JP2010234797A - Method for manufacturing decorative sheet and decorative sheet obtained by the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a decorative sheet, the change of the exterior appearance such as the glimmering surface (orange peel) of the surface of which is solved and which is superior in mirror-finishing properties. <P>SOLUTION: In the method for manufacturing the decorative sheet including a first thrusting process for crimplingly laminating a decorative sheet and a base material through adhesive with a first thrusting means, the temperature t<SB>1</SB>at crimping with the first thrusting means of the adhesive and the temperature K(°C) of the adhesive, the loss tangent tanδ of which is 1, has a relationship represented by the equation: t<SB>1</SB>-K≥0 and, at the same time, the los tangent tanδ at the peak temperature T(°C) of the loss tangent tanδ is larger than 1. Further, the loss tangent tanδ is measured by a dynamic test with a parallel plate type rheometer under the condition that frequence is 0.16 Hz (in angular velocity ω of 1 rad/sec), dynamic strain ε is 0.1% and temperature slope Δt is -2 K/min. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a method for producing a decorative plate used for building materials such as housing members, furniture, and doors, and particularly relates to a method for manufacturing a decorative decorative plate having high specularity and a decorative plate manufactured using the same.

Conventionally, a coating method has been widely used for decorative sheets with high specularity. However, the painting process requires undercoating, intermediate coating, and the like, and since painting and polishing are alternately repeated, the number of processes is large and the productivity is poor.
Therefore, in order to improve the production efficiency, a manufacturing method has been performed in which a mirror-like decorative sheet and a base material are bonded to each other via an adhesive to obtain a mirror finish equivalent to that of a coated product. When producing a decorative board by this method, a reactive hot melt adhesive is used as an adhesive. This reactive hot melt adhesive is solid at room temperature, and is applied to a base material or a sheet in a heated and melted state, and the base material and the decorative sheet are bonded together.
A urethane-based reactive hot melt (hereinafter referred to as “PUR”), which is a representative example of the reactive hot melt adhesive, contains a functional group (isocyanate group) that reacts with moisture in its components, and is cooled and cured. After that, it reacts with moisture adhering to the substrate and the decorative sheet and moisture given through them. After the reaction, it does not melt even when heated and has a high adhesive strength.

Regarding the manufacturing method using this PUR, Patent Document 1 proposes a manufacturing method of a mirror surface member in which a mirror surface sheet of a synthetic resin having a synthetic resin transparent layer on the surface of a synthetic resin base sheet is laminated on a substrate by a laminating roll. is doing. In this method, the adhesive made of PUR applied to the back surface of the mirror sheet is heated before the lamination so that the temperature becomes higher than the softening temperature and the substrate is heated, and then the laminate is laminated by a laminating roll to become a mirror surface. A mirror surface member is manufactured.
However, in order to heat the adhesive made of PUR so as to be higher than the softening temperature, a heating roll is provided at the front stage of the laminating roll and a cooling roll is provided at the rear stage. About temperature control of the laminating roll and the adhesive at the time of laminating Was not taken into account.

Further, Patent Document 2 discloses a laminate member manufacturing apparatus having an adhesive coating means for applying an adhesive to a core material and / or a decorative material, and a pressing means for bonding the decorative material to the core material. The pressing means has a decorative material pressing portion that presses the surface of the decorative material against the core material, the contact surface of the decorative material pressing portion with the decorative material is formed of a cushioning material, and the decorative material pressing portion is a cosmetic material. It has a structure that slides on the contact surface with the decorative material due to relative movement with the material. Also in this method, the reactive hot melt adhesive is only melted and applied by heating to 100 to 130 ° C., and no consideration has been given to the pressing means and temperature control of the adhesive.
Furthermore, in these methods, the appearance of the decorative board may fluctuate (i.e., the skin), and the specularity of the decorative board may be impaired.

Japanese Patent Laid-Open No. 2002-248689 JP 2005-288788 A

  In view of the above-described present situation, an object of the present invention is to provide a method for manufacturing a decorative board that eliminates a change in the appearance of the decorative board that fluctuates (i.e., the skin) and has excellent specularity.

  As a result of intensive studies to achieve the above object, the inventors of the present invention have made the base plate after taking out from the pressing means according to the temperature conditions of the pressing means and the adhesive in the decorative plate once mirrored by the pressing means. It has been found that the unevenness of the surface may appear on the surface of the decorative board and cause the skin phenomenon. Therefore, as a result of careful examination of the temperature conditions of the pressing means and the adhesive, it has been found that the above problem can be solved by appropriately controlling the temperatures of the pressing means and the adhesive. The present invention has been completed based on such findings.

That is, the present invention
[1] A decorative board manufacturing method including a first pressing step in which a decorative sheet and a substrate are pressed and bonded to each other with a first pressing means via an adhesive, and the adhesive is pressed by the first pressing means. It has a relationship that the temperature t ₁ and the loss tangent tanδ of the adhesive of the temperature K and (℃) is 1 represented by the following formula (1), and the loss tangent at the loss tangent tanδ peak temperature T (℃) tan δ is greater than 1
t ₁ −K ≧ 0 (1)
[Measurement conditions of loss tangent tan δ: measured by a dynamic test using a parallel plate rheometer at a frequency of 0.16 Hz (angular velocity ω 1 rad / sec), dynamic strain ε 0.1%, temperature gradient Δt −2 K / min . ]
[2] The temperature t ₁ when the adhesive is pressed by the first pressing means and the loss tangent tan δ peak temperature T (° C.) of the adhesive have a relationship represented by the following formula (2): The decorative board manufacturing method according to the above [1],
t ₁ −T ≧ 0 (2)
[3] A decorative board manufacturing method including a second pressing step in which the decorative sheet and the base material bonded together through the adhesive in the first pressing step are cooled and pressed by a second pressing means. The temperature t _C at the time of cooling and pressing by the second pressing means of the adhesive and the temperature K (° C.) at which the loss tangent tan δ of the adhesive is 1 have a relationship represented by the following formula (3): The method for producing a decorative board according to the above [1] or [2],
t _C −K <0 (3)
[4] The decorative board manufacturing method according to any one of [1] to [3], wherein the first pressing unit is a thermocompression bonding unit,
[5] The decorative plate manufacturing method according to [3] or [4], wherein the second pressing step is a final pressing step.
[6] The method for producing a decorative board according to any one of [1] to [5], wherein the adhesive is a reactive hot melt adhesive,
[7] The decorative board manufacturing method according to any one of [1] to [6], wherein the first pressing means is a flat table press or a press roll.
[8] The decorative board manufacturing method according to any one of [3] to [7], wherein the second pressing means is a flat table press or a press roll,
[9] A decorative board produced by the production method according to any one of [1] to [8] is provided.

  According to the production method of the present invention, it is possible to eliminate a change in appearance such that the surface of the decorative board fluctuates (i.e., yuzu skin) and to obtain a decorative board excellent in specularity.

It is a schematic diagram which shows an example of the manufacturing method of this invention. It is a schematic diagram which shows the outline | summary of the measuring device and measuring method of the dynamic test in this invention. It is a figure which shows the example of a measurement of the temperature dependence of the loss tangent tan-delta in the dynamic test of the adhesive agent which concerns on the manufacturing method of this invention. It is a schematic diagram which shows the cross section of one example of the decorative board obtained by the manufacturing method of this invention.

The decorative board manufacturing method of the present invention is a decorative board manufacturing method including a first pressing step in which a decorative sheet and a base material are pressure-bonded and bonded together by a first pressing means via an adhesive. The temperature t ₁ during pressure bonding by one pressing means and the temperature K (° C.) at which the loss tangent tan δ of the adhesive is 1 have the relationship represented by the following formula (1), and the loss tangent tan δ peak temperature T The loss tangent tan δ at (° C.) is larger than 1.
t ₁ −K ≧ 0 (1)
Here, the loss tangent tan δ is measured by a dynamic test using a parallel plate rheometer, with a frequency of 0.16 Hz (angular velocity ω 1 rad / sec), dynamic strain ε 0.1%, and temperature gradient Δt −2 K / min. To measure.
This is because if the temperature t ₁ when the adhesive is pressed by the first pressing means is equal to or higher than the temperature K (° C.) at which the loss tangent tan δ of the adhesive is 1, a decorative sheet with good specularity can be obtained. The upper limit of the temperature t ₁ at the time of pressure bonding by the first pressing means of the adhesive is not particularly limited, but is preferably (T + 30) (° C.) or less, more preferably (T + 25) (° C.) or less, and (T + 20) (° C.) or less. Is particularly preferred.
In the present invention, the surface temperature at the time of pressure bonding by the first pressing means of the adhesive is regarded as the temperature t ₁ at the time of pressure bonding of the adhesive.
In order to satisfy the above formula (1), the surface temperature t ₂ of the first pressing means is preferably not less than the temperature t ₁ (° C.) and not more than (t ₁ +15) (° C.) at the time of pressure bonding of the adhesive, It is more preferably (t ₁ +3) (° C.) or more and (t ₁ +15) (° C.) or less.

In the decorative board manufacturing method of the present invention, the temperature t ₁ when the adhesive is pressed by the first pressing means and the loss tangent tan δ peak temperature T (° C.) of the adhesive are expressed by the following formula (2): It is preferable to have.
t ₁ −T ≧ 0 (2)
Here, the measurement condition of the loss tangent tan δ is the same as the above formula (1).
This is because if the temperature t ₁ at the time of pressure bonding by the first pressing means of the adhesive is equal to or higher than the loss tangent tan δ peak temperature T of the adhesive, a decorative board with better specularity can be obtained.

In the decorative board manufacturing method of this invention, it is preferable to include the 2nd press process which cools and pressure-bonds the decorative sheet and the base material which were bonded together through this adhesive agent at the 1st press process with a 2nd press means. The temperature t _C at the time of cooling and pressing by the second pressing means of the adhesive and the temperature K (° C.) at which the loss tangent tan δ of the adhesive is 1 preferably have the relationship represented by the following formula (3). .
t _C −K <0 (3)
Here, the measurement condition of the loss tangent tan δ is the same as the above formula (1).
This is because the decorative sheet and the base material, which are bonded together through the adhesive in the first pressing step, are cooled and pressure-bonded by the second pressing means, whereby a decorative plate having further excellent specularity can be obtained. Here, in the second pressing step for cooling and pressure bonding, the temperature t _C at the time of cooling and pressing by the second pressing means of the adhesive may be lower than the temperature K (° C.) at which the loss tangent tan δ of the adhesive is 1. From this viewpoint, the relationship represented by the following formula (3-a) is more preferable, and the relationship represented by the following formula (3-b) is more preferable.
t _C −K ≦ −3 (3-a)
t _C −K ≦ −5 (3-b)
The temperature t _C has no particular lower limit, but if it is cooled too much, the workability is lowered and the cooling cost becomes excessive, so the relationship represented by the following formula (3-c) is preferable, and the following formula (3-d ) Is more preferable.
t _C −K ≧ −20 (3-c)
t _C −K ≧ −15 (3-d)
In the present invention, the surface temperature at the time of cooling and pressure bonding of the adhesive is regarded as the temperature t _C at the time of cooling and pressing by the second pressing means of the adhesive.
Further, in order to satisfy the above formula (3), the surface temperature t ₄ of the second pressing means is not more than the temperature t _C (° C.) and (t _C -25) (° C.) or more when the adhesive is cooled and pressure-bonded. Preferably, (t _C −3) (° C.) or lower and (t _C −20) (° C.) or higher are particularly preferable.

Hereinafter, the decorative board manufacturing method of this invention is demonstrated based on drawing. FIG. 1 is a schematic view showing an example of the production method of the present invention.
As shown in FIG. 1, in the 1st press process of the manufacturing method 10 of this invention, the base material 60 is conveyed by the conveyance roll 11 from a process line upstream, and is guide | induced to the 1st press means, press roll A16a here. In addition, the decorative sheet 40 supplied from the decorative sheet supply roll 12 is coated with the adhesive supplied from the adhesive coating head 13a of the adhesive supply device 13 on the backup roll 14, and the thermal insulation device 15 applies the adhesive. The temperature is maintained at a predetermined temperature and supplied to the press roll A16a. Via the applied adhesive, the decorative sheet 40 and the base material 60 pass through the press roll A16a, the press roll B16b, and the press roll C16c and are bonded by pressure bonding. At this time, since the adhesive pressed by the press roll A16a which is the first pressing means is controlled to the temperature represented by the above formula (1) as the first pressing step, the decorative board 30 having good specularity is obtained. Will be obtained.
Further, the adhesive pressed by the press roll C16c, which is the second pressing means, is controlled to the temperature represented by the above formula (3) as the second pressing step, thereby obtaining the decorative board 30 having further excellent specularity. Will be.
In order to satisfy the above formula (1), the first pressing means is preferably a thermocompression bonding means. This thermocompression bonding means can cause plastic flow better. The first pressing step is preferably the first pressing step.
Moreover, it is preferable that a 2nd press process is a final press process from a viewpoint which cools the obtained shape to the temperature area | region where elasticity control predominates, and maintains and fixes the outstanding specularity.

In the decorative board manufacturing method of the present invention, the press roll 16 is preferably composed of two or more press rolls, for example, 2 to 10 press rolls are preferably used. Among the press rolls 16, the first press roll A16a to be pressure-bonded is preferably a rubber roll, and for example, a silicone rubber roll is preferably used. In addition, a metal roll is preferably used as the press roll B16b, the press roll C16c, and the like to be pressure-bonded after the second.
When the press roll 16 is composed of two press rolls, the first press roll is the first pressing means, and the second press roll is the second pressing means.
The first pressing means may be composed of a plurality of press rolls, and the second pressing means may be composed of a plurality of press rolls. Moreover, both the 1st press means and the 2nd press means may each be comprised from several press rolls.
Although the case where the first pressing means and the second pressing means are press rolls has been described above, a flat table press may be used as the first pressing means and / or the second pressing means.
Further, the heat retaining device 15 is preferably a non-contact type heat retaining device, and for example, an infrared heater is preferably used because of easy temperature control.

The measuring method of the temperature K (° C.) at which the loss tangent tan δ of the adhesive used in the decorative plate manufacturing method of the present invention is 1 and the loss tangent tan δ peak temperature T (° C.) of the adhesive is an operation using a parallel plate rheometer. By a physical test, the frequency is 0.16 Hz (angular velocity ω 1 rad / sec), dynamic strain ε is 0.1%, and temperature gradient Δt is −2 K / min.
FIG. 2 is a schematic diagram showing an outline of a dynamic test measuring machine and measuring method in the present invention, and shows a parallel plate rheometer with a temperature control function. The movable plate (diameter 25 mm) 21 and the fixed plate 22 are parallel, and the gap is 1 mm. The adhesive 50a is filled between the gaps, and the dynamic strain is given by the driving and detecting device 23 to detect the dynamic stress.

FIG. 3 is a diagram showing a measurement example of the loss tangent tan δ which is temperature dependency in the dynamic test of the PUR adhesive according to the manufacturing method of the present invention. The loss tangent tan δ is determined based on the following formula (4) from the storage elastic modulus G ′ and the loss elastic modulus G ″ in the dynamic test.
tan δ = G "/ G '(4)
According to FIG. 3, the loss tangent tan δ peak temperature T of the test PUR adhesive is about 70 ° C., and the loss tangent tan δ value is 1 or more over 42 to 120 ° C.

Next, a typical example of the decorative board obtained in the decorative board manufacturing method of the present invention will be described with reference to the drawings. FIG. 4 is a schematic view showing a cross section of an example of a decorative board obtained by the production method of the present invention.
As shown in FIG. 4, the decorative board 30 obtained by the manufacturing method of the present invention has an adhesive layer 50 made of a reactive hot-melt adhesive or the like (for example, a PUR adhesive). It is laminated.

As the adhesive used in the present invention, a reactive hot melt adhesive is preferably used. Of these reactive hot melt adhesives, a PUR adhesive is particularly preferred.
Examples of the polyol component that can be used in the PUR adhesive include polyester polyols such as polyester diol, polyether polyols such as polyether diol, and mixtures or copolymers thereof. Furthermore, acrylic polyol, polycarbonate polyol, polyolefin polyol, castor oil polyol, polyhydric alcohol and the like, or a mixture or copolymer thereof can be mentioned.
Further, the polyisocyanate component is not particularly limited, but for example, aromatic such as phenylene diisocyanate, tolylene diisocyanate (TDI), 4,4′-diphenylmethane diisocyanate, 2,4-diphenylmethane diisocyanate, naphthalene diisocyanate, etc. Examples thereof include aliphatic or alicyclic diisocyanates such as diisocyanate, hexamethylene diisocyanate, lysine diisocyanate, cyclohexane diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, xylylene diisocyanate, and tetramethylxylylene isocyanate. Among these, it is preferable to use diphenylmethane diisocyanate (MDI) having a low vapor pressure during heating.
The PUR adhesive used in this embodiment is preferably a polyester polyol-based PUR adhesive that melts at 100 to 130 ° C. and has a viscosity of 1000 to 30000 mPa · s. Is preferred. In particular, such a PUR adhesive is preferably obtained by using polyester polyol in combination with polyether polyol or other polyol, such as acrylic polyol.
In addition, what is marketed can also utilize the polyurethane reactive hot melt, for example, DIC Corporation make and tie hose FH-100 are mentioned.
The application amount of the PUR adhesive is, for example, 50 to 150 μm as the thickness of the adhesive layer 50.

The base material 60 used in the present invention is not particularly limited, and various plate-like materials can be used. For example, wood boards such as high density wood fiber board, medium density fiber board (MDF), low density wood fiber board, particle board, wood powder plastic particle board and wood powder plastic board, plastic board (resin board), A paper laminated board etc. can be used.
The thickness of the substrate 60 is not particularly limited, but is preferably 1 to 50 mm, more preferably 2.5 to 30 mm, and still more preferably 4 to 30 mm from the viewpoints of manufacturing limitations and weight.

The high density wood fiberboard refers to a wood fiberboard having a density of 0.80 g / cm ² or more among fiberboards defined in JIS A5905-2003. The wood fiberboard specified by the above JIS is a board formed mainly from wood and other plant fibers. Generally, the surface hardness is high, and if an appropriate density is selected, a dent when an object collides with it is selected. It is a strong and useful material. In addition, the cost of the material can be obtained at a lower cost than plastic.
Preferred examples of such a high density wood fiberboard include HDF (high density fiberboard) and hard board.
The low density wood fiberboard refers to a wood fiberboard having a density of less than 0.35 g / cm ² among fiberboards defined in JIS A5905-2003. Examples of such a low density wood fiberboard include an insulation board, a tatami board, and a sizing board.

The decorative sheet 40 used in the present invention is not limited as long as it has at least the colored resin layer 41 and / or the pattern print layer 42. A decorative sheet 40 used in the manufacturing method of the present invention shown in FIG. 4 includes a colored resin layer 41, a pattern printing layer 42, a primer layer 43, a transparent resin layer 44, and a surface protective layer 45 that are laminated in that order.
The thickness of the decorative sheet 40 is preferably 35 to 400 μm.

The colored resin layer 41 laminated as desired in the decorative sheet 40 used in the present invention is provided in order to achieve a design effect and / or to conceal the color of the substrate 60. If it is not necessary to obtain a design effect and it is not necessary to conceal the color of the base material 60, it may not be provided.
The pattern print layer 42 that is laminated as desired in the decorative sheet 40 according to the present invention is provided in order to achieve a design effect, and may not be provided when the colored resin layer 41 has a sufficient design effect.
The pattern print layer 42 is a layer that represents a pattern, a character, and a pattern-like pattern. The pattern of the pattern print layer 42 is arbitrary, but is a pattern made of, for example, wood grain, stone grain, cloth grain, sand grain, geometric pattern, character, or the like. The pattern printing layer 42 is usually formed by a known printing method such as gravure printing, offset printing, silk screen printing, transfer printing from a transfer sheet, sublimation transfer printing, ink jet printing with printing ink.
The thickness of the colored resin layer 41 is preferably 35 to 200 μm, and the thickness of the pattern print layer 42 may be appropriately selected according to the pattern.

As a binder of ink or paint used for the colored resin layer 41 and / or the pattern print layer 42 according to the present invention, urethane resin, polyester resin, acrylic resin, vinyl acetate resin, vinyl chloride-vinyl acetate copolymer, cellulose resin Alternatively, chlorinated polyolefin resins such as chlorinated polyethylene and chlorinated polypropylene are used alone or in combination of two or more. As the ink or paint, in addition to the above-mentioned binders made of various resins, colorants such as pigments and dyes, extender pigments, solvents, stabilizers, plasticizers, catalysts, curing agents and the like are appropriately mixed. .
Examples of the colorant used in the above ink or paint include titanium white, zinc white, petal, vermilion, ultramarine, cobalt blue, titanium yellow, yellow lead, carbon black and other inorganic pigments, isoindolinone yellow, Hansa Yellow A, and quinacridone. Organic pigments (or dyes) such as red, permanent red 4R, phthalocyanine blue, indanthrene blue RS, aniline black, metal pigments made of metal powder such as aluminum, brass, titanium dioxide-coated mica, basic lead carbonate, etc. A pearlescent (pearl) pigment, a fluorescent pigment, or the like made of a foil powder is used.
The colored resin layer 41 or the pattern print layer 42 may be a metal thin film layer or the like. The metal thin film layer is formed by using a metal such as aluminum, chromium, gold, silver, or copper by a method such as vacuum deposition or sputtering. Or a combination of these may be used. The metal thin film layer may be provided on the entire surface or partially in a pattern.

  The primer layer 43 that is laminated as desired in the decorative sheet 40 according to the present invention is provided between the colored resin layer 41 and / or the pattern printing layer 42 and the transparent resin layer 44 and / or the surface protective layer 45 that is optionally provided. Optionally provided to enhance adhesion of the layers. The primer composition constituting the primer layer 43 includes urethane resin, (meth) acrylic resin, (meth) acrylic / urethane copolymer resin, vinyl chloride-vinyl acetate copolymer, polyester resin, butyral resin, chlorinated polypropylene. Chlorinated polyethylene or the like is used.

  As the urethane resin, a two-component polyurethane having a polyol (polyhydric alcohol) as a main component and an isocyanate as a crosslinking agent (curing agent) can be used. As the polyol, one having two or more hydroxyl groups in the molecule, for example, polyester polyol, polyethylene glycol, polypropylene glycol, acrylic polyol, polyether polyol and the like are used. Examples of the isocyanate include polyvalent isocyanate having two or more isocyanate groups in the molecule, aromatic isocyanate such as 4,4-diphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, hydrogenated tolylene diisocyanate, hydrogenated diphenylmethane diisocyanate. Aliphatic (or alicyclic) isocyanates such as are used. It is also possible to mix urethane resin and butyral resin.

(Meth) acrylic resins include (meth) acrylic acid ester homopolymers, copolymers of two or more different (meth) acrylic acid ester monomers, or (meth) acrylic acid esters and other monomers. Polymers, and specifically, poly (meth) methyl acrylate, poly (meth) ethyl acrylate, poly (meth) acrylate propyl, poly (meth) acrylate butyl, methyl (meth) acrylate (Meth) butyl acrylate copolymer, (meth) ethyl acrylate / (meth) butyl acrylate copolymer, ethylene / (meth) methyl acrylate copolymer, styrene / methyl (meth) acrylate copolymer A (meth) acrylic resin made of a homopolymer or a copolymer containing a (meth) acrylic acid ester such as the above is preferably used.
Here, (meth) acryl means acryl or methacryl.

  As the (meth) acryl / urethane copolymer resin, for example, an acrylic / urethane (polyester urethane) block copolymer resin is preferable. As the curing agent, the above-mentioned various isocyanates are used. The acrylic / urethane (polyester urethane) block copolymer resin may have an acrylic / urethane ratio (mass ratio) of preferably (9/1) to (1/9), more preferably (8/2) to (2). / 8) and can be used for various decorative sheets.

The thickness of the primer layer 43 according to the present invention is preferably 0.1 μm to 10 μm, and more preferably 1 to 10 μm.
As a method of forming the primer layer 43, gravure coating, gravure reverse coating, gravure offset coating, spinner coating, roll coating, reverse roll coating, kiss coating, wheeler coating, dip coating, silk screen solid coating, wire bar coating, flow coating, It can be formed by a coating method such as comma coating, flow coating, brush coating, spray coating or the like, and a transfer method can also be used.

The transparent resin layer 44 that is laminated as desired in the decorative sheet 40 according to the present invention is a resin layer that is transparent or translucent (uncolored or colored) so that the pattern printing layer 42 or the colored resin layer 41 can be seen through. It may be made of a polyolefin resin, but is preferably made of a polyester resin, particularly an amorphous polyester resin.
As an amorphous polyester resin, for example, a trademark “Eastar PETG 6763” (trade name) (extruded grade) manufactured by Eastman Chemical Co., Ltd. can be used. "Kanebo PET sheet" (trade name) by Kanebo Co., Ltd., "Teijin Tetron sheet" (trade name) by Teijin Ltd., "Denka A-PET sheet" (trade name) by Denki Kagaku Kogyo Co., Ltd., Toyo "Toyobo PETMAX sheet" (trade name) by Spinning Co., Ltd. "NAGASE A-PET sheet" (trade name) by Nagase Sangyo Co., Ltd., "Polytech A-PET sheet" (trade name) by Polytech Co., Ltd., SAEHAN "SAEHAN APET SEET" (trade name) by Mitsubishi Chemical Corporation "Nobakuria" (trade name), "sealer PT" (trade name), and the like can be used by DuPont-Mitsui poly Chemical Company. In addition, a resin or resin sheet called A-PET (sometimes referred to as APET) in the packaging material field is an amorphous polyester resin, and PET-G (sometimes referred to as PETG). The called resin or resin sheet is also an amorphous polyester resin.

  On the other hand, as the polyolefin resin used for the transparent resin layer 44, polyethylene (low density, medium density, or high density), polypropylene, polymethylpentene, polybutene, ethylene-propylene random copolymer (for example, metallocene catalyst isotactic). A highly crystalline non-elastomeric polyolefin resin such as a ticethylene-propylene random copolymer) or a propylene-butene copolymer, or various olefinic thermoplastic elastomers are used.

The transparent resin layer 44 is formed by laminating a colored resin layer 41 and / or a pattern printing layer 42 and then drying a resin sheet previously formed into a sheet (film) by a known film forming method such as a melt extrusion method or a calendar method. It can be formed by lamination or lamination by heat fusion. Alternatively, the resin constituting the transparent resin layer 44 may be formed simultaneously with the film formation by the melt extrusion coating method (EC method) after the colored resin layer 41 and / or the pattern layer 122 are laminated.
The thickness of the transparent resin layer (not a single layer but as a whole in the case of multiple layers) depends on the application, layer configuration (single layer, multilayer), etc., but is usually about 35 to 250 μm.

In addition, in the transparent resin layer 44, various additions such as a filler, a flame retardant, a lubricant, an antioxidant, an ultraviolet absorber, a light stabilizer, and the like, as long as the transparency or translucency is not impaired. An agent may be added. When the transparent resin layer 44 is used as a semitransparent layer, for example, fine particle silica or the like may be appropriately added to the transparent resin layer 44 to make it semitransparent.
In addition, as the ultraviolet absorber, in addition to organic ultraviolet absorbers such as benzotriazole, benzophenone, and salicylic acid ester, particulate zinc oxide, cerium oxide, titanium oxide, etc. having a particle size of 0.2 μm or less An inorganic substance can be used. As the light stabilizer, a radical scavenger such as a hindered amine radical scavenger such as bis- (2,2,6,6-tetramethyl-4-piperidinyl) sebacate or a piperidine radical scavenger can be used.

The surface protective layer 45 optionally laminated on the decorative sheet 40 according to the present invention crosslinks a resin composition containing an ionizing radiation curable resin and a thermoplastic resin in a ratio (mass ratio) of 100: 0 to 25:75. It is preferable that it is hardened. Here, the ionizing radiation curable resin has an energy quantum capable of crosslinking and polymerizing molecules in an electromagnetic wave or a charged particle beam, that is, a resin that is crosslinked and cured by irradiation with ultraviolet rays or electron beams. Point to. Specifically, it can be appropriately selected from polymerizable monomers, polymerizable oligomers, or prepolymers conventionally used as ionizing radiation curable resins.
The thickness of the surface protective layer 45 is preferably 1 to 20 μm. When the thickness is 1 μm or more, wear resistance and scratch resistance are improved. If it is 20 micrometers or less, a moldability will improve and the high followable | trackability to complicated three-dimensional shapes, such as a vehicle interior use, can be acquired.

  As the polymerizable monomer, typically, a (meth) acrylate monomer having a radical polymerizable unsaturated group in the molecule is suitable, and among them, a polyfunctional (meth) acrylate is preferable. Here, “(meth) acrylate” means “acrylate or methacrylate”, and other similar ones have the same meaning. The polyfunctional (meth) acrylate is not particularly limited as long as it is a (meth) acrylate having two or more ethylenically unsaturated bonds in the molecule. Specifically, ethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) ) Acrylate, polyethylene glycol di (meth) acrylate, hydroxypivalate neopentyl glycol di (meth) acrylate, dicyclopentanyl di (meth) acrylate, caprolactone-modified dicyclopentenyl di (meth) acrylate, ethylene oxide-modified phosphate di ( (Meth) acrylate, allylated cyclohexyl di (meth) acrylate, isocyanurate di (meth) acrylate, trimethylolpropane tri (meth) acrylate, ethylene oxide modified trimethylo Propane tri (meth) acrylate, dipentaerythritol tri (meth) acrylate, propionic acid modified dipentaerythritol tri (meth) acrylate, pentaerythritol tri (meth) acrylate, propylene oxide modified trimethylolpropane tri (meth) acrylate, tris ( Acryloxyethyl) isocyanurate, propionic acid modified dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, ethylene oxide modified dipentaerythritol hexa (meth) acrylate, caprolactone modified dipentaerythritol hexa (meth) acrylate, etc. Is mentioned. These polyfunctional (meth) acrylates may be used alone or in combination of two or more.

  In the present invention, a monofunctional (meth) acrylate can be used in combination with the polyfunctional (meth) acrylate as long as the object of the present invention is not impaired, for the purpose of lowering the viscosity. Examples of monofunctional (meth) acrylates include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, cyclohexyl ( Examples include meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, and isobornyl (meth) acrylate. These monofunctional (meth) acrylates may be used alone or in combination of two or more.

  Next, as the polymerizable oligomer, an oligomer having a radical polymerizable unsaturated group in the molecule, for example, epoxy (meth) acrylate, urethane (meth) acrylate, polyester (meth) acrylate, polyether (meth) acrylate And the like. Here, the epoxy (meth) acrylate oligomer can be obtained, for example, by reacting (meth) acrylic acid with an oxirane ring of a relatively low molecular weight bisphenol type epoxy resin or novolak type epoxy resin and esterifying it. . Further, a carboxyl-modified epoxy (meth) acrylate oligomer obtained by partially modifying this epoxy (meth) acrylate oligomer with a dibasic carboxylic acid anhydride can also be used. The urethane (meth) acrylate oligomer can be obtained, for example, by esterifying a polyurethane oligomer obtained by reaction of polyether polyol or polyester polyol and polyisocyanate with (meth) acrylic acid. Examples of polyester (meth) acrylate oligomers include esterification of hydroxyl groups of polyester oligomers having hydroxyl groups at both ends obtained by condensation of polycarboxylic acid and polyhydric alcohol with (meth) acrylic acid, It can be obtained by esterifying the terminal hydroxyl group of an oligomer obtained by adding an alkylene oxide to a carboxylic acid with (meth) acrylic acid. The polyether (meth) acrylate oligomer can be obtained by esterifying the hydroxyl group of the polyether polyol with (meth) acrylic acid.

  Furthermore, other polymerizable oligomers include polybutadiene (meth) acrylate oligomers with high hydrophobicity that have (meth) acrylate groups in the side chain of polybutadiene oligomers, and silicone (meth) acrylate oligomers that have polysiloxane bonds in the main chain. In a molecule such as an aminoplast resin (meth) acrylate oligomer modified with an aminoplast resin having many reactive groups in a small molecule, or a novolac type epoxy resin, bisphenol type epoxy resin, aliphatic vinyl ether, aromatic vinyl ether, etc. There are oligomers having a cationic polymerizable functional group.

Examples of the thermoplastic resin used in the resin composition constituting the surface protective layer 45 include (meth) acrylic resins such as (meth) acrylic acid esters, polyvinyl acetals (butyral resin) such as polyvinyl butyral, polyethylene terephthalate, and polybutylene. Polyester resins such as terephthalate, vinyl chloride resins, urethane resins, polyolefins such as polyethylene and polypropylene, styrene resins such as polystyrene and α-methylstyrene, acetal resins such as polyamide, polycarbonate, and polyoxymethylene, ethylene-4 fluoroethylene Fluorine resins such as copolymers, polyimide, polylactic acid, polyvinyl acetal resin, liquid crystalline polyester resin and the like may be mentioned, and these may be used alone or in combination of two or more. When combining 2 or more types, the copolymer of the monomer which comprises these resin may be sufficient, and each resin may be mixed and used.
Among the above thermoplastic resins, homopolymers of (meth) acrylate esters, copolymers of two or more different (meth) acrylate monomers, or copolymerization of (meth) acrylate esters with other monomers What has (meth) acrylic-type resin as a main component, such as a coalescence, is preferable, and what polymerized the monomer which contains at least (meth) acrylic acid ester as a monomer component among these is preferable.

When an ultraviolet curable resin is used as the ionizing radiation curable resin, it is desirable to add about 0.1 to 5 parts by mass of the photopolymerization initiator with respect to 100 parts by mass of the resin. The initiator for photopolymerization can be appropriately selected from those conventionally used and is not particularly limited. For example, for a polymerizable monomer or polymerizable oligomer having a radically polymerizable unsaturated group in the molecule. Benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin-n-butyl ether, benzoin isobutyl ether, acetophenone, dimethylaminoacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2 -Phenylacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino-propane-1 - 4- (2-hydroxyethoxy) phenyl-2 (hydroxy-2-propyl) ketone, benzophenone, p-phenylbenzophenone, 4,4′-diethylaminobenzophenone, dichlorobenzophenone, 2-methylanthraquinone, 2-ethylanthraquinone, 2 -Tertiary butylanthraquinone, 2-aminoanthraquinone, 2-methylthioxanthone, 2-ethylthioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, benzyl dimethyl ketal, acetophenone dimethyl ketal, etc. It is done.
Examples of the polymerizable oligomer having a cationic polymerizable functional group in the molecule include aromatic sulfonium salts, aromatic diazonium salts, aromatic iodonium salts, metallocene compounds, and benzoin sulfonic acid esters.
Moreover, as a photosensitizer, p-dimethylbenzoic acid ester, tertiary amines, a thiol type sensitizer, etc. can be used, for example.

  It is preferable to use an electron beam curable resin as the ionizing radiation curable resin according to the present invention. This is because the electron beam curable resin can be made solvent-free, is more preferable from the viewpoint of environment and health, and does not require a photopolymerization initiator, and can provide stable curing characteristics.

The formation of the surface protective layer 45 can be obtained by preparing a coating liquid containing the above-mentioned resin composition for forming the surface protective layer, applying it, and crosslinking and curing it. In addition, the viscosity of a coating liquid should just be a viscosity which can form a non-hardened resin layer on the surface of a base material by the below-mentioned coating system, and there is no restriction | limiting in particular.
In the present invention, the prepared coating liquid is applied to the surface of the colored resin layer 41 or the like so that the thickness after curing is 1 to 20 μm, such as gravure coating, bar coating, roll coating, reverse roll coating, comma. It coats by well-known systems, such as a coat, preferably a gravure coat, and forms an uncured resin layer.

In the decorative sheet 40 used in the present invention, the uncured resin layer is cured by irradiating the uncured resin layer formed as described above with ionizing radiation such as an electron beam or ultraviolet rays. Here, when an electron beam is used as the ionizing radiation, the acceleration voltage can be appropriately selected according to the resin used and the thickness of the layer, but the uncured resin layer is usually cured at an acceleration voltage of about 70 to 300 kV. preferable.
In addition, in electron beam irradiation, since the transmission capability increases as the acceleration voltage is higher, when a base material that deteriorates due to an electron beam is used as the base material 11, the transmission depth of the electron beam and the thickness of the resin layer are By selecting an accelerating voltage so as to be substantially equal, it is possible to suppress irradiation of an extra electron beam to the base material 11 and to minimize deterioration of the base material due to the excess electron beam. .
The irradiation dose is preferably such that the crosslink density of the resin layer is saturated, and is usually selected in the range of 5 to 300 kGy (0.5 to 30 Mrad), preferably 10 to 50 kGy (1 to 5 Mrad).
Further, the electron beam source is not particularly limited. For example, various electron beam accelerators such as a cockroft Walton type, a bandegraft type, a resonant transformer type, an insulated core transformer type, a linear type, a dynamitron type, a high frequency type, etc. Can be used.

  When ultraviolet rays are used as the ionizing radiation, those containing ultraviolet rays having a wavelength of 190 to 380 nm are emitted. There is no restriction | limiting in particular as an ultraviolet-ray source, For example, a high pressure mercury lamp, a low pressure mercury lamp, a metal halide lamp, a carbon arc lamp, etc. are used.

EXAMPLES Next, although an Example demonstrates this invention further in detail, this invention is not limited at all by this example.
Evaluation method (1) Loss tangent tan δ peak temperature, peak tan δ value, and temperature at which tan δ> 1 Measurement was performed by the method described above.
(2) Adhesive pressure bonding temperature and press roll surface temperature Measured with a contact infrared radiation thermometer (manufactured by AS ONE, trade name “Digital Thermometer IT-2000 (K-type thermocouple IK-500)”) did.
(5) Specularity By illuminating the light of the fluorescent lamp obliquely on the surface of the decorative sheet laminated with the decorative sheet, and visually observing the distortion of the mapping, the decorative sheet having the best specularity was evaluated as 7, A decorative board having an inferior specularity due to the appearance of yuzu skin on the decorative board surface was evaluated as 1 and evaluated based on the following relative evaluation criteria 1-7.
7: The specularity of the decorative board surface was very excellent.
6: The mirror surface property of the decorative board surface was further excellent.
5: The mirror surface property of the decorative board surface was more excellent.
4: The specularity of the decorative board surface was excellent.
3: No yuzu skin was observed on the decorative plate surface, and the mirror surface property was good.
2: Slight skin appeared on the decorative plate surface, and the mirror surface was slightly inferior.
1: Yuzu skin appeared on the surface of the decorative board, and the specularity was inferior.

Examples 1-15 and Comparative Examples 1-7
A mirror surface decorative sheet (Dai Nippon Printing Co., Ltd., trade name “PIAFORTE”) is unwound from the decorative sheet supply roll, and the PUR adhesive listed in Table 1 is supplied from the adhesive coating head of the adhesive supply device. A thickness of 100 μm was applied. The temperature of the PUR adhesive at the time of application was 80 to 130 ° C. This was kept warm with an infrared heater so as to have the temperature at the time of crimping described in Table 1, and supplied to the press roll. On the other hand, the base material which consists of MDF (medium density fiber board) is conveyed with the conveyance roll 11 from the process line upstream, it supplies to the press roll of a 1st press process, and it is with a decorative sheet through a PUR adhesive in the heated press roll. The substrate was adhered. The press roll in the first pressing step is composed of six rolls including the first silicone rubber roll and the second to sixth metal rolls. The dynamic strain at the time of pressure bonding with each roll as the first pressing means was 10%. The heating conditions are shown in Table 1.
For Examples 2 to 4 and 12 and Comparative Examples 2 and 6, a makeup for a decorative board that is further provided with a press roll for the second pressing step composed of three metal rolls and is heat-treated by the first pressing step. The sheet surface was cooled. The dynamic strain at the time of pressure bonding with each roll as the second pressing means was 10%. The cooling conditions are shown in Table 1.
The mirror properties of the decorative plates of Examples 1 to 15 and Comparative Examples 1 to 7 obtained were evaluated. The results are shown in Table 1.

(note)
Adhesive A: manufactured by Hitachi Chemical Co., Ltd., polyester-based adhesive B: manufactured by DIC Corporation, polyester-based adhesive C: manufactured by Sanyo Chemical Industries, Ltd., polyester-based adhesive D: manufactured by DIC Corporation, Product name, polyester-based adhesive E: manufactured by DIC Corporation, polyester-based adhesive F: manufactured by Aika Industry Co., Ltd., polyester-based adhesive G: manufactured by Aika Industry Co., Ltd., polyester-based

In any of the decorative plates obtained by the production methods of Examples 1 to 15, no yuzu skin was observed, and the specularity was good as compared with the decorative plates obtained by the production methods of Comparative Examples 1 to 7. In particular, Examples 3 and 4 were provided with a first pressing step for thermocompression bonding at a temperature t ₁ that is equal to or higher than the temperature T (° C.) and a second pressing step for cooling and pressing at a temperature t _C lower than the temperature K (° C.). And the mirror surface property of the decorative board obtained by the manufacturing method of No. 12 was very excellent.

  Since the decorative board manufacturing method of the present invention can provide a decorative board having excellent specularity, it is a building material such as a kitchen, a room partition door, furniture, a table, or a member for indoor equipment, or a house, commercial facility, hospital, nursing facility It is used suitably as a manufacturing method of a decorative board used for building materials, such as interior and exterior wall surfaces.

10. 10. Production method of the present invention Transport roll 12. Decorative sheet supply roll 13. Adhesive supply device 13a. Adhesive coating head 14. Backup roll 15. Thermal insulation device 16. Press roll 16a. Press roll A
16b. Press roll B
16c. Press roll C
20. Parallel plate type rheometer 21. Movable plate 22. Fixed plate 23. Drive and detection device 30. Decorative plate 40. Cosmetic sheet 41. Colored resin layer 42. Pattern print layer 43. Primer layer 44. Transparent resin layer 45. Surface protective layer 50. Adhesive layer 60. Base material

Claims (9)

A decorative board manufacturing method including a first pressing step in which a decorative sheet and a base material are pressed and bonded to each other with a first pressing means via an adhesive, and the temperature t when the adhesive is pressed by the first pressing means ₁ and the temperature K (° C.) at which the loss tangent tan δ of the adhesive is 1 have the relationship represented by the following formula (1), and the loss tangent tan δ at the loss tangent tan δ peak temperature T (° C.) is 1 A method for producing a decorative board, which is larger.
t ₁ −K ≧ 0 (1)
[Measurement conditions of loss tangent tan δ: measured by a dynamic test using a parallel plate rheometer at a frequency of 0.16 Hz (angular velocity ω 1 rad / sec), dynamic strain ε 0.1%, temperature gradient Δt −2 K / min . ] The temperature t ₁ when the adhesive is pressed by the first pressing means and the loss tangent tan δ peak temperature T (° C.) of the adhesive have a relationship represented by the following formula (2). A method for producing a decorative board according to 1.
t ₁ −T ≧ 0 (2) A decorative board manufacturing method including a second pressing step in which the decorative sheet and the base material bonded together via the adhesive in the first pressing step are cooled and pressure-bonded by a second pressing means, The temperature t _C at the time of cooling and pressing by the second pressing means of the agent and the temperature K (° C.) at which the loss tangent tan δ of the adhesive is 1 have a relationship represented by the following formula (3): Item 3. The decorative board manufacturing method according to Item 1 or 2.
t _C −K <0 (3)   The decorative board manufacturing method according to any one of claims 1 to 3, wherein the first pressing means is a thermocompression bonding means.   The decorative board manufacturing method according to claim 3 or 4, wherein the second pressing step is a final pressing step.   The decorative board manufacturing method according to any one of claims 1 to 5, wherein the adhesive is a reactive hot melt adhesive.   The said 1st press means is a flat stand press or a press roll, The decorative board manufacturing method in any one of Claims 1-6 characterized by the above-mentioned.   The said 2nd press means is a flat stand press or a press roll, The decorative board manufacturing method in any one of Claims 3-7 characterized by the above-mentioned.   A decorative board manufactured by the manufacturing method according to claim 1.

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