JPH10329248A - Manufacture of honeycomb sandwiching structure panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve heat resistant insufficiency and productivity insufficiency in the case of using hot-melt adhesive, by laminating a core material of a honeycomb core obtained by melting and coating with isocyanate end polyurethane hot-melt adhesive, reinforcing plate and surface plate, and heating and adhering the laminate at a high temperature. SOLUTION: The honeycomb sandwiching structure panel used for a building material is formed by using a honeycomb as a core material, laminating one or more reinforcing plates of surface plates on and underneath the core material, and adhering a surface material on and underneath or either on or underneath the honeycomb core via the reinforcing plate. In this case, as the adhesive, isocyanate end polyurethane hot-melt adhesive is used, and the adhesive is heated to a high temperature and adhered to obtain a predetermined honeycomb sandwiching structure panel. The hot-melt adhesive belongs to a moisture reactive type adhesive, and contains urethane prepolymer having isocyanate at its end as its main component.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a honeycomb sandwich structure panel, and more particularly to a method for manufacturing a honeycomb sandwich structure panel having a reinforcing plate provided between a core material of a honeycomb core and a surface plate. For example, after laminating a core material, a reinforcing plate and a surface plate of a honeycomb core melt-coated with an isocyanate-terminated polyurethane-based hot melt adhesive, the laminate is heated at a high temperature, and particularly, the temperature of the bonding interface is 100 to 150. The present invention relates to a method for manufacturing a honeycomb sandwich structure panel, wherein the panel is bonded by heating to a temperature of ℃. Therefore, the present invention belongs to a building material / structure material manufacturing technique for manufacturing a honeycomb sandwich structure panel.

[0002]

2. Description of the Related Art Honeycomb sandwich panels are lightweight and have excellent strength, heat insulation and soundproofing properties, so they are often used for indoor and outdoor partitions, building materials such as doors, furniture, blackboards, and office equipment housings. ing. Its structure is paper, plastic sheet, honeycomb shape, or roll core shape formed by molding into a complex shape other than hexagon, so-called honeycomb sheet as a core material, various surface plates on both sides, for example, It is manufactured by bonding metal, plastic and wood boards. Since these honeycomb sandwich structure panels generally have a thin surface plate of 0.3 to 5 mm, they are susceptible to deformation due to external impact or pressure, and are difficult to nail or attach with screws. It was necessary to prepare a bracket suitable for mounting. Honeycomb cores are used as the core material in honeycomb sandwich structural panels that improve the structural strength against such external shocks and stresses, and reduce the need for brackets, etc. in accordance with the mounting, and reinforce the top and bottom surfaces There is a type in which one or more plates are laminated. As a reinforcing board, a veneer board, a wood board such as a particle board,
Examples include a plastic board and a ceramic board. In general, the number of reinforcing plates is generally one in each case above and below the honeycomb core in consideration of the productivity of the honeycomb sandwich structure panel. On the other hand, the adhesive used for manufacturing the honeycomb sandwich structure panel is used by being applied to the honeycomb core side and / or a reinforcing plate and / or a surface plate.
Spray coating and roll coater methods are employed. Typical examples of such adhesives include solvent-type adhesives such as chloroprene-based adhesives, which have the danger of pollution and fire caused by solvents.

[0003] As an adhesive free of these drawbacks, there is a hot melt adhesive containing an ethylene-vinyl acetate copolymer or a styrene-butadiene copolymer as a main component. However, while the adhesive requires a high temperature of 140 to 200 ° C. at the time of application and bonding, the adhesive strength rapidly decreases at 60 to 80 ° C., so the surface material of the honeycomb sandwich structure panel or the surface material after the primer treatment is applied. When a urethane-based paint is applied by baking, a problem arises in that baking occurs under the conditions, that is, at a temperature of about 130 ° C., and the surfaces of the surface material and the reinforcing plate are raised. Also, when used for door panels exposed to direct sunlight, the surface material temperature may rise to around 100 ° C., depending on the constituent material or paint color. Therefore, it is difficult to apply the hot melt adhesive to the honeycomb sandwich panel adhesive from the viewpoint of heat resistance reliability. One-part urethane adhesives, two-part urethane adhesives, one-part epoxy adhesives, and two-part epoxy liquids at room temperature, which are solvent-free adhesives with excellent heat resistance and durability So-called moisture-curable adhesives and thermosetting adhesives such as a system-based adhesive have been proposed. Since these are liquid at normal temperature, the coating apparatus can use inexpensive equipment like the chloroprene-based adhesive, but it is difficult to handle the constituent material to which the adhesive is applied.
That is, after applying the adhesive on both sides of the honeycomb core,
The adhesive applied to the lower surface adheres to the work place and the equipment when the honeycomb core is moved or temporarily placed, and the cleaning work requires time and labor, and the workability and productivity are problems. . To solve these problems, isocyanate-terminated polyurethane hot melt adhesives have also been proposed, but it is difficult to satisfy the adhesive strength of a honeycomb sandwich panel with a reinforcing plate, which requires structural strength. Met.

[0004]

DISCLOSURE OF THE INVENTION The present invention has been studied variously in order to provide a method of manufacturing a honeycomb sandwich panel using a reinforcing plate which requires structural strength without the above-mentioned problems. It is.

[0005]

Means for Solving the Problems The inventors of the present invention have made intensive studies to solve such a problem, and as a result, have formed a honeycomb core as a core material and at least one reinforcing plate of a surface plate laminated on the core. In a honeycomb sandwich structure panel, an isocyanate-terminated polyurethane hot melt adhesive is used as an adhesive when manufacturing a sandwich structure panel in which a surface material is adhered to a top or a bottom or one of honeycomb cores via a reinforcing plate. The inventors have found that the above problem can be solved by using the adhesive and heating the adhesive to a high temperature to bond the adhesive, and have completed the present invention. That is,
The present invention is characterized in that a honeycomb, wherein a core material of a honeycomb core coated with a isocyanate-terminated polyurethane hot melt adhesive, a reinforcing plate and a surface plate are laminated, and then the laminated body is heated and bonded at a high temperature. The present invention relates to a method for manufacturing a sandwich structure panel, and more particularly to a method for manufacturing a honeycomb sandwich structure panel, wherein the heating is heating such that the temperature of the bonding interface becomes 100 to 150 ° C.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION

〇 Isocyanate-terminated polyurethane hot melt adhesive The isocyanate-terminated polyurethane hot melt adhesive used in the present invention is as follows. Isocyanate-terminated polyurethane hot-melt adhesives belong to the moisture-reactive adhesive, and the main components of the adhesive are one or more polyols having two or more hydroxyl groups in the molecule and two or more in the molecule. And a urethane prepolymer having an isocyanate group at the terminal obtained by reacting with at least one polyisocyanate having an isocyanate group. The urethane prepolymer is used alone or in combination of two or more. Preferred as the adhesive of the present invention is an adhesive containing the urethane prepolymer as a main component and having a melting point of 40 ° C. or more.

(1) Polyol As the polyol having two or more hydroxyl groups in the molecule used as a raw material of the urethane prepolymer, conventionally known polyols can be used. Specific examples of preferable polyols for the present invention are shown below. . First, polyester polyols obtained by random cocondensation polymerization of one or more polycarboxylic acids and one or more polyols are exemplified. Examples of the polycarboxylic acid as a raw material of the polyester polyol include succinic acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, dodecane diacid, icoic diacid, ε-caprolactone, terephthalic acid, isophthalic acid, and anhydride. Examples include, but are not limited to, phthalic acid, 2,6-naphthalenedicarboxylic acid, trimellitic acid, and paraoxybenzoic acid, and compounds having two or more carboxyl groups in the molecule are used in the present invention. . The polyol is ethylene glycol, propylene glycol, 1,4-butanediol, 1,5-pentanediol,
1,6-hexanediol, diethylene glycol, neopentyl glycol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol,
4-cyclohexanedimethanol, trimethylolpropane, pentaerythritol, 1,2,6-hexanetriol and the like, but are not limited thereto, and compounds having two or more hydroxyl groups in the molecule may be used in the present invention. Used for Next, polyether polyols are exemplified, specifically, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, and the like, but are not limited thereto, and compounds having one or more ether bonds in a molecule may be used. Used in the present invention. Thirdly, polyolefin polyols are mentioned, specifically,
Hydrogenated polybutadiene polyols, hydrides of polyalkylene polyols such as hydrogenated polyisoprene polyols, and copolymers of α-olefins,
It is not limited to these. Examples of the polyol of the present invention include, but are not limited to, polyalkylene polyols such as polybutadiene polyol and polyisoprene polyol, and polycarbonate polyols, and the like, and raw materials for the urethane polymer used in the present invention.

Polyisocyanate Polyisocyanate having two or more isocyanate groups in the molecule used as a raw material of the urethane prepolymer may be a conventionally known polyisocyanate. Specifically, p-phenylene diisocyanate , 4,4'-diphenylmethane diisocyanate, carbodiimide-modified 4,4'-diphenylmethane diisocyanate, tolylene diisocyanate, 4,4'-diphenylene diisocyanate, 1,5-octylene diisocyanate, trimethylene diisocyanate, tetramethylene diine cyanate, Hexamethylene diisocyanate, pentamethylene diisocyanate, 1,3-cyclopentane diisocyanate, 1,4-cyclohexane diisocyanate, 4,4'-methylene bis (cyclohexyl isocyanate), methyl 2,4-cyclohexane diisocyanate Isocyanate, methyl 2,6-cyclohexane diisocyanate, diphenylmethane diisocyanate, 1,4-bis (isocyanatomethyl) cyclohexane, 1,3-bis
Examples include (isocyanatomethyl) cyclohexane, isophorone diisocyanate, and carbodiimide-modified 4,4′-diphenylmethane diisocyanate, but are not limited thereto.

(1) Method for Preparing Adhesive As the urethane prepolymer as a main component of the adhesive used in the present invention, the amount of the polyisocyanate with respect to the polyol at the time of producing the polymer is represented by the group -NCO /
Those produced in a range where the equivalent ratio of the group —OH is 1 to 5 are preferable, and those produced in a range of 1.2 to 3 are more preferable. Further, as the adhesive of the present invention, in order to increase the moisture curing reactivity, tertiary amine-based or tin-based catalysts, tackifiers, fillers, plasticizers, waxes, stabilizers, antioxidants and the like It is preferable that various additives are added as necessary. More specifically, the adhesive of the present invention is an isocyanate-terminated urethane prepolymer 10
0 to 40 parts by weight of the thermoplastic polymer with respect to 0 parts by weight,
Examples of the composition include 0 to 100 parts by weight of a tackifier, 0 to 30 parts by weight of a plasticizer, 0 to 70 parts by weight of a filler, and an appropriate amount of other compounding agents. Usually, as a method of preparing the adhesive, there is no particular problem in the method of mixing the above various components at once, but it is divided into two or more in terms of pot life and work efficiency and adjusted, and a mixing machine is used immediately before application. It is also possible to mix or mix on a roll coater coater. That is, after various components are previously dehydrated and dehumidified by a method such as heating and vacuum drying,
At 80-150 ° C. using a mixer comprising a heatable ordinary stirrer, a planetary and a kneader, etc.
The adhesive is manufactured by mixing with the outside air containing moisture shut off by a method such as purging with dry nitrogen gas.

The melting point and melt viscosity of the adhesive The adhesive used in the present invention preferably has a melting point of 40 ° C. or higher, and if the melting point is lower than 40 ° C., it has tackiness at room temperature, The present invention cannot improve the productivity and workability at the time of adhesive application and at the time of adhesive assembly work after application. Further, the adhesive of the present invention has a viscosity suitable for application by heating and melting, that is, 80 to
It is preferably a hot melt adhesive having a melt viscosity of about 1,000 to 50,000 mPa · s at 150 ° C.

Method for Preparing Honeycomb Sandwich Structure Panel Application of Adhesive In the production of the honeycomb sandwich structure panel, the application location and the application amount of the adhesive are as follows. Only a small amount of coating is required on the honeycomb core side, and a sufficient adhesive strength can be obtained. The applied amount depends on the size of the core, but required adhesive characteristics can be obtained with an applied amount of 10 g / m ² or more, preferably 30 g / m ² or more.
Regarding the bonding between the reinforcing plate and the reinforcing plate (when a plurality of reinforcing plates are used) and the bonding between the reinforcing plate and the surface plate, it may be applied to either the reinforcing plate or the surface plate, but only one reinforcing plate is used. When two or more reinforcing plates are used on the surface of the surface plate, 2
It is preferable to apply it to both sides of the reinforcing plate after the first sheet. Therefore, a honeycomb core, two reinforcing plates and a surface plate,
In the case of a layer structure, it is preferable to apply and adhere to the surface of the honeycomb core and both surfaces of the second reinforcing plate. The amount of the adhesive applied to the surface of the reinforcing plate and the surface plate is 30 g / m ² or more, and preferably 50 g / m ² or more. As a method of applying the adhesive, a coating method which is usually used for a hot melt adhesive such as roll coater coating, spray coating, spiral coating, dot coating, or bead can be applied. Of these, the adhesion on the honeycomb side is preferably performed by roll coater coating, and the adhesion between the reinforcing plate and the reinforcing plate and between the reinforcing plate and the surface plate is not limited. Adhesive application temperature is 80 ~
The temperature is preferably 150 ° C., and as described above, an adhesive having an appropriate melt viscosity at this temperature is selected. Since the applied adhesive is a hot melt, it is solidified within several seconds to several tens of minutes. However, in consideration of productivity, it is preferable that the adhesive solidifies within several seconds to several minutes. In other words, the faster the solidification time is, the shorter the time that can be applied to the other side by applying one side and then reversing it, so that the time that can be applied to the other side can be shortened. The processed materials can be placed on top of each other, and the productivity and the like can be improved.

Adhesion method The honeycomb core, the reinforcing plate, and the surface plate coated with the adhesive are:
It is conveyed to a bonding work place by a roller conveyor, a hanger conveyor, etc., and is heated after lamination. The heating is performed under light pressure to fix the adherend, as is generally performed by the bonding method. For this purpose, it is preferable to use a heating press. The heating temperature, generally the temperature of the heating press,
Although a higher temperature is preferable at a temperature exceeding the melting point of the isocyanate-terminated polyurethane-based hot-melt adhesive, if the temperature is too high, in bonding the honeycomb core, the viscosity of the adhesive is too low, and a good fillet is not formed. In bonding the reinforcing plate and the surface plate, a large amount of CO ₂ is generated in a short time by reacting with moisture at the interface, destroying the adhesive layer, reducing the adhesive strength, and further reducing the coating material of the surface plate. Since a problem such as deterioration may occur, the temperature of the bonding interface is 100 to 150 ° C., particularly 12 ° C.
It is preferable to heat to 0 to 150 ° C. The bonding of the honeycomb core, the reinforcing plate and the surface plate can be performed integrally by, for example, sandwiching the reinforcing plate between the honeycomb core and the surface plate to which the adhesive has been applied and press-heating, or applying the adhesive to both sides of the honeycomb core. It is also possible to apply the adhesive, laminate it with a reinforcing plate in the form of sanguest, and then laminate and glue the surface plate with the adhesive applied on both sides. Alternatively, it is also possible to laminate and bond the honeycomb core after bonding the reinforcing plate and the surface plate. The heating temperature for bonding is as described above, and the bonding time is usually 10 seconds to 5 minutes. At the time of bonding, the laminate is pressurized in order to achieve good bonding of the laminate such as the honeycomb core, the reinforcing plate, and the surface plate. However, since the pressurization is mainly performed, it is not necessary to perform the pressing strongly. Also, strong pressurization may deform the honeycomb core, so that the pressure is 1 kg / cm ² or less, preferably 0.5 kg / cm ² or less.
Perform in about ² cm2. After the heating, the temperature of the press is set to 40
C. or lower, or transfer to another press exclusively for cooling to cool and solidify the laminate. The honeycomb sandwich structural panel in the stage of cooling and solidifying the adhesive has sufficient strength necessary for stacking, packing, transportation, and the like. The curing by the urethane-forming reaction of the adhesive proceeds due to moisture in the air or moisture existing at the bonding interface between the honeycomb, the reinforcing plate, and the surface plate, and reaches a sufficient bonding strength after curing at 23 ° C. and 65% RH for one day. .

[0013]

[Function] It is considered that the wet-curable isocyanate-terminated polyurethane hot-melt adhesive is heated to a high temperature to improve the wettability of the adhesive with the adhesive interface and the reactivity of the adhesive. However, according to the method of the present invention, it is possible to provide a honeycomb sandwich structure panel having the required adhesive strength as a structure without causing the problems of the conventional method.

[0014]

EXAMPLES Hereinafter, the present invention will be described in more detail based on a method for preparing an adhesive used in the present invention and specific examples.

Preparation Example 1 of Adhesive 1000 g of polyester polyol (OH value = 60.0 mg / KOH) containing adipic acid and 1,4-butanediol as main components
And 187 g of diphenylmethane diisocyanate were mixed and reacted at 80 ° C. for 4 hours to obtain a urethane prepolymer (melt viscosity at 120 ° C .: 27,200 mPa · s). 1 wt. Of dibutyltin dilaurate was added to the obtained prepolymer.
% To obtain an isocyanate-terminated polyurethane hot melt adhesive A. The melting point of this adhesive was 50 ° C. Preparation Example 2 of Adhesive Polyester polyol having an adipic acid and 1,6-hexanediol as main components (OH value = 22.5 mg / KOH) 1000
g and 117 g of diphenylmethane diisocyanate were reacted at 80 ° C. for 4 hours while mixing and stirring to obtain a urethane prepolymer (melt viscosity at 120 ° C .: 12,800 mPa · s).
Dibutyltin dilaurate is added to the obtained prepolymer by adding 1
wt%, to obtain an isocyanate-terminated polyurethane hot melt adhesive B. The melting point of this adhesive was 55 ° C. Preparation Example 3 of Adhesive 700 g of a polyester polyol composed mainly of adipic acid and 1,6-hexanediol (OH value = 20.5 mg / KOH)
And polyethylene glycol (OH value = 122mg / KOH) 3
00g Diphenylmethane diisocyanate 228.4 g
Was mixed and stirred at 80 ° C. for 4 hours to obtain a urethane prepolymer (melt viscosity at 120 ° C .: 29,000 mPa · s). 1 wt% of dibutyltin dilaurate was added to the obtained prepolymer to obtain an isocyanate-terminated polyurethane hot melt adhesive C. The melting point of this adhesive is 54
° C.

Example 1 Adhesive A was applied to one side of a phenol-impregnated paper honeycomb core (41 mm thick, 75 mm wide and 100 mm long) at 120 ° C. at 60 g / m ² . Three minutes later, the other surface was coated with the adhesive A in the same manner. However, the already applied surface was cooled and solidified, and there was no problem in workability. Next, the honeycomb core was placed on a reinforcing plate (veneer plate), and another reinforcing plate was superimposed on the honeycomb core, and the pressure was adjusted to 0.5 kg / cm ² with a heat press apparatus adjusted to 140 ° C. Pressed for 4 minutes. At this time, the bonding interface temperature reached 115 ° C. 4 minutes after the heating press. Then, it was immediately pressed at 0.5 kg / cm ² for 1 minute in a cold press machine through which cooling water was passed. Adhesive A was applied to the back (adhesive surface) of the coated steel sheet at 120 ° C. at 70 g / m ² . After that, the honeycomb panel that was made into the reinforcing plate created in the previous process was installed on the painted steel sheet, and another painted steel sheet coated with adhesive was superimposed on it,
0.5 kg / cm ² with a heat press adjusted to 120 ° C
For 2 minutes. At this time, the bonding interface temperature reached 110 ° C. 2 minutes after the heating press. Then, it was immediately pressed at 0.5 kg / cm ² for 1 minute in a cold press machine through which cooling water was passed. 24 hours adhesive curing at 23 ° C, 65% RH

Example 2 Adhesive B was applied to one side of a phenol-impregnated paper honeycomb core (41 mm thick, 75 mm wide, 100 mm long) at 120 ° C. at 60 g / m ² . After 30 seconds, the other surface was coated with the adhesive in the same manner. However, the already applied surface was cooled and solidified, and there was no problem in workability. Next, the honeycomb core was placed on a reinforcing plate (veneer plate), and another reinforcing plate was superimposed on the honeycomb core, and the pressure was adjusted to 0.5 kg / cm ² with a heat press apparatus adjusted to 140 ° C. Pressed for 4 minutes. At this time, the bonding interface temperature reached 115 ° C. 4 minutes after the heating press. Then, it was immediately pressed at 0.5 kg / cm ² for 1 minute in a cold press machine through which cooling water was passed. Adhesive B was applied to the back surface (adhesive surface) of the coated steel sheet at 120 ° C. at 70 g / m ² . After that, the honeycomb panel that was made into the reinforcing plate created in the previous process was installed on the painted steel sheet, and another painted steel sheet coated with adhesive was superimposed on it,
0.5 kg / cm ² with a heat press adjusted to 120 ° C
For 2 minutes. At this time, the bonding interface temperature reached 110 ° C. 2 minutes after the heating press. Then, it was immediately pressed at 0.5 kg / cm ² for 1 minute in a cold press machine through which cooling water was passed. 24 hours adhesive curing at 23 ° C, 65% RH

Example 3 Adhesive C was applied to one side of a phenol-impregnated paper honeycomb core (41 mm thick, 75 mm wide, 100 mm long) at 120 ° C. at 60 g / m ² . After 30 seconds, the other surface was coated with the adhesive in the same manner. However, the already applied surface was cooled and solidified, and there was no problem in workability. Next, the honeycomb core was placed on a reinforcing plate (veneer plate), and another reinforcing plate was superimposed on the honeycomb core, and the pressure was adjusted to 0.5 kg / cm ² with a heat press apparatus adjusted to 140 ° C. Pressed for 4 minutes. At this time, the bonding interface temperature reached 115 ° C. 4 minutes after the heating press. Then, it was immediately pressed at 0.5 kg / cm ² for 1 minute in a cold press machine through which cooling water was passed. Adhesive C was applied to the back surface (adhesion surface) of the coated steel sheet at 120 ° C. at 70 g / m ² . After that, the honeycomb panel that was made into the reinforcing plate created in the previous process was installed on the painted steel sheet, and another painted steel sheet coated with adhesive was superimposed on it,
0.5 kg / cm ² with a heat press adjusted to 120 ° C
For 2 minutes. At this time, the bonding interface temperature reached 110 ° C. 2 minutes after the heating press. Then, it was immediately pressed at 0.5 kg / cm ² for 1 minute in a cold press machine through which cooling water was passed. 24 hours adhesive curing at 23 ° C, 65% RH

Measurement of Adhesive Strength of Honeycomb Sandwich Structure Panel The adhesive strength of the honeycomb sandwich structure panels obtained in Examples 1 to 3 was measured by the following method, and the results are shown in Table 1. Method of measuring adhesive strength A honeycomb sandwich structure panel having an adhesive surface of 75 mm in width and 100 mm in length is prepared and used as a test body, and a steel plate on both sides is prepared.
(Surface plate) is peeled off by 20 mm and bent at 90 degrees, and the both sides of this part are grasped, and under a predetermined temperature environment, 20
Peeling was performed at a speed of 0 mm / min, and the strength was measured.

[0020]

[Table 1]

[0021]

As described above, according to the method for manufacturing a honeycomb sandwich panel of the present invention, the problems of the prior art relating to the present invention, such as the danger of pollution and fire caused by a solvent and the use of a hot melt adhesive, Lack of heat resistance,
In addition to solving workability and productivity defects, it has become possible to impart a sufficient adhesive strength to a honeycomb sandwich structural panel that requires particularly high structural strength.

 ────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor Shuta Nakagawa 1 Nagoya Research Laboratory, 1-A, Funami-cho, Minato-ku, Nagoya-shi, Aichi

Claims (2)

[Claims] 1. A core material of a honeycomb core melt-coated with an isocyanate-terminated polyurethane hot melt adhesive,
A method for manufacturing a honeycomb sandwich panel, comprising: laminating a reinforcing plate and a surface plate; and bonding the laminated body by heating the laminate at a high temperature. 2. The method for manufacturing a honeycomb sandwich structure panel according to claim 1, wherein the heating is performed so that the temperature of the bonding interface becomes 100 to 150 ° C.