JP6768274B2 - In-mold material and its manufacturing method, and manufacturing method of laminated molded body - Google Patents

Description

The present invention relates to an in-mold material used for in-mold molding including a fiber structure, a method for producing the same, and a method for producing a laminated molded product.

A laminated molded body in which an in-mold material is integrated on the surface of an injection molded body is known. Such a laminated molded body is manufactured by in-mold molding in which a sheet or an in-mold material which is a preformed preform molded body is placed in a cavity of a mold and injection molded.

An example of a method for producing a laminated molded product by in-mold molding will be described with reference to FIG. In FIG. 5, 11 is an in-mold material containing a fiber structure, 2a is a movable side type, 2b is a fixed side type, 3 is an injection part main body of an injection molding machine, 3a is a nozzle, 3b is a cylinder, and 3c is an inline screw. 4 is a filling gate, 5 is an injection molded product, 5a is a molten resin, and 20 is a laminated molded product.

In the method for manufacturing a laminated molded product using in-mold molding, first, as shown in FIG. 5A, the in-mold material 11 is arranged in a recess for forming a cavity of the movable side mold 2a. Then, after arranging the in-mold material 11 in the recess of the movable side mold 2a, the movable side mold 2a and the fixed side mold 2b are molded as shown in FIG. 5 (b). Then, as shown in FIG. 5C, the molten resin 5a is filled in the cavity c formed by molding the movable side mold 2a and the fixed side mold 2b. Then, after the cooling step of cooling the molten resin 5a in the cavity c is completed, as shown in FIG. 5D, the movable side mold 2a is retracted to open the movable side mold 2a and the fixed side mold 2b. By doing so, the laminated molded body 20 in which the in-mold material 11 is integrated with the injection molded body 5 is taken out.

As an in-mold material with excellent design and tactile sensation, fiber structures such as non-woven fabrics and textiles, leather-like materials such as artificial leather and synthetic leather including fiber structures, and materials including fiber structures such as paper are used. Has been done. For example, in Patent Document 1 below, an insert material having a suede-like or silver-like feel, in which a reinforcing sheet is attached to the back surface of artificial leather, is preformed into a three-dimensional shape and punched into a required shape to form an injection molding die. Disclosed is a molded product obtained by molding a resin molded product by injecting a molten resin from the reinforcing sheet side of the insert material after being housed in the inner cavity, and at the same time integrating the insert material on the surface thereof.

Japanese Unexamined Patent Publication No. 2005-104328

Compared to a general thermoplastic resin injection-molded body, there is a problem that the laminated molded body obtained by in-mold molding in which the in-mold material is integrated with the surface of the injection-molded body tends to have a large warp. .. In particular, when an in-mold material containing a fiber structure is laminated on an injection-molded product, the warp tends to increase.

As a post-treatment step for reducing warpage in a general injection molding method, an annealing treatment for eliminating residual strain accumulated in an injection-molded product by heating the molded injection-molded product has been known. However, when the in-mold material containing the fiber structure is laminated on the injection-molded product, it is difficult to sufficiently reduce the warpage by annealing the obtained laminated molded product.

An object of the present invention is to provide a means for reducing warpage generated in a laminated molded product obtained by laminating an in-mold material containing a fiber structure on an injection molded product.

The present inventors have diligently studied in order to reduce the warpage generated in the laminated molded product obtained by laminating the in-mold material containing the fiber structure on the injection molded product. Then, for example, the fiber structure is manufactured so as to be picked up in one direction, strongly stretched in the picking direction, and weakly stretched in the direction perpendicular to the picking direction. Therefore, when the fiber structure is heat-treated, the fiber structure is manufactured. Attention was paid to the fact that the fibers contracted significantly in the pick-up direction during production and the dimensions changed more than in the perpendicular direction. In in-mold molding, the in-mold material containing the fiber structure housed in the cavity of the mold is cooled while the injected molten resin is fixed, so that the stress strain of the fiber structure is fixed. The warp of the laminated molded body obtained by laminating the in-mold material containing the fiber structure on the injection molded body is the stress when the fiber structure tries to eliminate the residual strain in the state of being laminated on the injection molded body. I thought that mitigation was one of the causes. Then, they have found that a laminated molded product in which warpage is suppressed can be obtained by using an in-mold material in which the anisotropy of residual strain is reduced in advance, and have arrived at the present invention.

That is, one aspect of the present invention is an in-mold material used for in-mold molding including a fiber structure, which is 10 ° C. higher than the glass transition temperature (T _g ) of the resin forming the fiber of the fiber structure. It is an in-mold material having an area shrinkage rate of 2% or less when heat-treated at temperature. Such an in-mold material containing a fiber structure having an area shrinkage of 2% or less when heat-treated at a temperature 10 ° C. higher than the glass transition temperature (T _g ) for 10 minutes is an injection of in-mold molding. The residual strain that exists before the molding process is small. Therefore, when an in-mold material containing such a fiber structure having a small residual strain is used, a laminated molded product in which warpage is suppressed can be obtained.

Further, when the in-mold material is a preform molded body having a three-dimensional shape, the effect of suppressing warpage is particularly high, which is preferable.

Examples of the in-mold material containing the fiber structure include synthetic leather, artificial leather, leather-like material, non-woven fabric, woven fabric, knitted fabric, and paper.

Further, another aspect of the present invention is a step of preparing a material containing a fiber structure and a temperature of the material at a temperature equal to or higher than the glass transition temperature (Tg) of the resin forming the fiber of the fiber structure without applying an external force. after eliminating the residual strain by heating a certain time, a method of manufacturing the in-mold material used for in-mold molding comprising the steps of a Neil process is cooled by stopping the heating, the. By annealing the material containing the fiber structure in this way, the residual strain of the fiber structure is eliminated. As a result, a laminated molded product in which warpage is suppressed can be obtained. The annealing treatment is preferably a treatment in which the resin forming the fibers of the fiber structure is heated at a temperature equal to or higher than the glass transition temperature (T _g ) from the viewpoint of further eliminating residual strain.

Further, another aspect of the present invention is a step of preparing a material containing a fiber structure and a temperature of the material at a temperature equal to or higher than the glass transition temperature (Tg) of the resin forming the fiber of the fiber structure without applying an external force. after eliminating the residual strain by heating a predetermined time, a cavity by forming an in-mold material is subjected to a Neil process of cooling down the heating and clamping the fixed mold and the movable mold A step of forming a resin laminate in which the in-mold material is integrated on the surface of the injection-molded product to be molded by accommodating the in-mold material in the cavity of the injection-molding mold to be formed. , Is a method for producing a laminated molded product. According to such a manufacturing method, a laminated molded body in which an in-mold material containing a fiber structure with suppressed warpage is laminated and integrated on the surface can be obtained.

According to the present invention, a laminated molded body in which an in-mold material containing a fiber structure with suppressed warpage is laminated and integrated on the surface can be obtained.

FIG. 1 is an explanatory diagram illustrating each step of the method for manufacturing the laminated molded article of the embodiment. FIG. 2 is a graph showing the area change with respect to the heat treatment time in the annealing treatment at each temperature described in Example 1. FIG. 3 is a graph showing the amount of change in warpage due to heating in the annealing treatment at each temperature described in Example 2. FIG. 4 is a graph showing the amount of change in warpage of the preform pre-annealed molded product, the preform-post-annealed molded product, and the preform molded product without annealing treatment according to Example 3. FIG. 5 is an explanatory diagram illustrating each step of a conventional method for manufacturing a laminated molded product using an in-mold molded product.

The manufacturing method of the laminated molded article of this embodiment will be described with reference to the drawings. FIG. 1 is an explanatory diagram illustrating each step of the method for manufacturing the laminated molded product of the present embodiment.

In FIG. 1, 1 is an in-mold material containing a fiber structure, 1a is a material containing a fiber structure which is an in-mold material before annealing, 2a is a movable side type, 2b is a fixed side type, and 3 is an injection molding machine. 3a is a nozzle, 3b is a cylinder, 3c is an in-line screw, 4 is a filling gate, 5 is an injection molded product, 5a is a molten resin, and 10 is an in-mold molded product (laminated molded product). Further, reference numeral 100 denotes a heater for annealing the preform material 1a. The movable side mold 2a and the fixed side mold 2b form a pair to form the injection molding mold 2 forming the cavity c. In the present embodiment, the movable side mold 2a is a female mold for injection molding, and the fixed side mold 2b is a male mold for injection molding.

In the method for producing a laminated molded product of the present embodiment, as shown in FIG. 1A, a heating heater 100 is used to heat the material 1a containing the fiber structure at a predetermined temperature before injection molding is performed. Annealing treatment is performed by heat treatment.

The annealing treatment is a treatment for eliminating the residual strain of the material containing the fiber structure before the annealing treatment, which has residual strain, by heating the material containing the fiber structure. Such annealing treatment is performed using, for example, a hot air dryer set to a predetermined temperature, a far-infrared heater, or the like.

As described above, the fiber structure is manufactured, for example, by being strongly stretched in the pick-up direction and weakly stretched in the direction perpendicular to the pick-up direction. Therefore, strain tends to remain, and when injection molding is performed by accommodating a material containing the fiber structure before annealing in a state where strain remains in the cavity, the fiber structure is even in the laminated molded body obtained after injection molding. Due to the residual strain of the body, warpage is likely to occur. Further, even if the laminated molded body is annealed, the fiber structure and the injection molded body are integrated, so that the degree of freedom of movement of the fibers in the fiber structure is low. According to the annealing treatment of the material including the fiber structure which is the in-mold material before the annealing treatment in the present embodiment, the fiber structure which is not integrated with the injection molded body and has a high degree of freedom of the fiber is annealed. By doing so, the effect of eliminating the residual strain is high.

As will be described in detail later, as the conditions for the annealing treatment, conditions suitable for eliminating the residual strain are appropriately set according to the type of the fiber structure. An example of the temperature of the annealing treatment is the glass transition temperature (T _g ) or higher of the resin forming the fiber of the fiber structure, and further T _g + 10 ° C. or higher, particularly T _g + 20 ° C. or higher, and the fiber structure. It is preferably below the melting point or softening temperature of the resin that forms the body fibers. Further, as an example of the annealing treatment time, it is preferably 1 minute or more, further 5 minutes or more, particularly 30 minutes or more, 4 hours or less, and further preferably 3 hours or less. If the temperature of the annealing treatment is too low or the treatment time is too short, the residual strain tends not to be sufficiently eliminated. Further, if the annealing treatment takes too long, or if the treatment is performed at a temperature that is too high, for example, a temperature exceeding the rubber-like flat region, there is a tendency for thermal deterioration or deformation.

Next, as shown in FIG. 1B, the annealed in-mold material 1 is inserted into the recess for forming the cavity of the movable side mold 2a. The in-mold material 1 may be fixed to the recess of the movable side type in order to suppress the positional deviation when filling the molten resin. Specific examples of the fixing means include sticking to the surface of the movable side mold with double-sided tape, adsorbing in a vacuum, adhering using the surface adhesiveness of the in-mold material itself, and providing a protrusion in the concave portion of the movable side mold. Examples thereof include a method of providing and fitting an in-mold material. Further, only one in-mold material may be used, or two or more in-mold materials may be used in combination.

Next, as shown in FIG. 1C, the movable side mold 2a and the fixed side mold 2b are molded. Then, as shown in FIG. 1D, the molten resin 5a is filled in the cavity c formed by molding the movable side mold 2a and the fixed side mold 2b. Specifically, the injection portion 3 of the injection molding machine is advanced, the nozzle 3a is brought into contact with the filling gate 4 formed in the fixed side mold 2b, and the molten resin 5a is injected in the cylinder 3b with the in-line screw 3c. The molten resin 5a is completely filled in the cavity c at a predetermined filling pressure.

Specific examples of the injected resin include ABS-based resin, acrylic resin such as PMMA resin, polystyrene-based resin, polycarbonate-based resin, polyolefin-based resin such as polypropylene, polyethylene terephthalate (PET), and polybutylene terephthalate (PET). Examples thereof include polyester resins such as PBT), various polyamide resins, and COP resins. Further, these may be a compound product containing a filler or the like, or a mixed product obtained by alloying or blending a plurality of types of resins. These are appropriately selected according to the application. For example, as the resin used for the housing of mobile phones, mobile devices, home appliances, etc., a resin having excellent impact resistance such as ABS resin, polycarbonate resin, polyolefin resin such as polypropylene, etc. is preferably used.

The injection molding conditions are conditions that can be completely filled according to the thermal characteristics and melt viscosity of the injected resin, the shape of the molded body, and the resin thickness (resin temperature, mold temperature, injection pressure, injection speed, retention after injection). Pressure, cooling time) are set appropriately.

The thickness of the injection-molded article to be molded is also not particularly limited, and is appropriately selected depending on the application and moldability. For example, when it is used for a housing of a mobile phone, a mobile device, a home electric appliance, etc., 0.3 to 2 mm, more preferably 0.5 to 1.5 mm is selected as a preferable range.

Then, in the cooling step, the injection molded body 5 formed in the cavity c formed by molding the movable side mold 2a and the fixed side mold 2b, and the in-mold material 1 laminated on the injection molded body 5. After cooling the laminated body in which is integrated for a predetermined time, as shown in FIG. 1 (e), the movable side mold 2a and the fixed side mold 2b are opened, and the molded injection molded body 5 and the injection are injected. The in-mold molded body 10 in which the in-mold material 1 laminated on the molded body 5 is integrated is taken out. Then, the unnecessary portion of the obtained in-mold molded body 10, specifically, the end portion of the in-mold material is trimmed, and the gate and runner are cut and removed to prepare the final product shape.

Next, the material for the in-mold material used in the method for producing the laminated molded product of the present embodiment and the annealing treatment will be described in detail.

As the form of the material for the in-mold material, in FIG. 1 referred to in the present embodiment, a preform molded body preformed to a material including a fiber structure is illustrated, but the form is not limited to the preform molded body. A sheet of a fiber structure such as a non-woven fabric, a woven fabric, a woven fabric, or a knitted fabric, or a leather-like sheet such as artificial leather or synthetic leather containing the fiber structure may be used as it is without shaping. The preformed preform molded body is formed by hot-press molding, vacuum forming, vacuum forming, vacuum forming of a leather-like material such as artificial leather or synthetic leather, or a sheet of non-woven fabric, woven fabric, or paper. Obtained by shaping by means. The thickness of the in-mold material is not particularly limited, but is preferably 0.1 to 2 mm, more preferably about 0.2 to 1 mm.

Specific examples of the resin forming the fibers of the fiber structure include polyethylene terephthalate (PET), modified PET, polybutylene terephthalate (PBT), polytrimethylene terephthalate (PTT), polytriethylene terephthalate, and polyhexamethylene terephthalate. , Polyethylene terephthalate, polyethylene naphthalate, etc. Aromatic polyester resins; polylactic acid, polyethylene succinate, polybutylene succinate, polybutylene succinate adipate, polyhydroxybutyrate-polyhydroxyvariate copolymer, etc. Polyamide-based resin; polyamide-based resin such as polyamide 6, polyamide 66, polyamide 610, polyamide 10, polyamide 11, polyamide 12, polyamide 6-12, etc .; Polyamide, polyethylene, polybutene, polymethylpentene, chlorine-based polyolefin, ethylene vinyl acetate Polyethylene-based resins such as polymers and styrene-ethylene copolymers; modified polyvinyl alcohol-based resins formed from modified polyvinyl alcohols containing 25 to 70 mol% of ethylene units; and polyurethane-based elastomers, polyamide-based elastomers, polyesters. Examples thereof include thermoplastic resins such as crystalline elastomers such as based elastomers. Only one type of these may be used, or two or more types may be used in combination. Among these, in particular, the aromatic polyester-based resin having a glass transition temperature (T _g ) of 90 to 120 ° C. and further 100 to 115 ° C. provides fibers having high heat shrinkage, resulting in residual strain. Is preferable because the effect of eliminating the residual strain by the annealing treatment of the present embodiment is remarkable from the viewpoint that the temperature tends to increase.

For T _g , for example, a dynamic viscoelasticity measuring device (for example, FT Leospectra DDVIV manufactured by Rheology Co., Ltd.) is used to fix a test piece having a width of 5 mm and a length of 30 mm between chucks having an interval of 20 mm, and the measuring area 30 is measured. It is obtained by measuring the dynamic viscoelastic behavior under the conditions of ~ 250 ° C., a heating rate of 3 ° C./min, a strain of 5 μm / 20 mm, and a measurement frequency of 10 Hz.

Specific examples of aromatic polyesters having a T _g of 100 to 120 ° C. include modified polyethylene terephthalates containing a copolymerizing component that disturbs the linear structure as a constituent unit of polyethylene terephthalate, particularly isophthalic acid and phthalate. Examples thereof include modified polyethylene terephthalate containing an asymmetric aromatic carboxylic acid such as acid and 5-sodium sulfoisophthalic acid and an aliphatic dicarboxylic acid such as adipic acid as a copolymerization component in a predetermined ratio. More specifically, modified polyethylene terephthalate containing 2 to 12 mol% of isophthalic acid units as a monomer component is preferable.

Further, the fineness of the fibers forming the fibers of the fiber structure is not particularly limited, and even if the fineness of a normal fiber exceeding 1 dtex is 1 dtex or less, further 0.6 dtex or less, particularly 0.5 dtex or less. The fineness of ultrafine fibers may be used. It should be noted that the fiber having the fineness of the ultrafine fiber tends to have high heat shrinkage and tends to have a large residual strain, and is preferable because the effect of eliminating the residual strain by the annealing treatment of the present embodiment is remarkable.

Further, the fiber structure may contain a polymer elastic body in the internal voids for the purpose of improving morphological stability and a feeling of fullness. Specific examples of such polymer elastic bodies include various polyurethanes such as polycarbonate-based polyurethanes, polyester-based polyurethanes, and polyether-based polyurethanes, acrylic-based elastic bodies, polyurethane acrylic composite elastic bodies, polyvinyl chlorides, and synthetic rubbers. And so on. Among these, polyurethane is preferable because it has excellent adhesiveness and mechanical properties.

The content ratio of the polymer elastic body is preferably 0 to 40% by mass, more preferably 5 to 35% by mass, and particularly preferably 8 to 30% by mass. If the content of the polymer elastic body is too high, the shapeability tends to decrease.

When a grain-like resin layer is laminated on one surface of such a fiber structure, a grain-like leather-like sheet having a silver-attached leather-like appearance can be obtained. Further, by raising one surface of the fiber structure, a brushed leather-like sheet having a brushed appearance can be obtained.

As a method of forming a grain-like leather-like sheet, a method of forming a grain-like resin layer containing a polymer elastic material such as polyurethane on one surface of a fiber structure by a method such as a dry surface forming method or a direct coating method. Can be mentioned. In the dry surface forming method, a resin film containing a polymer elastic body is formed on a supporting base material such as a release paper, and then an adhesive is applied to the surface of the resin film and bonded to one surface of the fiber structure. This is a method of forming a grain-like resin layer by pressing and adhering if necessary and peeling off the release paper. Further, the direct coating method is a method in which a liquid resin or a resin liquid containing a polymer elastic body is directly applied to one surface of a fiber structure and then cured to form a grain-like resin layer.

As the polymer elastic body that forms the grain-like resin layer, polyurethane, an acrylic elastic body, or the like that has been conventionally used for forming the grain-like resin layer can be used. Specific examples thereof include various polyurethanes such as polycarbonate-based polyurethane, polyester-based polyurethane, and polyether-based polyurethane, acrylic elastic bodies, polyurethane acrylic composite elastic bodies, polyvinyl chloride elastic bodies, synthetic rubbers, and the like.

Further, as a method of forming a brushed leather-like sheet, a method of forming a brushed suede-like or nubuck-like decorative surface by buffing the surface of the fiber structure can be mentioned. The buffing treatment is a treatment in which the surface of the fiber structure is rubbed with sandpaper, a brush, or the like to raise the fibers.

The apparent density of the fiber structure is not particularly limited, but it should be 0.45 g / cm ³ or more, further 0.50 to 0.85 g / cm ³ , and particularly 0.50 to 0.80 g / cm ^3. Is preferable. In the case of such a high apparent density, the homogeneity is high even if it is thin, so that the molten resin filled in the cavity in the mold by injection molding stains the surface of the in-mold material including the fiber structure. It is preferable because it is suppressed from coming out.

Since the fiber structure as described above is manufactured so as to be picked up in one direction, for example, it tends to be easily heat-shrinked in the pick-up direction. The in-mold material used for the in-mold molding of the present embodiment relaxes the anisotropy of heat shrinkage of the material containing such a fiber structure before the in-mold molding.

Specifically, the residual strain accumulated in the fiber structure is eliminated by performing an annealing treatment by heat treatment before being subjected to in-mold molding. The elimination of the residual strain by the annealing treatment will be described with reference to FIG. 2, which shows the results of the examples, and will shrink significantly in a relatively short time, specifically, about 3 minutes after the start of the heat treatment, and then gradually shrink. It can be seen that it is contracting. Therefore, the heat treatment conditions for the annealing treatment are appropriately determined in consideration of the balance between the degree of elimination of such residual strain and the productivity.

Referring to FIG. 2, or T _g of the resin forming the fibrous structure, especially when heat-treated at a temperature of about 10 to 50 ° C. higher than the T _g, increased shrinkage in only about 3 minutes, then the large variation Stable without. Specifically, it can be seen that the subsequent area change rate is 2% or less. Therefore, the in-mold material containing the fiber structure subjected to such an annealing treatment has an area shrinkage rate (area shrinkage rate) when heat-treated for 10 minutes at a temperature of 10 ° C. or higher than T _{g of} the resin forming the fiber structure. It can be seen that the residual strain is sufficiently eliminated to the extent that the area change rate) is 2% or less.

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

[Example 1: Measurement of area shrinkage by annealing an artificial leather piece]
(In fineness 0.9 dtex, comprising ultrafine fibers of T _g 100 ° C. denaturation PET, apparent density 0.50 g / cm ³⁾ Artificial leather Leather with grain tone surface of thickness 0.5mm width 1000mm of I prepared the original fabric. Then, a rectangular artificial leather piece having a length of 300 mm and a width of 100 mm was cut out from the original fabric.

Then, the obtained artificial leather piece was left in a hot air dryer set at 100 ° C., 110 ° C., 130 ° C., and 150 ° C. for 5 minutes, 30 minutes, 60 minutes, and 240 minutes for heat treatment. Five pieces of artificial leather were prepared for each time at each temperature.

Then, assuming that the area of the artificial leather piece not heat-treated was 100%, the area change of the artificial leather piece after being heat-treated at 100 ° C., 110 ° C., 130 ° C., and 150 ° C. for each time and shrinking was measured. The area change is an average value of 5 sheets. A graph showing the area change with respect to the heat treatment time at each temperature is shown in FIG.

As shown in FIG. 2, it can be seen that the artificial leather piece used as the in-mold material shrank by 2% or more by any temperature of T _g or more and any time of annealing treatment. From this result, it can be seen that the annealing treatment eliminates the residual strain of the in-mold material including the fiber structure. The annealing treatment temperature was 100 ° C., which is the T _g of the ultrafine fibers of the modified PET contained in the artificial leather piece, and 110 ° C., 130 ° C., and 150 ° C., which are 10 ° C. or higher higher than the T _g . Comparing the annealing treatments, it can be seen that the shrinkage rate is remarkably increased at a temperature 10 ° C. or higher higher than T _g 100 ° C. of the ultrafine fibers of the modified PET. Further, it can be seen that the area change rate is stabilized by heating for about 5 minutes.

Further, the area change rate (area shrinkage) when the in-mold material after annealing at 100 ° C., 110 ° C., 130 ° C., and 150 ° C. is once cooled and then heat-treated at a temperature 10 ° C. higher than T _g for 10 minutes. The rates) were 1.6%, 1.0%, 0.8%, and 0.3%, respectively, and all were 2% or less.

[Example 2: In-mold molding using an annealed artificial leather piece]
In-mold molding was performed using five artificial leather pieces obtained in Example 1 that were heat-treated at each temperature for 240 minutes. Specifically, the movable side mold and the fixed side mold of the injection molding mold mounted on the electric injection molding machine (SE-180DU manufactured by Sumitomo Heavy Industries, Ltd.) are opened. A heat-treated artificial leather piece was placed on the cavity-forming surface of the movable side mold. Then, the movable side mold and the fixed side mold were molded. The cavity shape of the injection molding die was a rectangular square plate having a thickness of 1.5 mm and a length of 300 mm and a width of 100 mm.

Then, ABS resin (T _g 98 ° C./MFR: 4.2 g / 10 minutes 220 ° C.) was injected under the conditions of a resin temperature of 235 ° C., a mold temperature of 50 ° C., and an injection peak pressure of 140 MPa to fill the cavity. Then, after complete filling, the mold was opened after maintaining a cooling time of 40 seconds while applying a holding pressure of 20 MPa. Then, a laminated molded body in which an artificial leather piece was integrated on the surface of the ABS resin molded body was obtained.

Then, the amount of change in warpage due to heating of the five laminated molded products obtained at each temperature was evaluated as follows.

<Evaluation of warpage change amount>
The state of the molded laminated molded product was adjusted by leaving it in a constant temperature and humidity chamber at 23 ° C. and 50% RH for 24 hours. Then, the amount of warpage after the state adjustment was measured. Then, the laminated molded product whose warp amount was measured after the state adjustment was left in a constant temperature and humidity chamber at 70 ° C. and 95% RH for 200 hours to make the warp manifest. Then, the laminated molded product after the heat treatment was left in a constant temperature and humidity chamber at 23 ° C. and 50% RH for 1 hour to cool. Then, the amount of warpage that became apparent by the heat treatment was measured.
The amount of warpage is measured by placing the laminated molded product on a horizontal plate so as to warp upward in a convex state, and measuring from the surface of the laminated molded product arranged so as to warp in a convex state. The distance between the largest gaps was measured with a dial gauge. The average of the measured values of the five samples was taken as the amount of warpage (mm). Then, the absolute value of (warp amount after heat treatment-warp amount before heat treatment) is shown in the graph of FIG. 3 as the warp change amount.

As shown in FIG. 3, the amount of warpage of the laminated molded product in-molded using the artificial leather piece without annealing treatment was 2.90 mm, whereas the amount of warpage was 100 ° C., 110 ° C., 130 ° C., 150. The laminated molded body in-molded using the artificial leather piece annealed at ° C. had a small amount of change in warpage of 2.75 mm, 0.88 mm, 0.75 mm, and 0.75 mm, respectively. In particular, the laminated molded product obtained by using the artificial leather piece annealed at 110 ° C., 130 ° C. and 150 ° C., which is higher than 100 ° C., which is the T _g of the ultrafine fiber of the modified PET contained in the artificial leather piece, is warped. A remarkable improvement effect of the amount of change was observed.

[Example 3: In-mold molding using a preform molded body of artificial leather that has been annealed]
Used in Example 1, from raw artificial leather leather having a surface of suede thick 0.5 mm, a rectangular sheet of longitudinal 400 mm × horizontal 600mm were cut multiple sheets. Then, using the obtained sheet, vacuum pressure air molding was performed at a mold temperature of 60 ° C. and a pressing force of 300 kPa to form a box-shaped preform molded body having a length of 150 mm, a width of 300 mm, and a height of 20 mm.

When molding the preform molded product, five of the obtained rectangular sheets were annealed at 130 ° C. for 240 minutes in the state of the sheets, and then preform molding was performed. Further, among the obtained rectangular sheets, the other 5 sheets were preform-molded as they were, and then the obtained preform-molded article was annealed at 130 ° C. for 240 minutes. Further, the other five of the obtained rectangular sheets were not annealed before the preform molding or the obtained preform molded body. Each of the obtained preform molded products is referred to as a preform pre-annealed molded product, a preform post-annealed molded product, and a preform molded product without annealing treatment.

Then, from the top surface of each of the five preform pre-annealed molded bodies, post-preform annealed molded bodies, and non-annealed preform molded bodies, they are cut into a rectangular square plate shape of length 300 x width 100 mm and in-molded. Molding was performed. Specifically, the movable side mold and the fixed side mold of the injection molding mold mounted on the electric injection molding machine (SE-180DU manufactured by Sumitomo Heavy Industries, Ltd.) are opened. An artificial leather piece was placed on the cavity forming surface of the movable side type. Then, the movable side mold and the fixed side mold were molded. The cavity shape of the injection molding die was a rectangular square plate having a thickness of 1.5 mm and a length of 300 mm and a width of 100 mm.

Then, in each in-mold molding, ABS resin (T _g 87 ° C.) was injected under the conditions of a resin temperature of 235 ° C., a mold temperature of 50 ° C., and an injection peak pressure of 140 MPa to fill the cavity. Then, after complete filling, the mold was opened after maintaining a cooling time of 40 seconds while applying a holding pressure of 20 MPa. Then, a laminated molded body in which each preform molded body was integrated on the surface of the ABS resin molded body was obtained.

Then, the amount of change in warpage of each laminated molded product was evaluated in the same manner as in Example 2. The result of the amount of change in warpage is shown in the graph of FIG.

As shown in FIG. 4, the amount of change in warpage of the laminated molded product in-molded using the preform molded product without annealing treatment was 2.9 mm, whereas the amount of change in warpage was 2.9 mm, whereas the amount of change in warpage was 2.9 mm after annealing treatment in the sheet state. The amount of change in warpage of the laminated molded product in-molded using the preform pre-annealed molded product that had been reform-molded was clearly as small as 1.8 mm. Further, the amount of change in warpage of the laminated molded product in-molded by using the preform-annealed molded product, which was annealed after molding of the preform molded product, was remarkably small at 0.75 mm. From this, it can be seen that in the case of in-mold molding using the preform molded body, the effect of improving the amount of change in warpage is remarkably improved by performing the annealing treatment after molding the preform molded body.

According to the present invention, it is possible to manufacture an in-mold molded product (laminated molded product) in which an in-mold material including a fiber structure is integrated, in which the occurrence of warpage is suppressed.

1,11 In-mold material containing fiber structure 1a Material containing fiber structure before annealing treatment 2 Injection molding die 2a Movable side mold 2b Fixed side mold 3 Injection part body of injection molding machine 3a Nozzle 3b Cylinder 3c In-line Screw 4 Filling gate 5 Injection molded product 5a Molten resin 10 In-mold molded product (laminated molded product)
100 heater c cavity

Claims (7)

An in-mold material used for in-mold molding, including a fiber structure, which is heat-treated for 10 minutes at a temperature 10 ° C. higher than the glass transition temperature (Tg) of the resin forming the fibers of the fiber structure. An in-mold material characterized by an area shrinkage rate of 2% or less. The in-mold material according to claim 1, wherein the in-mold material is a preform molded body. The in-mold material according to claim 1, wherein the in-mold material is a fiber structure sheet. The in-mold material according to any one of claims 1 to 3, wherein the in-mold material is at least one selected from the group consisting of a leather-like material, a non-woven fabric, a woven fabric, a knitted fabric, and paper. Step and the glass transition temperature (Tg) of more than a temperature of the resin forming the fibers of the fiber structure by heating the pre Kimoto material fixed time residual strain without giving an external force to prepare a material containing fibrous structure after eliminating the heating, characterized in that it comprises a step of a Neil process is cooled to stop the method of in-mold material used for in-mold molding. Manufacturing said material, leather-like material, a nonwoven fabric, a woven fabric, a knitted fabric, and in-mold material according to at least one selected from the group consisting of paper 請Motomeko 5 is a preform body including material Method. The process of preparing the material including the fiber structure and
After eliminating the residual strain by heating a certain period of time before Kimoto material at the glass transition temperature (Tg) of more than a temperature of the resin forming the fibers of the fibrous structure without applying an external force, by stopping the heating forming an in-mold material is subjected to a Neil process for cooling,
A cavity is formed by molding a movable side mold and a fixed side mold. By accommodating the in-mold material in the cavity of an injection molding mold and performing injection molding, the surface of the injection molded body is formed. A method for producing a laminated molded body, which comprises a step of forming a resin laminated body in which the in-molded material is integrated.

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