JP7002896B2 - Manufacturing method of three-dimensional molded product - Google Patents

Description

The present invention relates to a method for producing a three-dimensional molded product.

Attempts have been made to decorate the surface of the adherend by laminating a colored or designed resin film on the surface of the adherend, which has a complicated shape such as unevenness on the surface, instead of conventional painting. There is. Examples of such an adherend include exterior parts and interior parts of automobiles and motorcycles, electronic parts, furniture and the like.
As a method of laminating a film on the surface of such an article, a film laminating molding method using a vacuum forming apparatus is known.
The film laminate molding method is a molding method in which a decorative film is inserted into an injection molding die and then injection-molded, so that the decorative film is attached to the surface of the molded body at the same time as molding to decorate the molded body. According to this method, it is possible to decorate a molded product having a complicated shape by using a decorative film. Further, it can be easily decorated in a short time as compared with the case where the molded product is painted or printed.

Patent Document 1 describes a laminated adhesive film for insert molding in which an adhesive is laminated on a polyphenylene sulfide-based resin film.
The insert molding film described in Patent Document 1 is attached to a molded product after being softened by vacuum heating. Therefore, the laminated adhesive film for insert molding in a state of being sandwiched between the release films is used by peeling off the release film.
Since an adhesive resin is used in film laminating molding in which injection molding and film laminating are performed at the same time, and in-mold laminating molding in which transfer is performed at the same time as injection molding, a release film is not required in the first place.

Japanese Patent No. 5912411

When performing in-mold laminating molding, if injection molding is performed while molding a flat adhesive film into a three-dimensional shape, a gap will be created between the adhesive film and the mold so that the adhesive film will completely follow the shape of the mold. It is difficult to mold. For this reason, there is a problem that a desired molded product cannot be obtained, or the adhesive film cannot be completely deformed, and a portion having poor adhesion is generated, resulting in partial peeling.
It is an object of the present invention to provide a method for producing a three-dimensional molded product capable of satisfactorily adhering a base material layer to the surface of an adherend along a shape without delamination.

That is, the present invention has adopted the following configuration.
[1] A step of forming a laminated molded body by three-dimensionally molding a laminate while heating a laminated body having at least a base material layer, an adhesive sheet layer, and a mold release sheet in this order, and a release sheet from the laminated molded body. The laminated body is measured as follows, comprising a step of peeling off the adhesive sheet layer to expose the adhesive sheet layer to obtain a molded body, and a step of attaching the molded body to the surface of the adherend to obtain a three-dimensional molded product. When measured under the conditions, the release strength of the release sheet with respect to the base material layer is 5 N / 50 mm or less, and the break point elongation of the release sheet is higher than the break point elongation of the base material layer. A method for producing a three-dimensional molded product, which is large and has a breaking point elongation of the release sheet exceeding 135%.
(Measurement condition)
The release sheet and the adhesive sheet layer when the laminate was heated at 120 ° C. for 5 minutes and the release sheet was peeled off over a length of 100 mm at a release angle of 180 degrees and a tensile speed of 300 m / min using a release tester. Measure the adhesive strength between.
[2] The three-dimensional molded product according to [1], wherein the release sheet is a film that has been subjected to a release treatment to one selected from the group consisting of a polyester film, a polyolefin film, an ABS resin film, and a polycarbonate resin film. Manufacturing method.
[3] The method for producing a three-dimensional molded product according to [1] or [2], wherein the material for forming the base material layer is one or more selected from the group consisting of polyolefin, ABS resin, and polycarbonate.
[4] The method for producing a three-dimensional molded product according to any one of [1] to [3], wherein the material for forming the adhesive sheet layer contains an acrylic polymer.
[5] The method for producing a three-dimensional molded product according to any one of [1] to [4], wherein the material for forming the adhesive sheet layer is a thermosetting resin.

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide a method for producing a three-dimensional molded product capable of satisfactorily adhering a base material layer to the surface of an adherend along a shape without delamination.

It is sectional drawing of an example of the adhesive sheet holding body used in this embodiment. It is a schematic process diagram of an example of the manufacturing method of the three-dimensional molded article of this embodiment. It is a schematic process diagram of an example of the manufacturing method of the three-dimensional molded article of this embodiment.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. The following embodiments are examples of the present invention, and the present invention is not limited thereto.

<Manufacturing method of three-dimensional molded product>
The method for producing a three-dimensional molded product of the present embodiment includes a step of three-dimensionally forming a mold while heating a laminated body including at least a base material layer, an adhesive sheet layer, and a release sheet in this order to form a laminated molded body. A step of peeling the release sheet from the laminated molded body to expose the adhesive sheet layer to obtain a molded body, and a step of laminating the molded body to the surface of the adherend to obtain a three-dimensional molded product. When the laminate is measured under the following measurement conditions, the release strength of the release sheet from the base material layer is 5 N / 50 mm or less, and the break point elongation of the release sheet is the basis. It is characterized in that it is larger than the break point elongation of the material layer and the break point elongation of the release sheet exceeds 135%.
(Measurement condition)
The release sheet and the adhesive sheet layer when the laminate was heated at 120 ° C. for 5 minutes and the release sheet was peeled off over a length of 100 mm at a release angle of 180 degrees and a tensile speed of 300 m / min using a release tester. Measure the adhesive strength between.

According to the present embodiment, the base material layer can be adhered along the shape of the surface of the adherend having a complicated shape without delamination.
Hereinafter, each configuration of the present embodiment will be described.

≪Process to form laminated molded body≫
In the present embodiment, first, a laminated body having at least a base material layer, an adhesive sheet layer, and a mold release sheet is three-dimensionally molded into a mold while heating the laminated body in this order to form a laminated molded body. The laminate used in the present embodiment may be provided with a base material layer, an adhesive sheet layer, and a release sheet as essential layers, but the laminate may be any hard coat layer, base material layer, or adhesive sheet. It may have a layer, a release sheet, and an arbitrary protective film layer in this order.
FIG. 2A shows an example of the laminated body 20 used in the present embodiment. The laminate 20 includes a release sheet 10, an adhesive sheet layer 11, and a base material layer 13 in this order. The laminated body 20 has a release sheet 10 in the outermost layer. The laminated molded body 20a shown in FIG. 2B is formed by three-dimensionally molding the laminate while heating the laminated body 20.

Hereinafter, each material used in this embodiment will be described.

[Release sheet]
The mold release sheet used in this embodiment is a sheet obtained by subjecting a resin base material to a mold release treatment. When measured under the following measurement conditions, the release strength of the release sheet with respect to the base material layer is 5N / 50 mm or less, preferably 3N / 50 mm or less, and more preferably 1N / 50 mm or less. (Measurement condition)
The release sheet and the adhesive sheet layer when the laminate was heated at 120 ° C. for 5 minutes and the release sheet was peeled off over a length of 100 mm at a release angle of 180 degrees and a tensile speed of 300 m / min using a release tester. Measure the adhesive strength between.

The mold release sheet may be subjected to a mold release treatment by applying a mold release agent, and examples of the mold release agent include silicone-based mold release agents. The peel strength can be set to a desired value depending on the type of mold release agent and the coating conditions.
Further, in the release sheet used in the present embodiment, the break point elongation of the release sheet is larger than the break point elongation of the base material layer. More specifically, when the break point elongations of the release sheet, the MD direction (transport direction) and the TD direction (mechanical direction) of the base material layer are measured, the average break point elongation of the release sheet is obtained. The value is preferably 150% or more and 500% or less of the average value of the elongation at break point of the base material layer.
The adhesive force of the release sheet to the base material layer and the elongation at break point are measured by the methods described in Examples described later.

The release sheet is not particularly limited as long as the above conditions are satisfied, but a material having good ductility of the resin when thermoformed is preferable. If the ductility at the time of thermoforming is good, the three-dimensional molding can be performed in a state where the adhesive sheet of the laminated body is protected by the release sheet. For example, unstretched polypropylene film (breaking point elongation with respect to the base material layer; 100% or more and 600% or less), polyethylene film (breaking point elongation with respect to the base material layer; 10% or more and 1200% or less), biaxially stretched polypropylene film ( Breaking point elongation with respect to the base material layer; 100% or more and 600% or less), Polypropylene terephthalate film (breaking point elongation with respect to the base material layer; 30% or more and 300% or less), ABS resin film (breaking point elongation with respect to the base material layer) ; 15% or more and 80% or less), polypropylene resin film (breaking point elongation with respect to the base material layer; 110% or more and 120% or less) and the like.

Further, the elongation at break point of the release sheet exceeds 135%, preferably 200% or more, and more preferably 300% or more.

In the present embodiment, a resin film containing polypropylene or a resin film containing polyethylene is preferable, and a resin film containing polypropylene is more preferable from the viewpoint of facilitating the mold release treatment. In the present embodiment, the main component may be a propylene homopolymer, and other components may be contained as long as the heat resistance of polypropylene can be exhibited. In the present embodiment, it is preferable to contain 99% by mass or more of the propylene homopolymer having a melting point of 162 ° C. or higher.

[Adhesive sheet layer]
The adhesive sheet layer is preferably produced from an adhesive resin composition prepared by preparing an adhesive resin composition containing an acrylic polymer and a polymerization initiator.
It is preferable that the adhesive resin composition contains an organic solvent because it is possible to apply the adhesive resin composition with higher accuracy when it is dissolved in an organic solvent. An adhesive sheet layer is obtained by drying the solvent from the adhesive resin composition. That is, the composition of the adhesive resin composition may be a composition of the adhesive resin composition constituting the adhesive sheet layer, to which a solvent is added. The adhesive sheet before thermosetting preferably has adhesiveness at room temperature. Having the adhesive property has an advantage that it can be temporarily fixed to the adherend and it becomes easy to work in the process work.
In addition, the lower the adhesive strength of the adhesive sheet layer after heating, the easier it is to peel off the adjacent mold release sheet in a later step.

As shown in FIG. 1, the adhesive sheet layer used in the present embodiment is coated with the adhesive resin composition on the release sheet 12 in a state of containing a solvent, dried, and further protected by the release sheet 10. It can be manufactured by.
An adhesive resin composition is produced by mixing an acrylic polymer and a polymerization initiator, the adhesive resin composition is applied onto a release sheet 12, and another release sheet 10 is laminated and sandwiched. It is preferable that the adhesive sheet layer 11 has a step of manufacturing the adhesive sheet sandwiching body 1 sandwiched between the detachable sheets 10 and 12.

In the present embodiment, the forming materials of the release sheets 10 and 12 of the adhesive sheet holding body 1 shown in FIG. 1 may be the same or different. For example, when a polyethylene film is used for the release sheet 10 and a polypropylene film is used for the release sheet 12, it is preferable to peel off the release sheet 10 which is a polyethylene film in the release step from the viewpoint of easier molding. ..

The adhesive resin composition is preferably applied using a die or a pipe doctor. In the drying of the solvent, it is preferable to dry by heating, blowing air, reducing the pressure, or a combination thereof. The drying time of the solvent is preferably 10 minutes or less, more preferably 2 to 5 minutes, in consideration of productivity. Further, since it is necessary to sufficiently dry the organic solvent, it is preferable to dry the organic solvent at a temperature equal to or higher than the boiling point of the organic solvent, and it is preferable to dry the thermal polymerization initiator at a half-life temperature of 1 minute or lower.

Hereinafter, each material constituting the adhesive resin composition will be described.

-Acrylic polymer The monomer constituting the acrylic polymer is an acrylic monomer having an ester group (-COO-), an acrylic monomer having a carboxyl group (-COOH), an amide group (-CONR ₂ , R is a hydrogen atom or R). Examples thereof include acrylic monomers having a substituent (such as an alkyl group), acrylic monomers having a nitrile group (-CN), olefins, styrene, vinyl esters, vinyl ethers, and non-acrylic monomers such as vinyl silane. The acrylic polymer is preferably a copolymer composed of two or more kinds of monomers. The number average molecular weight of the acrylic polymer before photopolymerization is preferably, for example, about 50,000 to 1,000,000. The viscosity may be, for example, about 1000 to 10000 mPa · s.

Acrylic monomers having an ester group (-COO-) include alkyl (meth) acrylates, (meth) acrylates having a hydroxy group (hydroxyl group), (meth) acrylates having an alkoxy group or a polyether group, amino groups or substitutions. Examples thereof include (meth) acrylate having an amino group. In addition, in this specification, (meth) acrylate is a general term of acrylate and methacrylate.

Examples of the acrylic monomer having a carboxy group (-COOH) include acrylic acid, methacrylic acid, and (meth) acrylate having a carboxyl group (-COOH).
Examples of the acrylic monomer having an amide group (-CONR ₂ , R is a substituent such as a hydrogen atom or an alkyl group) include acrylamide and methacrylamide.
Examples of the acrylic monomer having a nitrile group (-CN) include acrylonitrile and methacrylonitrile.

It is preferable that 50% by mass or more of the constituent monomer of the acrylic polymer is composed of the acrylic monomer. In particular, 50% by mass or more of the constituent monomers are represented by the general formula CH ₂ = CR ¹ -COOR ² (in the formula, R ¹ represents a hydrogen or methyl group, and R ² represents an alkyl group having 1 to 14 carbon atoms). It is preferable that the alkyl (meth) acrylate is composed of one kind or two or more kinds. Specific examples of alkyl (meth) acrylates include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, and isobutyl (meth) acrylate. , T-butyl (meth) acrylate, n-pentyl (meth) acrylate, isopentyl (meth) acrylate, n-hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, isooctyl (meth) ) Acrylate, isononyl (meth) acrylate, decyl (meth) acrylate, dodecyl (meth) acrylate. In particular, it is preferable to use an alkyl (meth) acrylate having an alkyl group ^R2 having 4 to 12 carbon atoms as an essential (for example, 50 to 100 mol%).

Examples of the (meth) acrylate containing a hydroxyl group include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, and 4-hydroxybutyl (meth) acrylate. , 6-Hydroxyhexyl (meth) acrylate, 8-hydroxyoctane (meth) acrylate, polyethylene glycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate, cyclohexanedimethanol mono (meth) acrylate, etc. The above can be mentioned.

-Acrylic-based monomer or acrylic-based oligomer Among acrylic-based monomers or acrylic-based oligomers, the acrylic-based monomer contains a monomer similar to the monomer constituting the acrylic-based polymer, for example, an alkyl (meth) acrylate or a hydroxyl group ( Meta) One kind or two or more kinds such as acrylate and acrylamide can be mentioned. The number of polymerizable functional groups such as (meth) acryloyl group in one molecule may be one or two or more.

In particular, when the acrylic monomer or the (meth) acrylate monomer having a hydroxyl group is contained as at least a part of the acrylic monomer or the acrylic oligomer, the polar hydroxyl group is easily dispersed in the entire adhesive sheet. This is preferable because even in a high humidity (higher temperature) environment, moisture is less likely to aggregate and white turbidity of the adhesive sheet is suppressed. In a (meth) acrylate having a hydroxyl group, the number of hydroxyl groups in one molecule may be one or two or more.

Further, a curable urethane acrylate can be used as at least a part of the acrylic monomer or the acrylic oligomer. Urethane acrylate is a compound having a urethane bond (-NH-COO-) and a (meth) acryloyloxy group (CH ₂ = CX-COO- as X = H or CH ₃ ) in the same molecule. The curable urethane acrylate is a compound having curability due to the (meth) acryloyloxy group, which is a polymerizable functional group, among urethane acrylates. The number of urethane bonds in one molecule may be one or two or more. Further, the number of (meth) acryloyloxy groups in one molecule may be one or two or more.

As the urethane acrylate, for example, a compound obtained by reacting a (meth) acrylate compound having a hydroxyl group with an isocyanate compound, or a urethane prepolymer obtained by reacting a polyol compound with a polyisocyanate compound has a hydroxyl group (meth). ) Examples thereof include compounds obtained by reacting an acrylate compound. Examples of the polyol compound include polyester polyols and polyether polyols.

The acrylic monomer or the acrylic oligomer is preferably a liquid (fluid) that becomes a part of the polymer by curing with a polymerization initiator and has a viscosity lower than that of the polymer. It is also possible to use an acrylic monomer and an acrylic oligomer in combination. Examples of the acrylic oligomer include acrylate oligomers such as urethane acrylate oligomers. The number of polymerizable functional groups contained in the acrylic monomer or the acrylic oligomer is, for example, 1 to 10 or 2 to 5. In this embodiment, it is preferable to use a polyfunctional acrylate monomer.
When the adhesive resin composition contains an acrylic monomer or an acrylic oligomer, the fluidity of the adhesive resin composition is increased. When the fluidity of the adhesive resin composition is high, even if the surface of the adherend has fine irregularities, the adhesive resin composition easily fits on the surface of the adherend. Therefore, the surface of the adherend after coating can be smoothed, and the appearance after coating can be improved.

The adhesive resin composition preferably contains 5 to 50 parts by mass of an acrylic monomer or an acrylic oligomer with respect to 100 parts by mass of the acrylic polymer. If the amount of the acrylic monomer or the acrylic oligomer added is too large, the adhesive strength of the adhesive resin layer may be excessively lowered when polymerized.

-Polymerization initiator As the polymerization initiator, a thermal polymerization initiator is preferable, and examples thereof include a radical initiator that decomposes by heat to initiate polymerization of a monomer (radical polymerization) and curing of a resin. As the radical initiator, (organic) peroxide type, azo type and the like are preferable from the viewpoint of facilitating the handling of the adhesive sheet.

In the present embodiment, the polymerization initiation temperature of the thermal polymerization initiator is preferably 10 ° C. or higher and 50 ° C. or lower lower than the melting temperature of the resin in the injection molding step. When the polymerization start temperature satisfies the above conditions, the polymerization reaction of the polymer component contained in the adhesive sheet layer can be simultaneously carried out depending on the temperature of the molten resin in the injection molding step.

Specific examples of the (organic) peroxide-based thermal polymerization initiator include diacyl peroxides such as benzoyl peroxide, acetyl peroxide, decanoyl peroxide, and lauroyl peroxide, dicumyl peroxide, and di-t-butyl peroxide. Examples thereof include alkyl peroxy esters such as dialkyl peroxides, t-butyl peroxybenzoates and t-butyl peroxy-2-ethyl hexanoates, and hydroperoxides such as cumene hydroperoxides and t-butyl hydroperoxides. Preferred organic peroxides include t-hexylperoxyneodecanoate, t-butylperoxyneodecanoate, t-butylperoxyneoheptanoate, t-hexylperoxypivalate, t-butylperoxypivalate and di. Lauroyl peroxide, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, dissuccinic acid peroxide, t-hexylperoxy-2-ethylhexanoate, t-butylperoxy-2-ethylhexanoate Ate, 1,1-bis (t-hexylperoxy) cyclohexane, 1,1-bis (t-butylperoxy) cyclohexane, t-hexylperoxyisopropyl monocarbonate, t-butylperoxymaleic acid, t-butylperoxy 3,5 , 5-trimethylhexanoate, t-butylperoxyisopropyl monocarbonate, t-butylperoxy2-ethylhexylmonocarbonate, t-butylperoxylaurate, t-hexylperoxybenzoate, t-butylperoxyacetate, t-butylperoxybenzoate , N-butyl 4,4-bis (t-butylperoxy) peroxide, dicumyl peroxide, di-t-hexyl peroxide, di-t-butyl peroxide, p-menthan hydroperoxide and the like.

Examples of the azo-based thermal polymerization initiator include 2,2'-azobis (isobutyronitrile), 2,2'-azobis (2-methylbutyronitrile), and 2,2'-azobis (2,4-dimethyl). Valeronitrile), 2,2'-azobis (4-cyanovaleronitrile), 2,2'-azobis (4-methoxy-2,4-dimethylvaleronitrile), 2,2'-azobis (methylisobutyrate) , 1,1'-azobis (1-cyclohexanecarbonitrile) and the like.

The amount of the thermal polymerization initiator added is preferably 0.001 to 0.5 parts by mass with respect to 100 parts by mass of the acrylic polymer.

The adhesive resin composition can further contain any component other than the above.
For example, a cross-linking agent (curing agent) such as an isocyanate-based cross-linking agent, an epoxy-based cross-linking agent, and a metal chelate compound is preferably used because it cross-links an acrylic polymer or a polymer produced by polymerization of an acrylic monomer or an acrylic oligomer. Be done. In this case, if necessary, a polymer or monomer having a functional group that reacts with a cross-linking agent is used as at least a part of the acrylic polymer or acrylic monomer or acrylic oligomer. The functional group that reacts with the cross-linking agent is, for example, a hydroxyl group, a carboxyl group, or the like in the case of an isocyanate-based cross-linking agent. The amount of the cross-linking agent added is preferably, for example, 1.5 equivalents or less with respect to the functional group of the polymer.
The curing of the acrylic polymer by the cross-linking agent (curing agent) may be promoted by aging at the stage of producing the adhesive sheet before being bonded to the adherend.

Other optional components include, for example, antioxidants, fillers, plasticizers and the like. The adhesive raw material composition used for producing the adhesive resin layer may contain a solvent such as water or an organic solvent, or may be a solvent-free syrup-like composition. When a material having a possibility of corrosion such as an oxide conductive film such as ITO or a base metal exists on the base material and the adhesive resin layer comes into contact with the material, the material of the adhesive resin composition is corrosion such as acid. It is preferable to reduce the sex component and use, for example, a polymer having a low acid value.

[Base layer]
As the material of the base material layer, for example, a resin film made of polyester, polyolefin, polyamide or the like can be used. The polyester is, for example, polyethylene terephthalate, polyethylene naphthalate, polyethylene isophthalate, polybutylene terephthalate and the like. The polyolefin is polyethylene, polypropylene and the like.
The material of the base material layer that can be used in this embodiment is preferably a material that can follow the stretching of other layers when a method such as a vacuum forming method or a compressed air forming method is carried out in the laminate molding step. Therefore, among the above, a stretched film is preferable.

[Hard coat layer]
As the material of the hard coat layer that can be used in this embodiment, a thermosetting hard coat resin such as silicone-based or melamine-based resin, an ultraviolet-curable hard coat resin such as silicone-based or acrylic-based resin can be used. The thickness of the hard coat layer is preferably 1 to 10 μm, more preferably 2 to 8 μm. If the thickness of the hard coat layer is thinner than 1 μm, the hard coat property cannot be obtained and the scratch resistance is lowered, and when an ultraviolet curable hard coat resin is used, curing failure is likely to occur.
Further, additives for imparting various functions such as an antistatic agent and an ultraviolet absorber may be added to the hard coat layer as needed.

[Protective film layer]
The protective film layer is peeled off and removed at any stage from the manufacturing process of the three-dimensional molded product to before the use of the three-dimensional molded product. For this reason, it is preferable to have a structure in which the pressure-sensitive adhesive is peelably attached so that the pressure-sensitive adhesive does not transfer to the hard coat layer (the pressure-sensitive adhesive does not remain).
In the present embodiment, the material of the protective film layer is not particularly limited as long as it is a material having the above-mentioned characteristics, but for example, polyethylene terephthalate (PET) film, polyolefin film (for example, polyethylene, polypropylene, etc.) are preferable.

[resin]
In the present embodiment, the resin film forming material is preferably one or more selected from the group consisting of acrylic resin, polyolefin resin, urethane resin, polyamide resin, polycarbonate resin, and ABS resin. Of these, acrylic resin, polycarbonate resin, and ABS resin are particularly preferable.

The laminated body 20 is obtained by laminating the adhesive sheet sandwiching body 1 shown in FIG. 1 and the base material layer 13 shown in FIG. In the adhesive sheet holding body 1, a single-layer adhesive sheet layer 11 is sandwiched between the release sheet 10 and the release sheet 12. The mold release sheet 10 is subjected to a mold release treatment with a silicone-based mold release agent, a fluorine-based mold release agent, or the like on the surface on the side to be combined with the adhesive sheet layer 11. The laminated body 20 shown in FIG. 2A can be manufactured by peeling off and removing the release sheet 12 of the adhesive sheet holding body 1 to expose the adhesive sheet layer 11 and laminating it with the base material layer 13.
The release sheet 10 of the laminated body 20 preferably contains polypropylene, which is a material having high heat resistance and excellent mechanical strength, and then three-dimensional molding is performed with the adhesive sheet of the laminated body protected by the release sheet. It will be easier.
FIG. 2B describes an example of a case where the laminated body 20 is three-dimensionally molded into a molded body 20a having a curved surface while being heated.

In the present embodiment, it is preferable to mold the laminated molded body 20a with the release sheet 10 provided. Before molding, the flat laminated body 20 is molded in advance to form a laminated molded body 20a which is a three-dimensional molded product, so that the laminated body 20 follows the shape of the surface of the adherend in the step of bonding to the surface of the adherend. , The base material layer can be adhered well without delamination.

As a method for obtaining the laminated body 20a which is a three-dimensional molded product by thermoforming the laminated body 20, a known method such as a vacuum forming method or a compressed air molding method can be mentioned. More specifically, after the flat laminated body 20 is heated by an infrared heater or the like, the laminated body 20 is brought into close contact with the mold by an external force such as mechanical force, vacuum, or pneumatic air, or sandwiched between the molds. It may be tightened and then heated.

In the present embodiment, it is preferable to mold the laminated body 20 by a vacuum forming method. The vacuum forming method is a method in which a laminated body 20 is heated under vacuum and then brought into contact with a prefabricated molded product to form the laminated body 20 by an air pressure difference applied to both surfaces of the laminated body 20.

When the laminated body 20 is molded by heating, the heating temperature is not particularly limited as long as the release sheet 10 can be peeled from the adhesive sheet layer 11. Examples of the lower limit of the heating temperature include 100 ° C. or higher, 120 ° C. or higher, and 150 ° C. or higher. Further, examples of the upper limit of the heating temperature include 200 ° C. or lower, 180 ° C. or lower, and 160 ° C. or lower.
The upper limit value and the lower limit value of the heating temperature can be arbitrarily combined.

Examples of the lower limit of the heating time include 10 seconds or more, 30 seconds or more, and 1 minute or more. Further, as an example of the upper limit value of the heating time, 5 minutes or less, 3 minutes or less, 2 minutes or less can be mentioned.
The upper limit value and the lower limit value of the heating time can be arbitrarily combined.

≪Peeling process≫
In the present embodiment, after the step of forming the laminated molded body, a step of peeling off the release sheet 10 of the laminated molded body 20a which is a three-dimensional molded product to expose the adhesive sheet layer 11 is provided. The release sheet 10 is a layer having a function of protecting the adhesive sheet layer 11 in the step of forming the laminated molded body, and after the molding of the laminated body is completed, the release sheet 10 is peeled off and removed. Then, the adhesive sheet layer 11 is exposed. By this step, the base material layer 13 and the adhesive sheet layer 13 are laminated to obtain a three-dimensionally molded molded body 20c.

≪Process to obtain three-dimensional molded product≫
The step of bonding the molded body 20c to the surface of the adherend to obtain a three-dimensional molded product is preferably performed by an injection molding step or a vacuum forming step. Hereinafter, each step will be described.

-Injection molding process When the injection molding process is carried out, the laminated molded body 20a, which is a three-dimensional molded product after the peeling process, is installed in the injection molding mold so that the adhesive sheet layer 11 is on the void side in the mold. A molding step of injecting a resin into a mold with respect to the surface of the laminate 20 on the adhesive sheet layer 11 side is provided.
As shown in FIG. 2C, the molded body 20c is installed between the mold 34a and the mold 34b so as to be on the side of the gap 34c in the mold. The mold 34a includes a sprue 35 for inserting a resin.

The mold 34a is moved toward the mold 34b, and the molten resin 35a is injected into the gap 34c in the mold from the mold 34a side via the sprue 35.
At this time, due to the amount of heat of the molten resin 35a, the adhesive sheet layer 11 is polymerized to form the adhesive layer 11a, and the adhesive sheet layer 11 is fused and attached to the molten resin.
Since the adhesive sheet layer 11 and the base material layer 13 are pre-molded according to the shape of the mold of the injection molding machine, the resin is inserted without gaps at the time of injection molding, and a molded product that follows the shape of the mold is manufactured. can do.
FIG. 2 (e) shows a cross-sectional view of the molded product manufactured by this step. The three-dimensional molded product (1) 20b includes a resin layer 35b, an adhesive layer 11a, and a base material layer 13 in this order.

-Vacuum forming step A method of bonding a molded body 20c to the surface of an adherend and obtaining a three-dimensional molded product by a vacuum forming method will be described with reference to FIG. In the vacuum forming step, as shown in FIG. 3A, the molded body 20c is brought into contact with the adherend 30 prepared in advance by the adhesive sheet layer 11 under vacuum, and the molded body 20c is formed on both sides of the molded body 20c. This is a method of molding a three-dimensional molded product (2) 30a by such an air pressure difference.
A cross-sectional view of the three-dimensional molded product (2) 30a manufactured by this step is shown in FIG. 3 (b). The three-dimensional molded product (2) 30a includes a base material layer 13, an adhesive layer 11a, and an adherend 30 in this order.

Hereinafter, the present invention will be specifically described with reference to Examples.

<Measurement of break point elongation>
The elongation at break was measured by the following method.
Five rectangular parallelepiped test pieces having a length of 10 mm and a length of 50 mm, which were long in the length direction (MD) of the film, were prepared and used as samples in the MD direction. Five rectangular parallelepiped test pieces having a length of 10 mm and a length of 50 mm, which were long in the width direction (TD) of the film, were prepared and used as samples in the TD direction. Under the temperature and humidity conditions of 23 ° C and 55%, a tensile tester with a constant temperature bath (Autograph AG-100; manufactured by Shimadzu Corporation) was used to chuck the ends of each test piece, and the tensile speed was 30 mm / The elongation at break (unit:%) was measured while pulling at a speed of minutes. The measurement was performed 5 times each for the sample in the MD direction and the sample in the TD direction, and the maximum value was used as the maximum value of the breaking strength.

<Adhesive strength after heating>
The adhesive sheet layer side of the laminated body was attached to a PET film having a mold release treatment on its surface, and the adhesive strength of the laminated body was measured by holding it at 120 ° C. for 5 minutes while pressing the bonded portion. The PET film side was peeled off using a peeling tester manufactured by Shimadzu Corporation, and the average value of the stable numerical values was taken as the adhesive strength over a length of 100 mm at a peeling angle of 180 degrees and a tensile speed of 300 m / min.

-Example 1
<Manufacturing of adhesive sheet layer>
Each component shown in Table 1 below was mixed to produce adhesive resin compositions 1 to 3, respectively.

In Table 1 above, the following materials were used for each component. The value in [] is the blending amount (part by mass).
-Acrylic polymer 1: SK Dyne 2094 (registered trademark, Soken Chemical Co., Ltd., acid value: 33, number average molecular weight 70,000, solid content concentration 25%)
-Acrylic polymer 2: SK Dyne 2147 (registered trademark, Soken Chemical Co., Ltd., acid value: 33)
・ Curing agent 1: E-AX (Soken Chemical Co., Ltd., epoxy curing agent)
-Curing agent 2: Coronate (registered trademark) HX (Tosoh Corporation) -Thermal polymerization initiator 1: Perbutyl O (registered trademark-NOF CORPORATION-One minute half-life is 134 ° C)
"4HBA" represents 4-hydroxybutyl acrylate of an acrylic monomer.
"UV-3310" represents a trade name of urethane acrylate (Nippon Synthetic Chemical Industry Co., Ltd.). The physical characteristics of UV-3310 are viscosity at 60 ° C.: 40,000 to 70,000 mPa · s, weight average molecular weight Mw: 5000, number of oligomer functional groups: 2, and glass transition temperature Tg: 22 ° C.

Adhesives after drying the obtained adhesive resin compositions 1 to 3 on the upper surface of each release sheet (manufactured by Fujimori Kogyo Co., Ltd .; product name: 125E-0010DG2.5AS, thickness 125 μm) using an applicator. After coating so that the thickness of the resin layer (adhesive layer) was 50 μm, the solvent was dried at 90 ° C. for 2 minutes in the drying step to prepare an adhesive sheet on which the adhesive resin layer was laminated.
Next, a release sheet (manufactured by Fujimori Kogyo Co., Ltd .; product name; 38E-0010BDAS, thickness 38 μm) was bonded to the upper surface of the adhesive resin layer of the obtained laminate to prepare an adhesive sheet sandwiching body. ..

<Laminated body>
One of the release sheets of the obtained adhesive sheet holding body was peeled off and bonded to the base material layers shown in Table 2 below, and the release sheet, the adhesive sheet layer, and the base material layer were laminated in this order. Body 20 was manufactured (corresponding to FIG. 2A). Laminates 1 to 4 using the adhesive resin compositions 1 to 4, respectively, were designated as laminates 1 to 4. The laminates 1 to 4 are each cut into a size of 20 cm × 20 cm, and have a mold having a concave portion with a depth of 5 cm heated to 60 ° C. and a convex portion paired with the concave portion heated to 60 ° C. It was sandwiched between the dies for 20 seconds to form a laminated molded body 20a having a recess (corresponding to FIG. 2B). As shown in FIG. 2 (c), the laminated molded body 20a was sandwiched between the molds 34a and 34b connected to the in-mold molding machine, and melt-kneaded from the sprue 35 at a temperature of 130 ° C. as shown in FIG. 2 (d). The methyl methacrylate resin was poured and the resin and the laminated molded product were held for 30 seconds while being sandwiched between the molds. Then, the resin and the laminated molded body were removed from the mold and taken out to obtain a three-dimensional molded product 20b having a base material layer, an adhesive layer, and a resin layer (FIG. 2 (e)). At this time, the thickness of the resin layer 35b made of methyl methacrylate was 100 μm.

-Examples 2 to 6 and Comparative Examples 1 to 2.
A three-dimensional molded product was produced in the same manner as in Example 1 except that the configuration was changed to that shown in Table 2 below.

The obtained three-dimensional molded product was evaluated according to the following evaluation criteria, and the results are shown in Table 1. In the following evaluation criteria, "○" or higher was regarded as acceptable.

[Evaluation criteria]
⊚: Each layer of the laminated body was in close contact with each other, and the release sheet could be easily peeled off in the injection molding process.
◯: Each layer of the laminated body was in close contact with each other, and the release sheet could be peeled off in the injection molding process.
Δ: The release sheet of the laminated body was partially peeled off. It was possible to peel off the release sheet.
X: The adhesive strength of the adhesive layer was low, and peeling was observed in each layer of the laminated body. It was also difficult to peel off the release sheet.

As shown in the above results, Examples 1 to 6 to which the present invention was applied showed no peeling in each layer of the laminated body as compared with Comparative Examples 1 and 2 to which the present invention was not applied, and they were in close contact with each other.

1 ... Adhesive sheet holding body, 10 ... Release sheet, 11 ... Adhesive sheet layer, 11a ... Adhesive layer, 12 ... Release sheet, 13 ... Base material layer, 20 ... Laminated body, 20a ... Laminated molded body, 20b ... Solid Molded product (1), 20c ... Molded body, 30 ... Adhesive, 30a ... Three-dimensional molded product (2), 34a ... Mold, 34b ... Mold, 35 ... Sprue, 35a ... Molten resin, 35b ... Resin layer

Claims (2)

A step of forming a laminated molded body by three-dimensionally molding a die while heating a laminated body having at least a base material layer, an adhesive sheet layer, and a mold release sheet in this order.
The process of peeling the release sheet from the laminated molded body to expose the adhesive sheet layer and obtaining the molded body.
The step of attaching the molded body to the surface of the adherend to obtain a three-dimensional molded product is provided.
The step of obtaining the three-dimensional molded product is an injection molding step.
When the laminate was measured under the following measurement conditions, the release strength of the release sheet from the base material layer was 5 N / 50 mm or less.
The release sheet is an unstretched polypyrene film.
The material for forming the base material layer is ABS resin or polycarbonate, and the material is
The breaking point elongation of the release sheet is larger than the breaking point elongation of the base material layer.
The elongation at break point of the release sheet with respect to the base material layer exceeded 135%, and
The adhesive sheet layer contains an acrylic polymer and a thermal polymerization initiator.
A method for producing a three-dimensional molded product , wherein the polymerization start temperature of the thermal polymerization initiator is 10 ° C. or higher and 50 ° C. or lower lower than the melting temperature of the resin in the injection molding step .
(Measurement condition)
The release sheet and the adhesive sheet layer when the laminate was heated at 120 ° C. for 5 minutes and the release sheet was peeled off over a length of 100 mm at a release angle of 180 degrees and a tensile speed of 300 m / min using a release tester. Measure the adhesive strength between. The method for producing a three-dimensional molded product according to claim 1 , wherein the material for forming the adhesive sheet layer is a thermosetting resin.

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