JP2012144036A - Compound molded article, method for manufacturing compound molded article, and in-mold label - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technology for improving the adhesiveness of a thin layer derived to a molded article of a thin shape to a molded article layer derived to a resin composition without substantially increasing manufacturing cost, and without substantially deteriorating productivity.SOLUTION: A compound molded article is manufactured in the vicinity of a boundary between a thin layer derived from a crystalline thermoplastic resin-made thin-walled molded article and a molded article layer derived from a molten resin composition under a condition that materials of both layers are melted with each other to form a mixed layer in a crystal state. The compound molded article is manufactured by a method including a molding step in which, for example, the crystalline thermoplastic resin-made thin-walled molded article is arranged in a die with a heat insulating layer formed at least at a part of an inner surface of the die, and the molten resin composition containing crystalline resin is poured. In the manufacturing method, the crystalline thermoplastic resin-made thin-walled molded article is arranged so that at least a part of the thin-walled portion overlaps the heat insulating layer, and the relative crystallinity of the thin-walled portion is ≤60% in the crystalline thermoplastic resin-made thin-walled molded article.

Description

  The present invention relates to a composite molded body, a method for producing a composite molded body, and an in-mold label.

  Many crystalline thermoplastic resins having excellent mechanical strength, heat resistance, chemical resistance, electrical properties, and the like are known. In recent years, crystalline thermoplastic resins having excellent physical properties have been widely used as raw materials for molded articles used as parts for automobiles, electronic / electronic parts, chemical equipment and the like.

  In many cases, the molded body for such use is generally completed by one molding, but in some cases, it may be unavoidable to use a double molding method in which molding is performed in two steps. In particular, it is often difficult to obtain a desired molded body in a single molding with a complicated shape. Also, when obtaining a molded part in which all or a part of other parts, metal wirings, etc. (terminals, printed wirings, coils, etc.) are obtained, there are many cases where the double molding method must be used.

  Here, the double molding method is a method for producing a composite molded body by placing a molded body inside a mold and then pouring a molten resin composition into the mold.

  The composite molded body produced by the double molding method as described above is configured such that a portion derived from the molded body and a portion derived from the resin composition are integrated. For this reason, the joint part formed by integration needs to have high adhesiveness. However, when the molded body is composed of a crystalline thermoplastic resin composition, the adhesion tends to be insufficient. For this reason, the method of improving the said adhesiveness is examined.

  For example, a method for improving the adhesion using an adhesive, a method for improving the adhesion by the anchor effect by roughening the joint surface of the molded product with another molded product, and the like are known. However, the former method using an adhesive requires an adhesive coating step, which decreases the productivity of the composite molded body and increases the manufacturing cost. Moreover, the latter roughening method complicates the mold structure for producing a roughened molded body, and increases the manufacturing cost of the composite molded body.

  An improved method that hardly causes problems such as an increase in manufacturing cost is disclosed in Patent Document 1. The manufacturing method of the composite molded object of patent document 1 improves the said adhesiveness by using the molded object which suppressed the crystallinity degree low as the said molded object arrange | positioned inside a metal mold | die.

  By the way, when the crystallinity of the molded body is low, the characteristics of the crystalline thermoplastic resin are hardly exhibited. For this reason, in patent document 1, the method etc. which set the metal mold | die temperature at the time of injecting the resin composition of a molten state more than the glass transition temperature of the crystalline resin contained in a molded object are employ | adopted. Thereby, the part derived from the said molded object in a composite molded object fully progresses, and the composite molded object which utilized the characteristic of crystalline thermoplastic resin is obtained.

Japanese Patent Laid-Open No. 06-47830

  As described above, according to Patent Document 1, the manufacturing cost is hardly increased, and the productivity of the composite molded body is hardly reduced. However, in the case of a thin shape such as a sheet, a film, etc., when the mold temperature is raised to the glass transition temperature or higher, crystallization of the molded body arranged in the mold proceeds, The effect of improving the adhesion due to the low crystallinity of the molded product cannot be obtained sufficiently. For this reason, in film-in-mold molding and the like, it is difficult to employ the technique described in Patent Document 1, and as a result, a method using an adhesive is generally employed.

  The present invention has been made in order to solve the above-described problems, and the object thereof is a thin layer derived from a thin shaped molded body with little increase in production cost and almost no reduction in productivity. It aims at providing the technique which improves the adhesiveness of the molded object layer originating in a resin composition.

  The inventors of the present invention have made extensive studies to solve the above problems. As a result, in the vicinity of the boundary between the thin layer derived from the crystalline thermoplastic resin thin-walled molded body and the molded body layer derived from the molten resin composition, a mixed layer is formed in which the respective materials are melted and become a crystalline state. It discovered that the said subject could be solved by manufacturing on conditions, and came to complete this invention. More specifically, the present invention provides the following.

(1) A molten resin composition in which a crystalline thermoplastic resin thin molded article is disposed in a mold having a heat insulating layer formed on at least a part of the inner surface of the mold and can be welded to the crystalline thermoplastic resin. A crystalline thermoplastic resin thin-walled molded article is arranged such that at least a part of the thin-walled portion overlaps the heat-insulating layer, and at least the thin-walled portion of the crystalline thermoplastic resin thin-walled molded body comprises: The relative crystallinity is 60% or less,
(The relative crystallinity refers to the crystallinity when the molten resin composition is molded and the crystallinity of the portion that is in direct contact with the heat insulating layer and solidified is 100%.)
The temperature of the mold in the molding step is lower than the recrystallization temperature of the crystalline thermoplastic resin, and the temperature of the molten resin composition in the molding step is equal to or higher than the glass transition temperature. Production method.

  (2) The method for producing a composite molded body according to (1), wherein the mold temperature is lower than the glass transition temperature.

  (3) The method for producing a composite molded body according to (1) or (2), wherein the thickness of the crystalline thermoplastic resin thin molded body is 10 μm or more and 1000 μm or less.

  (4) The crystalline thermoplastic resin thin-walled molded body and the molten resin composition include a polyarylene sulfide-based resin or a polybutylene terephthalate-based resin, the composite molded body according to any one of (1) to (3) Production method.

  (5) The said heat insulation layer is a manufacturing method of the composite molded object in any one of (1) to (4) containing a polyimide resin and / or a zirconium oxide.

  (6) The method for producing a composite molded body according to any one of (1) to (5), wherein the crystalline thermoplastic resin thin-walled molded body is an in-mold label.

  (7) A composite molded body formed by film-in-mold molding, which is a thin layer derived from a crystalline thermoplastic resin film, a molded body layer that is a crystalline thermoplastic resin molded body layer, the thin layer, and the molded body A composite molded body comprising a mixed layer in which the thin layer and the molded body layer are in a mixed state at a boundary with the body layer, and the crystalline thermoplastic resin in the mixed layer is in a crystalline state.

  (8) The composite molded body according to (7), wherein the mixed layer has a relative crystallinity of 90% or more.

  (9) An in-mold label having a crystalline thermoplastic resin portion having a relative crystallinity of 60% or less on the affixing surface.

  According to the present invention, when film-in-mold molding is performed, the adhesion between a thin primary molded body and a secondary molded body is improved with little increase in manufacturing cost and almost no decrease in productivity. be able to

It is a figure for demonstrating the effect of this invention, (a) is a figure which shows typically the cross section of the metal mold | die used with the conventional method, (b) is a figure of the metal mold | die used with the method of this invention. It is a figure which shows a cross section typically.

  Hereinafter, embodiments of the present invention will be described. In addition, this invention is not limited to the following embodiment.

<Method for producing composite molded body>
The method for producing a composite molded body of the present invention is characterized by a mold used for pouring the molten resin composition. The feature is that a heat insulating layer is formed on at least a part of the inner surface of the mold.

  In the production method of the present invention, first, a crystalline thermoplastic resin thin molded article is placed in a mold. At this time, at least a part of the crystalline thermoplastic resin thin-walled molded product is overlapped with the heat insulating layer. Second, a molten resin composition containing a crystalline resin is poured into the mold. Before describing a specific manufacturing method, a crystalline thermoplastic resin thin molded article, a molten resin composition, and a mold used for molding will be described.

[Crystalline thermoplastic thin-walled molded product]
A crystalline thermoplastic resin thin molded article is a resin thin molded article containing a crystalline thermoplastic resin. The crystalline thermoplastic resin that can be contained is not particularly limited, and general ones can be used. Examples thereof include polyolefin resins, polyester resins, polyacetal resins, polyphenylene sulfide resins, and the like. Moreover, the crystalline thermoplastic resin thin-walled molded product may contain two or more crystalline thermoplastic resins. Moreover, arbitrary monomer components may be contained in the crystalline thermoplastic resin as long as the effects of the present invention are not impaired.

  The crystalline thermoplastic resin thin molded article may contain components other than the crystalline thermoplastic resin as long as the effects of the present invention are not impaired. Examples of other components include general additives such as resins other than crystalline thermoplastic resins, inorganic fillers, antioxidants, pigments, plasticizers, and stabilizers.

  The content of the crystalline thermoplastic resin in the crystalline thermoplastic resin thin molded article is not particularly limited, but if the content is 10% by mass or more and 100% by mass or less, excellent physical properties of the crystalline thermoplastic resin However, it is preferable because it tends to appear as a physical property of the crystalline thermoplastic resin thin molded article.

  The thickness of the crystalline thermoplastic resin thin-walled molded product is not particularly limited. The crystalline thermoplastic resin thin-walled molded body tends to be crystallized. When the thickness is less than 10 μm, the advantage of the composite molded body over the molded body made of a single material is reduced, and the practical application range is narrowed. In addition, when the thickness is 1000 μm or less, under general molding conditions, if the technology of the present application is not used, crystallization from the surface of the thin molded body that comes into contact with the molten resin composition is very easy to proceed. It is extremely difficult to produce a composite molded body with stable quality by this method. That is, in the above range, it is very difficult to improve the adhesion between the thin layer and the molded body layer without using an adhesive or the like in the prior art. If the manufacturing method of this invention is employ | adopted, it will become unnecessary to use an adhesive agent.

  Prior to the molding step, it is necessary to make the crystalline thermoplastic resin thin molded body amorphous. In order to improve adhesion, which is an effect of the present invention, an amorphous crystalline thermoplastic resin thin-walled molded article is melted by bringing the molten resin composition into contact with the melted portion and the molten resin composition. This is because it is necessary to crystallize while mixing. The amorphous state refers to a case where the relative crystallinity is 60% or less. Although the minimum of the said relative crystallinity degree is not specifically limited, For example, it is 10% or more. The relative crystallinity is obtained by calculating a relative value using a value obtained by measuring the crystallinity by an X-ray diffraction method. Specifically, the degree of crystallinity of the portion in contact with the heat insulating layer at the time of molding in the composite molded body is set to 100%, and the degree of crystallinity at a desired location is calculated based on this.

  Although the manufacturing method of the amorphous thermoplastic resin thin-walled molded body as described above is not particularly limited, for example, it can be manufactured by rapidly cooling a resin that has been molded in a molten state. Specifically, for example, a resin composition as a raw material for a crystalline thermoplastic resin thin-walled molded product is prepared by using a cavity surface temperature equal to or lower than the softening temperature of the crystalline thermoplastic resin contained in the resin composition (multiple types of crystals In the case of including the properties, the mold surface can be manufactured by cooling the mold surface after filling the mold set at the lowest softening temperature or lower. If the thickness of the crystalline thermoplastic resin thin molded article is too large, the inside of the thin molded article may not crystallize and crystallize, but if the thickness of the thin molded article is set within the above preferred range, It tends to be in an amorphous state up to the inside of the compact.

  In addition, an in-mold film is mentioned as a specific example of the crystalline thermoplastic resin thin molded article used in the present invention.

[Molten resin composition]
The molten resin composition is a resin composition containing a crystalline thermoplastic resin. Examples of the crystalline thermoplastic resin that can be contained include the same ones as exemplified in the description of the thin crystalline thermoplastic resin molded article. In the present invention, the crystalline thermoplastic resin contained in the molten resin composition and the crystalline thermoplastic resin contained in the crystalline thermoplastic resin thin molded article are preferably of the same type. If the same kind of crystalline thermoplastic resin is used, the melted portion of the crystalline thermoplastic resin thin molded product and the molten resin composition are likely to be mixed in the molding process, resulting in an improved adhesion at the joint. This is because it increases.

  In addition, the crystalline thermoplastic resin contained in the crystalline thermoplastic resin thin-walled molded product and the crystalline thermoplastic resin contained in the molten resin composition are both polyphenylene sulfide resins or polybutylene terephthalate resins. Most preferred. As the polyphenylene sulfide-based resin, for example, those described in JP2009-132935A can be used. As the polybutylene terephthalate resin, for example, those described in JP-A-2006-111893 can be used.

  The content of the crystalline thermoplastic resin in the molten resin composition is not particularly limited, but if the content is 10% by mass or more and 100% by mass or less, the excellent physical properties of the crystalline thermoplastic resin are composite molded articles. It is preferable because it tends to appear as a physical property. In particular, when the molten resin composition becomes a material that forms most of the composite molded body, the physical properties of the molten resin composition greatly affect the physical properties of the composite molded body.

  The molten resin composition may contain components other than the crystalline thermoplastic resin as long as the effects of the present invention are not impaired. Examples of other components include general additives such as resins other than crystalline thermoplastic resins, inorganic fillers, antioxidants, pigments, plasticizers, and stabilizers.

[Mold]
The metal mold | die used for the manufacturing method of this invention has the heat insulation layer formed in at least one part of the inner surface. By forming the heat insulating layer, it becomes difficult to release the heat of the molten resin composition injected into the mold to the outside. As a result of making it difficult to release the heat of the molten resin composition to the outside, the mold temperature condition can be kept low as will be described later.

  The heat insulating layer may be formed of any material, but preferably includes a polyimide resin and / or zirconium oxide. This is because the polyimide resin and zirconium oxide have a heat conductivity of 5 W / m · K or less and a sufficient heat insulation effect, and also have heat resistance sufficiently withstanding high temperatures during injection molding. Specific examples of polyimide resins that can be used include pyromellitic acid (PMDA) -based polyimide, biphenyltetracarboxylic acid-based polyimide, polyamideimide using trimellitic acid, bismaleimide-based resins (bismaleimide / triazine-based, etc.), benzophenone Examples include tetracarboxylic acid-based polyimides, acetylene-terminated polyimides, and thermoplastic polyimides. In addition, it is especially preferable that it is a heat insulation layer which consists of a polyimide resin and / or a zirconium oxide, and these can be used individually or in a laminated form. Examples of preferable materials other than polyimide resin or zirconium oxide include tetrafluoroethylene resin and polybenzimidazole resin.

  The method for forming the heat insulating layer on the inner surface of the mold is not particularly limited. For example, it is preferable to form the heat insulating layer on the inner surface of the mold by the following method.

  A solution of a polymer precursor such as a polyimide precursor capable of forming a polymer heat insulating layer is applied to the mold surface, heated to evaporate the solvent, and further heated to polymerize to form a heat insulating layer such as a polyimide film. For forming, heat-resistant polymer monomers, for example, pyromellitic anhydride and 4,4-diaminodiphenyl ether are vapor-deposited, or for planar molds, a polymer heat insulating film is used as an appropriate bonding method Or the method of sticking on the desired part of a metal mold | die using an adhesive tape-shaped polymer heat insulation film, and forming a heat insulation layer is mentioned. It is also possible to form a polyimide film and further form a chromium (Cr) film or a titanium nitride (TiN) film as a metal-based hard film on the surface thereof. Further, as a method of forming a heat insulating layer of zirconium oxide, there is a method of spraying zirconium oxide on a metal mold surface and laminating, and a polyimide film may be further formed on the surface.

  The position where the heat insulating layer is formed needs to overlap the position where the crystalline thermoplastic resin thin molded article is attached. This is to prevent the heat of the molten resin composition flowing into the mold from being immediately released to the outside after being transferred to the crystalline thermoplastic resin thin molded article. Therefore, in this invention, it is preferable to form a heat insulation layer so that substantially the whole surface which contact | connects the heat insulation layer of a crystalline thermoplastic resin thin molded object may be formed on a heat insulation layer. Here, the almost entire crystalline thermoplastic resin thin molded article refers to a case where 90% or more of the area of the crystalline thermoplastic resin thin molded article is attached on the heat insulating layer. More preferably, 95% or more of the area of the crystalline thermoplastic resin thin molded body is attached on the heat insulating layer, and most preferably 100% of the area of the crystalline thermoplastic resin thin molded body is on the heat insulating layer. It is a case where it is attached to.

  The thickness of a heat insulation layer is not specifically limited, It can set to preferable thickness suitably with the material etc. to be used. A thickness of the heat insulation layer of 20 μm or more is preferable because a sufficiently high heat insulation effect can be obtained. The thickness of the heat insulating layer formed on the inner surface of the mold may be uniform or may include portions having different thicknesses.

[Molding process]
The molding process uses a mold in which a crystalline thermoplastic resin thin molded body is attached to a desired position on the inner surface, and the molten resin composition is poured into the mold, and the crystalline thermoplastic resin thin molded body and the molten resin are poured. This is a process for producing a composite molded body by integrating the composition.

  On the inner surface of the mold, the position at which the crystalline thermoplastic resin thin molded article is disposed is not particularly limited, and is determined according to the composite molded article to be manufactured. The method for disposing the crystalline thermoplastic resin thin molded article on the inner surface of the mold is not particularly limited, and a method similar to general film-in-mold molding can be employed.

  After the thin molded body is disposed on the inner surface of the mold, the molten resin composition is poured into the mold. The method for pouring the molten resin composition into the mold is not particularly limited. For example, a conventionally known injection molding machine or the like can be used. In the production method of the present invention, when the molten resin composition is poured into a mold, the following molding conditions are required.

  The mold temperature at which the molten resin composition is poured into the mold needs to be set to be lower than the recrystallization temperature of the crystalline thermoplastic resin contained in the crystalline thermoplastic resin thin molded article. When the mold temperature is set to be equal to or higher than the recrystallization temperature, the crystallinity of the crystalline thermoplastic resin thin molded article is high when the mold temperature is set before the molten resin composition is poured into the mold. turn into. On the other hand, when the mold temperature is set below the recrystallization temperature, the crystallization of the thin molded body does not proceed rapidly, so the molten resin composition is quickly inserted into the mold after the thin molded body is inserted into the mold. By pouring in, the contact surface with the molten resin composition of a thin molded object is maintained in a state with low crystallinity. When it is set below the glass transition temperature, the crystallinity of the thin molded body is maintained as it is. Even when the thin-walled molded body having an increased degree of crystallinity and the molten resin composition are in contact with each other, the adhesion at the joint portion is not sufficient. Therefore, it is necessary to set the mold temperature as described above. The preferable mold temperature is not particularly limited, and can be set by appropriately adjusting the molding conditions. For example, the mold temperature is preferably set to the glass transition temperature of −50 ° C. or higher and the glass transition temperature of −10 ° C. or lower. The mold temperature on the side where the thin molded product is placed and the mold temperature on the other side need not be the same. After pouring the molten resin composition into the mold, the mold temperature is raised or rapidly cooled. May be.

  The temperature of the molten resin composition is equal to or higher than the glass transition temperature of the thermoplastic resin contained in the crystalline thermoplastic resin thin molded article. By satisfying this condition, the crystalline thermoplastic resin thin molded article and the molten resin composition can be integrated as follows. The thin molded body melted by the heat of the molten resin composition that has flowed into the mold and the molten resin composition are mixed together at the joint portion where they are integrated. Then, in a mixed state, the crystalline resin is crystallized while being cooled. As a result, the adhesion at the joint is improved. In addition, although the temperature of a preferable molten resin composition is not specifically limited, For example, it is preferable that it is melting | fusing point +10 degreeC or more and melting | fusing point +50 degrees C or less.

  Other molding conditions can be appropriately set according to the type of material, the thickness of the crystalline thermoplastic resin thin molded body, and the like.

<Composite molded body>
The composite molded body produced by the above-described method can achieve adhesion between a thin layer derived from a crystalline thermoplastic resin thin-walled molded body and a molded body layer derived from a molten resin composition without particularly using an adhesive or the like. Excellent. In the case of the conventional method, it is difficult to integrate them without using an adhesive or the like. This is because, as described above, it is necessary to set the mold temperature condition to be equal to or higher than the glass transition temperature of the crystalline resin contained in the crystalline thermoplastic resin thin molded article.

  In order to explain the effect of the present invention, the conventional method will be described more specifically. In the case of the conventional method, as shown in FIG. 1 (a), in a state where the crystalline thermoplastic resin thin molded article is disposed in the mold, when the mold temperature is equal to or higher than the glass transition temperature of the crystalline resin, The crystallinity of the crystalline thermoplastic resin thin molded article is increased. When the crystallinity of the crystalline thermoplastic resin thin-walled molded body increases, even if the molten resin composition is subsequently injected into the mold, it is not integrated or integrated with a very low adhesion.

  On the other hand, in the case of this invention, as shown in FIG.1 (b), the heat insulation layer is formed in the metal mold | die. For this reason, even if the mold temperature condition is set to be equal to or lower than the glass transition temperature of the crystalline thermoplastic resin, the heat of the molten resin composition is easily held in the mold. As a result, the crystallinity of the composite molded body can be sufficiently increased by the heat of the molten resin composition.

  The composite molded body of the present invention has a mixed layer between the thin layer and the molded body layer. The mixed layer is a portion where the material constituting the crystalline thermoplastic resin thin molded body and the material constituting the molten resin composition are mixed. The mixed layer is a layer formed by mixing the molten resin composition with the portion where the crystalline thermoplastic resin thin molded article is dissolved in the molten resin composition during the molding step. For this reason, the boundary of a thin layer, a mixed layer, and a molded object layer is not clear normally.

  The mixed layer preferably has a relative crystallinity of 90% or more. Although depending on the material, if the crystallinity of the mixed layer is within the above range, the adhesion between the thin layer and the molded body layer tends to be sufficient. A more preferable range of crystallinity is 95% or more and 100% or less.

  When the crystalline thermoplastic resin contained in the crystalline thermoplastic resin thin molded article and the crystalline thermoplastic resin contained in the molten resin composition are of the same type, whether or not a mixed layer is formed, It can confirm indirectly from the magnitude | size of the adhesive force between a thin layer and a molded object layer. This is because, when an adhesive or the like is not used, in order to sufficiently adhere the thin layer and the molded body layer, it is necessary to mix and solidify the materials to be integrated in a melted state. Here, the adhesion that can be said to be the formation of the mixed layer varies depending on the material used, but is approximately 50% or more of the tensile strength of the crystalline thermoplastic resin. In addition, the said adhesive force employ | adopts the value measured by the method called a peel test.

<Molded body with in-mold label>
Specific examples of the composite molded body of the present invention include a molded body with an in-mold label. The molded body with an in-mold label is a composite molded body in which an in-mold label and a resin are integrated. The in-mold label is a film provided with a part having design properties such as a printed layer, and corresponds to the crystalline thermoplastic resin thin-walled molded product in the present invention.

  The position at which the print layer or the like is provided is not particularly limited, and may be on the front side or the back side of the thin crystalline thermoplastic resin molded body. Further, the method for forming the print layer is not particularly limited, and a conventionally known method can be employed.

  Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

<Crystalline thermoplastic resin film 1>
Using a polyphenylene sulfide resin (glass transition temperature (Tg) of 80 ° C., recrystallization temperature (Tc) of 120 ° C., “Fortron (registered trademark) 0220A9” manufactured by Polyplastics Co., Ltd.), a melt extrusion method using a T-die The crystalline thermoplastic resin film 1 having a length of 45 mm, a width of 45 mm, and a thickness of 0.1 mm (100 μm) was produced by quenching at a temperature lower than the glass transition temperature from the molten state.

  The crystallinity of the crystalline thermoplastic resin film 1 was measured by a general method using an X-ray diffraction method. The crystallinity was 14.4%. As will be described later, in the composite molded body, the crystallinity of the portion that was in direct contact with the heat insulating layer at the time of molding was 33.9%. When this is 100%, the relative crystallinity of the crystalline thermoplastic resin film 1 is 42.3%.

  A printed layer having design properties was formed on the crystalline thermoplastic resin film 1 by screen printing to produce an in-mold label 1.

<Crystalline thermoplastic resin film 2>
Using a polybutylene terephthalate resin (glass transition temperature (Tg) of 30 ° C., “Duranex (registered trademark) 500FP” manufactured by Polyplastics Co., Ltd.), it is lower than the glass transition temperature from the molten state by a melt extrusion method using a T-die. Crystalline thermoplastic resin film 2 having a length of 45 mm, a width of 45 mm, and a thickness of 0.1 mm (100 μm) was produced by quenching at a temperature.

  The crystallinity of the crystalline thermoplastic resin film 2 was measured by the X-ray diffraction method as in the case of the film 1. The crystallinity was 12.5%. As will be described later, in the composite molded body, the crystallinity of the portion that was in direct contact with the heat insulating layer at the time of molding was 28.5%. When this is 100%, the relative crystallinity of the crystalline thermoplastic resin film 2 is 43.9%.

  A printed layer having design properties was formed on the crystalline thermoplastic resin film 2 by screen printing to produce an in-mold label 2.

<Mold 1>
As a material for forming the heat insulating layer, polyimide resin varnish (manufactured by Fine Chemical Japan Co., Ltd.) and thermal conductivity of 0.2 W / m · K were used. The thermal conductivity of the polyimide resin was calculated by measuring thermal diffusivity by laser flash method, specific gravity by Archimedes method, and specific heat by DSC.

  A polyimide resin varnish is sprayed on the inner surface of a mold for injection molding having a width of 50 mm, a length of 50 mm, and a thickness of 2 mm. After baking at 250 ° C. for 1 hour, the polyimide surface is polished to increase the thickness of the heat insulation layer The thickness was adjusted to 100 μm.

<Mold 2>
A mold similar to the mold 1 except that the heat insulating layer was not formed was prepared as a mold for a comparative example.

<Method for producing composite molded body 1>
For the production of the composite molded body 1, an injection molding machine and a mold 1 were used. First, the in-mold label 1 was arrange | positioned on the heat insulation layer in a metal mold | die. More specifically, it was arranged so that the surface having the printed layer and the heat insulating layer were in contact. Then, the mold temperature was set to 70 ° C., and the molten resin composition at 320 ° C. (in the production of composite molded bodies 1 and 2, polyphenylene sulfide resin (glass transition temperature (Tg) was 80 ° C., recrystallization temperature) (Tc) 120 ° C., “Fortron (registered trademark) 6165A6” manufactured by Polyplastics Co., Ltd. was used) was set to flow into the mold. The composite molded body 1 was taken out from the mold by cooling and solidification. The crystallinity of the portion where the in-mold label and the molten resin composition were in contact (the portion corresponding to the mixed layer) and the portion where the molten resin composition was in direct contact with the heat-insulating layer and solidified were measured by X-ray diffraction (more Specifically, the measurement was performed in the same manner as the measurement with the crystalline thermoplastic resin film 1). The crystallinity of each was 31.4% and 33.9%. Accordingly, the relative crystallinity is 92.6%.

<Method for producing composite molded body 2>
A composite molded body 2 was produced in the same manner as the composite molded body 1 except that the mold 2 was used instead of the mold 1 and the mold temperature condition was set to 140 ° C.

<Method for producing composite molded body 3>
An in-mold label 2 is used in place of the in-mold label 1, the mold temperature condition is set to 40 ° C., and a molten resin composition (in the production of the composite molded bodies 3 and 4, a polybutylene terephthalate resin (glass The transition temperature (Tg) was 30 ° C., and the temperature of “Juranex (registered trademark) 3300” manufactured by Polyplastics Co., Ltd.) was used. A composite molded body 3 was produced. The crystallinity of the portion where the in-mold label and the molten resin composition were in contact (the portion corresponding to the mixed layer) and the portion where the molten resin composition was in direct contact with the heat-insulating layer and solidified were measured by X-ray diffraction. The crystallinity of each was 28.2% and 28.5%. Therefore, the relative crystallinity is 98.9%.

<Method for producing composite molded body 4>
A composite molded body 4 was produced in the same manner as the composite molded body 3 except that the mold 2 was used instead of the mold 1 and the mold temperature condition was set to 20 ° C.

<Method for producing composite molded bodies 5 and 6>
The mold temperature was set to 110 ° C., and a composite molded body was obtained in the same manner as the composite molded body 1. At that time, 3 seconds after the in-mold label was placed on the mold, the molten resin composition was injected and filled to obtain a composite molded body 5. Further, 20 seconds after the placement, the molten resin composition was injected and filled to obtain a composite molded body 6.

<Evaluation>
It was evaluated by a method called a peel test whether or not the in-mold label was sufficiently adhered to the molded body layer formed of the molten resin composition.
In composite molded body 1 and composite molded body 3, the film and the molten resin composition were integrated, and it was not possible to peel only the film. Moreover, in the composite molded body 2 and the composite molded body 4, the film peeled easily from the molten resin composition, and the peel strength was 0.3 N / mm or less. The peel test method is in accordance with the 90 ° peel test of JIS K6854-1, in which the in-mold label on the molded body layer is cut into a strip of 10 mm width, one end of the in-mold label is peeled off, fixed with a jig, and then at a constant speed. The film was peeled off vertically and evaluated by the strength or the fracture mode. In the composite molded body 5, the film and the molten resin composition are integrated, and only the film cannot be peeled off. However, in the composite molded body 6, the film and the molten resin composition are easily peeled off.

Claims (9)

A crystalline thermoplastic resin thin molded article is placed inside a mold having a heat insulating layer formed on at least a part of the inner surface of the mold, and a molten resin composition that can be welded to the crystalline thermoplastic resin is poured into the mold. With a molding process,
The crystalline thermoplastic resin thin molded article is disposed so that at least a part of the thin part overlaps the heat insulating layer,
At least the thin part of the crystalline thermoplastic resin thin molded article has a relative crystallinity of 60% or less,
(The relative crystallinity refers to the crystallinity when the molten resin composition is molded and the crystallinity of the portion that is in direct contact with the heat insulating layer and solidified is 100%.)
The mold temperature in the molding step is less than the recrystallization temperature of the crystalline thermoplastic resin,
In the molding step, the temperature of the molten resin composition is a method for producing a composite molded body having a glass transition temperature or higher.   The method for producing a composite molded body according to claim 1, wherein the mold temperature is lower than the glass transition temperature.   The method for producing a composite molded body according to claim 1 or 2, wherein the thickness of the crystalline thermoplastic resin thin-walled molded body is 10 µm or more and 1000 µm or less.   The method for producing a composite molded body according to any one of claims 1 to 3, wherein the crystalline thermoplastic resin thin-walled molded body and the molten resin composition include a polyarylene sulfide-based resin or a polybutylene terephthalate-based resin.   The said heat insulation layer is a manufacturing method of the composite molded object in any one of Claim 1 to 4 which consists of a polyimide resin or / and a zirconium oxide.   The method for producing a composite molded body according to claim 1, wherein the crystalline thermoplastic resin thin-walled molded body is an in-mold label. Using a crystalline thermoplastic resin film, a composite molded body formed by film in-mold molding,
A molded body layer integrated with the crystalline thermoplastic resin film,
Mixing in which the material constituting the crystalline thermoplastic resin film and the material constituting the molded body layer are in a mixed state at the portion where the crystalline thermoplastic resin film and the molded body layer are integrated A layer, and
The composite molded body in which the crystalline thermoplastic resin in the mixed layer is in a crystalline state.   The composite molded body according to claim 7, wherein the mixed layer has a relative crystallinity of 90% or more.   An in-mold label having a crystalline thermoplastic resin portion having a relative crystallinity of 60% or less on the affixing surface.

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