JP2006264024A - Polystyrenic resin laminated foamed sheet, its manufacturing method and manufacturing method of molded product - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polystyrenic resin laminated foamed sheet capable of being accurately molded into a desired shape under a stable molding condition without producing a drawdown phenomenon at the time of molding. <P>SOLUTION: This long polystyrenic resin laminated foamed sheet is constituted by integrally laminating a polystyrenic resin non-foamed sheet layer on one side of a polystyrenic resin foamed sheet layer, which is obtained by extrusion foaming, by a coextrusion method and, when it is heated at 125°C for 150 s, the surface of the polystyrenic resin non-foamed sheet layer is shrunk in a dimensional change ratio of -45 to -15°C in its lateral direction to deform the polystyrenic resin laminated foamed sheet into an arcuate shape in its lateral direction so that the polystyrenic resin non-foamed sheet layer becomes inside. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a polystyrene resin laminated foam sheet, a method for producing the same, and a method for producing a molded product.

  Today, instant noodle containers are provided in a wide variety. Containers for packaging or cooking instant noodles are strong against impacts applied during transportation or storage, and have excellent appearance. In order to satisfy such a requirement, a material in which a polystyrene resin non-foamed sheet is laminated on one surface of a polystyrene resin foam sheet is widely used as a raw material for instant noodle containers.

  The outer surface of the instant noodle container is printed, and the printing procedure is as follows. In addition to the method of forming the original noodles, there is a method in which the raw fabric is formed into an instant noodle container shape and then printed directly on the outer surface of the instant noodle container using a curved surface printing machine.

  However, when printing is performed on the outer surface of the instant noodle container using a curved surface printing machine, depending on the state of the outer surface of the container, there has been a problem that printed characters and patterns are blurred or the printing is faint.

Therefore, in Patent Document 1, as a raw material for instant noodles, a polystyrene resin foam sheet and a non-foamed polystyrene resin film are laminated and integrated, and the polystyrene resin foam sheet is not foamed with a polystyrene resin foam sheet. A polystyrene-based resin laminated foam sheet having an average cell number of 410 to 5000 / mm ² in the range from the interface of the polystyrene-based resin film to 200 μm has been proposed.

  On the other hand, in order to obtain a container of instant noodles from the raw fabric, first, a long polystyrene-based resin laminated foam sheet is continuously supplied to a heating furnace of a molding machine, and the polystyrene-based resin laminated foam sheet is supplied in the heating furnace. After heating with the heaters arranged on both sides to soften the polystyrene resin laminated foam sheet, the polystyrene resin laminated foam sheet is continuously fed to the molding die of the molding machine and pressed into a container shape for instant noodles. By molding, a container for instant noodles can be continuously produced.

  In general, in order to mold a deep container, the heating temperature of the polystyrene resin laminated foam sheet is increased in a heating furnace in order to improve the elongation of the polystyrene resin laminated foam sheet during molding. Or measures such as increasing the heating time are taken.

  However, when the heating temperature of the polystyrene-based resin laminated foam sheet is increased, the polystyrene-based resin laminated foam sheet becomes soft, so that a phenomenon in which the polystyrene-based resin laminated foam sheet hangs down due to its own weight, that is, a so-called draw-down phenomenon easily occurs.

  When this draw-down phenomenon occurs, the distance between the polystyrene-based resin laminated foam sheet and the heater in the heating furnace becomes non-uniform between the two surfaces, resulting in uneven heating of the polystyrene-based resin laminated foam sheet, and the resulting molded product meat There has been a problem that the thickness becomes non-uniform, or a part of the polystyrene-based resin laminated foam sheet is excessively heated to deteriorate the appearance.

  Here, as is clear from the paragraph number [0029], the polystyrene-based resin laminated foam sheet disclosed in Patent Document 1 uses an extrusion laminating method to laminate and integrate a non-foamed film on one surface of the foamed sheet. It is used.

  Thus, when producing a polystyrene resin laminated foam sheet using the extrusion laminating method, the melt immediately after being extruded from the extruder on the foam sheet while unwinding the long polystyrene resin foam sheet. While the non-foamed film in a state is continuously laminated, the foamed sheet and the non-foamed film are laminated and integrated in a state in which a tension is applied in the length direction thereof, so that the obtained polystyrene-based resin laminate The foam sheet is in a state in which strain remains in the length direction.

  Therefore, when the polystyrene resin laminated foam sheet is continuously unwound and the polystyrene resin laminated foam sheet is continuously heated in the heating furnace of the molding machine, and then molded with the molding die of the molding machine, the polystyrene resin lamination The foamed sheet is shrunk with the strain being relaxed with the heating in the heating furnace, but the shrinking direction is the length direction (unwinding direction) of the polystyrene-based resin laminated foamed sheet. Even if the laminated foam sheet shrinks, the shrinkage may be absorbed by the polystyrene-based resin laminated foam sheet that is continuously unwound, and the above-described drawdown phenomenon may not be effectively prevented. It was.

  Therefore, it may be possible to leave a large strain in the length direction of the polystyrene resin laminated foam sheet so that the polystyrene resin laminated foam sheet contracts to such an extent that the drawdown phenomenon can be prevented. If the strain remains, the polystyrene-based resin laminated foam sheet is in a free state in the length direction, and the polystyrene-based resin laminated foam sheet undergoes large shrinkage deformation in the length direction, and the molding machine Another problem was that the polystyrene-based resin laminated foam sheet could not be stably molded in the molding die.

  Furthermore, a polystyrene-based resin foam sheet in which non-expanded polystyrene-based resin films are laminated and integrated is usually used after being aged at room temperature for a predetermined period after being manufactured. The amount of foaming gas remaining in the polystyrene resin foam sheet increases and decreases due to fluctuations in the aging period, and the change in the amount of foam gas causes the non-expanded polystyrene resin film on the polystyrene resin foam sheet. The state of occurrence of fine bubbles at the interface between the polystyrene resin foam sheet and the non-expanded polystyrene resin film when the laminate is integrated or when the polystyrene resin laminate foam sheet is heated for molding, or The above-mentioned shrinkage amount of the polystyrene-based resin laminated foam sheet fluctuates, so that the polystyrene-based resin laminated foam sheet Molding conditions Width molding conditions in producing et moldings on is difficult to constant even narrow, there is a problem that variations in the quality of the molded article obtained may occur.

Japanese Patent Laid-Open No. 10-16025 (claims, paragraph number [0029])

  The present invention is a polystyrene-based resin laminated foam sheet that can be molded into a desired shape under stable molding conditions without causing a drawdown phenomenon during molding, and a method for producing the polystyrene-based resin laminated foam sheet, And the manufacturing method of the molded article using this polystyrene resin laminated foam sheet is provided.

  The long polystyrene-based resin laminated foam sheet A of the present invention is formed by laminating and integrating a polystyrene-based resin non-foamed sheet layer 2 on one surface of a polystyrene-based resin foamed sheet layer 1 obtained by extrusion foaming by a coextrusion method. When it is a long polystyrene-based resin laminated foamed sheet and heated at 125 ° C. for 150 seconds, the surface of the polystyrene-based resin non-foamed sheet layer has a dimensional change rate of −45 to −15% in the width direction. It is characterized in that it is configured to be deformed in a circular arc shape in the width direction with the polystyrene-based resin non-foamed sheet layer inside.

  It does not specifically limit as polystyrene-type resin which comprises the polystyrene-type resin foam sheet 1 of the polystyrene-type resin laminated foam sheet A of this invention, For example, styrene, (alpha) -methylstyrene, vinyl toluene, chlorostyrene, ethyl styrene, Examples thereof include homopolymers of styrene monomers such as i-propylstyrene, t-butylstyrene, and dimethylstyrene, or copolymers thereof.

  In addition, the polystyrene resin is a copolymer of the styrene monomer having the styrene monomer as a main component and a vinyl monomer copolymerizable with the styrene monomer. Such vinyl monomers may include, for example, alkyl (meth) acrylates such as methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, cetyl (meth) acrylate, (meth ) Acrylonitrile, dimethyl maleate, dimethyl fumarate, diethyl fumarate, ethyl fumarate and the like.

  A polystyrene resin non-foamed sheet layer 2 is laminated and integrated on one surface of the polystyrene resin foamed sheet layer 1. As the polystyrene resin constituting the polystyrene resin non-foamed sheet layer, in addition to the polystyrene resin described above, a rubber component is added to the polystyrene resin, and the impact resistant polystyrene resin improved in impact resistance. Alternatively, it may be a mixed resin obtained by adding a polystyrene elastomer such as a styrene-butadiene-styrene copolymer to a polystyrene resin. The melt flow rate of the polystyrene resin constituting the polystyrene resin non-foamed sheet layer 2 is preferably 5 to 15 g / 10 minutes.

  Furthermore, when the thickness of the polystyrene-based resin non-foamed sheet layer 2 is thin, the mechanical strength of the polystyrene-based resin laminated foam sheet may be lowered. On the other hand, when the thickness is thick, the moldability of the polystyrene-based resin laminated foam sheet is lowered. Therefore, 60 to 200 μm is preferable, and 100 to 160 μm is more preferable.

Further, the configuration of the polystyrene-based resin foamed sheet layer 1 is not particularly limited. As shown in FIG. 1, the polystyrene-based resin foamed sheet layer 1 may have substantially the same expansion ratio as a whole. as shown in FIG. 2, the low-foamed sheet layer 11 having a density of 0.16~0.4g / cm ^3, density and the high foamed sheet layer 12 of 0.07~0.15g / cm ³ to each other Direct integration is preferred.

  This is due to the following reasons. In the polystyrene resin laminated foam sheet A of the present invention, the polystyrene resin non-foamed sheet layer 2 is laminated and integrated on one surface of the polystyrene resin foam sheet layer 1 by a coextrusion method, but is coextruded from a coextrusion die. At that time, the polystyrene-based resin non-foamed sheet layer 2 has a higher heating temperature than the polystyrene-based resin foamed sheet layer 1 because it does not contain a foaming agent and is not plasticized, thereby reducing the resin viscosity. Above, it is necessary to extrude from a coextrusion die.

  However, if the resin temperature at the time of co-extrusion is set to a temperature that matches the polystyrene-based resin non-foamed sheet layer, the viscosity of the resin constituting the polystyrene-based resin foamed sheet layer becomes too low, causing problems such as foam breakage. If the resin temperature at the time of co-extrusion is the temperature matched to the polystyrene resin foam sheet layer, the viscosity of the resin constituting the polystyrene resin non-foam sheet layer becomes too high, and the extrusion stability of the polystyrene resin non-foam sheet layer Sex is reduced.

  Therefore, when the polystyrene resin non-foamed sheet layer is laminated and integrated on one surface of the polystyrene resin foam sheet layer by coextrusion, the polystyrene resin foam sheet layer 1 is combined with the low foam sheet layer 11 and the high foam sheet layer 12. The low foam sheet layer 11 is less plasticized than the high foam sheet layer 12 by the amount of the foaming agent, and is coextruded at a higher temperature than the high foam sheet layer 12, and The amount of the foaming agent contained can be coextruded at a temperature lower than that of the polystyrene resin non-foamed sheet layer 2.

  That is, the temperature suitable for coextrusion that the low foam sheet layer 11 has is the temperature suitable for coextrusion that the high foam sheet layer 12 has and the temperature suitable for coextrusion that the polystyrene resin non-foam sheet layer 2 has. It is in between.

  By comprising in this way, the temperature difference suitable for the coextrusion between the high foam sheet layer 12 and the polystyrene resin non-foam sheet layer 2 is relieved by the low foam sheet layer 11, and each layer is co-extruded. The low-foamed sheet layer 11 and the high-foamed sheet layer 12 in the polystyrene resin laminated foamed sheet A have a low open cell ratio and excellent mechanical strength, and are particularly low foamed. The sheet layer 11 has excellent surface smoothness.

  The polystyrene-based resin non-foamed sheet layer 2 laminated and integrated on the low-foamed sheet layer 11 having excellent surface smoothness is also excellent in surface smoothness. Since the mechanical strength is strong, a printing process can be stably performed on the polystyrene-based resin non-foamed sheet layer 2.

Here, if the density of the low foamed sheet layer 11 is low, the open cell ratio of the low foamed sheet layer is increased and the mechanical strength is lowered. As a result, the printing characteristics on the polystyrene resin non-foamed sheet layer may be lowered. On the other hand, if it is high, the thickness of the low foam sheet layer becomes thin and the surface smoothness of the polystyrene resin non-foamed sheet layer decreases when trying to make the basis weight of the polystyrene resin laminated foam sheet the same. Alternatively, the temperature difference between the low foam sheet layer and the high foam sheet layer during coextrusion becomes large, and the bubbles on the high foam sheet layer side in the vicinity of the interface between the low foam sheet layer and the high foam sheet layer become continuous cells. Therefore, the mechanical strength of the polystyrene-based resin laminated foam sheet is lowered, so 0.16 to 0.4 g / cm ³ is preferable.

Further, if the density of the high foam sheet layer 12 is small, the mechanical strength of the polystyrene resin laminated foam sheet may be lowered. On the other hand, if the density is large, the basis weight of the polystyrene resin laminated foam sheet is tried to be the same. In such a case, the thickness of the highly foamed sheet layer is reduced, and the mechanical strength of the polystyrene-based resin laminated foamed sheet may be reduced. Therefore, 0.07 to 0.15 g / cm ³ is preferable.

In addition, the density of the low foam sheet layer and the high foam sheet layer in the polystyrene resin laminated foam sheet can be calculated in the following manner. First, the basis weight W (g / cm ² ) of the polystyrene-based resin laminated foam sheet A is measured, and the extrusion amount E ₀ (kg / hour) of the polystyrene-based resin non-foamed sheet layer 2 and the extrusion amount E of the low-foamed sheet layer 11 are measured. Based on the following formula, the basis weight W ₁ of the low foam sheet layer 11 and the basis weight W ₂ of the high foam sheet layer 12 are calculated from ₁ (kg / hour) and the extrusion amount E ₂ (kg / hour) of the high foam sheet layer 12. To do.
Weight per unit area of low foam sheet layer W ₁ (g / cm ² ) = W × E ₁ / (E ₀ + E ₁ + E ₂ )
Highly foamed sheet layer weight W ₂ (g / cm ² ) = W × E ₂ / (E ₀ + E ₁ + E ₂ )

Next, the low foaming thickness T ₁ of the sheet layer 11 (cm) and high foam sheet layer thickness T ₂ was measured (cm), the density D ₁ and highly foamed sheet layer having a low foam sheet layer based on the following formula it is possible to calculate the density D _2.
Density D ₁ (g / cm ³ ) = W ₁ / T _{1 of} low foam sheet layer
Density D ₂ (g / cm ³ ) = W ₂ / T _{2 of} highly foamed sheet layer

  Further, if the thickness of the entire polystyrene resin foam sheet layer 1 is thin, the mechanical strength of a molded product obtained by molding the polystyrene resin laminate foam sheet may be reduced. Since the moldability of a foam sheet may fall, 1.0-3 mm is preferable, 1.5-3 mm is more preferable, 1.8-2.8 mm is especially preferable.

  Further, if the thickness of the low foam sheet layer 11 of the polystyrene resin foam sheet layer 1 is small, the surface smoothness of the polystyrene resin non-foamed sheet layer of the polystyrene resin laminate foam sheet may be lowered. 1 mm or more is preferable and 0.2 mm or more is more preferable.

  Furthermore, when the ratio of the thickness of the low foam sheet layer 11 to the thickness of the high foam sheet layer 12 in the polystyrene resin laminated foam sheet A (thickness of the low foam sheet layer 11 / thickness of the high foam sheet layer 12) is small, polystyrene. The surface smoothness of the polystyrene resin non-foamed sheet layer of the polystyrene resin laminated foam sheet may decrease, or the mechanical strength of the polystyrene resin laminated foam sheet may decrease. Therefore, 0.08 to 0.2 is preferable.

  Moreover, if the average cell diameter in the thickness direction of the low foam sheet layer of the polystyrene resin foam sheet layer is large, the surface smoothness of the polystyrene resin non-foam sheet layer integrated on the low foam sheet layer may be reduced. Therefore, it is preferably less than 200 μm, more preferably less than 150 μm, and particularly preferably less than 120 μm.

  The average cell diameter in the thickness direction of the low foam sheet layer is calculated based on the average chord length measured according to the test method of ASTM D2842-69. Specifically, the polystyrene-based resin laminated foam sheet is cut in a direction perpendicular to the surface (thickness direction), and the central portion of the low foam sheet layer 11 on the cut surface is 17 to 17 using a scanning electron microscope. Shoot at 20x (200x in some cases).

Next, the average chord length (t) of each bubble is expressed by the following formula 1 from the number of bubbles on a straight line oriented in the thickness direction of the polystyrene-based resin laminated foam sheet having a length of 60 mm in the photograph taken. Calculate based on And the average bubble diameter D is computable by following formula 2. If the polystyrene resin laminated foam sheet has a thin low foam sheet layer and a straight line with a length of 60 mm cannot be drawn on the photograph, draw a straight line with as long a length as possible on the photograph. The average bubble diameter D is calculated by converting the length to 60 mm.
Average chord length (t) = 60 / (number of bubbles × photo magnification) Formula 1
Average bubble diameter D = t / 0.616 Equation 2

  And since the mechanical strength of a polystyrene resin laminated foam sheet may fall when the open cell ratio of the whole polystyrene resin foam sheet layer 1 is large, less than 20% is preferable.

  In addition, the open cell ratio of the whole polystyrene-type resin foam sheet layer says what was measured by the 1-1 / 2-1 atmospheric pressure method based on ASTM D-2856-87. Specifically, a polystyrene resin foam sheet layer of a polystyrene resin laminated foam sheet is cut into a plane square shape with a side of 25 mm, and a plurality of these cut pieces are stacked in the thickness direction to produce a test piece having a thickness of about 25 mm. To do. Five test pieces were prepared in this manner, and the open cell ratio of each test piece was determined by using the air comparison type hydrometer (trade name “1000 type” manufactured by Tokyo Science Co., Ltd.). The arithmetic average value is defined as the open cell ratio of the polystyrene resin foam sheet layer.

  Furthermore, when the polystyrene-based resin laminated foam sheet of the present invention is heated at 125 ° C. for 150 seconds, the surface of the polystyrene-based resin non-foamed sheet layer has a dimensional change rate of −45 to −15% in the width direction. And is deformed into an arc shape in the width direction with the polystyrene resin non-foamed sheet layer inside.

  That is, the polystyrene-based resin laminated foam sheet of the present invention is configured to shrink the polystyrene-based resin non-foamed sheet layer by heating under a predetermined condition, while maintaining the flexibility of the polystyrene-based resin foamed sheet layer. It is configured to exhibit excellent moldability.

  Therefore, as will be described later, the both ends in the width direction of the polystyrene-based resin laminated foam sheet are held by a pair of left and right holders holding a constant interval, and the distance between both ends of the polystyrene-based resin laminated foam sheet is fixed. When the polystyrene resin laminated foam sheet is heated and press-molded, the polystyrene resin laminated foam sheet has a fixed shrinkage force in the width direction of the polystyrene resin non-foamed sheet layer because the positions of both ends thereof are fixed. The polystyrene resin laminate foam sheet has a shrinkage force in the width direction, and the polystyrene resin laminate foam sheet can be reliably shrunk in the width direction to effectively prevent the drawdown phenomenon, while the polystyrene resin As described above, the shrinkage in the width direction of the laminated foam sheet is mainly caused by the shrinkage of the polystyrene resin non-foamed sheet layer. As caused by, since the secure flexibility of polystyrene resin foamed sheet layer, it is possible to accurately mold the molded article having a desired shape by press-molding a polystyrene resin foam laminates.

  Here, if the dimensional change rate in the width direction of the surface of the polystyrene resin non-foamed sheet layer 2 of the polystyrene resin laminated foam sheet A is small in shrinkage, a drawdown phenomenon at the time of molding the polystyrene resin laminated foam sheet is caused. On the other hand, if the shrinkage is large, a pair of left and right holders that hold both ends of the polystyrene resin laminated foam sheet are contracted too much in the width direction when the polystyrene resin laminated foam sheet is molded. There is a possibility that both ends of the polystyrene-based resin laminated foam sheet may come off from each other, or the tension applied in the width direction of the polystyrene-based resin laminated foam sheet becomes too large, and the polystyrene-based resin laminated foam sheet cannot be deep drawn. Therefore, it is limited to −45 to −15%. In addition, the width direction of a polystyrene-type resin laminated foam sheet means the direction orthogonal to an extrusion direction.

  Moreover, when the dimensional change rate in the extrusion direction (length direction) in the polystyrene resin non-foamed sheet layer 2 of the polystyrene resin laminated foam sheet A is too large, when the polystyrene resin laminated foam sheet is formed, Since the polystyrene-based resin laminated foam sheet may be deformed by heating and the molding of the polystyrene-based resin laminated foam sheet may become unstable, -10 to 10% is preferable.

  Here, the dimensional change rate of the surface of the polystyrene-based resin non-foamed sheet layer of the polystyrene-based resin laminated foamed sheet refers to that measured in the following manner. First, five flat square test pieces each having a side of 10 cm are cut out from a polystyrene resin laminated foam sheet so that each side is parallel to the extrusion direction or the width direction of the polystyrene resin laminated foam sheet.

  Thereafter, two straight lines connecting the central portions of the sides facing each other are drawn in a cross shape on the polystyrene-based resin non-foamed sheet layer of each test piece. Next, after leaving each test piece in an atmosphere of 125 ° C. for 150 seconds, the test piece is left at 20 ° C. for 1 hour.

Next, of the straight lines drawn on the test piece, the length L of the straight line oriented in the direction in which the dimensional change rate is desired to be measured is measured for each test piece, and the dimensional change rate is calculated for each test piece based on the following formula. The arithmetic average value of the dimensional change rate of each test piece is defined as the dimensional change rate of the surface of the polystyrene resin non-foamed sheet layer of the polystyrene resin laminated foam sheet. In addition, what is necessary is just to measure the length L of the straight line on a test piece, for example using the measurement tool made from cloth etc. which can bend along a straight line. In addition, when the dimensional change rate has a positive value, it indicates that it has expanded, and when it has a negative value, it has contracted.
Dimensional change rate (%) = 100 × (L−10) / 10

  Furthermore, on the polystyrene resin non-foamed sheet layer 2 of the polystyrene resin laminated foam sheet, a polystyrene resin sheet having a surface printed thereon may be laminated and integrated as a print layer. In addition, a general-purpose method is used as a method of laminating and integrating this print layer on the polystyrene resin non-foamed sheet layer 2. Moreover, since it is the same as that of the polystyrene resin which comprises a polystyrene resin non-foamed sheet layer as a polystyrene resin which comprises a printing layer, the description is abbreviate | omitted.

  Next, the manufacturing method of the said polystyrene-type resin laminated foam sheet is demonstrated. In the following, the case where the polystyrene-based resin foam sheet layer is composed of a low foam sheet layer and a high foam sheet layer will be described.

  First, in order to manufacture a polystyrene-based resin laminated foam sheet, as shown in FIGS. 3 and 4, a coextrusion die 6 including a joining die 61 and an annular die 62 connected to the joining die 61, ~ Third extruders 3 to 5 are prepared, and all of the three extruders 3 to 5 are connected to the merge die 61 of the same coextrusion die 6.

  Then, the polystyrene resin and the foaming agent are supplied to the first extruder 3 and the third extruder 5 and melt kneaded, while the polystyrene resin is supplied to the second extruder 4 and the foaming agent is not present or foamed. Melt-knead in the presence of a blowing agent that does not. Note that the amount of the foaming agent relative to the polystyrene resin needs to be adjusted so that the first extruder 3 is larger than the third extruder 5.

  Here, an amount of foaming agent that does not foam may be supplied to the second extruder 4 together with the polystyrene resin. However, this is not intended to foam the polystyrene resin, and the polystyrene resin is foamed. Plasticizing with an agent to lower the resin temperature during extrusion, and as close as possible to the extrusion foaming temperature of the polystyrene resin foam sheet layer 1, open cells of the polystyrene resin foam sheet layer 1, that is, the low foam sheet layer 11 This is to prevent the rate from rising.

  In addition, as said foaming agent, a general purpose thing is used, for example, aliphatic hydrocarbons, such as propane, butane, and pentane; 1,1-dichloro-1-fluoroethane (HCFC-141b), 1-chloro-1 , 1-difluoroethane (HCFC-142b), 2-chloro-1,1,1,2-tetrafluoroethane (HCFC-124), 1,1,1,2-tetrafluoroethane (HFC-134a), 1, Fluorocarbon blowing agents such as 1-difluoroethane (HFC-152a) can be mentioned, and aliphatic hydrocarbons are preferable.

  Next, a high-expandable polystyrene resin from the first extruder 3, a non-expanded polystyrene-based resin from the second extruder 4, and a low-expandable polystyrene-based resin from the third extruder 5 are combined in the coextrusion die 6. The polystyrene resin is extruded into 61, and these polystyrene resins are merged in the merging die 61, and a low foam polystyrene resin layer and a polystyrene resin non-foamed layer are formed on the outer peripheral surface of the high foam polystyrene resin layer having a circular cross section. A foamable laminate having a circular cross section laminated in layers in this order.

Then, this foamable laminate is supplied to the annular die 62 of the coextrusion die 6 so that the foamable laminate is cylindrical, and this cylindrical foamable laminate is extruded and foamed from the front end opening of the annular die 62. A foam layer obtained by extrusion foaming a highly foamable polystyrene resin is used as a high foam layer, and a foam layer obtained by extrusion foaming a low foam polystyrene resin is used as a low foam layer. A cylindrical foam is produced in which a layer, a low foam layer and a high foam layer are laminated in layers from the outside to the inside.

  At this time, the polystyrene resin non-foamed layer does not contain a foaming agent and is not plasticized by the foaming agent, while the low foamed layer and the high foamed layer are plasticized by containing the foaming agent, The high foam layer has a higher degree of plasticization than the low foam layer.

  Therefore, when the resin temperature at the time of coextrusion is the same as that of the polystyrene resin non-foamed layer, the low foamed layer and the high foamed layer have a melt viscosity that is too low by the amount plasticized by the foaming agent. Since it may occur, it is necessary to set the temperature lower than that of the polystyrene-based resin non-foamed layer.

  Therefore, when the low foamed layer and the high foamed layer are extruded from the coextrusion die, the resin temperature is set lower than the resin temperature of the polystyrene resin non-foamed layer, and the low foamed layer is extruded from the coextrusion die. The resin temperature of the low foam layer is set higher than that of the high foam layer, and the resin temperature of the low foam layer is brought close to the resin temperature of the polystyrene resin non-foamed layer. The difference in the resin temperature during extrusion from the coextrusion die is moderated by the presence of the low foam layer, and the melt viscosity when extruding from the coextrusion die between the polystyrene resin non-foam layer and the high foam layer This difference is also mitigated by the presence of the low foam layer.

  Therefore, it is possible to give a wide range of conditions when the foamable laminate is extruded and foamed from the coextrusion die, and to obtain a cylindrical foam by stably extruding and foaming the foamable laminate from the coextrusion die. In addition, this cylindrical foam has a beautifully laminated polystyrene resin non-foamed layer on a high foam layer via a low foam layer. The polystyrene resin non-foamed layer has a smooth surface. Is excellent.

  Since both the high foam layer and the low foam layer are extruded and foamed at a resin temperature suitable for each foaming, unnecessary strain is hardly generated in the high foam layer and the low foam layer during coextrusion foaming. The polystyrene-based resin foam sheet layer obtained by developing the high foam layer and the low foam layer has little distortion, is rich in flexibility, and has excellent moldability.

  Next, after gradually expanding the diameter of the cylindrical foam and supplying the cooling mandrel 7 to cool the cylindrical foam, the cylindrical foam is stretched between the inner and outer peripheral surfaces in the extrusion direction. Continuously cut and open, expand the cylindrical foam into the polystyrene resin non-foamed layer with strain remaining in the width direction, and form a sheet, and the low foamed layer is directly integrated on the high foamed layer A long polystyrene-based resin laminated foam sheet in which a polystyrene-based resin non-foamed sheet layer is directly laminated and integrated on the polystyrene-based resin foamed sheet layer is manufactured, and this long polystyrene-based resin laminated foam is produced. The sheet is continuously wound on the winding shaft. In the course of expanding the diameter of the cylindrical foam, it is preferable to blow cooling air on the inner and outer peripheral surfaces of the cylindrical foam.

  Here, in order to develop the cylindrical foam while leaving the distortion in the width direction in the polystyrene-based resin non-foamed layer, the aperture diameter of the annular die 62 of the coextrusion die 6 and the diameter of the mandrel 7 are These ratios, the shape of the annular die 62 of the coextrusion die 6 and the cooling degree of the cylindrical foam may be adjusted.

  As described above, the cylindrical foam is expanded after being extruded and foamed from a co-extrusion die, and is expanded into a polystyrene-based resin laminated foamed sheet, and is wound around a take-up shaft. By adjusting the take-up speed of the sheet to the take-up shaft and the extrusion speed from the coextrusion die, the extrusion direction (long) of the cylindrical foam and the polystyrene-based resin laminated foam sheet obtained by developing the cylindrical foam is developed. It is possible to adjust the tension applied in the vertical direction.

  And as above-mentioned, when the polystyrene-type resin laminated foam sheet A of this invention is heated on predetermined conditions, the surface of the polystyrene-type resin non-foamed sheet layer 2 will shrink | contract with a predetermined dimensional change rate, and a polystyrene type Since the resin non-foamed sheet layer 2 needs to be adjusted so as to be deformed in an arc shape in the width direction with the resin non-foamed sheet layer 2 inside, the winding speed of the polystyrene-based resin laminated foam sheet to the winding shaft, It is preferable to adjust the extrusion speed so that distortion in the extrusion direction (length direction) of the resulting polystyrene-based resin laminated foam sheet is minimized.

  In the above description, the case where the polystyrene resin foam sheet layer is composed of the low foam sheet layer and the high foam sheet layer has been described, but when the polystyrene resin foam sheet layer has the same expansion ratio as a whole, What is necessary is just to manufacture a polystyrene-type resin laminated foam sheet, without connecting the 3rd extruder 5 to the coextrusion die | dye 6. FIG.

  Next, the point which manufactures a molded article using the said polystyrene-type resin laminated foam sheet is demonstrated. First, the molding machine B will be described. As shown in FIG. 5, the molding machine B used for molding the polystyrene-based resin laminated foam sheet includes a heating furnace B1 for heating the polystyrene-based resin laminated foam sheet, and the heating furnace. And a molding die B2 for molding the polystyrene-based resin laminated foam sheet heated in B1 into a predetermined shape. The heating furnace B1 and the molding die B2 are entirely covered with a single cover so that the heated polystyrene-based resin laminated foam sheet is not unexpectedly cooled. In FIG. Omitted for convenience of explanation.

  And to the said molding machine B, the both ends of the width direction of the polystyrene-type resin laminated foam sheet supplied to this molding machine B are hold | maintained one by one, and the polystyrene-type resin laminated foam sheet A is conveyed toward the front. For this purpose, a pair of left and right holders B3 and B3 are provided. Specifically, as shown in FIGS. 5 and 6, the holder B3 has an outer periphery of an endless chain B32 spanned between sprockets B31 and B31 disposed at a predetermined interval in the front-rear direction. A large number of needle members B33, B33... Project outward from the surface. The pair of left and right holders B3 and B3 are placed at a constant distance substantially matching the width dimension of the polystyrene resin laminated foam sheet A in a direction orthogonal to the unwinding direction (length direction) of the polystyrene resin laminate foam sheet A. And are disposed so as to extend over the heating furnace B1 and the forming die B2.

  When the polystyrene-based resin laminated foam sheet A is unwound from the winding shaft and continuously supplied to the molding machine B configured as described above, the needle members B33, B33,... The both ends of the polystyrene-based resin laminated foam sheet are sequentially pierced at both ends in the width direction of the polystyrene-based resin laminated foam sheet, and the both ends of the polystyrene-based resin laminated foam sheet are held by a pair of left and right holders B3, B3, and by this pair of left and right holders B3, B3, The polystyrene resin laminated foam sheet A is continuously conveyed to the front heating furnace B1.

  When the polystyrene-based resin-laminated foam sheet is heated to a predetermined temperature in the heating zone B1 and softened, the polystyrene-based resin-laminated foam sheet contracts in the width direction due to the relaxation of the strain remaining in the polystyrene-based resin non-foamed sheet layer 2, while the polystyrene resin laminate Since both ends of the foam sheet A are held by a pair of left and right holders and the distance between the both ends is regulated so as not to shrink, the polystyrene-based resin laminated foam sheet contracts smoothly and reliably in its width direction. In addition, the drawdown phenomenon is effectively prevented.

  As described above, since the draw-down phenomenon of the polystyrene-based resin laminated foam sheet A is prevented, the heating unevenness is prevented by heating the polystyrene-based resin laminated foam sheet A uniformly from both sides in the heating furnace B1. can do.

  In addition, since the polystyrene-based resin laminated foam sheet A is configured so that distortion in the extrusion direction does not remain as much as possible, almost no deformation such as undulation in the extrusion direction (length direction) by heating in the heating furnace B1. It does not occur.

  Then, the polystyrene resin laminated foam sheet A heated to a predetermined temperature in the heating furnace B1 of the molding machine B is supplied to a forming die B2 disposed in front of the heating furnace B1 by a pair of left and right holders B3 and B3. Is done.

  Next, the polystyrene-based resin laminated foam sheet A has a desired shape by the molding die B2 while the both ends in the width direction of the polystyrene-based resin laminated foam sheet A are held by the pair of left and right holders B3 and B3. A large number of molded articles C are stably molded.

  Next, the polystyrene-based resin laminated foam sheet formed with a large number of molded products is further conveyed forward by the pair of left and right holders B3 and B3, but the front sprocket B31 in the pair of left and right holders B3 and B3, When reaching a position exceeding B31, the needle members B33, B33... Of the holders B3, B3 pierced at both ends of the polystyrene resin laminated foam sheet A are extracted from the polystyrene resin laminate foam sheet A.

  After that, the polystyrene-based resin laminated foam sheet in which a large number of molded products are molded is cut at predetermined lengths, and a plurality of molded products are obtained simultaneously by punching the molded product from the polystyrene-based resin laminated foam sheet. be able to.

  The long polystyrene-based resin laminated foam sheet of the present invention is a long shape obtained by laminating and integrating a polystyrene-based resin non-foamed sheet layer by coextrusion on one surface of a polystyrene-based resin foamed sheet layer obtained by extrusion foaming. Because of the polystyrene resin laminated foam sheet, a polystyrene resin non-foamed sheet layer is simultaneously laminated and integrated on the polystyrene resin foam sheet layer when the polystyrene resin foam sheet layer is formed. There is no need to manufacture the sheet separately, due to fluctuations in the maturation conditions of the polystyrene resin foam sheet, and fluctuations in the conditions when extruding a polystyrene resin non-foamed sheet on the polystyrene resin foam sheet, There is no room for variations in quality such as the amount of foaming agent in the foam sheet and the bubble diameter. Ming polystyrene resin laminate foam sheet has become a homogeneous.

  Furthermore, when the polystyrene-based resin laminated foam sheet of the present invention is heated at 125 ° C. for 150 seconds, the surface of the polystyrene-based resin non-foamed sheet layer has a dimensional change rate of −45 to −15% in the width direction. It is configured to shrink and deform into an arc shape with the polystyrene resin non-foamed sheet layer inside.

  Therefore, in order to continuously form a molded product using the polystyrene resin laminated foam sheet of the present invention, both ends in the width direction of the polystyrene resin laminated foam sheet are held by a pair of left and right holders, and this state is maintained. When heated and molded with a molding machine while holding, the polystyrene-based resin laminated foam sheet is held by a pair of left and right holders and the distance between both ends is held at a constant interval. When a polystyrene resin laminated foam sheet is heated by a molding machine, the entire polystyrene resin laminated foam sheet shrinks smoothly in the width direction due to the shrinkage of the polystyrene resin non-foamed sheet layer, and the drawdown phenomenon occurs in the polystyrene resin laminated foam sheet. Generation | occurrence | production can be prevented reliably and it can shape | mold correctly, after heating a polystyrene-type resin laminated foam sheet uniformly.

Further, in the above-mentioned polystyrene-based resin laminate foam sheet, a polystyrene resin foamed sheet layer, a low foamed sheet layer having a density of 0.16~0.4g / cm ^3, density of 0.07~0.15g / cm ³ The high-foamed sheet layer is directly integrated with each other, and when the polystyrene-based resin non-foamed sheet layer is laminated and integrated on the low-foamed sheet layer, the high-foamed sheet layer is generated during coextrusion. The difference in melt viscosity between the polystyrene resin non-foamed sheet layer and the polystyrene resin non-foamed sheet layer is alleviated by a low foam layer having a melt viscosity lower than that of the polystyrene resin non-foamed sheet layer and higher than that of the high foam layer. In addition, it is manufactured after smoothly absorbing the difference in melt viscosity of the three layers at the time of coextrusion.

  Therefore, the polystyrene-based resin laminated foam sheet of the present invention is excellent in lightness due to the presence of the high-foamed sheet layer, and further, the polystyrene-based resin non-foamed sheet layer laminated and integrated on the low-foamed sheet layer is In addition to being excellent in surface smoothness, it is also excellent in printing characteristics because it is stably supported by the low foam sheet layer when printing on the surface using a curved surface printing machine.

  Moreover, in the said polystyrene-type resin laminated foam sheet, when the average cell diameter of the thickness direction in a low foam sheet layer is less than 200 micrometers, and the continuous cell rate of the whole polystyrene-type resin foam sheet layer is less than 20%, it is polystyrene. The resin-based resin laminated foam sheet has superior mechanical strength, and the polystyrene-based resin non-foamed sheet layer also has superior surface smoothness.

Example 1
As the first extruder 3, a first-stage single-screw extruder having a diameter of 90 mm, a second-stage single-screw extruder having a diameter of 115 mm connected to the first-stage single-screw extruder, and A tandem type extruder consisting of A single screw extruder having a diameter of 90 mm was prepared as the second extruder 4, while a single screw extruder having a diameter of 65 mm was prepared as the third extruder 5. Further, as the coextrusion die 6, there is prepared a confluence die 61 and an annular die 62 connected to the confluence die 61, and the first to third extruders 3 are added to the confluence die 61 of the coextrusion die 6. All of ~ 5 were connected.

  Then, in the first-stage single screw extruder in the first extruder 3, 100 parts by weight of polystyrene (trade name “HRM50” manufactured by Toyo Styrene Co., Ltd.) and a particle size of 5 to 15 μm as an air conditioner in polystyrene are used. After adding 1.5 parts by weight of a master batch (trade name “DSM1401A” manufactured by Toyo Styrene Co., Ltd., talc: about 40% by weight) to which talc and a dispersant are added, the resin is melt-kneaded at 220 ° C. A high-expandable polystyrene is prepared by press-fitting 3.5 parts by weight of butane (normal butane: 65% by weight, isobutane: 35% by weight) as a foaming agent into the first-stage single-screw extruder and then melt-kneading the polystyrene resin. Next, the high-expandable polystyrene melt-kneaded by the first-stage single-screw extruder is continuously supplied to the second-stage single-screw extruder and melted and kneaded until the resin temperature reaches 148 ° C. It cooled.

  Also, impact-resistant polystyrene (trade name “HIPS, H350” manufactured by Toyo Styrene Co., Ltd., melt flow rate: 8.3 g / 10 min) was supplied to the second extruder and melt-kneaded at a resin temperature of 220 ° C. The resin temperature was later cooled to 176 ° C.

  Furthermore, 100 parts by weight of polystyrene (trade name “GPPS, HRM18” manufactured by Toyo Styrene Co., Ltd.) and talc having a particle size of 5 to 15 μm and a dispersing agent as a foam regulator are added to the third extruder. 6 parts by weight of a master batch (trade name “DSM1401A” manufactured by Toyo Styrene Co., Ltd., talc: about 40% by weight) is supplied, melted and kneaded at a resin temperature of 220 ° C., butane (normal butane: 65% by weight, isobutane: 35 1.9 parts by weight) After press-fitting 1.9 parts by weight, the mixture was melt-kneaded to obtain low-expandable polystyrene. The melt-kneaded low-expandable polystyrene was cooled to a resin temperature of 173 ° C.

  The high-expandable polystyrene from the first extruder 3 to the coextrusion die, the impact-resistant polystyrene from the second extruder 4, and the low-expandable polystyrene from the third extruder 5, respectively. The resin is extruded into the joining die 61 of the coextrusion die 6 to which 3 to 5 are connected. A foamable laminate is formed by laminating a polystyrene layer and an impact-resistant polystyrene layer in this order, and this foamable laminate is continuously supplied to the annular die 62 of the coextrusion die 6 to form a cylindrical shape. It is obtained by extruding and foaming a cylindrical foamable laminate from the tip opening of the die 62, and extruding and foaming high-expandable polystyrene as a high-expandable layer, and extruding and foaming low-expandable polystyrene. The foam layer as a low foam layer High impact polystyrene unfoamed layer, low foaming layer and high foam layer to produce a laminated cylindrical foam in layers from the outside to the inside. The amount of extrusion from the first extruder 3 was 60 kg / hour, the amount of extrusion from the second extruder 4 was 49.5 kg / hour, and the amount of extrusion from the third extruder 5 was 20.5 kg / hour. . Further, the annular die 62 of the coextrusion die 6 had a tip surface 621a diameter of the inner die 621 of 140 mm and an opening clearance of 0.55 mm.

Next, the cylindrical foam was gradually expanded in diameter while blowing a cooling air of 20 ° C. at an air volume of 0.25 m ³ / min on the outer peripheral surface and an air volume of 0.7 m ³ / min on the inner peripheral surface. Later, the cylindrical foam is continuously supplied to a cylindrical cooling mandrel 7 (diameter: 410 mm) having a constant diameter to cool the cylindrical foam, and then the cylindrical foam is inserted between the inner and outer peripheral surfaces in the extrusion direction. Continuously cut and open, the cylindrical foam is developed in the polystyrene non-foamed layer with strain remaining in the width direction to form a sheet, and the low foamed sheet layer 11 on the high foamed sheet layer 12 A long polystyrene-based resin-laminated foam sheet A in which the impact-resistant polystyrene sheet layer 2 is laminated and integrated on the low-foam sheet layer 11 in the polystyrene foam sheet layer 1 that is directly integrated is manufactured. Scaled polystyrene laminate It took continuously around the winding axis of the sheet A. Adjust the extrusion speed of the cylindrical foam and the winding speed of the polystyrene laminated foam sheet A so that almost no tension is applied to the cylindrical foam and polystyrene laminated foam sheet A in the length direction. did.

  Next, the long polystyrene laminated foam sheet A wound around the take-up shaft is unwound, and the polystyrene laminated foam sheet A is made horizontal so that the impact-resistant polystyrene sheet layer 2 is on the upper side. 5 is continuously supplied to the molding machine B shown in FIG. 5, and needle members B33 and B33 provided on the pair of left and right holders B3 and B3 are sequentially pierced at both ends in the width direction of the polystyrene laminated foam sheet, The pair of left and right holders B3 and B3 were conveyed forward at the same speed, and the polystyrene laminated foam sheets were sequentially conveyed forward and supplied to the heating furnace B1 of the molding machine B. Note that the pair of left and right holders B3 and B3 were disposed at regular intervals substantially matching the width dimension of the polystyrene laminated foam sheet over the entire length in the front-rear direction.

  Then, in the heating furnace B1, the surface temperature of the impact-resistant polystyrene sheet layer 2 is 110 ° C., and the surface temperature of the polystyrene foam sheet layer 1 (high foam sheet layer 12) is 100 ° C. Heated. Then, the polystyrene laminated foam sheet A shrinks in the width direction as a whole due to the shrinkage of the impact resistant polystyrene sheet layer 2 due to the relaxation of the strain, and the polystyrene laminated foam sheet does not cause a drawdown phenomenon or a wavy phenomenon. It was heated and softened uniformly.

  Subsequently, the polystyrene laminated foam sheet A is supplied to a forming die B2 disposed in front of the heating furnace B1 by a pair of left and right holders B3 and B3, and the polystyrene is formed by plug-assisted vacuum forming using this forming die B2. A large number of bowl-shaped molded products C were molded on the resin-based resin laminated foam sheet A. The molded product C had an opening having an inner diameter of 13.5 cm, an outer diameter of 14.5 cm, and a depth of 7.5 cm, and the impact-resistant polystyrene sheet layer 2 was on the outer side.

  Thereafter, the polystyrene laminated foam sheet A formed with a large number of molded articles C is further conveyed forward by a pair of left and right holders B3 and B3, and the front sprockets B31 and B31 in the pair of left and right holders B3 and B3 are used. At the time when it was transported to the position exceeding the upper limit, the needle members B33 and B33 of the holders B3 and B3 pierced at both ends of the polystyrene laminated foam sheet A were extracted from the polystyrene resin laminated foam sheet A.

  Next, the polystyrene laminated foam sheet A formed with a large number of molded articles C can be obtained at the same time by cutting the molded article C from the polystyrene laminated foam sheets after being cut into predetermined lengths. did it.

(Example 2)
A cage-shaped molded product was obtained in the same manner as in Example 1 except that the diameter of the tip surface 621a of the inner die 621 in the annular die 62 of the coextrusion die 6 was 125 mm and the clearance of the opening was 0.6 mm.

(Example 3)
A cage-shaped molded product was obtained in the same manner as in Example 1 except that the amount of cooling air blown onto the outer peripheral surface of the cylindrical foam was 1.2 m ³ / min.

(Comparative Example 1)
Implemented except that the diameter of the inner die in the annular die of the coextrusion die was 125 mm, the clearance of the opening was 0.6 mm, and the amount of cooling air blown to the outer peripheral surface of the cylindrical foam was 0.1 m ³ / min. A bowl-shaped molded product was obtained in the same manner as in Example 1.

(Comparative Example 2)
An attempt was made to obtain a bowl-shaped molded product in the same manner as in Example 1 except that the amount of cooling air blown to the outer peripheral surface of the cylindrical foam was 2 m ³ / min and the temperature of the cooling air was 15 ° C. However, the polystyrene laminated foam sheet contracted too much in the width direction and was detached from the holders B3 and B3, and a bowl-shaped molded product could not be obtained.

  The thickness and basis weight of the obtained polystyrene laminated foam sheet, the thickness of the impact-resistant polystyrene sheet layer (indicated as “non-foamed sheet layer” in Table 1), the open cell ratio of the entire polystyrene foam sheet layer, and the low foam sheet layer Table 1 shows the thickness, basis weight, density and average cell diameter, and the thickness, basis weight, density and average cell diameter of the highly foamed sheet layer.

  In addition, Table 2 shows the dimensional change rate of the surface of the impact-resistant polystyrene sheet layer in the obtained polystyrene laminated foam sheet.

  When the molded products obtained in each Example and Comparative Example were visually observed, the molded products of Examples 1 to 3 were formed with a uniform and accurate thickness overall, but in Comparative Example 1, Due to the occurrence of the drawdown phenomenon, the heating of the polystyrene laminated foam sheet was non-uniform, and this non-uniform heating caused a molding defect, resulting in a non-uniform thickness of the molded product.

  Further, the drawdown amount and the printing characteristics in each Example and Comparative Example were measured in the manner shown below, and the results are shown in Table 2.

(Drawdown amount)
When the polystyrene laminated foam sheet was heated with a molding machine, the maximum amount of sag of the polystyrene laminated foam sheet was taken as the drawdown amount, and judged based on the following criteria.
A: The maximum amount of sag was 30 mm or less.
X: The maximum amount of sagging exceeded 30 mm.

(Print characteristics)
Printing was performed on the outer peripheral surface of the bowl-shaped molded product using a curved surface printing machine. This print was visually observed, and the case where it was not faint was marked with ◯, and the case where it was faint was marked with ×.

It is the schematic cross section which showed an example of the elongate polystyrene type resin laminated foam sheet of this invention. It is the schematic cross section which showed another example of the elongate polystyrene-type resin laminated foam sheet of this invention. It is the schematic diagram which showed the manufacturing apparatus of the elongate polystyrene-type resin laminated foam sheet. It is the longitudinal cross-sectional view which showed an example of the coextrusion die. It is the perspective view which showed the molding machine of the elongate polystyrene-type resin laminated foam sheet. It is the expansion schematic diagram which showed a part of holder of a molding machine.

Explanation of symbols

1 Polystyrene resin foam sheet layer
11 Low foam sheet layer
12 Highly foamed sheet layer 2 Polystyrene resin non-foamed sheet layer 3 First extruder 4 Second extruder 5 Third extruder 6 Coextrusion die
61 Junction die
62 Ring die 7 Mandrel A Polystyrene resin laminated foam sheet B Molding machine
B1 furnace
B2 Molding die
B3 Holder

Claims (8)

An elongated polystyrene resin laminated foam sheet obtained by laminating and integrating a polystyrene resin non-foamed sheet layer by coextrusion on one surface of a polystyrene resin foam sheet layer obtained by extrusion foaming, at 125 ° C. When heated for 150 seconds, the surface of the polystyrene resin non-foamed sheet layer shrinks in the width direction at a dimensional change rate of −45 to −15%, and the polystyrene resin non-foamed sheet layer faces in the width direction. A long polystyrene-based resin laminated foam sheet characterized by being configured to deform into an arc shape. Polystyrene type resin foamed sheet layer, a low foamed sheet layer having a density of 0.16~0.4g / cm ^3, density of the high foamed sheet layer and directly with each other 0.07~0.15g / cm ^3, integral The polystyrene resin laminated foam sheet according to claim 1, wherein a polystyrene resin non-foamed sheet layer is laminated and integrated on the low foam sheet layer. 3. The polystyrene-based resin laminate foam according to claim 2, wherein an average cell diameter in a thickness direction in the low-foamed sheet layer is less than 200 μm, and an open cell ratio of the entire polystyrene-based resin foamed sheet layer is less than 20%. Sheet. 4. The polystyrene-based resin laminated foam sheet according to claim 1, wherein a print layer made of a polystyrene-based resin is laminated and integrated on the polystyrene-based resin non-foamed sheet layer. 5. . The polystyrene resin is supplied to the first extruder and melt-kneaded in the presence of the foaming agent, while the polystyrene resin is supplied to the second extruder and the foaming agent is in the absence of the foaming agent or does not foam. A polystyrene resin foam layer extruded from the first extruder and extruded from the second extruder from a coextrusion die that is melt-kneaded in the presence and connected together with the first and second extruders. A polystyrene foam non-foamed layer was extruded and foamed into a layer to produce a cylindrical foam. After expanding the diameter of the cylindrical foam, the cylindrical foam was cooled by supplying it to a mandrel. The cylindrical foam is opened by continuously cutting in the extruding direction, and the polystyrene resin non-foamed layer is expanded with strain remaining in the width direction, and polystyrene is spread on one surface of the polystyrene resin foam sheet layer. A polystyrene-based resin laminated foam sheet formed by laminating and integrating resin non-foamed sheet layers, and adjusting the winding speed of the polystyrene-based resin laminated foam sheet and the extrusion speed from the coextrusion die, the above-mentioned polystyrene resin laminate When the foamed sheet is heated at 125 ° C. for 150 seconds, the surface of the polystyrene resin non-foamed sheet layer shrinks in the width direction at a dimensional change rate of −45 to −15%, and the above polystyrene resin laminated foam sheet. Has a polystyrene resin non-foamed sheet layer inside, and is deformed in an arc shape in the width direction. A third extruder is connected to the coextrusion die to which the first and second extruders are connected, and the polystyrene resin is melt-kneaded in the presence of a foaming agent in the third extruder, while the first extruder The polystyrene resin foam layer extruded from the machine is a high foam layer, and the polystyrene resin foam layer extruded from the third extruder is a low foam layer having a lower foaming ratio than the high foam layer. The cylindrical foam is produced by extruding and foaming the high foam layer and the polystyrene resin non-foam layer from the coextrusion die through the low foam layer. The manufacturing method of the elongate polystyrene-type resin laminated foam sheet of description. The polystyrene resin is supplied to the first extruder and melt-kneaded in the presence of the foaming agent, while the polystyrene resin is supplied to the second extruder and the foaming agent is in the absence of the foaming agent or does not foam. From the coextrusion die that is melt-kneaded in the absence and connected to the first and second extruders together, the polystyrene resin foam layer extruded from the first extruder and the second extruder A cylindrical foam is produced by extruding and foaming the formed polystyrene-based resin non-foamed layer into a layer, and after expanding the diameter of the cylindrical foam, supplying it to a mandrel and cooling it, The cylindrical foam is opened by continuously cutting in the extruding direction, and the polystyrene resin non-foamed layer is expanded with strain remaining in the width direction on one surface of the polystyrene resin foam sheet layer. polystyrene With a polystyrene-based resin laminate foam sheet comprising a resin non-foamed sheet layer laminated integrally, by adjusting the extrusion rate from the take-up speed and co-extrusion die of the polystyrene-based resin laminate foam sheet, 150 at 125 ° C. When heated for 2 seconds, the surface of the polystyrene-based resin non-foamed sheet layer shrinks in the width direction at a dimensional change rate of −45 to −15%, and the polystyrene-based resin non-foamed sheet layer becomes the inner side of the polystyrene-based resin non-foamed sheet layer. The manufacturing process of a laminated foam sheet for producing a long polystyrene-based resin laminated foam sheet configured to be deformed in an arc shape, and both end portions in the width direction of this long polystyrene-based resin laminated foam sheet are fixed. The polystyrene-based resin laminated foam sheet is continuously fed forward by a pair of holders arranged at intervals, and the polystyrene-based resin laminated foam sheet is continuously fed forward. A heating step of supplying the len-based resin laminated foam sheet to a heating device and heating it to a predetermined temperature; and the polystyrene-based resin laminated foam sheet is continuously fed forward by the pair of holders, and the polystyrene-based resin laminated foam sheet. And a molding step of molding a molded product of a predetermined shape by supplying the molded product to a molding die while holding both ends thereof with the pair of holders. A third extruder is connected to the coextrusion die to which the first and second extruders are connected, and the polystyrene resin is melt-kneaded in the presence of a foaming agent in the third extruder, while the first extruder The polystyrene resin foam layer extruded from the machine is a high foam layer, and the polystyrene resin foam layer extruded from the third extruder is a low foam layer having a lower foaming ratio than the high foam layer. The cylindrical foam is manufactured by extruding and foaming the high-foamed layer and the polystyrene-based resin non-foamed layer from the co-extrusion die through the low foamed layer. The manufacturing method of the molded article as described in 2.

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