymer (i) can be easily designed in the above range, and excellent initial adhesive strength and impact resistance can be obtained. Further, it is more preferable to use the crystalline polyester polyol (a2) and the polyether polyol (a3) together.

The acrylic polyol (a1) is obtained by polymerizing a (meth)acrylic compound containing a (meth)acrylic compound having a hydroxyl group as an essential component. In addition, in this invention, a "(meth)acrylic compound" shows a methacrylic compound and/or an acrylic compound.

As the (meth)acrylic compound having a hydroxyl group, for example, 2-hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylate and the like can be used. The content of the (meth)acrylic compound having a hydroxyl group is preferably in the range of 0.05 to 10 mass% with respect to the total mass of the (meth)acrylic compound constituting the acrylic polyol (a1), and is preferably 0. It is more preferably in the range of 1 to 3 mass %.

Examples of other (meth)acrylic compounds include (meth)acrylic acid, methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth). Acrylate, neopentyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, octyl (meth)acrylate, stearyl (meth)acrylate, isostearyl (meth)acrylate, cetyl (meth)acrylate, lauryl (meth)acrylate, etc. (Meth)acrylic acid alkyl ester (meth)acrylic acid alkyl ester; 2,2,2-trifluoroethyl (meth)acrylate, 2,2,3,3-tetrafluoropropyl (meth)acrylate, 1H,1H,5H -(Meth)acrylic compounds having a fluorine atom such as octafluoropentyl(meth)acrylate and 2-(perfluorooctyl)ethyl(meth)acrylate; isobornyl(meth)acrylate, cyclohexyl(meth)acrylate, diciplopentanyl( (Meth)acrylic compounds having an alicyclic structure such as (meth)acrylate and dicyclopentenyloxyethyl (meth)acrylate; polyethylene glycol mono(meth)acrylate, methoxyethyl (meth)acrylate, methoxybutyl (meth)acrylate, methoxytri (Meth)acrylic compound having an ether group such as ethylene glycol (meth)acrylate and methoxypolyethylene glycol (meth)acrylate; benzyl (meth)acrylate, 2-ethyl-2-methyl-[1,3]-dioxolane-4- Il-methyl (meth)acrylate, dimethylaminoethyl (meth)acrylate and the like can be used. These (meth)acrylic compounds may be used alone or in combination of two or more kinds.

As the acrylic polyol (a1), it is easy to design the melt viscosity of the urethane prepolymer (i) within the above range, and more excellent initial adhesive strength and impact resistance are obtained, and therefore the polyol (A) is used. It is preferably contained in the range of 20 to 35% by mass, more preferably 22 to 32% by mass.

Further, as the acrylic polyol (a1), the acrylic polyol (a1-1) having a glass transition temperature of 0° C. or lower, which can further improve the impact resistance, and the glass transition, which can further improve the initial adhesive strength, It is preferable to use the acrylic polyol (a1-2) whose temperature exceeds 0° C. in combination. The glass transition temperature of the acrylic polyol (a1) is a value measured by DSC (differential scanning calorimeter) according to JIS K7121-1987. Specifically, the acrylic scanning in the differential scanning calorimeter is shown. A polyol was added, the temperature was raised to (Tg+50° C.) at a temperature rising rate of 10° C./min, then the temperature was held for 3 minutes and then rapidly cooled, and the midpoint glass transition temperature (Tmg) read from the obtained differential thermal curve is shown. ..

As a method for obtaining the acrylic polyol (a1-1) having a glass transition temperature of 0° C. or lower, for example, a homopolymer having a glass transition temperature of 0° C. or lower can be formed as the other (meth)acrylic compound (meta). ) Polymerization using an acrylic compound in an amount of 25% by mass or more is preferable, and n-butyl acrylate is preferably used in an amount of 25% by mass or more, more preferably 25 to 80% by mass, and further preferably It is possible to use n-butyl acrylate in the range of 25 to 80 mass% and n-butyl methacrylate in the range of 10 to 74 mass %. Further, the glass transition temperature of the acrylic polyol (a1-1) is preferably in the range of −2 to −40° C. from the viewpoint of further improving the impact resistance.

The content of the acrylic polyol (a1-1) is preferably 8 to 30% by mass, and 10 to 22% by mass, in the polyol (A), from the viewpoint that even more excellent impact resistance can be obtained. The range is more preferably.

As a method for obtaining the acrylic polyol (a1-2) having a glass transition temperature of higher than 0° C., for example, a homopolymer having a glass transition temperature of higher than 80° C. can be formed as the other (meth)acrylic compound (meta). ) Polymerization using an acrylic compound in an amount of 30% by mass or more, preferably methyl methacrylate in an amount of 30% by mass or more, more preferably 30 to 80% by mass, and further preferably methyl methacrylate. Is used in the range of 30 to 80% by mass, and n-butyl methacrylate is used in the range of 10 to 50% by mass. The glass transition temperature of the acrylic polyol (a1-1) is preferably in the range of 50 to 80°C from the viewpoint of further improving the initial adhesive strength.

The number average molecular weight of the acrylic polyol (a1) is preferably in the range of 1,000 to 50,000, and more preferably 10,000 to 50,000, from the viewpoint of obtaining more excellent initial adhesive strength and impact resistance. More preferably, it is in the range of 30,000. The number average molecular weight of the acrylic polyol (a1) is a value measured by the gel permeation chromatography (GPC) method under the following conditions.

Measuring device: High-speed GPC device ("HLC-8220GPC" manufactured by Tosoh Corporation)
Column: The following columns manufactured by Tosoh Corporation were connected in series and used.
"TSKgel G5000" (7.8 mm ID x 30 cm) x 1 "TSK gel G4000" (7.8 mm ID x 30 cm) x 1 "TSK gel G3000" (7.8 mm ID x 30 cm) x 1 This "TSKgel G2000" (7.8 mm ID x 30 cm) x 1 Detector: RI (differential refractometer)
Column temperature: 40°C
Eluent: Tetrahydrofuran (THF)
Flow rate: 1.0 mL/min Injection volume: 100 μL (tetrahydrofuran solution with a sample concentration of 0.4% by mass)
Standard sample: A calibration curve was prepared using the following standard polystyrene.

(Standard polystyrene)
Tosoh Corporation "TSKgel Standard Polystyrene A-500"
Tosoh Corporation "TSK gel standard polystyrene A-1000"
Tosoh Corporation "TSK gel standard polystyrene A-2500"
Tosoh Corporation "TSK gel standard polystyrene A-5000"
"TSK gel standard polystyrene F-1" manufactured by Tosoh Corporation
"TSK gel standard polystyrene F-2" manufactured by Tosoh Corporation
"TSK gel standard polystyrene F-4" manufactured by Tosoh Corporation
Tosoh Corporation "TSK gel standard polystyrene F-10"
Tosoh Corporation "TSK gel standard polystyrene F-20"
Tosoh Corporation "TSK gel standard polystyrene F-40"
Tosoh Corporation "TSK gel standard polystyrene F-80"
Tosoh Corporation "TSK gel standard polystyrene F-128"
Tosoh Corporation "TSK gel standard polystyrene F-288"
Tosoh Corporation "TSK gel standard polystyrene F-550"

The crystalline polyester polyol (a2) is preferably used from the viewpoint of obtaining a more excellent initial adhesive strength, and for example, a reaction product of a compound having a hydroxyl group and a polybasic acid can be used. In addition, in this invention, "crystalline" shows what can confirm the peak of crystallization heat or the heat of fusion in DSC measurement based on JISK7121-1987, and "amorphous" confirms the said peak. Indicates what cannot be done.

As the compound having a hydroxyl group, for example, ethylene glycol, propylene glycol, butanediol, pentanediol, hexanediol, heptanediol, octanediol, nonanediol, decanediol, trimethylolpropane, trimethylolethane, glycerin, etc. may be used. You can These compounds may be used alone or in combination of two or more. Among these, it is preferable to use at least one compound selected from the group consisting of butanediol, hexanediol, octanediol, and decanediol from the viewpoint of enhancing the crystallinity and obtaining a more excellent initial adhesive strength.

Examples of the polybasic acid that can be used include oxalic acid, malonic acid, succinic acid, adipic acid, sebacic acid, azelaic acid, and 1,12-dodecanedioic acid. These polybasic acids may be used alone or in combination of two or more kinds. Among these, at least one polybasic acid selected from the group consisting of adipic acid, sebacic acid, and 1,12-dodecanedioic acid from the viewpoint of increasing the crystallinity among these and obtaining a more excellent initial adhesive strength. Is preferably used.

The number average molecular weight of the crystalline polyester polyol (a2) is preferably in the range of 500 to 5,000, and more preferably in the range of 1,000 to 4,000, from the viewpoint of obtaining a more excellent initial adhesive strength. Is more preferable. The number average molecular weight of the crystalline polyester polyol (a2) is a value obtained by measuring in the same manner as the number average molecular weight of the acrylic polyol (a1).

The content of the crystalline polyester polyol (a2) is in the range of 31 to 50% by mass in the polyol (A) in order to obtain a more excellent initial adhesive strength. Is more preferable.

The polyether polyol (a3) is preferably used in order to obtain even more excellent impact resistance, and for example, polyethylene glycol, polyoxypropylene glycol, polyoxytetramethylene glycol, polyoxyethylene polyoxypropylene glycol or the like is used. be able to. These polyether polyols may be used alone or in combination of two or more kinds. Among these, it is preferable to use polyoxypropylene glycol from the viewpoint that even more excellent impact resistance and mechanical strength can be obtained.

The number average molecular weight of the polyether polyol (a3) is preferably in the range of 500 to 10,000, and more preferably in the range of 800 to 4,000, from the viewpoint that more excellent impact resistance can be obtained. Is more preferable. The number average molecular weight of the polyether polyol (a3) is a value measured in the same manner as the number average molecular weight of the acrylic polyol (a1).

The content of the polyether polyol (a3) is preferably in the range of 15 to 48% by mass, and more preferably in the range of 25 to 40% by mass, from the viewpoint that more excellent impact resistance can be obtained. More preferable.

Examples of the polyisocyanate (B) include polymethylene polyphenyl polyisocyanate, diphenyl methane diisocyanate, carbodiimide-modified diphenyl methane diisocyanate isocyanate, phenylene diisocyanate, tolylene diisocyanate, naphthalene diisocyanate, and other aromatic polyisocyanates, hexamethylene diisocyanate, lysine diisocyanate, Aliphatic or alicyclic polyisocyanates such as cyclohexane diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, xylylene diisocyanate, and tetramethyl xylylene diisocyanate can be used. Among these, aromatic polyisocyanate is preferably used, and diphenylmethane diisocyanate is more preferably used, because excellent reactivity and adhesiveness are obtained.

The urethane prepolymer (i) is obtained by reacting the polyol (A) with the polyisocyanate (B), and is used in the air or in a case or adherend to which the urethane prepolymer is applied. It has an isocyanate group capable of reacting with existing water to form a crosslinked structure at the polymer terminal or in the molecule.

As the method for producing the urethane prepolymer (i), for example, the mixture of the polyol (A) is dropped into a reaction container containing the polyisocyanate (B) and then heated to obtain the polyisocyanate (B). Examples thereof include a method in which an isocyanate group is reacted with the hydroxyl group of the polyol (A) in an excess amount.

When producing the urethane prepolymer (i), the equivalence ratio ([isocyanate group/hydroxyl group]) of the isocyanate group of the polyisocyanate (B) and the hydroxyl group of the polyol (A) is mechanical strength, From the viewpoint of production stability, the range of 1.1 to 5 is preferable, and the range of 1.5 to 3 is more preferable.

The urethane prepolymer (i) can be usually produced in the absence of a solvent, but may be produced by reacting the polyol (A) with the polyisocyanate (B) in an organic solvent. When the reaction is carried out in an organic solvent, an organic solvent which does not inhibit the reaction, such as ethyl acetate, n-butyl acetate, methyl ethyl ketone, or toluene, can be used, but it may be heated under reduced pressure during or after the reaction. It is necessary to remove the organic solvent.

When producing the urethane prepolymer (i), a urethanization catalyst can be used if necessary. The urethanization catalyst can be appropriately added at any stage of the above reaction.

As the urethanization catalyst, for example, nitrogen-containing compounds such as triethylamine, triethylenediamine, N-methylmorpholine; metal salts such as potassium acetate, zinc stearate, tin octylate; organometallic compounds such as dibutyltin dilaurate are used. be able to. These urethanization catalysts may be used alone or in combination of two or more kinds.

From the viewpoint of mechanical strength, the isocyanate group content (NCO%) of the urethane prepolymer (i) is preferably in the range of 1.5 to 8% by mass, and in the range of 1.7 to 5% by mass. More preferably. The NCO% of the urethane prepolymer (i) is a value measured by a potentiometric titration method based on JISK1603-1:2007.

The inorganic filler (ii) is an essential component for obtaining excellent thread-pulling resistance. Examples of the inorganic filler (ii) that can be used include oxides such as silica and alumina; carbonates such as calcium carbonate; silicates such as talc, clay, mica, montmorillonite, and bentonite. These inorganic fillers may be used alone or in combination of two or more. Among these, it is preferable to use calcium carbonate because it has good compatibility with the moisture-curable polyurethane hot melt resin composition, is less likely to cause clogs during bead application, and can further improve the stringing resistance.

The content of the inorganic filler (ii) is preferably in the range of 1 to 20% by mass in the moisture-curable polyurethane hot melt resin composition, from the viewpoint of further excellent threading resistance. More preferably, it is in the range of 15% by mass.

The moisture-curable polyurethane hot melt resin composition used in the present invention contains the urethane prepolymer (i) and the inorganic filler (ii) as essential components, but contains other additives as necessary. May be.

As the other additives, for example, antioxidants, tackifiers, plasticizers, stabilizers, dyes, pigments, optical brighteners and the like can be used. These additives may be used alone or in combination of two or more kinds.

As a method of applying the moisture-curable polyurethane hot melt resin composition in a bead form on a substrate, for example, a known bead application device used for bead application of a hot melt adhesive such as a bead gun or a cold glue gun is used. There is a method. As the bead coating device, for example, “classic blue series hot melt gun”, “LA820 electric gun” (above, manufactured by Nordson Co., Ltd.) and the like can be obtained as commercial products.

The bead width of the moisture-curable polyurethane hot melt resin composition applied in the form of beads is appropriately determined according to the intended use, but is, for example, in the range of 1 to 20 mm.

The thickness of the moisture-curable polyurethane hot melt resin composition applied in the form of beads is appropriately determined depending on the intended use, but is, for example, in the range of 10 μm to 5 mm.

Examples of the base material to which the moisture-curable polyurethane hot melt resin composition is applied include glass, lenses; wood; metal plates such as steel; polyamide resin, acrylic resin, urethane resin, silicon resin, epoxy resin, fluororesin. , Polystyrene resin, polyester resin, polysulfone resin, polyarylate resin, polyvinyl chloride resin, polyvinylidene chloride resin, norbornene resin, polyolefin resin, polyimide resin, alicyclic polyimide resin, cellulose resin, PC (polycarbonate), PBT (polybutylene) Base materials obtained from terephthalate), modified PPE (polyphenylene ether), PEN (polyethylene naphthalate), PET (polyethylene terephthalate), lactic acid polymer, ABS resin, AS resin and the like can be used. Further, the base material may be subjected to treatments such as corona treatment, plasma treatment, and primer treatment, if necessary.

The bead-coated moisture-curable polyurethane hot melt resin composition is preferably aged for, for example, half a day to 5 days under the conditions of a temperature of 20 to 80° C. and a relative humidity of 50 to 90%.

The laminate produced by the production method of the present invention is excellent in the shape retention property of the bead-coated product of the moisture-curable polyurethane hot melt resin composition and in the yarn pulling resistance. Therefore, it is easy to form a cured product layer of the moisture-curable polyurethane hot melt resin composition into a desired shape. In addition to the above effects, when a moisture-curable polyurethane hot melt resin composition having a specific composition is used, excellent initial adhesive strength and impact resistance can be obtained.

Therefore, the manufacturing method of the present invention can be suitably used not only for fiber bonding/laminating of building materials but also for manufacturing optical members, and particularly for manufacturing vehicle headlights.

Examples of the method for producing a vehicle headlight using the moisture-curable polyurethane hot melt resin composition include, for example, a joint between a housing (housing) and a lens, or one of the housing and the lens. A method may be mentioned in which the moisture-curable polyurethane hot melt resin composition is bead-coated in a ring shape, then adhered to the other adherend, and then the moisture-curable polyurethane hot melt resin composition is aged. When a moisture-curable polyurethane hot melt resin composition having excellent initial adhesive strength and impact resistance is used, it functions as an adhesive and sealing material.

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

[Example 1]
In a four-necked flask equipped with a thermometer, a stirrer, an inert gas inlet, and a reflux condenser, acrylic polyol-1 (n-butyl acrylate, n-butyl methacrylate, and 2-hydroxyethyl acrylate were used in a mass ratio [71 .7/28/0.3] to obtain an acrylic polyol, glass transition temperature: -27[deg.] C., number average molecular weight: 12,000, hereinafter abbreviated as "AC-1".) 10 parts by mass. , Acrylic polyol-3 (methyl methacrylate, n-butyl methacrylate, and acrylic hydroxy obtained by polymerizing 2-hydroxyethyl acrylate at a mass ratio [66.5/33/0.5], glass transition temperature: 68 C, number average molecular weight: 20,000, hereinafter abbreviated as "AC-3") 10 parts by mass, crystalline polyester polyol (1,6-hexanediol, and reaction product of 1,12-dodecanedioic acid, Number average molecular weight: 3,500, hereinafter abbreviated as “crystalline PEs-1”) 32 parts by mass, polyoxypropylene glycol (number average molecular weight: 2,000, hereinafter abbreviated as “PPG”) 30 Parts by mass were charged and dehydrated under reduced pressure until the water content became 0.05% by mass or less.
Next, after cooling to a container internal temperature of 70° C., 13 parts by mass of 4,4′-diphenylmethane diisocyanate (hereinafter abbreviated as “MDI”) was added, and the temperature was raised to 100° C. to make the NCO group content constant. The reaction was continued for about 3 hours to obtain a urethane prepolymer having an isocyanate group.
Next, 5 parts by mass of calcium carbonate was added and mixed to obtain a moisture-curable polyurethane hot melt resin composition.
The obtained moisture-curable polyurethane hot melt resin composition is melted at 120° C. for 1 hour, and a bead coating device (“PUR BLUE 4” manufactured by Nordson Co., Ltd., “LA820 Electric Gun”) is used to measure 5 cm in length and 5 cm in width. Then, it was applied on a polycarbonate plate having a thickness of 2 mm in a bead shape so as to have a width of 5 mm so as to draw a 4 cm×4 cm square. A similar polycarbonate plate was attached thereto and left standing for 3 days at 23° C. and a humidity of 65% to obtain a laminate having a cured product layer of the moisture-curable polyurethane hot melt resin composition.

[Examples 2 to 4, Comparative Examples 1 to 4]
A moisture-curable polyurethane hot melt resin composition was obtained in the same manner as in Example 1 except that the type and/or amount of the polyol used and the amount of calcium carbonate were changed as shown in Table 1, to obtain a laminate. It was

[Method for measuring melt viscosity of moisture-curable polyurethane hot melt resin composition]
The moisture-curable polyurethane hot melt resin compositions obtained in Examples and Comparative Examples were melted at 120° C. for 1 hour and then 1 ml was sampled to obtain a cone plate viscometer (Digital Viscometer manufactured by MST Engineering Co., Ltd.). The melt viscosity (120° C. melt viscosity) was measured with “CV-1S RT type”, 40P cone, rotor rotation speed: 50 rpm) (40P cone, rotor rotation: 50 rpm).

[Evaluation method of shape retention of bead coating]
The moisture-curable polyurethane hot melt resin compositions obtained in Examples and Comparative Examples were melted at 120° C. for 1 hour, and using a bead coating device (“LA820 Electric Gun” manufactured by Nordson Co., Ltd.), length 5 cm, width On a polycarbonate plate having a thickness of 5 cm and a thickness of 2 mm, a bead shape was applied so that a width of 5 mm was drawn so as to draw a square of 4 cm×4 vm. The width of the bead-coated product immediately after coating was measured and evaluated as follows.
"○": The width of the bead-coated article is less than 5.5 mm "X": The width of the bead-coated article is 5.5 mm or more

[Evaluation method of thread-pulling resistance of bead coating]
According to the above [Method for evaluating shape retention of bead coating], when the bead-shaped application of the moisture-curable polyurethane hot melt resin composition is completed, the moisture-curable polyurethane hot melt resin is discharged from the discharge port of the bead coating device. The composition was visually observed for stringiness, and when the stringing was not confirmed, it was evaluated as “◯”, and when the stringing was confirmed, it was evaluated as “x”.

[Evaluation method of initial adhesive strength]
The moisture-curable polyurethane hot-melt resin compositions obtained in Examples and Comparative Examples were melted at 120° C. for 1 hour, and then dried on a corona-treated polyethylene terephthalate film having a thickness of 100 μm. The composition was applied to a thickness of 200 μm using a roll coater, the same polyethylene terephthalate film was attached, and 180 minutes peel strength (N/25 mm) was measured after 3 minutes and evaluated as follows. did.
“◯”: 180 degree peel strength is 10 (N/25 mm) or more.
“X”: 180 degree peel strength is less than 10 (N/25 mm).

[Impact resistance evaluation method]
From the top of the laminates obtained in Examples and Comparative Examples, a DuPont-type drop impact tester was used to apply a shock 5 times at a load of 300 g and a height of 50 cm from a polycarbonate plate through a wick, The presence or absence of peeling of the polycarbonate plate was visually observed and judged as follows.
"○": Peeling did not occur.
“×”: Peeling occurred.

The abbreviations in Tables 1 and 2 will be described.
"Tg": glass transition temperature "AC-2": n-butyl acrylate, n-butyl methacrylate, and 2-hydroxyethyl acrylate are polymerized at a mass ratio of [28/71.7/0.3]. Obtained acrylic polyol, glass transition temperature: -3°C, number average molecular weight: 15,000
"Amorphous PEs-1": Amorphous polyester polyol obtained by reacting ethylene glycol, neopentyl glycol, isophthalic acid, and terephthalic acid, number average molecular weight: 2,600

According to the production method of the present invention, it has been found that a laminate having excellent shape retention of the bead-coated article and the stringing resistance of the moisture-curable polyurethane hot melt resin composition can be obtained. It was also found that excellent initial adhesive strength and impact resistance can be obtained by using a moisture-curable polyurethane hot melt resin composition having a specific composition.

On the other hand, Comparative Examples 1 and 2 are embodiments in which the melt viscosity of the urethane prepolymer exceeds the range specified in the present invention, but stringing of the moisture-curable polyurethane hot melt resin composition occurred.

Comparative Example 3 is an embodiment in which the melt viscosity of the urethane prepolymer is below the range specified in the present invention, but the shape retention of the bead coating of the moisture-curable polyurethane hot melt resin composition was poor.

Comparative Example 4 is an embodiment using a moisture-curable polyurethane hot melt resin composition containing no inorganic filler (ii), but stringing of the moisture-curable polyurethane hot melt resin composition occurred.

Claims (2)

A urethane prepolymer (i) having an isocyanate group, which is a reaction product of the polyol (A) and the polyisocyanate (B) and has a melt viscosity at 120° C. in the range of 6,000 to 50,000 mPa·s, and an inorganic material. the moisture-curable polyurethane hot-melt resin composition containing the filler (ii) a method for producing a product layer body you coated bead on a substrate,
The polyol (A) contains the acrylic polyol (a1) in the range of 20 to 35% by mass in the polyol (A),
The acrylic polyol (a1) contains an acrylic polyol (a1-1) having a glass transition temperature of 0° C. or lower, and an acrylic polyol (a1-2) having a glass transition temperature of higher than 0° C.,
The polyol (A) further contains a crystalline polyester polyol (a2) and a polyether polyol (a3),
The method for producing a laminated body, wherein the inorganic filler (ii) is calcium carbonate . The method for manufacturing a laminate according to claim 1, wherein the content is in the range polyol (A) in 8 to 30% by weight of the acrylic polyol (a1-1).