JP5960013B2 - Thermoplastic polyester resin foamed particles, method for producing foam molded body using the same, foam molded body, and composite foam - Google Patents

Description

  The present invention relates to foamed thermoplastic polyester resin particles, a method for producing a foamed molded product using the same, a foamed molded product, and a composite foamed product.

  Thermoplastic polyester resins have high rigidity and excellent shape stability, and have excellent properties that are not found in polyolefin resins such as polyethylene resins and polypropylene resins. Therefore, it is intended to produce a foamed molded article that is lightweight and has excellent heat resistance, heat insulation, buffering and mechanical strength by foaming a thermoplastic polyester resin.

  In-mold foam molding is an example of a method for producing a foam molded article by foaming a thermoplastic polyester resin. In-mold foam molding is a method in which thermoplastic polyester resin foam particles are filled into a mold cavity, and the thermoplastic polyester resin foam particles are heated and foamed with a heating medium such as hot water or water vapor. This is a method for producing a foamed molded article having a desired shape by heat-sealing and integrating secondary foamed particles obtained by secondary foaming of thermoplastic polyester resin foamed particles with the foaming pressure of the resin-based resin foamed particles.

  As a method for producing a foamed molded article using such in-mold foam molding, Patent Document 1 describes (1) a thermoplastic polyester-based resin in a cavity formed by closing a male mold and a female mold. Step of filling pre-expanded particles, (2) 0.02 MPa (gauge pressure) or more so that a peak showing an endotherm of 100 to 150 ° C. lower than the melting point of the thermoplastic polyester resin itself appears in the obtained foamed molded product From the step of in-mold foam molding by blowing steam of less than 0.10 MPa for 240 to 600 seconds, (3) after cooling the foam molded body, opening the male mold and the female mold and taking out the molded body A method for producing a foamed molded article of a thermoplastic polyester resin with improved heat resistance is disclosed.

  However, although the foamed molded product produced by the method for producing a thermoplastic polyester resin foamed product certainly has excellent heat resistance, water vapor is blown into the mold cavity for 240 seconds or more. There is a problem that production efficiency is low.

  Patent Document 2 discloses a foamed molded article in which thermoplastic aromatic polyester resin foam particles having a crystallinity of 16% or less are filled in a mold, and then the foam particles are heated to fuse the foam particles together. In the method for producing a foam molded article, a method for producing a foam molded article is disclosed in which the crystallinity of the surface of the obtained foam molded article is 20% or more and the crystallinity inside the foam molded article is 18% or less.

  However, the produced foamed molded article has a crystallinity of 20% or more on the surface and an internal crystallinity of 18% or less, so that the internal crystallization is insufficient, and an extremely high temperature of 180 ° C. However, it has a problem of low heat resistance at high temperatures.

Japanese Patent No. 3722727 Japanese Patent No. 4577802

  The present invention relates to a thermoplastic polyester resin foamed particle capable of producing a foamed molded article having high production efficiency and excellent heat resistance, a method for producing a foamed molded article using the same, and a thermoplastic polyester resin foamed particle. The present invention provides a foamed molded article obtained by molding and a composite foam using the foamed molded article.

  The thermoplastic polyester resin foam particles of the present invention are thermoplastic polyester resin foam particles used for in-mold foam molding, and have a half crystallization time at 120 ° C. measured by DSC of 155 to 300 seconds. It includes a plastic polyester resin.

  As said thermoplastic polyester-type resin, the half crystallization time in 120 degreeC measured by DSC (Differential scanning calorimeter, differential scanning calorimetry) should just be 155-300 seconds, for example, dicarboxylic acid and bivalent alcohol And a linear polyester-based resin obtained by copolymerization of

 Examples of the dicarboxylic acid include aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, diphenyl ether dicarboxylic acid, and diphenoxydicarboxylic acid, and terephthalic acid is preferable.

  Examples of the divalent alcohol include ethylene glycol, cyclohexanedimethanol, α-butylene glycol (1,2-butanediol), β-butylene glycol (1,3-butanediol), and tetramethylene glycol (1,4- Butanediol), 2,3-butylene glycol (2,3-butanediol), neopentyl glycol and the like, and ethylene glycol is preferred.

  In addition to the dicarboxylic acid component and the dihydric alcohol component, the thermoplastic polyester resin includes, for example, a tricarboxylic acid such as trimellitic acid, a trivalent or higher polyvalent carboxylic acid such as tetracarboxylic acid such as pyromellitic acid, and its anhydride. Products, triols such as glycerin, and trihydric or higher polyhydric alcohols such as tetraols such as pentaerythritol may be contained as constituent components.

  Specific examples of the thermoplastic polyester resin include polyethylene terephthalate, polybutylene terephthalate, a copolymer of terephthalic acid, isophthalic acid and ethylene glycol, a copolymer of terephthalic acid, ethylene glycol and neopentyl glycol, and terephthalic acid. Examples include a copolymer of an acid, ethylene glycol, and cyclohexanedimethanol, and polyethylene terephthalate is preferable. In addition, a thermoplastic polyester-type resin may be used independently, or 2 or more types may be used together.

  The thermoplastic polyester resin may be crosslinked with a crosslinking agent. As a crosslinking agent, a well-known thing is used, For example, the compound which has an acid anhydride group, a polyfunctional epoxy compound, an oxazoline compound, an oxazine compound etc. are mentioned, The compound which has an acid anhydride group is preferable. In addition, a crosslinking agent may be used independently or 2 or more types may be used together.

  The compound having an acid anhydride group is not particularly limited, and for example, it may belong to any of aromatic, alicyclic and aliphatic, and may be a halogenated acid anhydride. Examples of the compound having an acid anhydride group include pyromellitic anhydride, benzophenonetetracarboxylic dianhydride, cyclopentanetetracarboxylic dianhydride, diphenylsulfonetetracarboxylic dianhydride, and the like. In addition, the compound which has an acid anhydride group may be used independently, or 2 or more types may be used together.

  When the thermoplastic polyester resin is crosslinked with a crosslinking agent, for example, the crosslinking agent may be supplied to the extruder together with the thermoplastic polyester resin.

  It is preferable that the plant degree measured based on ASTM D6866 of a thermoplastic polyester-type resin is 5% or more. Thus, protection of the global environment can be achieved by using a thermoplastic polyester resin having a high plant degree.

  In the thermoplastic polyester resin constituting the thermoplastic polyester resin foamed particles of the present invention, the half crystallization time at 120 ° C. measured by DSC is limited to 155 to 300 seconds, preferably 155 to 290 seconds, 170 to 280 seconds are more preferable. In the present invention, the half crystallization time measured by DSC is simply referred to as “half crystallization time”.

  This is because if the half-crystallization time at 120 ° C. of the thermoplastic polyester resin constituting the thermoplastic polyester resin expanded particles is too short, the crystallization of the thermoplastic polyester resin expanded particles at the time of in-mold foam molding will cause heat. It progresses prior to the thermal fusion of the foamed thermoplastic polyester resin particles, and the thermal fusion between the secondary foamed particles obtained by secondary foaming of the thermoplastic polyester resin foamed particles decreases. In order to prevent this problem, increase the content of non-crystalline or slow-crystalline thermoplastic polyester resin in the thermoplastic polyester resin, or supply it into the mold cavity during in-mold foam molding. As a result, in the former case, the mechanical strength of the resulting foamed molded product is reduced, and in the latter case, the time required for in-mold foam molding is long. This causes another problem that the production efficiency of the foam molded article is lowered. In addition, when a foamed molded product in which the thermal expansion of secondary foamed particles obtained by secondary foaming of thermoplastic polyester resin foamed particles is insufficient is used at high temperatures, secondary foaming is caused by expansion of the secondary foamed particles. Cracks may occur at the heat fusion interface between the particles, and the foamed molded product may not be able to maintain its external shape. On the other hand, even when the thermal expansion of the secondary foamed particles obtained by secondary foaming of the thermoplastic polyester resin foamed particles is sufficient, if the degree of crystallinity is not increased, the heat resistance will be insufficient. . Therefore, in order to impart sufficient heat resistance to the foam molded article, it is necessary to sufficiently increase the crystallinity of the thermoplastic polyester resin constituting the secondary foamed particles. In order to increase the degree of crystallinity, it is necessary to lengthen the heating time, which causes a problem that the production efficiency of the foamed molded product is lowered.

  On the other hand, if the half-crystallization time at 120 ° C. of the thermoplastic polyester resin constituting the thermoplastic polyester resin expanded particles is too long, the thermoplastic polyester resin expanded particles are sufficiently crystallized during in-mold foam molding. In order to improve the heat resistance of the resulting foam molded article, it takes a long molding time. As a result, the time required for in-mold foam molding becomes longer, and the production efficiency of the foam molded article decreases. Cause another problem.

  The half crystallization time at 120 ° C. measured by DSC in the thermoplastic polyester resin constituting the thermoplastic polyester resin expanded particles refers to the time measured in the following manner.

  Specifically, using a differential scanning calorimeter device, about 6 mg of thermoplastic polyester resin expanded particles are filled so that there is no gap at the bottom of an aluminum measurement container, and the nitrogen gas flow rate is 30 ml / min. Then, alumina was used as a reference material. As heat treatment conditions, the temperature of the thermoplastic polyester resin expanded particles is increased from 30 ° C. to 290 ° C. at a temperature increase rate of 30 ° C./min, and the thermoplastic polyester resin expanded particles are held at 290 ° C. for 10 minutes. After that, the thermoplastic polyester resin expanded particles were taken out from the heating furnace and allowed to cool in air for 10 minutes. After this heat treatment, the thermoplastic polyester resin expanded particles were heated from 30 ° C. to 120 ° C. at a temperature increase rate of 30 ° C./min, and the thermoplastic polyester resin expanded particles were held at 120 ° C. for 30 minutes. The calorific value due to crystallization of the thermoplastic polyester resin at the time was measured, and a DSC curve with the horizontal axis as time as shown in FIG. 1 was obtained. In the DSC curve, a point a at which heat generation has started, a point b at which heat generation has ended (the earliest point at which the DSC curve returns to the baseline after the peak top point c), and a peak top point c of the DSC curve are specified. Note that the point a is an intersection of an extension line of the base line (a straight line portion immediately after the exothermic peak) and the DSC curve. Here, the time T elapsed from the point a to the point c is defined as “half-crystallization time of the thermoplastic polyester resin”. The half-crystallization time of the thermoplastic polyester resin can be obtained by preparing two samples of thermoplastic polyester resin foam particles and measuring the half-crystallization time of the thermoplastic polyester resin from each sample. The arithmetic mean value of the half crystallization time of each sample. In addition, as a differential scanning calorimeter apparatus, the apparatus marketed with the brand name "DSC6220 type | mold" from SII nanotechnology company can be used, for example.

  As a method for adjusting the semi-crystallization time at 120 ° C. in the thermoplastic polyester resin, a thermoplastic polyester resin having a semi-crystallization time at 140 ° C. measured by DSC of 120 seconds or more is selected, and this thermoplastic polyester And a method of crosslinking the resin with a crosslinking agent. Specifically, for example, a thermoplastic polyester resin and a crosslinking agent such as a compound having an acid anhydride group are supplied to an extruder and melt-kneaded, and the thermoplastic polyester resin is crosslinked with the crosslinking agent. The half crystallization time of the thermoplastic polyester resin can be adjusted.

  The 140 ° C. half crystallization time in the thermoplastic polyester resin is the same as that in the measuring method of the 120 ° C. half crystallization time in the thermoplastic polyester resin constituting the thermoplastic polyester resin expanded particles described above. It can be measured in the same manner except that the temperature at which the calorific value due to crystallization of the plastic polyester resin is measured is 120 ° C to 140 ° C.

  As a guideline for selecting a thermoplastic polyester resin having a half crystallization time at 140 ° C. measured by DSC of 120 seconds or more, the IV value of the thermoplastic polyester resin can be mentioned, and the IV value is 0.70. It can be easily selected from the above thermoplastic polyester resins. On the other hand, if the IV value of the thermoplastic polyester resin is too high, the load on the extruder during the extrusion foaming of the thermoplastic polyester resin becomes high, the extrusion foaming becomes unstable, and the thermoplastic polyester resin melts. Since it becomes difficult to adjust the viscosity to a value suitable for extrusion foaming, 1.05 or less is preferable. The thermoplastic polyester resin having an IV value of 0.70 to 1.05 is commercially available from Mitsui Chemicals under the trade name “SA-135” and from HONAM Petrochemical under the trade name “TB-380”, for example. Yes.

  Further, as a thermoplastic polyester resin having a plant degree of 5% or more and an IV value of 0.70 to 1.05, a trade name “BCB-80” from HONAM Petrochemical, a trade name “PW” from East West Chemical Co., Ltd. From the viewpoint of environmental compatibility, it is preferable to use a thermoplastic polyester-based resin produced using such a plant component as a raw material.

  The IV value of the thermoplastic polyester-based resin means intrinsic viscosity (Intrinsic Viscosity), and represents the rate of increase in the viscosity of the solution when a minute unit amount of the solute is dissolved in the solvent. The IV value of the thermoplastic polyester resin expanded particles refers to a value measured according to ASTM D4603.

  If the amount of the crosslinking agent that crosslinks the thermoplastic polyester resin is too small, the half crystallization time at 120 ° C. of the thermoplastic polyester resin constituting the thermoplastic polyester resin expanded particles may not be shortened. In the control of the melt tension of the resulting thermoplastic polyester resin, the degree of cross-linking is low, so the thermoplastic polyester resin cannot be increased to a melt viscosity suitable for foaming. If it is too high, the half-crystallization time at 120 ° C. of the thermoplastic polyester resin constituting the thermoplastic polyester resin expanded particles becomes too short, or the melting of the thermoplastic polyester resin due to the progress of crosslinking Viscosity increases and the extrusion load during extrusion foaming becomes too high. Since it may become difficult, 0.01-5 weight part is preferable with respect to 100 weight part of thermoplastic polyester-type resin, 0.1-1 weight part is more preferable, 0.1-0.4 weight part is Particularly preferred.

  If the residence time in the extruder of the thermoplastic polyester resin is too short, the crosslinking of the thermoplastic polyester resin by the crosslinking agent becomes insufficient, and the thermoplastic polyester resin constituting the thermoplastic polyester resin foamed particles is insufficient. It may be difficult to control the crystallization time at 120 ° C. to be long, and it may be difficult to control the thermoplastic polyester resin to a melt viscosity suitable for foaming. If it is too high, the resin viscosity increases due to the progress of cross-linking and the extrusion load during extrusion foaming becomes high, and it may be difficult to extrude with a general-purpose extruder, and the thermoplastic polyester resin is decomposed in the extruder and obtained. Since the physical properties of the foamed molded article to be obtained may be deteriorated, 5 to 30 minutes are preferable, and 5 to 20 minutes are more preferable.

  If the melting temperature of the thermoplastic polyester resin in the extruder is too low, the crosslinking of the thermoplastic polyester resin by the crosslinking agent becomes insufficient, and the thermoplastic polyester resin constituting the thermoplastic polyester resin foamed particles is used. It may be difficult to control the crystallization time at 120 ° C to be long, and it may be difficult to control the thermoplastic polyester resin so that the melt viscosity is suitable for foaming. If it is too high, crosslinking of the thermoplastic polyester resin proceeds, but the melt viscosity of the thermoplastic polyester resin at the time of extrusion becomes low, and foam breakage may be observed during foaming. When producing foamed plastic polyester resin particles, the pelletized thermoplastic polyester resin foam is extruded with a pelletizer. When, because bonding between a plurality of thermoplastic polyester resin foam particles may be generated, preferably two hundred fifty to three hundred thirty ° C., more preferably 270 to 300 ° C..

  First, an example of a production apparatus used for producing thermoplastic polyester resin expanded particles will be described. In FIG. 2, 1 is a nozzle die attached to the front end of the extruder. This nozzle mold is preferable because it can form uniform fine bubbles by extruding and foaming a thermoplastic polyester resin. As shown in FIG. 3, a plurality of nozzle outlet portions 11, 11... Are formed on the same virtual circle A at equal intervals on the front end surface 1 a of the nozzle mold 1. The nozzle mold attached to the front end of the extruder is not particularly limited as long as the thermoplastic polyester resin does not foam in the nozzle.

  The extruder is not particularly limited as long as it is a conventionally used extruder. For example, a single-screw extruder, a twin-screw extruder, and a tandem extruder in which a plurality of extruders are connected. Is mentioned.

  If the number of nozzles of the nozzle mold 1 is too small, the production efficiency of the thermoplastic polyester resin foamed particles is reduced, while if too large, the thermoplastic polyester resin extrudates extruded and foamed from the nozzles adjacent to each other 2 or 80, preferably 5 to 60, because the thermoplastic polyester resin expanded particles obtained by contacting or coalescing or cutting the thermoplastic polyester resin extrudate may be combined. More preferably, 8 to 50 are particularly preferable.

  If the diameter of the outlet 11 of the nozzle in the nozzle mold 1 is too small, the extrusion pressure may be too high and extrusion foaming may be difficult. On the other hand, if the diameter is too large, the diameter of the thermoplastic polyester resin expanded particles may be small. Since it becomes large and the filling property to a metal mold | die falls, 0.2-2 mm is preferable, 0.3-1.6 mm is more preferable, 0.4-1.2 mm is especially preferable.

  The length of the land portion of the nozzle die 1 is preferably 4 to 30 times the diameter of the outlet portion 11 in the nozzle of the nozzle die 1, and 5 to 20 times the diameter of the outlet portion 11 in the nozzle of the nozzle die 1. More preferred. This is because if the length of the land portion of the nozzle mold is too small compared to the nozzle outlet diameter of the nozzle mold, fracture may occur and stable extrusion foaming may not be possible. This is because if the length of the land portion of the mold is too large compared to the diameter of the nozzle outlet of the nozzle mold, a large pressure is applied to the nozzle mold and extrusion foaming may not be performed.

  In the portion surrounded by the nozzle outlets 11, 11,... On the front end face 1a of the nozzle mold 1, the rotary shaft 2 is disposed so as to protrude forward. 2 penetrates the front part 41a of the cooling drum 41 which comprises the cooling member 4 mentioned later, and is connected with drive members 3, such as a motor.

  Further, one or a plurality of rotary blades 5, 5... Are integrally provided on the outer peripheral surface of the rear end portion of the rotary shaft 2, and all the rotary blades 5 are nozzles when rotating. The mold 1 is always in contact with the front end face 1a. When the plurality of rotary blades 5, 5,... Are integrally provided on the rotary shaft 2, the plurality of rotary blades 5, 5,. Each is arranged. 3 shows a case where four rotary blades 5, 5,... Are integrally provided on the outer peripheral surface of the rotary shaft 2 as an example.

  As the rotary shaft 2 rotates, the rotary blades 5, 5,... Are always in contact with the front end surface 1a of the nozzle mold 1 to form nozzle outlet portions 11, 11,. The thermoplastic polyester resin extrudate that moves on the virtual circle A and is extruded from the outlet portions 11, 11... Of the nozzle is sequentially and continuously cut.

  A cooling member 4 is disposed so as to surround at least the front end of the nozzle mold 1 and the rotating shaft 2. The cooling member 4 has a front circular front portion 41a having a larger diameter than the nozzle mold 1 and a cylindrical peripheral wall portion 41b extending rearward from the outer peripheral edge of the front portion 41a. And a bottom cylindrical cooling drum 41.

  Further, a supply port 41c for supplying the cooling liquid 42 is formed in a portion of the peripheral wall portion 41b of the cooling drum 41 corresponding to the outside of the nozzle mold 1 so as to penetrate between the inner and outer peripheral surfaces. Yes. A supply pipe 41 d for supplying the cooling liquid 42 into the cooling drum 41 is connected to the outer opening of the supply port 41 c of the cooling drum 41.

  The coolant 42 is configured to be supplied obliquely forward along the inner peripheral surface of the peripheral wall portion 41b of the cooling drum 41 through the supply pipe 41d. Then, the coolant 42 spirals along the inner peripheral surface of the peripheral wall portion 41b of the cooling drum 41 due to the centrifugal force accompanying the flow velocity when being supplied from the supply pipe 41d to the inner peripheral surface of the peripheral wall portion 41b of the cooling drum 41. Go forward as you draw. Then, the coolant 42 gradually spreads in the direction perpendicular to the traveling direction while traveling along the inner peripheral surface of the peripheral wall portion 41b, and as a result, the inner surface of the peripheral wall portion 41b in front of the supply port 41c of the cooling drum 41 is increased. The peripheral surface is configured to be entirely covered with the coolant 42.

  The coolant 42 is not particularly limited as long as the thermoplastic polyester resin expanded particles can be cooled, and examples thereof include water and alcohol, but water is preferable in consideration of the treatment after use.

  A discharge port 41e is formed on the lower surface of the front end portion of the peripheral wall portion 41b of the cooling drum 41 so as to penetrate between the inner and outer peripheral surfaces. A discharge pipe 41f is formed at the outer opening of the discharge port 41e. Are connected so that the thermoplastic polyester resin expanded particles and the cooling liquid 42 can be discharged continuously.

  The thermoplastic polyester resin foamed particles are produced by extrusion foaming. For example, after a thermoplastic polyester resin and, if necessary, a crosslinking agent are supplied to an extruder and melt-kneaded in the presence of a foaming agent, the thermoplastic polyester resin is crosslinked with a crosslinking agent as necessary. The thermoplastic polyester resin extrudate is cut by the rotary blade 5 while being extruded and foamed from the nozzle mold 1 attached to the front end of the extruder to produce thermoplastic polyester resin expanded particles.

  Further, as the foaming agent, those conventionally used are used, for example, chemical foaming agents such as azodicarbonamide, dinitrosopentamethylenetetramine, hydrazoyldicarbonamide, sodium bicarbonate; propane, normal butane, Saturated aliphatic hydrocarbons such as isobutane, normal pentane, isopentane, hexane, ethers such as dimethyl ether, chlorofluorocarbons such as methyl chloride, 1,1,1,2-tetrafluoroethane, 1,1-difluoroethane, monochlorodifluoromethane, Examples thereof include physical blowing agents such as carbon dioxide and nitrogen, dimethyl ether, propane, normal butane, isobutane and carbon dioxide are preferred, propane, normal butane and isobutane are more preferred, and normal butane and isobutane are particularly preferred. In addition, a foaming agent may be used independently or 2 or more types may be used together.

  If the amount of the foaming agent supplied to the extruder is too small, the foamed thermoplastic polyester resin particles may not be foamed to the desired foaming ratio, while if too large, the foaming agent is used as the plasticizer. Since the viscoelasticity of the thermoplastic polyester resin in the molten state is excessively lowered due to the action, the foamability may be reduced and good thermoplastic polyester resin expanded particles may not be obtained. 0.1-5 weight part is preferable with respect to a weight part, 0.2-4 weight part is more preferable, 0.3-3 weight part is especially preferable.

  In addition, it is preferable that a bubble regulator is supplied to an extruder. As such a bubble regulator, polytetrafluoroethylene (PTFE) powder, polytetrafluoroethylene powder modified with an acrylic resin, talc, or the like can be used. Here, talc has a high crystallization accelerating action of the thermoplastic polyester resin, and when an excessive amount is used, the crystallization half time of the thermoplastic polyester resin may be too short. On the other hand, polytetrafluoroethylene powder modified with polytetrafluoroethylene powder or acrylic resin does not promote crystallization as much as talc, but increases the melt tension of thermoplastic polyester resin and improves extrusion foamability. It is preferable from the point that there may be an effect.

  In addition, if the amount of the air conditioner supplied to the extruder is too small, the foam of the thermoplastic polyester resin foamed particles becomes coarse, and the appearance of the obtained foamed molded product may be deteriorated, but is too large. When the thermoplastic polyester resin is extruded and foamed, foam breakage may occur and the closed cell ratio of the thermoplastic polyester resin foamed particles may be lowered. 01-5 weight part is preferable, 0.05-3 weight part is more preferable, 0.1-2 weight part is especially preferable.

  And the thermoplastic polyester-type resin extrudate extruded from the nozzle metal mold | die 1 continues to a cutting process. The thermoplastic polyester resin extrudate is cut by rotating the rotary shaft 2 and rotating the rotary blades 5, 5... Disposed on the front end surface 1 a of the nozzle mold 1, preferably at a constant rotational speed of 2000 to 10000 rpm. It is preferable to carry out by rotating with.

  All the rotary blades 5 are always rotating while being in contact with the front end face 1a of the nozzle mold 1, and the thermoplastic polyester resin extrudate extruded and foamed from the nozzle mold 1 includes the rotary blade 5 and the nozzle mold. The sheared stress generated between the nozzle 11 and the edge of the nozzle outlet 11 in the mold 1 is cut in the atmosphere at regular time intervals to form expanded thermoplastic polyester resin particles. At this time, water may be sprayed on the thermoplastic polyester resin extrudate in a range where cooling of the thermoplastic polyester resin extrudate does not become excessive.

  The thermoplastic polyester resin is prevented from foaming in the nozzle of the nozzle mold 1. The thermoplastic polyester resin is not yet foamed immediately after being ejected from the nozzle outlet 11 of the nozzle mold 1 and starts to foam after a short time has elapsed since ejection. Accordingly, the thermoplastic polyester resin extrudate is a foam that has been extruded prior to the non-foamed portion that continues from the non-foamed portion immediately after being discharged from the nozzle outlet portion 11 of the nozzle mold 1. It consists of a foaming part on the way.

  The non-foamed portion maintains its state from when it is projected from the outlet 11 of the nozzle of the nozzle mold 1 until foaming is started. The time during which the unfoamed portion is maintained can be adjusted by the resin pressure at the nozzle outlet 11 of the nozzle mold 1, the amount of foaming agent, and the like. When the resin pressure at the nozzle outlet 11 of the nozzle mold 1 is high, the thermoplastic polyester resin extrudate does not foam immediately after being extruded from the nozzle mold 1 and maintains an unfoamed state. The resin pressure at the nozzle outlet 11 of the nozzle mold 1 can be adjusted by the nozzle diameter, the extrusion amount, the melt viscosity and the melt tension of the thermoplastic polyester resin. By adjusting the amount of the foaming agent to an appropriate amount, the thermoplastic polyester resin can be prevented from foaming inside the mold, and the unfoamed portion can be reliably formed.

  Since all the rotary blades 5 cut the thermoplastic polyester resin extrudate in a state where they are always in contact with the front end face 1a of the nozzle mold 1, the thermoplastic polyester resin extrudate is a nozzle mold. The foamed thermoplastic polyester resin particles are produced by cutting at an unfoamed portion immediately after being discharged from the outlet portion 11 of one nozzle.

  Since the obtained thermoplastic polyester resin expanded particles are obtained by cutting a thermoplastic polyester resin extrudate at its unfoamed portion, there is no or no cell cross section on the surface of the cut portion. There are also a few. The entire surface of the thermoplastic polyester resin foamed particles is covered with a skin layer that has no or a slight cross section of bubbles. Therefore, the thermoplastic polyester resin foamed particles have excellent foamability without foaming gas removal, a low open cell ratio, and excellent surface heat-fusibility.

  When the thermoplastic polyester resin foam particles are used for in-mold foam molding, the surface of the thermoplastic polyester resin foam particles is formed from a skin layer that has no or only a few cell cross sections. Therefore, the heat-fusible property between the foamed particles is good, and the obtained foamed molded article has no surface unevenness and has almost no bubble cross section appearing on the surface, and has excellent appearance. Has excellent mechanical strength.

  Further, as described above, the rotary blade 5 rotates at a constant rotational speed, but the rotational speed of the rotary blade 5 is preferably 2000 to 10000 rpm, more preferably 2000 to 9000 rpm, and particularly preferably 2000 to 8000 rpm.

  This is because when the rotary blade 5 is less than 2000 rpm, the thermoplastic polyester resin extrudate cannot be reliably cut by the rotary blade 5, and the thermoplastic polyester resin foam particles are fused together or are thermoplastic. This is because the shape of the polyester resin expanded particles may be non-uniform.

  On the other hand, if the rotational speed of the rotary blade 5 exceeds 10,000 rpm, the following problems are likely to occur. The first problem is that when the cutting stress due to the rotary blade increases and the thermoplastic polyester resin foam particles are scattered from the nozzle outlet toward the cooling member, the initial speed of the thermoplastic polyester resin foam particles is increased. Will be faster. As a result, the time from when the thermoplastic polyester resin extrudate is cut until the thermoplastic polyester resin foam particles collide with the cooling member is shortened, and the foam of the thermoplastic polyester resin foam particles becomes insufficient. Thus, the expansion ratio of the thermoplastic polyester resin expanded particles may be lowered. The second problem is that the wear of the rotary blade and the rotary shaft is increased and the life of the rotary blade and the rotary shaft may be shortened.

  The thermoplastic polyester resin foam particles obtained as described above are scattered toward the cooling drum 41 simultaneously with the cutting by the cutting stress by the rotary blade 5, and are spread on the inner peripheral surface of the peripheral wall portion 41b of the cooling drum 41. Clash immediately. The thermoplastic polyester resin foamed particles continue to foam until they collide with the cooling drum 41, and the thermoplastic polyester resin foamed particles grow into a substantially spherical shape by foaming. Therefore, when filling the cavity of the mold with the thermoplastic polyester resin foamed particles and performing the foam molding in the mold, the thermoplastic polyester resin foamed particles are excellent in the filling ability of the mold cavity. The foamed thermoplastic polyester resin foam particles can be uniformly filled in the cavity, and a homogeneous foamed molded product can be obtained.

  On the other hand, the inner peripheral surface of the peripheral wall portion 41b of the cooling drum 41 is entirely covered with the cooling liquid 42, but this cooling liquid 42 is applied to the inner peripheral surface of the peripheral wall portion 41b of the cooling drum 41 through the supply pipe 41d. Along the inner peripheral surface of the peripheral wall portion 41b of the cooling drum 41 by the centrifugal force accompanying the flow velocity when being supplied obliquely forward along the supply pipe 41d to the inner peripheral surface of the peripheral wall portion 41b of the cooling drum 41. The cooling liquid 42 gradually spreads in a direction perpendicular to the traveling direction while traveling along the inner peripheral surface of the peripheral wall portion 41b, and as a result, the cooling drum 42 The inner peripheral surface of the peripheral wall portion 41b in front of the supply port 41c of 41 is in a state of being entirely covered with the coolant 42.

  As described above, after the thermoplastic polyester resin is cut by the rotary blade 5, the thermoplastic polyester resin foam particles are immediately cooled by the cooling liquid 42, so that the thermoplastic polyester resin foam particles are excessively foamed. Is prevented.

  If the temperature of the cooling liquid 42 is too low, the nozzle mold located in the vicinity of the cooling drum 41 is excessively cooled, which may adversely affect the extrusion foaming of the thermoplastic polyester-based resin. 10-40 degreeC is preferable since cooling of thermoplastic polyester-type resin expanded particle becomes inadequate.

  In the above, although the case where the manufacturing apparatus shown in FIGS. 2 and 3 was used as a method for manufacturing the thermoplastic polyester resin expanded particles was described, the present invention is not limited to the above manufacturing method. For example, (1) thermoplastic polyester After feeding the resin based resin and, if necessary, a crosslinking agent to the extruder and melt-kneading in the presence of a foaming agent to crosslink the thermoplastic polyester resin with the crosslinking agent as necessary, the front end of the extruder A strand-like thermoplastic polyester resin extrudate is produced by extrusion foaming from a nozzle mold attached to the nozzle, and after the strand-like thermoplastic polyester resin extrudate is cooled, a thermoplastic polyester resin extrusion is performed using a pelletizer or the like. A method for producing foamed thermoplastic polyester resin particles by cutting a product into particles, (2) a thermoplastic polyester resin, and if necessary A crosslinking agent is supplied to an extruder, melted and kneaded in the presence of a foaming agent, and a thermoplastic polyester resin is crosslinked with a crosslinking agent as necessary, and then thermoplastic from a T die attached to the front end of the extruder. A method for producing a polyester resin sheet, and after cooling the thermoplastic polyester resin sheet, cutting the thermoplastic polyester resin sheet into particles to produce foamed thermoplastic polyester resin particles; (3) thermoplastic polyester After feeding the resin based resin and, if necessary, a crosslinking agent to the extruder and melt-kneading in the presence of a foaming agent to crosslink the thermoplastic polyester resin with the crosslinking agent as necessary, the front end of the extruder An annular thermoplastic polyester resin extrudate is produced from a circular die attached to the cylindrical die, and the annular thermoplastic polyester resin extrudate is extruded. After continuously cutting between the inner and outer peripheral surfaces and developing an annular thermoplastic polyester resin extrudate to produce a thermoplastic polyester resin sheet, the thermoplastic polyester resin sheet is cut into particles Then, a method of producing thermoplastic polyester resin expanded particles may be used.

  If the open cell ratio of the thermoplastic polyester resin foamed particles is too high, the retention of the foaming gas will be reduced, and the foaming pressure of the thermoplastic polyester resin foamed particles during in-mold foam molding will be insufficient, so that secondary foaming will occur. Since the thermal fusion between the particles becomes insufficient and the mechanical strength and appearance of the foamed molded article may be lowered, it is preferably less than 15%, more preferably 10% or less, and particularly preferably 7% or less. . The open cell ratio of the thermoplastic polyester resin foam particles is adjusted by adjusting the extrusion foaming temperature of the thermoplastic polyester resin foam particles from the extruder, the supply amount of the foaming agent to the extruder, and the like. .

Here, the open cell ratio of the thermoplastic polyester resin expanded particles is measured in the following manner. First, a sample cup of a volumetric air comparison type hydrometer is prepared, and the total weight A (g) of the thermoplastic polyester resin expanded particles in an amount satisfying about 80% of the sample cup is measured. Next, the volume B (cm ³ ) of the entire thermoplastic polyester resin expanded particles is measured by a 1-1 / 2-atm method using a hydrometer. The volumetric air comparison type hydrometer is commercially available, for example, from Tokyo Science Co. under the trade name “1000 type”.

  Subsequently, a wire mesh container is prepared, the wire mesh container is immersed in water, and the weight C (g) of the wire mesh container in the state immersed in the water is measured. Next, after all the thermoplastic polyester resin foamed particles are put in the wire mesh container, the wire mesh container is immersed in water, and the wire mesh container and the wire mesh The weight D (g) of the total amount of the thermoplastic polyester resin expanded particles put in the container is measured.

Then, the apparent volume E (cm ³ ) of the thermoplastic polyester resin expanded particles is calculated based on the following formula, and based on the apparent volume E and the entire volume B (cm ³ ) of the thermoplastic polyester resin expanded particles. The open cell ratio of the thermoplastic polyester resin expanded particles can be calculated by the following formula. The volume of 1 g of water was 1 cm ³ .
E = A + (CD)
Open cell ratio (%) = 100 × (EB) / E

If the bulk density of the thermoplastic polyester resin foamed particles is too small, the open cell ratio of the thermoplastic polyester resin foamed particles will increase, and foaming required for the thermoplastic polyester resin foamed particles during foaming in in-mold foam molding On the other hand, if it is too large, the density of the obtained foamed molded product is increased, and there is a possibility that the characteristic of light weight which is an excellent effect of the foamed molded product cannot be fully utilized. In addition, the foamed thermoplastic polyester resin foam particles obtained are non-uniform, and the foamability of the thermoplastic polyester resin foam particles during in-mold foam molding may be insufficient. 01 to 0.7 g / cm ³ is preferable, 0.05 to 0.6 g / cm ³ is more preferable, and 0.08 to 0.5 g / cm ³ is particularly preferable. The bulk density of the thermoplastic polyester resin foamed particles can be adjusted by the resin pressure at the nozzle outlet 11 of the nozzle mold 1, the amount of foaming agent, and the like. The resin pressure at the nozzle outlet 11 of the nozzle mold 1 can be adjusted by adjusting the nozzle diameter, the amount of extrusion, and the melt viscosity of the thermoplastic polyester resin.

  In addition, the bulk density of the thermoplastic polyester resin expanded particles refers to that measured in accordance with JIS K6911: 1995 “General Test Method for Thermosetting Plastics”. That is, it can measure using the apparent density measuring device based on JISK6911, and can measure the bulk density of a thermoplastic polyester-type resin expanded particle based on a following formula.

Bulk density (g / cm ³ ) of thermoplastic polyester resin foam particles
= [Mass of measuring cylinder with sample (g) -Mass of measuring cylinder (g)]
/ [Capacity of measuring cylinder (cm ³ )]

  As described above, the entire surface of the obtained foamed thermoplastic polyester resin foamed particles is covered with a skin layer in which there are no or only a few cell cross sections, the open cell ratio is low, and the foam is expanded. Excellent gas retention.

  If the degree of crystallinity of the thermoplastic polyester resin foamed particles is too high, the heat-fusability between the foamed particles may be reduced at the time of in-mold foam molding, so it is preferably less than 15%, more preferably 10% or less. . The degree of crystallinity of the thermoplastic polyester resin expanded particles is determined by the time from when the thermoplastic polyester resin extrudate is extruded from the nozzle mold 1 until the thermoplastic polyester resin expanded particles collide with the cooling liquid 42, The temperature of the liquid 42 can be adjusted.

Here, the degree of crystallinity of the thermoplastic polyester resin foamed particles is increased at a rate of temperature increase of 10 ° C./min using a differential scanning calorimeter (DSC) according to the measurement method described in JIS K7121. However, it can be calculated by the following formula based on the heat of crystallization per mg and the heat of fusion per mg measured. ΔH ₀ means the theoretical heat of fusion in the case of 100% crystallization [complete heat of crystal melting (theoretical value)]. For example, ΔH ₀ of polyethylene terephthalate is 140.1 mJ / mg.

Crystallinity (%)
= 100 × (| heat of fusion (mJ / mg) | − | heat of crystallization (mJ / mg) |) / ΔH ₀

  The foamed thermoplastic polyester resin particles thus obtained are filled into a mold cavity, a heating medium is supplied into the mold cavity, and the thermoplastic polyester resin foam particles are heated to be thermoplastic. By foaming the polyester resin foam particles, the secondary foam particles obtained by foaming the thermoplastic polyester resin foam particles are thermally fused and integrated with each other by their foam pressure, and the thermoplastic polyester resin By increasing the crystallinity of the foamed molded article, it is possible to obtain a foamed molded article having a desired shape excellent in fusion and heat resistance. The heating medium for the thermoplastic polyester resin expanded particles filled in the mold cavity is not particularly limited, and includes hot air, hot water, etc. in addition to water vapor.

  If the gauge pressure of the water vapor supplied into the mold cavity is too low, the thermoplastic polyester resin foam particles will not be sufficiently heated, and secondary foam particles obtained by secondary foaming of the thermoplastic polyester resin foam particles. The heat resistance and mechanical strength of the resulting foamed molded product may be lowered due to insufficient heat fusion and crystallinity, and if it is too high, the thermoplastic polyester system filled in the mold cavity Out of the foamed resin particles, the foamed thermoplastic polyester resin particles on the outside expand faster than the foamed thermoplastic polyester resin particles on the inside, and the secondary foamed particles are fused together. , Water vapor does not come into contact with the thermoplastic polyester resin foam particles located on the inside, and the thermoplastic polyester resin foam particles are not sufficiently heated and foamed. , Since the heat fusion integration between the secondary expanded particles becomes insufficient, and the mechanical strength of the obtained foamed molded article may be lowered, it is preferably 0.02 MPa or more and less than 0.12 MPa, 0.05 -0.10 MPa is more preferable.

  If the time for supplying water vapor into the cavity of the mold is too short, the heating of the thermoplastic polyester resin expanded particles becomes insufficient, and the secondary expanded particles obtained by secondary expansion of the thermoplastic polyester resin expanded particles Heat fusion and increase in crystallinity may be insufficient, and the heat resistance and mechanical strength of the resulting foamed molded product may be reduced. Even if it is long, the heat resistance of the resulting foamed molded product may be reduced. In addition, the amount of water vapor required to heat the thermoplastic polyester resin foamed particles is increased, and the production efficiency of the foamed molded product may be lowered. Therefore, 20 to 120 seconds is preferable, and 30 to 90 seconds is more. preferable.

  If the temperature of the water vapor supplied into the cavity of the mold is too low, heating of the thermoplastic polyester resin expanded particles becomes insufficient, and secondary expanded particles obtained by secondary expansion of the thermoplastic polyester resin expanded particles Thermal fusion and increase in crystallinity may be insufficient, and the heat resistance and mechanical strength of the resulting foamed molded product may decrease. If it is too high, the thermoplastic polyester resin foam particles cannot withstand heating. May be shrunk to 105 to 130 ° C, more preferably 110 to 125 ° C.

  The foamed thermoplastic polyester resin particles of the present invention include a thermoplastic polyester resin having a half crystallization time of 155 to 300 seconds at 120 ° C. measured by DSC, and the foamed thermoplastic polyester resin foamed particles. The secondary foamed particles have excellent heat-fusibility and can sufficiently increase the crystallinity of the secondary foamed particles within a short time. Therefore, the foamed molded article obtained using the thermoplastic polyester resin foamed particles of the present invention has all the foamed particles constituting the foamed molded article including the secondary foamed particles constituting the inside thereof. It has a sufficient degree of crystallinity, has excellent heat resistance, and the secondary foamed particles are sufficiently heat-sealed and integrated, and has excellent mechanical strength.

  If the open cell ratio of the foamed molded product is too large, the heat resistance and mechanical strength of the foamed molded product may be lowered. Therefore, it is preferably 40% or less, more preferably 20% or less.

In addition, the open cell rate of a foaming molding is measured in the following way. First, a rectangular parallelepiped test piece having a side of 25 mm is cut out from the foam molded article, and the apparent volume F (cm ³ ) is calculated. Next, the true volume G (cm ³ ) of the test piece is measured by a 1-1 / 2-1 atmospheric pressure method using a hydrometer. The volumetric air comparison type hydrometer is commercially available, for example, from Tokyo Science Co. under the trade name “1000 type”.

Based on the apparent volume F and the true volume G (cm ³ ) of the test piece, the open cell ratio of the test piece is calculated by the following formula.
Open cell ratio (%) = 100 × (F−G) / F

  Furthermore, before the in-mold foam molding, the thermoplastic polyester resin foam particles may be further impregnated with air or an inert gas to improve the foaming power of the thermoplastic polyester resin foam particles. Thus, by improving the foaming power of the thermoplastic polyester resin foamed particles, the fusibility of the thermoplastic polyester resin foamed particles is improved at the time of in-mold foam molding, and the resulting foam molded article is a more excellent machine. Strength. Examples of the inert gas include carbon dioxide, nitrogen, helium, and argon. The gas to be impregnated into the thermoplastic polyester resin expanded particles is preferably air or nitrogen, more preferably nitrogen.

  As a method for impregnating the thermoplastic polyester resin expanded particles with air or an inert gas, for example, the thermoplastic polyester resin expanded particles are placed in an air or inert gas atmosphere having a pressure higher than normal pressure. A method of impregnating polyester resin expanded particles with air or an inert gas can be mentioned. In such a case, air or an inert gas may be impregnated before the thermoplastic polyester resin foam particles are filled in the mold, but the mold is filled after the thermoplastic polyester resin foam particles are filled in the mold. The mold may be placed in an air or inert gas atmosphere, and the thermoplastic polyester resin expanded particles may be impregnated with air or an inert gas.

  And the temperature when impregnating the thermoplastic polyester resin expanded particles with air or an inert gas is preferably 5 to 40 ° C, more preferably 10 to 30 ° C. This is because if the temperature is too low, the foamed thermoplastic polyester resin particles are cooled too much, and the foamed thermoplastic polyester resin particles cannot be sufficiently heated during in-mold foam molding, and the thermoplastic polyester resin This is because the heat-fusability between the foamed particles is lowered, and the mechanical strength of the obtained foamed molded product may be lowered. On the other hand, if the temperature is too high, the amount of air or inert gas impregnated into the thermoplastic polyester resin expanded particles is low, and sufficient foamability may not be imparted to the thermoplastic polyester resin expanded particles. At the same time, the crystallization of the thermoplastic polyester resin foam particles is promoted, the heat fusion property of the thermoplastic polyester resin foam particles is lowered, and the mechanical strength of the resulting foamed molded article may be lowered. .

  The pressure when impregnating the thermoplastic polyester resin expanded particles with air or an inert gas is preferably 0.2 to 2.0 MPa, and more preferably 0.25 to 1.5 MPa. When the inert gas is nitrogen, 0.2 to 1.5 MPa is preferable, and 0.25 to 1.2 MPa is more preferable. If the pressure is too low, the impregnation amount of air or inert gas into the thermoplastic polyester resin expanded particles is low, and sufficient foamability cannot be imparted to the thermoplastic polyester resin expanded particles, This is because the mechanical strength of the obtained foamed molded product may be lowered.

  On the other hand, if the pressure is too high, the degree of crystallinity of the thermoplastic polyester resin foam particles increases, the heat-fusibility of the thermoplastic polyester resin foam particles decreases, and the mechanical strength of the resulting foam molded article decreases. Because there are things to do.

  Furthermore, the time for impregnating the thermoplastic polyester resin expanded particles with air or inert gas is preferably 10 minutes to 72 hours, more preferably 15 minutes to 64 hours, and particularly preferably 20 minutes to 48 hours. When the inert gas is nitrogen, 20 minutes to 24 hours are preferable. This is because if the impregnation time is too short, the thermoplastic polyester resin expanded particles cannot be sufficiently impregnated with air or an inert gas. On the other hand, if the impregnation time is too long, the production efficiency of the foamed molded product is lowered.

  Thus, the thermoplastic polyester resin foam particles are impregnated with air or an inert gas at a pressure of 5 to 40 ° C. and a pressure of 0.2 to 2.0 MPa, thereby crystallizing the thermoplastic polyester resin foam particles. The foamability can be improved while suppressing the increase in the degree of conversion. Therefore, the thermoplastic polyester resin foam particles can be firmly and heat-bonded with each other with sufficient foaming force during in-mold foam molding. A foamed molded article having excellent mechanical strength can be obtained.

  After impregnating the thermoplastic polyester resin expanded particles with air or an inert gas as described above, the thermoplastic polyester resin expanded particles are pre-expanded into pre-expanded particles. You may shape | mold a foaming molding by filling in a cavity and heating and foaming a pre-expanded particle. The pre-foamed particles may be further impregnated with air or inert gas in the same manner as the method of impregnating the thermoplastic polyester resin expanded particles with air or inert gas.

  As a method of pre-foaming thermoplastic polyester resin foam particles to obtain pre-foam particles, for example, foaming is performed by heating thermoplastic polyester resin foam particles impregnated with air or inert gas to 50 to 90 ° C. And a method of producing pre-expanded particles.

  As described above, the foamed molded article obtained by in-mold foam molding using the thermoplastic polyester resin foamed particles of the present invention is excellent in heat resistance and mechanical strength, and particularly resistant to high temperatures. Since it is excellent in loadability, it can be suitably used for, for example, automobile parts, in particular, parts used near the engine, exterior materials, and the like.

  Furthermore, you may use as a composite foam by laminating | stacking and integrating a skin material on the surface of a foaming molding. The composite foam is further excellent in heat resistance and mechanical strength, and can be suitably used as a structural member constituting the main body of an automobile, an aircraft, a railway vehicle, or a ship, in addition to the above-mentioned uses.

  Examples of the skin material include a fiber reinforcing material, a metal sheet, and a synthetic resin film, and a fiber reinforcing material is preferable.

  It does not specifically limit as a metal sheet, For example, an aluminum sheet, a stainless steel sheet, an iron sheet, a steel sheet, a titanium sheet etc. are mentioned, Since it is excellent in both lightweight and mechanical strength, an aluminum sheet is preferable. The aluminum sheet includes an aluminum alloy sheet containing 50% by weight or more of aluminum. If the thickness of the metal sheet is too thin, the mechanical strength may decrease, and if it is too thick, the lightness decreases, so 0.1 to 0.5 mm is preferable, and 0.2 to 0.5 mm is more. preferable.

  The synthetic resin film is not particularly limited, and examples thereof include polyolefin resin films such as polyethylene resin films and polypropylene resin films, polyester resin films such as polyethylene terephthalate films and polycarbonate films, and acrylic resin films. .

  The fiber constituting the fiber reinforcing material is not particularly limited, and examples thereof include carbon fiber, glass fiber, aramid fiber, boron fiber, metal fiber, etc., and has excellent mechanical strength and heat resistance. Therefore, carbon fiber, glass fiber, and aramid fiber are preferable, and carbon fiber is more preferable.

  The form of the fiber reinforcement is not particularly limited. For example, a woven fabric, a knitted fabric, a nonwoven fabric, a fiber bundle (strand) in which fibers are aligned in one direction, a synthetic resin yarn such as a polyamide resin or a polyester resin, or a glass fiber yarn. And face materials formed by binding (stitching) with stitch yarns. Examples of the weaving method include plain weave, twill weave and satin weave.

  The fiber reinforcing material is (1) a multilayer surface material formed by laminating a plurality of woven fabrics, knitted fabrics or non-woven fabrics in any combination, and (2) a fiber bundle (strand) in which fibers are aligned in one direction. A plurality of face materials formed by binding (stitching) with synthetic resin yarns such as resin and polyester resin, or stitch yarns such as glass fiber yarns are overlapped so that the fiber directions of the fiber bundles are different from each other. A multi-layered surface material may be used in which the combined face materials are integrated (stitched) with synthetic resin yarns such as polyamide resin and polyester resin, or stitch yarns such as glass fiber yarns.

  The fiber reinforcement is preferably impregnated with a synthetic resin. Examples of the synthetic resin include uncured thermosetting resins and thermoplastic resins. The thermosetting resin is not particularly limited. For example, epoxy resin, unsaturated polyester resin, phenol resin, melamine resin, polyurethane resin, silicon resin, maleimide resin, vinyl ester resin, cyanate ester resin, maleimide resin and cyanide Examples include resins obtained by prepolymerization of acid ester resins, and epoxy resins and vinyl ester resins are preferred because of excellent heat resistance, elastic modulus, and chemical resistance. The thermosetting resin may contain additives such as a curing agent and a curing accelerator. In addition, a thermosetting resin may be used independently or 2 or more types may be used together.

  The thermoplastic resin is not particularly limited, and examples thereof include polyolefin resins such as polyethylene resins and polypropylene resins, and acrylic resins.

  If the content of the synthetic resin in the fiber reinforcement is too small, the bonds between the fibers constituting the fiber reinforcement are weakened, the mechanical strength of the resulting composite may be reduced, and if too much Since the amount of the synthetic resin present between the fibers constituting the fiber reinforcement becomes too large, the mechanical strength of the fiber reinforcement is lowered, and the mechanical strength of the resulting composite may be lowered. 20 to 70% by weight is preferable, and 30 to 60% by weight is more preferable.

  The method of impregnating the fiber reinforcement with the synthetic resin is not particularly limited. For example, (1) a method of immersing the fiber reinforcement in the synthetic resin and impregnating the fiber reinforcement with the synthetic resin, (2) Examples thereof include a method in which a synthetic resin is applied to a fiber reinforcement and the fiber reinforcement is impregnated with the synthetic resin.

  The method of laminating and integrating the skin material on the surface of the foam molded body is not particularly limited. For example, (1) the method of laminating and integrating the skin material on the surface of the foam molded body via an adhesive, (2) A method of laminating a fiber reinforcing material impregnated with a thermoplastic resin on the surface of a foam molded article, and laminating and integrating the fiber reinforcing material on the surface of the foam molded article using the thermoplastic resin impregnated in the fiber reinforcing material as a binder. (3) A fiber reinforcing material impregnated with an uncured thermosetting resin is laminated on the surface of the foam molded article, and the thermosetting resin impregnated in the fiber reinforcing material is used as a binder, A method of stacking and integrating a fiber reinforcement on the surface of the foamed molded body, and (4) arranging a heated and softened skin material on the surface of the foamed molded body, and placing the skin material on the surface of the foamed molded body By pressing the outer skin material as needed Examples include a method of laminating and integrating on the surface of the foamed molded product while deforming along the surface, and the foamed molded product has excellent load resistance in a high temperature environment. Therefore, the method (4) is also suitable. Can be used.

  The foamed thermoplastic polyester resin particles of the present invention include a thermoplastic polyester resin having a half crystallization time of 155 to 300 seconds at 120 ° C. measured by DSC, and the foamed thermoplastic polyester resin foamed particles. The secondary foamed particles have excellent heat-fusibility and can sufficiently increase the crystallinity of the secondary foamed particles within a short time.

  Therefore, according to the thermoplastic polyester resin foamed particles of the present invention, a foamed molded article having excellent heat resistance and mechanical strength can be produced in a short time.

It is the graph which showed an example of the DSC curve for calculating the half crystallization time in 120 degreeC of a thermoplastic polyester-type resin. It is the schematic cross section which showed an example of the manufacturing apparatus of a thermoplastic polyester-type resin expanded particle. It is the schematic diagram which looked at the multi-nozzle mold from the front.

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

Example 1
The manufacturing apparatus shown in FIGS. 2 and 3 was used. First, polyethylene terephthalate (trade name “PW-1” manufactured by East West Chemical Co., Ltd., semi-crystallization time at 140 ° C .: 134 seconds, plant degree: 15%, melting point: 248 ° C., IV value: 0.76) 100 parts by weight Then, a polyethylene terephthalate composition containing 0.72 parts by weight of talc and 0.2 parts by weight of pyromellitic anhydride was supplied to a single screw extruder having a diameter of 65 mm and an L / D ratio of 35, and melt kneaded at 290 ° C. did.

  Subsequently, from the middle of the extruder, butane composed of 35% by weight of isobutane and 65% by weight of normal butane was pressed into the molten polyethylene terephthalate composition so as to be 0.7 parts by weight with respect to 100 parts by weight of polyethylene terephthalate. And uniformly dispersed in the polyethylene terephthalate composition.

  Thereafter, the polyethylene terephthalate composition in a molten state was cooled to 280 ° C. at the front end of the extruder, and then the polyethylene terephthalate composition was extruded and foamed from each nozzle of the multi-nozzle mold 1 attached to the front end of the extruder. . The residence time of the polyethylene terephthalate composition in the extruder was 20 minutes.

  The multi-nozzle mold 1 has 20 nozzles having an outlet portion 11 having a diameter of 1 mm, and all the outlet portions 11 of the nozzle are assumed to have a diameter of 139 on the front end face 1a of the multi-nozzle die 1. It was arranged on a virtual circle A of 5 mm at regular intervals.

  Then, two rotary blades 5 are integrally provided on the outer peripheral surface of the rear end portion of the rotary shaft 2 with a phase difference of 180 ° in the circumferential direction of the rotary shaft 2. It was configured to move on the virtual circle A while always in contact with the front end face 1a of the mold 1.

Further, the cooling member 4 includes a cooling drum 41 including a front circular front part 41a and a cylindrical peripheral wall part 41b extending rearward from the outer peripheral edge of the front part 41a and having an inner diameter of 320 mm. It was. The cooling water 42 at 20 ° C. was supplied into the cooling drum 41 through the supply pipe 41d and the supply port 41c of the cooling drum 41. The volume in the cooling drum 41 was 17684 cm ³ .

  The cooling water 42 is spirally drawn along the inner peripheral surface of the peripheral wall portion 41b of the cooling drum 41 by the centrifugal force accompanying the flow velocity when being supplied from the supply pipe 41d to the inner peripheral surface of the peripheral wall portion 41b of the cooling drum 41. The cooling liquid 42 gradually spreads in the direction perpendicular to the traveling direction while traveling along the inner peripheral surface of the peripheral wall portion 41b, and as a result, the supply port 41c of the cooling drum 41 The inner peripheral surface of the more peripheral wall portion 41b was in a state of being entirely covered with the coolant 42.

  The rotating blade 5 disposed on the front end face 1a of the multi-nozzle mold 1 is rotated at a rotational speed of 2500 rpm, and the polyethylene terephthalate extrudate extruded and foamed from the outlet portion 11 of each nozzle of the multi-nozzle mold 1 Was cut with a rotary blade 5 to produce substantially spherical polyethylene terephthalate expanded particles. The polyethylene terephthalate extrudate was composed of an unfoamed portion immediately after being extruded from the nozzle of the multi-nozzle mold 1 and a foamed portion in the course of foaming continuous with the unfoamed portion. The polyethylene terephthalate extrudate was cut at the open end of the outlet portion 11 of the nozzle, and the polyethylene terephthalate extrudate was cut at the unfoamed portion.

  In the production of the above-mentioned polyethylene terephthalate expanded particles for in-mold foam molding, first, the rotating shaft 2 was not attached to the multi-nozzle mold 1 and the cooling member 4 was retracted from the multi-nozzle mold 1. In this state, the polyethylene terephthalate extrudate is extruded and foamed from an extruder, and the polyethylene terephthalate extrudate immediately after being extruded from the nozzle of the multi-nozzle mold 1 and in the process of foaming continuous to the unfoamed portion. It confirmed that it consisted of a foaming part. Next, after attaching the rotating shaft 2 to the multi-nozzle mold 1 and disposing the cooling member 4 at a predetermined position, the rotating shaft 2 is rotated, and the polyethylene terephthalate extrudate is rotated at the opening end of the outlet portion 11 of the nozzle. 5 was cut to produce polyethylene terephthalate expanded particles.

  The polyethylene terephthalate foamed particles are blown outward or forward by the cutting stress of the rotary blade 5, and the flow of the cooling water 42 flows into the cooling water 42 flowing along the inner surface of the cooling drum 41 of the cooling member 4. The polyethylene terephthalate foamed particles entered the cooling water 42 and immediately cooled as they collided with the surface of the cooling water 42 so as to follow the cooling water 42 from the upstream side to the downstream side.

  The cooled polyethylene terephthalate expanded particles were discharged together with the cooling water 42 through the discharge port 41e of the cooling drum 41, and then separated from the cooling water 42 by a dehydrator.

  About the polyethylene terephthalate which comprises the obtained polyethylene-terephthalate expanded particle, when the half crystallization time in 120 degreeC was measured by DSC, it was 172 second.

The polyethylene terephthalate expanded particles had an open cell ratio of 5%, a bulk density of 0.10 g / cm ³ , and a crystallinity of 5%.

  An in-mold foam molding machine equipped with molds (male mold and female mold) was prepared. In a state where the male mold and the female mold are clamped, a rectangular parallelepiped cavity having an internal dimension of 300 mm in length, 400 mm in width, and 20 mm in height is formed between the male and male molds.

  The mold cavity was filled with polyethylene terephthalate foam particles in the mold cavity of the in-mold foam molding machine. Then, after supplying water vapor of 112 ° C. with a gauge pressure of 0.05 MPa from the male mold side into the mold cavity for 20 seconds, the gauge pressure of 0.05 MPa from the female mold side into the mold cavity. Of 112 ° C. was supplied over 10 seconds. Thereafter, water vapor of 112 ° C. with a gauge pressure of 0.05 MPa is supplied over 30 seconds from both sides of the male and female molds into the mold cavity, and the polyethylene terephthalate foamed particles are heated and subjected to secondary foaming. The secondary foamed particles obtained by secondary foaming of the terephthalate foamed particles were heat-sealed and integrated with each other by these foaming pressures to obtain a rectangular solid foam product having a length of 300 mm × width of 400 mm × height of 20 mm. .

  Next, cooling water was supplied into the mold cavity to cool the foam molded article, and then the cavity was opened to obtain a foam molded article. The obtained foamed molded article had no cracks or swelling, and the foamed molded article had a beautiful form.

(Example 2)
Foam molded body in the same manner as in Example 1 except that the gauge pressure of water vapor supplied into the mold cavity was all set to 0.10 MPa and the temperature of water vapor was all set to 120 ° C. Got. The obtained foamed molded article had no cracks or swelling, and the foamed molded article had a beautiful form.

Example 3
At the time of foam molding in the mold, 112 ° C water vapor with a gauge pressure of 0.05 MPa was supplied from the male mold side into the mold cavity for 30 seconds, and the gauge was inserted into the mold cavity from the female mold side. Steam of 112 ° C. with a pressure of 0.05 MPa was supplied over 30 seconds, and steam at 112 ° C. with a gauge pressure of 0.05 MPa was supplied into the mold cavity from both sides of the male and female molds over 60 seconds. A foamed molded article was obtained in the same manner as in Example 1 except that. The obtained foamed molded article had no cracks or swelling, and the foamed molded article had a beautiful form.

Example 4
As polyethylene terephthalate, polyethylene terephthalate (trade name “SA-135” manufactured by Mitsui Chemicals, Ltd., semi-crystallization time at 140 ° C .: 306 seconds, plant degree: 0%, melting point: 247 ° C., IV value: 0.88) is used. In addition, polyethylene terephthalate expanded particles were obtained in the same manner as in Example 1 except that the polyethylene terephthalate composition was melt-kneaded at 285 ° C. in a single screw extruder.

  About the polyethylene terephthalate which comprises the obtained polyethylene terephthalate expanded particle, when the half crystallization time in 120 degreeC was measured by DSC, it was 155 seconds.

The polyethylene terephthalate expanded particles had an open cell ratio of 6%, a bulk density of 0.12 g / cm ³ , and a crystallinity of 6%.

  An in-mold foam molding machine equipped with molds (male mold and female mold) was prepared. In a state where the male mold and the female mold are clamped, a rectangular parallelepiped cavity having an internal dimension of 300 mm in length, 400 mm in width, and 20 mm in height is formed between the male and male molds.

  The mold cavity was filled with polyethylene terephthalate foam particles in the mold cavity of the in-mold foam molding machine. Thereafter, 120 ° C. water vapor with a gauge pressure of 0.10 MPa is supplied from the male mold side into the mold cavity for 20 seconds, and then the gauge pressure is 0.10 MPa from the female mold side into the mold cavity. Of 120 ° C. was supplied over 10 seconds. Thereafter, water vapor of 120 ° C. with a gauge pressure of 0.10 MPa is supplied over 30 seconds from both sides of the male and female molds into the mold cavity, and the polyethylene terephthalate foamed particles are heated and subjected to secondary foaming. The secondary foamed particles obtained by secondary foaming of the terephthalate foamed particles were heat-sealed and integrated with each other by these foaming pressures to obtain a rectangular solid foam product having a length of 300 mm × width of 400 mm × height of 20 mm. .

  Next, cooling water was supplied into the mold cavity to cool the foam molded article, and then the cavity was opened to obtain a foam molded article. The obtained foamed molded article had no cracks or swelling, and the foamed molded article had a beautiful form.

(Example 5)
At the time of foam molding in the mold, 112 ° C water vapor with a gauge pressure of 0.05 MPa was supplied from the male mold side into the mold cavity for 30 seconds, and the gauge was inserted into the mold cavity from the female mold side. Steam of 112 ° C. with a pressure of 0.05 MPa was supplied over 30 seconds, and steam at 112 ° C. with a gauge pressure of 0.05 MPa was supplied into the mold cavity from both sides of the male and female molds over 60 seconds. A foamed molded article was obtained in the same manner as in Example 4 except that. The obtained foamed molded article had no cracks or swelling, and the foamed molded article had a beautiful form.

(Example 6)
1 weight of polytetrafluoroethylene powder modified with acrylic resin instead of talc (acrylic modified PTFE powder, trade name “Methbrene A-3000” manufactured by Mitsubishi Rayon Co., Ltd., content of polytetrafluoroethylene component: 20% by weight) Polyethylene terephthalate foamed particles were obtained in the same manner as in Example 5 except that the parts were used.

  About the polyethylene terephthalate which comprises the obtained polyethylene-terephthalate expanded particle, when the half crystallization time in 120 degreeC was measured by DSC, it was 246 second.

The polyethylene terephthalate expanded particles had an open cell ratio of 6%, a bulk density of 0.12 g / cm ³ , and a crystallinity of 6%.

  Using the obtained polyethylene terephthalate foamed particles, a foam molded article was obtained in the same manner as in Example 5. The obtained foamed molded article had no cracks or swelling, and the foamed molded article had a beautiful form.

(Example 7)
As polyethylene terephthalate, polyethylene terephthalate (trade name “BCB-80” manufactured by HONAM Petrochemical, semi-crystallization time at 140 ° C .: 408 seconds, plant degree: 28%, melting point: 247 ° C., IV value: 0.83) is used. In the same manner as in Example 1 except that 0.24 parts by weight of pyromellitic anhydride was used instead of 0.2 parts by weight, expanded polyethylene terephthalate particles were obtained.

  About the polyethylene terephthalate which comprises the obtained polyethylene terephthalate expanded particle, when the half crystallization time in 120 degreeC was measured by DSC, it was 252 second.

The polyethylene terephthalate expanded particles had an open cell ratio of 5%, a bulk density of 0.11 g / cm ³ , and a crystallinity of 5%.

  An in-mold foam molding machine equipped with molds (male mold and female mold) was prepared. In a state where the male mold and the female mold are clamped, a rectangular parallelepiped cavity having an internal dimension of 300 mm in length, 400 mm in width, and 20 mm in height is formed between the male and male molds.

  The mold cavity was filled with polyethylene terephthalate foam particles in the mold cavity of the in-mold foam molding machine. After that, after supplying 112 ° C. water vapor with a gauge pressure of 0.05 MPa from the male mold side into the mold cavity for 30 seconds, the gauge pressure of 0.05 MPa from the female mold side into the mold cavity. Of 112 ° C. was supplied over 30 seconds. Thereafter, water vapor of 112 ° C. with a gauge pressure of 0.05 MPa is supplied over 30 seconds from both sides of the male and female molds into the mold cavity, and the polyethylene terephthalate foamed particles are heated and subjected to secondary foaming. The secondary foamed particles obtained by secondary foaming of the terephthalate foamed particles were heat-sealed and integrated with each other by these foaming pressures to obtain a rectangular solid foam product having a length of 300 mm × width of 400 mm × height of 20 mm. .

  Next, cooling water was supplied into the mold cavity to cool the foam molded article, and then the cavity was opened to obtain a foam molded article. The obtained foamed molded article had no cracks or swelling, and the foamed molded article had a beautiful form.

(Example 8)
1 weight of polytetrafluoroethylene powder modified with acrylic resin instead of talc (acrylic modified PTFE powder, trade name “Methbrene A-3000” manufactured by Mitsubishi Rayon Co., Ltd., content of polytetrafluoroethylene component: 20% by weight) Polyethylene terephthalate foamed particles were obtained in the same manner as in Example 7 except that the parts were used.

  About the polyethylene terephthalate which comprises the obtained polyethylene terephthalate expanded particle, when the half crystallization time in 120 degreeC was measured by DSC, it was 298 second.

The polyethylene terephthalate expanded particles had an open cell ratio of 5%, a bulk density of 0.11 g / cm ³ , and a crystallinity of 4%.

  Using the obtained polyethylene terephthalate foamed particles, a foam molded article was obtained in the same manner as in Example 7. The obtained foamed molded article had no cracks or swelling, and the foamed molded article had a beautiful form.

Example 9
As polyethylene terephthalate, polyethylene terephthalate (trade name “BCB-80” manufactured by HONAM Petrochemical, semi-crystallization time at 140 ° C .: 408 seconds, plant degree: 28%, melting point: 247 ° C., IV value: 0.83) 75 weight Parts and polyethylene terephthalate (copolymer, trade name “MA-1344” manufactured by Unitika Ltd., semi-crystallization time at 140 ° C .: 330 seconds, plant degree: 0%, melting point: 231 ° C., IV value: 0.72,) 25 weight Part, polytetrafluoroethylene powder modified with an acrylic resin instead of talc (acrylic modified PTFE powder, trade name “METABRENE A-3000” manufactured by Mitsubishi Rayon Co., Ltd.), content of polytetrafluoroethylene component: 20 wt%) Same as Example 7 except that 1 part by weight was used Thus, polyethylene terephthalate expanded particles were obtained.

  About the polyethylene terephthalate which comprises the obtained polyethylene-terephthalate expanded particle, when the half crystallization time in 120 degreeC was measured by DSC, it was 300 seconds.

The polyethylene terephthalate expanded particles had an open cell ratio of 6%, a bulk density of 0.10 g / cm ³ , and a crystallinity of 4%.

  Using the obtained polyethylene terephthalate foamed particles, a foam molded article was obtained in the same manner as in Example 7. The obtained foamed molded article had no cracks or swelling, and the foamed molded article had a beautiful form.

(Example 10)
Expanded polyethylene terephthalate particles were obtained in the same manner as in Example 9 except that pyromellitic anhydride was changed to 0.28 parts by weight instead of 0.24 parts by weight.

  About the polyethylene terephthalate which comprises the obtained polyethylene terephthalate expanded particle, when the half crystallization time in 120 degreeC was measured by DSC, it was 270 second.

The polyethylene terephthalate expanded particles had an open cell ratio of 5%, a bulk density of 0.11 g / cm ³ , and a crystallinity of 6%.

  Using the obtained polyethylene terephthalate expanded particles, at the time of in-mold foam molding, water vapor of 112 ° C. with a gauge pressure of 0.05 MPa was supplied into the cavity of the mold from the male mold side over 20 seconds, 112 ° C. water at a gauge pressure of 0.05 MPa was supplied into the cavity of the mold for 10 seconds from the female mold side, and 112 ° C. at a gauge pressure of 0.05 MPa from both sides of the male and female molds into the cavity of the mold. A foamed molded article was obtained in the same manner as in Example 7 except that the water vapor was supplied over 30 seconds. The obtained foamed molded article had no cracks or swelling, and the foamed molded article had a beautiful form.

(Example 11)
As polyethylene terephthalate, polyethylene terephthalate (trade name “BCB-80” manufactured by HONAM Petrochemical, semi-crystallization time at 140 ° C .: 408 seconds, plant degree: 28%, melting point: 247 ° C., IV value: 0.83) 75 weight Parts and polyethylene terephthalate (copolymer, trade name “MA-1344” manufactured by Unitika Ltd., semi-crystallization time at 140 ° C .: 330 seconds, IV value: 0.72, melting point: 231 ° C., plant degree: 0%) 25 parts by weight In the same manner as in Example 7 except that 0.28 parts by weight of pyromellitic anhydride was used instead of 0.24 parts by weight, expanded polyethylene terephthalate particles were obtained.

  About the polyethylene terephthalate which comprises the obtained polyethylene terephthalate expanded particle, when the half crystallization time in 120 degreeC was measured by DSC, it was 180 seconds.

The polyethylene terephthalate expanded particles had an open cell ratio of 3%, a bulk density of 0.09 g / cm ³ , and a crystallinity of 5%.

  Using the obtained polyethylene terephthalate foamed particles, a foam molded article was obtained in the same manner as in Example 7. The obtained foamed molded article had no cracks or swelling, and the foamed molded article had a beautiful form.

(Comparative Example 1)
Polyethylene terephthalate (copolymer, trade name “MA-1344” manufactured by Unitika Ltd., IV value: 0.72, melting point: 231 ° C., plant degree: 0%) 25 parts by weight, polyethylene terephthalate (recovered PET (recycled product), yono Semi-crystallization time at 140 ° C. manufactured by Pet Co .: no peak is observed, IV value: 0.67, plant degree: 0%) 75 parts by weight, talc 0.72 parts by weight and pyromellitic anhydride 0.2 parts by weight Was supplied to a single screw extruder having a diameter of 65 mm and an L / D ratio of 35, and melt kneaded at a barrel temperature of 270 to 290 ° C. The polyethylene terephthalate (mixture) constituting the polyethylene terephthalate composition had a half crystallization time at 140 ° C. of 108 seconds and a plant degree of 0%.

  Subsequently, from the middle of the extruder, butane was pressed into the molten polyethylene terephthalate composition so as to be 1 part by weight with respect to 100 parts by weight of polyethylene terephthalate, and was uniformly dispersed in the polyethylene terephthalate composition.

  At the tip of the extruder, a nozzle die (nozzle diameter: 0.8 mm) having 21 nozzles arranged in a straight line is attached, and a polyethylene terephthalate composition is extruded and foamed from the nozzle die to form a strand-like polyethylene terephthalate extrudate. The polyethylene terephthalate extrudate was floated on the water surface of 25 ° C. and cooled.

  Next, the strand-like polyethylene terephthalate extrudate was cut at predetermined intervals with a pelletizer to obtain substantially cylindrical polyethylene terephthalate foamed particles.

  About the polyethylene terephthalate which comprises the obtained polyethylene terephthalate expanded particle, when the half crystallization time in 120 degreeC was measured by DSC, it was 151 seconds.

The polyethylene terephthalate expanded particles had an open cell ratio of 20%, a bulk density of 0.12 g / cm ³ , and a crystallinity of 6%.

  A foamed molded article was obtained in the same manner as in Example 1 using the polyethylene terephthalate foamed particles. The obtained foamed molded article had no cracks or swelling, and the foamed molded article had a beautiful form. However, after the heating test described later, the foamed molded product was cracked and swollen, and the appearance of the foamed molded product after the heating test was not beautiful.

(Comparative Example 2)
Foam molded body in the same manner as in Comparative Example 1, except that the gauge pressure of water vapor supplied into the mold cavity was all set to 0.10 MPa and the temperature of water vapor was all set to 120 ° C. Got. The obtained foamed molded article had no cracks or swelling, and the foamed molded article had a beautiful form. However, after the heating test described later, the foamed molded product was cracked and swollen, and the appearance of the foamed molded product after the heating test was not beautiful.

(Comparative Example 3)
At the time of foam molding in the mold, 112 ° C water vapor with a gauge pressure of 0.05 MPa was supplied from the male mold side into the mold cavity for 30 seconds, and the gauge was inserted into the mold cavity from the female mold side. Steam of 112 ° C. with a pressure of 0.05 MPa was supplied over 30 seconds, and steam at 112 ° C. with a gauge pressure of 0.05 MPa was supplied into the mold cavity from both sides of the male and female molds over 60 seconds. Except that, a foamed molded article was obtained in the same manner as in Comparative Example 1. The obtained foamed molded article had no cracks or swelling, and the foamed molded article had a beautiful form. However, after the heating test described later, the foamed molded product was cracked and swollen, and the appearance of the foamed molded product after the heating test was not beautiful.

(Comparative Example 4)
Except that the polyethylene terephthalate composition of Comparative Example 1 was used, polyethylene terephthalate foamed particles and foamed molded articles were obtained in the same manner as in Example 1.

  About the polyethylene terephthalate which comprises the obtained polyethylene terephthalate expanded particle, when the half crystallization time in 120 degreeC was measured by DSC, it was 151 seconds.

The obtained polyethylene terephthalate expanded particles had an open cell ratio of 6%, a bulk density of 0.11 g / cm ³ , and a crystallinity of 5%.

  The obtained foamed molded article had no cracks or swelling, and the foamed molded article had a beautiful form. However, after the heating test described later, the foamed molded product was cracked and swollen, and the appearance of the foamed molded product after the heating test was not beautiful.

(Comparative Example 5)
In the in-mold foam molding, water vapor of 112 ° C. with a gauge pressure of 0.05 MPa was supplied from the male mold side into the mold cavity for 60 seconds, and the gauge from the female mold side into the mold cavity. Supplying steam at 112 ° C. with a pressure of 0.05 MPa over 60 seconds, and supplying steam at 112 ° C. with a gauge pressure of 0.05 MPa over 60 seconds from both male and female molds into the mold cavity. Except for the above, a foamed molded article was obtained in the same manner as in Comparative Example 1. The obtained foamed molded article had no cracks or swelling, and the foamed molded article had a beautiful form.

  About the obtained foaming molding, the heat fusion rate, heat resistance evaluation, and the crystallinity degree were measured in the following way, and the result was shown in Table 1. Table 2 shows the half crystallization time at 140 ° C., IV value, and plantiness of the thermoplastic polyester resins used in Examples and Comparative Examples.

[Thermal fusion rate]
On the surface of a rectangular parallelepiped foam molded body having a length of 300 mm, a width of 400 mm, and a height of 20 mm, a cutting line having a length of 300 mm and a depth of 5 mm is put in a horizontal direction with a cutter, and the foam is cut along the cutting line. To divide. Then, on the divided surface of the foam, the number of expanded particles broken in the secondary expanded particles (a) and the number of expanded particles broken at the interface between the secondary expanded particles (b) were measured. The thermal fusion rate was calculated based on the formula. The thermal fusion rate is preferably 60% or more, and more preferably 70% or more.
Thermal fusion rate (%) = 100 × (a) / [(a) + (b)]

[Heat resistance evaluation]
(Heating dimensional change rate)
The heating dimensional change rate of the foamed molded product was measured by the B method described in JIS K 6767: 1999 “Foamed Plastics-Polyethylene Test Method”. Specifically, a test piece having a length of 150 mm, a width of 150 mm, and a height of 20 mm was cut out from the foam molded article.

  On the surface of the test piece, three straight lines with a length of 50 mm directed in the vertical direction are written in parallel with each other at intervals of 50 mm, and three straight lines with a length of 50 mm directed in the horizontal direction are set with 50 mm in parallel with each other. Filled in at every interval.

Thereafter, the test piece was left in a 180 ° C. hot air circulating drier for 168 hours to conduct a heating test and then taken out and left at 25 ° C. for 1 hour. Next, the lengths of the six straight lines entered on the surface of the test piece were measured, and the arithmetic average value L ₁ of the lengths of the six straight lines was calculated. The degree of change S was calculated based on the following formula, and the absolute value of the degree of change S was defined as the heating dimensional change rate. The heating dimensional change rate is preferably 1.5% or less, more preferably 1.3% or less, and particularly preferably 1.0% or less.
S (%) = 100 × (L ₁ −50) / 50

(Appearance evaluation)
The test piece after the heating test was visually observed and evaluated based on the following criteria.
○ ・ ・ The specimen did not crack or bulge.
Δ ·· Slightly cracked or swollen in the test piece, but there was no problem in use.
× ·· The test piece was cracked or swollen, causing problems in use.

(Crystallinity)
The foamed molded product part existing between the surface of the foamed molded product and a part that was 2 mm in the direction perpendicular to the surface was used as the surface layer. A rectangular parallelepiped sample having a thickness of 2 mm and a weight of 3 to 10 mg was cut out from the surface layer of the foam molded article. Next, this sample was cut so as to maintain a thickness of 2 mm and to have a rectangular parallelepiped shape with a weight of 2 mg, thereby producing a surface sample.

  Further, a rectangular parallelepiped sample having a thickness of 2 mm and a weight of 3 to 10 mg was cut out from the foam molded product while not including the surface layer of the foam molded product and including the center of gravity of the foam molded product. Next, this sample was cut so as to maintain a thickness of 2 mm and to have a rectangular parallelepiped shape with a weight of 2 mg, thereby producing an internal sample.

  Surface samples and internal samples were prepared from four separately prepared foamed molded articles in the same manner as described above, and a total of five surface samples and internal samples were prepared.

  The crystallinity of the surface sample and the internal sample was measured using a differential scanning calorimeter (DSC) according to the measurement method described in JIS K7121 while measuring the temperature at a heating rate of 10 ° C./min. It calculated by the following formula based on the amount of heat of crystallization per unit and the amount of heat of fusion per mg.

Crystallinity (%)
= 100 × (│heat of fusion (mJ / mg) │-│heat of crystallization (mJ / mg) │) /140.1

  The arithmetic average value of the crystallinity of each of the five surface samples is defined as the surface crystallinity of the foam molded product, and the arithmetic average value of the crystallinity of each of the five internal samples is defined as the internal crystal of the foam molded product. The degree of conversion. The crystallinity of the foam molded article is preferably 25% or more on both the surface and the inside.

1 Nozzle mold 2 Rotating shaft 3 Drive member 4 Cooling member
41 Cooling drum
42 Coolant 5 Rotary blade

Claims (8)

Thermoplastic polyester resin foamed particles used for in-mold foam molding, which is a cross-linked polyethylene terephthalate having an IV value of 0.70 to 1.05 and semi-crystallized at 120 ° C. measured by DSC Thermoplastic polyester resin expanded particles comprising polyethylene terephthalate having a time of 155 to 300 seconds. 2. The thermoplastic polyester resin foamed particles according to claim 1, wherein the open cell ratio is less than 15%. The thermoplastic polyester resin expanded particles according to claim 1 or 2, wherein the thermoplastic polyester resin is polyethylene terephthalate having a plant degree measured by ASTM D6866 of 5% or more. A foamed molded article obtained by molding using the thermoplastic polyester resin foamed particles according to any one of claims 1 to 3. A composite foam comprising a surface material laminated and integrated on the surface of the foam molded article according to claim 4. The composite foam according to claim 5, wherein the composite foam is used for an automobile part. A thermoplastic polyester resin foam comprising polyethylene terephthalate having a IV value of 0.70 to 1.05 and a polyethylene terephthalate having a semi-crystallization time at 120 ° C. of 155 to 300 seconds measured by DSC. A filling step of filling the cavities of the mold with the particles, and water vapor having a gauge pressure of 0.02 MPa or more and less than 0.12 MPa is supplied into the cavities of the mold for 20 to 120 seconds, and the thermoplastic polyester resin A foaming step in which the foamed particles are subjected to secondary foaming, and the secondary foamed particles obtained by secondary foaming of the thermoplastic polyester resin foamed particles are heat-fused together to produce a foam molded article. A method for producing a foam-molded article. The method for producing a foamed molded product according to claim 7, wherein the gauge pressure of water vapor is 0.05 to 0.10 MPa.

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