JP2016094532A - Manufacturing method of thermoplastic resin extrusion foaming heat insulation plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To develop a manufacturing method of a thermoplastic resin extrusion foaming heat insulation plate smaller in heat conductivity than a conventional foaming heat insulation plate and more excellent in long-term insulation property.SOLUTION: The manufacturing method of a thermoplastic resin extrusion foaming heat insulation plate is a method for manufacturing an extrusion foaming heat insulation plate having thickness in a specific range and apparent density in a specific range by performing extrusion foaming of a foamable resin molten article obtained by mixing a thermoplastic resin and a physical foaming agent. The thermoplastic resin consists of a polystyrene resin and a specific polyethylene terephthalate copolymer (I). The weight percentage of the polystyrene resin and the polymer (I) is 95:5 to 50:50, and a melt viscosity (η1) under a specific condition of the copolymer (I) is 1000 to 3000 Pa s.SELECTED DRAWING: None

Description

  The present invention relates to a method for producing a thermoplastic oil extrusion foam insulation board, and more particularly, to a method for producing a thermoplastic resin extrusion foam insulation board that can be suitably used as a heat insulation material such as a wall, floor, or roof of a building. is there.

  Since the polystyrene resin extruded foam heat insulating plate has excellent heat insulating properties and mechanical strength, those formed into a plate shape are widely used as heat insulating materials and the like. Such a foam insulation board is generally provided with a foamable melt-kneaded product obtained by heat-melting a polystyrene resin in an extruder and then press-fitting a physical foaming agent into the resulting melt and kneading it at the tip of the extruder. It is manufactured by extrusion foaming from a flat die or the like into a low pressure region and shaping it into a plate shape.

  Fluorocarbons such as fluorinated fluorinated hydrocarbons, hydrogen atom-containing fluorinated fluorinated hydrocarbons, and fluorinated hydrocarbons have been used as physical foaming agents in the production of polystyrene resin extruded foam insulation boards as described above. From the viewpoint of protecting the ozone layer and preventing global warming, foaming agents containing hydrocarbons such as normal butane and isobutane and hydrofluoroolefins (hereinafter also referred to as HFO) have been used. . The HFO is a nonflammable foaming agent, has an ozone depletion coefficient of 0 (zero), a small global warming coefficient, and has a characteristic of lowering the thermal conductivity of the obtained foam insulation board. .

  Note that foaming agents containing these hydrocarbons and hydrofluoroolefins have low thermal conductivity, so if they remain in the bubbles, they will contribute to improving heat insulation, but will gradually dissipate, so extruded foam plates There was a problem that the thermal conductivity of the steel gradually increased. Patent Document 1 discloses a technique for preventing the physical foaming agent such as hydrocarbons from escaping.

  Patent Document 1 discloses a mixture of a polystyrene resin and an amorphous polyester resin having an endothermic peak heat amount of less than 5 J / g accompanying melting of a polyester resin based on a specific DSC curve as a base resin constituting a foam insulation board. It is disclosed that it is possible to effectively prevent the foaming agent from escaping from the foam insulation board and achieve excellent heat insulation over a long period of time.

JP 2013-82805 A

  However, in recent years, further improvement in long-term heat insulation has been demanded, and there has been a demand for a foam heat insulating plate with further improved long-term heat insulation.

  This invention makes it a subject to develop the manufacturing method of the thermoplastic resin extrusion foam insulation board which is smaller in heat conductivity than the conventional foam insulation board, and is excellent in long-term insulation.

According to this invention, the manufacturing method of the thermoplastic resin extrusion foam heat insulating board shown below is provided.
[1] In a method for producing an extruded foam insulation board having a thickness of 10 to 150 mm and an apparent density of 20 to 50 kg / m ³ by extrusion foaming a foamable resin melt obtained by kneading a thermoplastic resin and a physical foaming agent, The thermoplastic resin comprises a polystyrene resin and a polyethylene terephthalate copolymer (I) having a heat of fusion of less than 5 J / g based on JIS K7122 (1987), and the polystyrene resin and the copolymer (I) The weight ratio of the copolymer (I) is 95: 5 to 50:50, and the melt viscosity (η1) of the copolymer (I) at a measurement temperature of 200 ° C. and a shear rate of 100 sec ⁻¹ is 1000 to 3000 Pa · s. The manufacturing method of the thermoplastic resin extrusion foam heat insulating board made into.
[2] The polystyrene resin has a melt viscosity (η2) of 800 to 2000 Pa · s at a measurement temperature of 200 ° C. and a shear rate of 100 sec ⁻¹ , and the copolymer with respect to the melt viscosity (η2) of the polystyrene resin ( 2. The method for producing a thermoplastic resin extruded foam heat insulating board according to 1 above, wherein a ratio (η1 / η2) of melt viscosity (η1) of I) is 1.0 to 3.5.
[3] The method for producing a thermoplastic resin extruded foam heat insulating board according to the above 1 or 2, wherein the copolymer (I) contains a glycol component having a cyclic ether skeleton as a diol component.
[4] The physical blowing agent is selected from 1,3,3,3-tetrafluoropropene, 2,3,3,3-tetrafluoropropene, 1-chloro-3,3,3-trifluoropropene The manufacturing method of the thermoplastic resin extrusion foam heat insulating board in any one of Claims 1-3 containing at least 1 sort (s).

  In the method for producing a thermoplastic resin extruded foam insulation board according to the present invention, a thermoplastic resin containing a specific amount of a polystyrene resin and a specific polyethylene terephthalate copolymer (I) is used, and the copolymer (I) is further used as the copolymer (I). By using a material having a melt viscosity in a specific range, it is possible to form a phase structure in which the streaky phase of the copolymer (I) is confirmed in the foam film cross-sectional photograph of the obtained extruded foam insulation board. Become. The gas barrier effect is expressed by the phase structure of the copolymer (I) in the bubble film, and the dissipation of the physical foaming agent from the inside of the bubble to the atmosphere is suppressed and the inflow of air into the bubble is suppressed. Thus, an extruded foam heat insulating plate having a lower thermal conductivity than the conventional extruded foam heat insulating plate and excellent in long-term heat insulation can be obtained.

FIG. 1 is a cross-sectional photograph of the bubble film of the foam insulation board obtained in Example 1. FIG. 2 is a cross-sectional photograph of the cell membrane of the foam insulation board obtained in Example 2. FIG. 3 is a cross-sectional photograph of the cell membrane of the foam insulation board obtained in Example 3. FIG. 4 is a cross-sectional photograph of the bubble film of the foam insulation board obtained in Example 6. FIG. 5 is a cross-sectional photograph of the bubble film of the foam insulation board obtained in Comparative Example 1. FIG. 6 is a cross-sectional photograph of the bubble film of the foam insulation board obtained in Comparative Example 2. FIG. 7 is a cross-sectional photograph of the bubble film of the foam insulation board obtained in Comparative Example 3.

Hereinafter, the manufacturing method of the thermoplastic resin extrusion foam heat insulating board of this invention is demonstrated in detail.
In the method for producing a thermoplastic resin extruded foam insulation board (hereinafter also simply referred to as a foam insulation board) of the present invention, a foamable resin melt containing a thermoplastic resin and a physical foaming agent is attached to the extruder outlet. A foam insulation board is produced by extrusion foaming through a flat die and shaping into a plate shape.

  The thermoplastic resin used in the present invention comprises a polystyrene-based resin and a specific polyethylene terephthalate copolymer (I) (hereinafter also simply referred to as copolymer (I)).

Examples of the polystyrene-based resin include styrene-acrylic acid ester copolymers, styrene-methacrylic acid ester copolymers, styrene-acrylic acid copolymers, styrene-methacrylic acid copolymers mainly containing polystyrene or styrene, Styrene-maleic anhydride copolymer, styrene-polyphenylene ether copolymer, styrene-butadiene copolymer, styrene-acrylonitrile copolymer, acrylonitrile-butadiene-styrene copolymer, acrylonitrile-styrene acrylate copolymer, styrene- Examples include methylstyrene copolymer, styrene-dimethylstyrene copolymer, styrene-ethylstyrene copolymer, styrene-diethylstyrene copolymer, and high impact polystyrene (impact polystyrene resin). Alone or in combination of two or more are used. In addition, the styrene component content in the styrene copolymer is preferably 50 mol% or more, and particularly preferably 80 mol% or more.
Among the polystyrene resins, polystyrene, styrene-methacrylic acid ester copolymer, styrene-acrylic acid ester copolymer, styrene-acrylic acid copolymer, styrene-methacrylic acid copolymer, styrene-maleic anhydride copolymer. A styrene-polyphenylene ether copolymer is preferable, and polystyrene is more preferable.

The polystyrene resin used in the present invention preferably has a melt viscosity (η2) of 800 to 2000 Pa · s, more preferably 850 to 1500 Pa · s under conditions of a temperature of 200 ° C. and a shear rate of 100 sec ⁻¹ . Since the melt viscosity (η2) of the polystyrene resin is within this range, the extrudability during production of the foam insulation board is secured, and the kneadability with the copolymer (I) is also improved. It becomes easy to form a copolymer (I) phase capable of exhibiting an excellent gas barrier effect in the bubble film. In addition, when a polystyrene resin contains another component, recycled resin, etc., it is preferable that the polystyrene-type resin composition containing them has said melt viscosity.

  The copolymer (I) phase formed in the polystyrene resin constituting the cell membrane is a transmission electron micrograph of the cell membrane cross section of the resulting extruded foam insulation board (hereinafter cell membrane cross-section photo or cross-section photo). In other words, it is preferably observed as a phase formed in a streak shape in a direction intersecting the thickness direction of the bubble film.

  Furthermore, the polystyrene resin used in the present invention preferably contains polystyrene (a) having a melt tension at 200 ° C. of 30 cN or more. By blending the polystyrene (a), it is difficult to break bubbles during extrusion foaming while maintaining a melt viscosity suitable for forming a polystyrene resin phase. It becomes easy to obtain an excellent foam insulation board. From this viewpoint, the melt tension of polystyrene (a) is preferably 35 cN or more, and more preferably 40 cN or more. In addition, the upper limit of the melt tension of polystyrene (a) is approximately 100 cN, and preferably 60 cN. The melt tension (MT) is a value measured according to ASTM D1238, and can be measured by, for example, Capillograph 1D manufactured by Toyo Seiki Seisakusho.

The weight average molecular weight (Mw) of the polystyrene (a) is preferably 20 × 10 ⁴ to 70 × 10 ⁴ , more preferably 30 × 10 ^{4 to} 60 × 10 ⁴ , and still more preferably. Is 35 × 10 ^{4 to} 55 × 10 ⁴ . The number average molecular weight (Mn) is preferably 9 × 10 ⁴ or more, and the ratio Mw / Mn of the weight average molecular weight (Mw) to the number average molecular weight (Mn) is preferably 3 or more, more preferably. Is 4 or more.
Furthermore, the Z average molecular weight (Mz) of polystyrene (a) is preferably 70 × 10 ⁴ or more, more preferably 80 × 10 ⁴ or more, and further preferably 100 × 10 ⁴ or more.

  The number average molecular weight (Mn), weight average molecular weight (Mw) and Z average molecular weight (Mz) of polystyrene (a) in this specification are all values obtained by gel permeation chromatography (GPC method). is there. Specifically, after dissolving 30 mg of polystyrene-based resin in 20 mL of tetrahydrofuran (THF) (however, when insoluble matter in THF exists, the insoluble matter is removed by filtration), the analysis shown below Standard measured by GPC method under the conditions, and a baseline was drawn horizontally (parallel to the horizontal axis) with reference to the peak start position of polystyrene resin in the chart obtained by this measurement, using standard polystyrene Each molecular weight is calculated from the calibration curve.

Equipment: GPC high performance liquid chromatograph column manufactured by GL Sciences Inc .: Showa Denko Co., Ltd., trade name Shodex GPC KF-806, KF-805, KF-803 are connected in series in this order. Temperature: 40 ° C
Solvent: THF
Flow rate: 1.0 mL / min Concentration: 0.15 w / v%
Injection volume: 0.2ml
Detector: UV-visible detector manufactured by GL Sciences Inc., trade name UV702 type (measurement wavelength 254 nm)
Molecular weight range of calibration curve used for calculation of molecular weight distribution: 1.9 × 10 ^{7 to} 5.4 × 10 ³

  As the polystyrene (a) having the specific melt tension, for example, a special branched structure is introduced into the molecule, such as HP780 manufactured by DIC, which is obtained by polymerization using a macromonomer having a branched structure. Examples thereof include polystyrene resins.

  The content of the polystyrene (a) is preferably 5% by weight or more and preferably 10% by weight or more in 100% by weight of the polystyrene resin. Moreover, it is preferable that it is 40 weight% or less, and it is more preferable that it is 30 weight% or less.

  Polyethylene terephthalate copolymer (I) (hereinafter also simply referred to as copolymer (I)) used in the present invention is a heat of fusion (A) (hereinafter simply referred to as “melting resin” based on JIS K7122 (1987)). A copolymer having a heat of fusion (also referred to as (A)) of less than 5 J / g. Here, the copolymer (I) having a heat of fusion of less than 5 J / g means an amorphous or low crystalline polyethylene terephthalate copolymer.

  If the degree of crystallization of the copolymer (I) is high and the heat of fusion (A) is too high, the crystals of the polyethylene terephthalate copolymer are cooled before cooling the thermoplastic resin to the foaming temperature in the extruder. It will be difficult to obtain the desired foam insulation board. From this viewpoint, the heat of fusion (A) of the copolymer (I) is preferably less than 2 J / g (including 0), more preferably less than 1 J / g (including 0).

  In this specification, the heat of fusion (A) is described in JIS K7122 (1987) “when heat of fusion is measured after performing a certain heat treatment” (the heating rate and cooling rate in adjusting the condition of the test piece are , Both are set to 10 ° C./min.) And measured based on a DSC curve obtained using a heat flux differential scanning calorimeter (hereinafter referred to as a DSC device).

  The copolymer (I) used in the present invention has a terephthalic acid component unit as a dicarboxylic acid component unit and an ethylene glycol component unit as a diol component unit as main component units. Furthermore, other component units are used to control the crystallinity of the copolymer (I).

  As the other dicarboxylic acid component of the copolymer (I), dicarboxylic acid or an ester-forming derivative thereof can be used. Examples of ester-forming derivatives include ester derivatives such as alkyl esters having about 1 to 4 carbon atoms, salts such as diammonium salts, acid halides such as dichloride, and the like. The dicarboxylic acid component units in the copolymer (I) include isophthalic acid, 2,6-naphthalenedicarboxylic acid, phthalic acid, 4,4′-diphenyldicarboxylic acid, 3,4′-diphenyldicarboxylic acid, Aromatic dicarboxylic acids such as 4-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, 2,5-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid or derivatives thereof, such as oxalic acid and succinic acid , Aliphatic dicarboxylic acids such as adipic acid, sebacic acid, dodecanedioic acid or derivatives thereof, or alicyclic dicarboxylic acids such as 1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, decalindicarboxylic acid, tetralindicarboxylic acid Examples include acids. These dicarboxylic acid components may be used alone or in combination of two or more.

  As the other diol component of the copolymer (I), aliphatic and aromatic diols (including divalent phenols) or ester-forming derivatives thereof can be used.

  Specific examples of the other diol component units in the copolymer (I) include aliphatic diols such as propylene glycol, trimethylene glycol, diethylene glycol, 1,4-butanediol, and neopentyl glycol, 1,4 -Cyclohexanedimethanol, 1,3-cyclohexanedimethanol, alicyclic diols such as 1,6-cyclohexanediol, aromatic diols such as bisphenol A, or 3,9-bis (1,1-dimethyl-2-hydroxy) Ethyl) 2,4,8,10-tetraoxaspiro [5.5] undecane (hereinafter referred to as spiroglycol) and (1,1-dimethyl-2-hydroxyethyl) -5-ethyl-5-hydroxymethyl-1 , 3-dioxane (hereinafter referred to as dioxane glycol) and other cyclic ether skeletons It can be mentioned diol. These diol components may be used alone or in combination of two or more.

Among the above, the copolymer (I) used in the present invention preferably contains a diol component unit having a cyclic ether skeleton as the diol component unit, and the total amount of these diol components having a cyclic ether skeleton is It is preferable that it is 10 mol% or more in a diol component, It is more preferable that it is 15-60 mol% in a diol component, It is further more preferable that it is 20-50 mol%.
The copolymer (I) more preferably contains a diol component unit having a cyclic acetal skeleton as the diol component unit. The diol component unit having the cyclic acetal skeleton is preferably spiro glycol or dioxane glycol.

  Moreover, what contains 1 or more types selected from a cyclohexane dimethanol component unit and a neopentyl glycol component unit as this diol component unit is also preferable. In addition, it is preferable that content of alicyclic diol component units, such as cyclohexane dimethanol, is 25-40 mol% in a diol component.

  The degree of crystallinity of the copolymer (I) is determined by a method in which isophthalic acid or the like is used in addition to terephthalic acid as the dicarboxylic acid component, and the molar ratio of these dicarboxylic acid component units is changed. It can be adjusted by a method of changing the molar ratio of these diol component units using cyclohexanedimethanol, spiroglycol or the like.

  The copolymer (I) may have its molecular ends sealed with component units derived from a monofunctional compound such as a small amount of benzoic acid, benzoylbenzoic acid, methoxypolyethylene glycol, and the like. Moreover, a small amount of component units derived from a polyfunctional compound such as pyromellitic acid, trimellitic acid, trimesic acid, glycerin, pentaerythritol may be included.

In the present invention, it is necessary that the melt viscosity (η1) of the copolymer (I) at a temperature of 200 ° C. and a shear rate of 100 sec ⁻¹ is 1000 to 3000 Pa · s. The copolymer (I) having a melt viscosity in this range is excellent in kneadability with a polystyrene resin, and can easily form a phase structure having an excellent gas barrier effect in the polystyrene resin constituting the cell membrane. As described above, the phase structure is preferably confirmed as a streak phase in the bubble film cross-sectional photograph of the foam heat insulating plate of the present invention, more preferably confirmed as a phase having a length of 5 μm or more, and a continuous phase. Those identified as are more preferred. More preferably, a plurality of phases are confirmed in the thickness direction. The phase structure in which the streak phase is confirmed can keep the thermal conductivity of the obtained foam insulation board low for a long period of time. If the melt viscosity is too high, the copolymer (I) may be dispersed in an island shape or a lump. On the other hand, if the melt viscosity is too low, the pressure in the die in the extruder is lowered, and it may be difficult to maintain the shape as a heat insulating plate. Therefore, the melt viscosity (η1) is preferably 1100 to 2600 Pa · s, more preferably 1200 to 2500 Pa · s, and particularly preferably 1400 to 2400 Pa · s.

  In the present invention, the ratio (η1 / η2) of the melt viscosity (η1) of the polyethylene terephthalate copolymer (I) to the melt viscosity (η2) of the polystyrene resin is 1.0 to 3.5. More preferably, it is 1.2-3.0, More preferably, it is 1.3-2.5, Most preferably, it is 1.4-2.3. When the ratio is within this range, the kneadability between the polystyrene resin and the copolymer (I) is good, and the copolymer (I) is a streak phase in a cross-sectional photograph of a bubble film of an extruded heat insulating plate. The confirmed copolymer (I) phase is easily formed.

In the thermoplastic resin of the present invention, the weight ratio of the polystyrene resin to the copolymer (I) (polystyrene resin: copolymer (I)) is 95: 5 to 50:50. When there are too few compounding quantities of copolymer (I), there exists a possibility that the improvement effect of the gas-barrier property of a foam heat insulation board may fall. On the other hand, if the amount of the copolymer (I) is too large, the melt tension of the thermoplastic resin is lowered and extrusion foaming becomes difficult, and a foam insulation board having a low apparent density (high expansion ratio) cannot be obtained. There is a fear.
Furthermore, from the viewpoint of forming a copolymer (I) phase having excellent gas barrier properties, the blending ratio of polystyrene resin: copolymer (I) is preferably 85:15 to 51:49, and 80: It is more preferably 20 to 52:48, and further preferably 70:30 to 54:46.

  In the present invention, by using the copolymer (I) having a melt viscosity in the above range, a morphology in which the copolymer (I) phase is present in the polystyrene-based resin capable of exhibiting the gas barrier effect is formed. Can do. The morphology is preferably a phase structure in which it is confirmed that a plurality of streaky phases of the copolymer (I) are formed in the foam film cross-sectional photograph of the obtained extruded foam insulation board. It is more preferable that the continuity of the polymer (I) phase is improved and a continuous phase is formed in the same manner as the polystyrene-based resin to form a co-continuous phase. When the copolymer (I) forms such a morphology, the physical foaming agent remaining in the bubbles after the extrusion foaming is effectively prevented from escaping into the atmosphere, The physical foaming agent with low conductivity remains in the bubbles for a long time, and the inflow of oxygen and nitrogen from the atmosphere into the bubbles in the foam insulation board is suppressed, thereby reducing the thermal conductivity of the foam insulation board. It will be possible to keep it low for a long time.

  In the present invention, within the range that does not impair the object of the present invention, the thermoplastic resin contains other resins and copolymers other than the polystyrene resin and the copolymer (I), such as a polyolefin resin and a styrene resin. Elastomers, polyphenylene ether resins, and the like can be mixed depending on the blending purpose. In addition, the upper limit of the blending amount is preferably 30% by weight, more preferably 20% by weight or less, and more preferably 10% by weight or less, based on 100% by weight of the entire thermoplastic resin constituting the foam insulation board. It is particularly preferred.

  As the physical foaming agent used in the present invention, an organic physical foaming agent and / or an inorganic physical foaming agent can be used. Examples of the organic physical foaming agent include saturated hydrocarbons having 3 to 5 carbon atoms, aliphatic alcohols having 1 to 5 carbon atoms, hydrofluoroolefin (HFO), ethers, and alkyl chlorides. Examples of the inorganic physical foaming agent include water, carbon dioxide and nitrogen. These foaming agents can be used alone or in admixture of two or more.

  Examples of the saturated hydrocarbon having 3 to 5 carbon atoms include propane, n-butane, i-butane, n-pentane, i-pentane, cyclopentane, neopentane and the like.

  Examples of the hydrofluoroolefin (HFO) include trans-1,3,3,3-tetrafluoropropene (trans HFO-1234ze), cis-1,3,3,3-tetrafluoropropene (cisHFO-1234ze), Fluorine unsaturated hydrocarbons such as 1,1,1,2-tetrafluoropropene (HFO-1234yf) and 2,3,3,3-tetrafluoropropene, and 1-chloro-3,3,3-trifluoro And chlorofluorinated unsaturated hydrocarbons such as propene. In the method of the present invention, at least one selected from 1,3,3,3-tetrafluoropropene, 2,3,3,3-tetrafluoropropene and 1-chloro-3,3,3-trifluoropropene. In order to achieve long-term heat insulation.

  Examples of the aliphatic alcohol having 1 to 5 carbon atoms include methyl alcohol (methanol), ethyl alcohol (ethanol), n-propyl alcohol, isopropyl alcohol, butyl alcohol, sec-butyl alcohol (isobutyl alcohol), and tert-butyl alcohol. , Aryl alcohol, crotyl alcohol, propargyl alcohol, n-amyl alcohol, sec-amyl alcohol, isoamyl alcohol, tert-amyl alcohol, neopentyl alcohol, 3-pentanol, 2-methyl-1-butanol, 3-methyl -2-butanol and the like. Among these, ethanol is preferable because it is excellent in safety to the environment and the human body.

  Examples of the ethers include dimethyl ether, diethyl ether, ethyl methyl ether, di-n-butyl ether, diisopropyl ether and the like.

  Examples of the alkyl chlorides include formate esters such as methyl formate, ethyl formate, and butyl formate, methyl chloride, and ethyl chloride.

The total amount of the physical foaming agent per 1 kg of the thermoplastic resin is appropriately selected in relation to the desired apparent density. In order to obtain a foam insulation board having an apparent density of 20 to 50 kg / m ³ , it is generally 0. 0.5-3 mol, preferably 0.6-2.5 mol.

  In the present invention, among the physical foaming agents, physical foaming in which the saturated hydrocarbon having 3 to 5 carbon atoms, the hydrofluoroolefin (HFO), the aliphatic alcohol having 1 to 5 carbon atoms and water are combined. Agent (A) is preferred, and the blending ratio thereof is 20 to 60 mol% of a saturated hydrocarbon having 3 to 5 carbon atoms, 3 to 50 mol% of HFO, 3 to 40 mol% of an aliphatic alcohol having 1 to 5 carbon atoms, water 5 -50 mol% (however, the total amount of the mixing ratio of HFO, aliphatic alcohol having 1 to 5 carbon atoms, saturated hydrocarbon having 3 to 5 carbon atoms, and water is 100 mol%) Is preferred.

  In the physical foaming agent (A), if the blending ratio of the saturated hydrocarbon is within the above range, the apparent density can be reduced without lowering the extrusion stability, and a large amount of flame retardant is added. Even if it does not do, the foam heat insulating board excellent in long-term heat insulation can be obtained easily. Further, since the saturated hydrocarbon has high solubility in polystyrene resin, it can improve the extrusion stability, and since the gas permeation rate with respect to polystyrene resin is slow, the thermal conductivity can be kept low for a relatively long period. From this viewpoint, the blending ratio of the saturated hydrocarbon is preferably 25 to 60 mol%, more preferably 30 to 50 mol%.

  The blending amount of the saturated hydrocarbon per kg of the thermoplastic resin is preferably from 0.1 to 3 mol, more preferably from 0.2 to 2.5 mol, still more preferably from 0.3 to 2 mol. If it is in this range, stable extrusion foaming becomes possible, and it becomes easy to obtain a foam insulation board having a desired apparent density.

  The hydrofluoroolefin is a foaming agent having a zero ozone depletion coefficient, a very low global warming coefficient, and a small burden on the environment. Furthermore, since the thermal conductivity in the gaseous state is low and it has the property of being difficult to burn, the use amount of the saturated hydrocarbon can be reduced by using it together with the saturated hydrocarbon, and the amount of flame retardant added can be reduced. it can.

  In the physical foaming agent (A), if the blending ratio of the HFO is within the above range, the foamed heat insulating plate can be obtained without reducing the closed cell ratio, apparent density, and foaming state. Since a large amount of HFO can be left inside, a foam insulation board excellent in long-term heat insulation can be obtained. From this point of view, the blending ratio of the HFO is preferably 5 to 40 mol%, more preferably 10 to 30 mol%.

  The amount of HFO blended per kg of thermoplastic resin is preferably 0.05 to 0.5 mol / kg. When the blending amount is within this range, an effective amount of HFO remains in the foam insulation board after extrusion foaming, and an extruded foam insulation board having long-term insulation properties is obtained. From this viewpoint, the blending amount of the HFO is more preferably 0.1 to 0.4 mol / kg, and further preferably 0.15 to 0.3 mol / kg.

In the physical foaming agent (A), when the blending ratio of the aliphatic alcohol having 1 to 5 carbon atoms is within the above range, the copolymer (I) excellent in gas barrier properties while obtaining a desired apparent density. A phase can be formed.
Moreover, this C1-C5 aliphatic alcohol has the characteristic which improves the plasticity of copolymer (I) specifically rather than a polystyrene resin. Due to its function, by reducing the viscosity of the copolymer (I) relative to the polystyrene resin in the thermoplastic resin, it is possible to easily form the streaky phase of the copolymer (I). The blending ratio of the aliphatic alcohol having 1 to 5 carbon atoms is more preferably 5 to 30 mol%, and still more preferably 8 to 20 mol%.

  The blending amount of the aliphatic alcohol having 1 to 5 carbon atoms is preferably 0.05 to 0.3 mol, more preferably 0.07 to 0.28 mol, and 0.08 to 0 mol per kg of the thermoplastic resin. More preferably, 0.25 mol is preferable, and 0.10 to 0.23 mol is particularly preferable.

Furthermore, in the physical foaming agent (A), the molar ratio (a / b) of the amount (a) of the hydrofluoroolefin to the amount (b) of the aliphatic alcohol having 1 to 5 carbon atoms is 0. It is preferable that it is 3-4. When the molar ratio is within such a range, a foamed heat insulating board having excellent long-term heat insulating properties can be obtained.
From this viewpoint, the molar ratio is more preferably 0.5 to 3.5, and still more preferably 1 to 2.

  In addition, in the conventional foam insulation board using the hydrocarbon or HFO as a foaming agent, these foaming agents have a relatively high permeation rate with respect to polystyrene resin compared to conventional fluorocarbons. Later, the foaming agent gradually dissipated from the foam, and as a result, the long-term heat insulation property of the foam heat insulating plate tended to decrease. On the other hand, in the foam insulation board obtained by the present invention, the thermoplastic resin constituting the foam insulation board consists of the polystyrene resin and the copolymer (I) and is specified as the copolymer (I). In the bubble film cross-sectional photograph of the obtained extruded foam insulation board by using the one having a melt viscosity in the range, the copolymer (I) is a streak of the copolymer (I) in the continuous phase of the polystyrene resin. It is formed as a morphology of a phase structure in which a plurality of state phases are confirmed. As a result, in the foam insulation board obtained by the present invention, the physical foaming agent, in particular, HFO is effectively prevented from escaping, and the inflow of air from the atmosphere into the bubbles is also prevented. Is superior to conventional foam insulation boards.

  In addition, in this physical foaming agent (A), it is further preferable to use water as a physical foaming agent. By using water in addition to the saturated hydrocarbon, the HFO, and the aliphatic alcohol, it is possible to further improve the expansion ratio of the resulting foam insulation board and reduce the apparent density. The mixing ratio of water is preferably 5 to 50 mol% (however, the total amount of mixing ratio of HFO, the aliphatic alcohol, the saturated hydrocarbon, and water is 100 mol%).

  If the mixing ratio of the water is within this range, it is easy to prevent deterioration of the bubble shape of the foam insulation board while obtaining a desired apparent density, and easy to obtain a foam insulation board excellent in long-term insulation. Can be obtained. From this viewpoint, the blending ratio is 10 to 40 mol%, more preferably 15 to 35 mol%.

  Since the thermoplastic resin extruded foam insulation board obtained by the present invention is mainly used as a construction insulation board, it is defined in JIS A9511 (2006R) 5 · 13 · 1, as described in “Measurement method A”. It is preferable that the flammability standard for the extruded polystyrene foam heat insulating plate is satisfied. The thermoplastic resin extruded foam insulation board that satisfies this standard can be achieved by adding a flame retardant in addition to adjusting the content of the saturated hydrocarbon foam insulation board.

  A brominated flame retardant is preferably used as the flame retardant that can be blended in the thermoplastic resin extruded foam insulation board of the present invention. Examples of the brominated flame retardant include brominated bisphenol based flame retardant, brominated isocyanurate based flame retardant, brominated butadiene-styrene copolymer based flame retardant, and the like.

  The brominated bisphenol-based flame retardant is a brominated product of bisphenol A, bisphenol F, bisphenol S, or a derivative thereof. Tetrabromobisphenol A-bis (2,3-dibromo-2-methylpropyl ether) and tetrabromo Bisphenol A-bis (2,3-dibromopropyl ether) and the like can be mentioned.

  The brominated isocyanurate-based flame retardant is a brominated product of isocyanuric acid or an isocyanuric acid derivative, and examples thereof include mono (2,3-dibromopropyl) isocyanurate.

  As the brominated butadiene-styrene copolymer, conventionally known ones such as block copolymers, random copolymers, and graft copolymers can be used as they are, and examples thereof include polystyrene-brominated polybutadiene copolymers. Specific examples include commercial products such as Chemtura's Emerald 3000 and ICL-IP's FR122P.

  The total amount of the brominated flame retardant is appropriately determined according to the desired flame retardancy, but a polystyrene resin satisfying the flammability standard of the extruded polystyrene foam heat insulating plate described in JIS A9511 (2006R). In order to obtain an extruded foam, it is preferable to blend 1 to 10 parts by weight with respect to 100 parts by weight of the thermoplastic resin, and more preferably 2 to 8 parts by weight. When the total blending amount is within this range, an extruded foam having a good surface state can be obtained without the flame retardant inhibiting the foaming property.

  In addition, the said flame retardant can contain other flame retardants other than a brominated bisphenol flame retardant, a brominated isocyanurate flame retardant, and a brominated butadiene-styrene copolymer flame retardant. The amount of other flame retardant added is preferably 20% by weight or less, more preferably 10% by weight or less, based on the total amount of brominated flame retardant added.

  As a method of blending the flame retardant into the thermoplastic resin, a method in which a predetermined ratio of the flame retardant is supplied to the supply unit provided upstream of the extruder together with the thermoplastic resin and kneaded in the extruder is adopted. Can do. In addition, a method of supplying a flame retardant into the molten thermoplastic resin from a flame retardant supply unit provided in the middle of the extruder can also be employed. In addition, when supplying a flame retardant to an extruder, a method of supplying a dry blend of a flame retardant and a polystyrene resin constituting a thermoplastic resin to the extruder, a flame retardant master batch or a flame retardant melt kneaded product The method of producing and supplying to an extruder with a thermoplastic resin is employable. In particular, it is preferable to adopt a method of preparing a flame retardant master batch and supplying it to an extruder from the viewpoint of dispersibility.

  In the present invention, stabilizers such as hindered phenol stabilizers, phosphorus stabilizers, and hindered amine stabilizers can be added to the thermoplastic resin. These stabilizers can suppress a decrease in molecular weight and coloring of the polystyrene resin by capturing halogen radicals and halogen ions generated by decomposition of the brominated flame retardant during processing.

  In the present invention, as flame retardant aids, diphenylalkanes such as 2,3-dimethyl-2,3-diphenylbutane and 2,3-diethyl-2,3-diphenylbutane, and 2,4-diphenyl-4- Diphenylalkenes such as methyl-1-pentene and 2,4-diphenyl-4-ethyl-1-pentene, polyalkylbenzenes such as poly-1,4-diisopropylbenzene, triphenyl phosphate, cresyl di-2,6-xylenyl Phosphate, antimony trioxide, antimony pentoxide, ammonium sulfate, zinc stannate, cyanuric acid, isocyanuric acid, triallyl isocyanurate, melamine cyanurate, melamine, melam, melem and other nitrogen-containing cyclic compounds, silicone compounds, boron oxide Inorganic compounds such as zinc borate and zinc sulfide, red System, ammonium polyphosphate, phosphazene, a phosphorus-based compounds such as hypophosphorous acid salts can be incorporated into the thermoplastic resin. These compounds can be used alone or in admixture of two or more.

  In the present invention, the heat insulating property can be further improved by blending the thermoplastic resin as the base resin with a heat insulating property improving agent. Examples of the heat insulation improver include metal oxides such as titanium oxide, metals such as aluminum, fine powders such as ceramics, carbon black and graphite, infrared shielding pigments, hydrotalcite and the like. These can use 1 type (s) or 2 or more types. The amount of the heat insulation improver used is in the range of 0.5 to 5 parts by weight with respect to 100 parts by weight of the thermoplastic resin.

  Further, in the present invention, various additives such as a bubble adjusting agent, a colorant such as a pigment and a dye, a heat stabilizer and a filler can be appropriately blended with the base resin as necessary.

  Examples of the air conditioner include conventionally known chemical foams such as talc, kaolin, mica, silica, calcium carbonate, barium sulfate, titanium oxide, aluminum oxide, clay, bentonite, diatomaceous earth and the like, and azodicarbodiamide. An agent or the like can be used. Of these, talc is preferred because it does not impair flame retardancy and allows easy adjustment of the bubble diameter. The addition amount of the cell regulator varies depending on the type of the cell regulator, the target cell diameter, etc., but is generally 0.01 to 8 parts by weight, more preferably 0.01 to 5 parts per 100 parts by weight of the thermoplastic resin. Part by weight, particularly 0.05 to 3 parts by weight is preferred.

  It is preferable from the viewpoint of the dispersibility of the additive that the bubble adjusting agent is prepared and used in the same manner as other additives. For example, when talc is used as the foam regulator, the master batch of the foam regulator is preferably prepared so that the content of talc is 20 to 80% by weight with respect to the base resin. It is more preferable to adjust so that it may become -70weight%.

  Hereinafter, various physical properties of the thermoplastic resin extruded foam heat insulating board obtained by the present invention will be described in detail.

  In the foam insulation board obtained by the present invention, the thermoplastic resin constituting the cell membrane is composed of a polystyrene resin and the copolymer (I). Furthermore, according to the present invention, by using the copolymer (I) having a specific melt viscosity, it is possible to suppress the dispersion of the copolymer (I) in the form of islands or lumps, and the continuous phase of the polystyrene resin. A copolymer (I) phase capable of exhibiting a gas barrier effect can be formed therein. The copolymer (I) phase is confirmed as a plurality of streaky phases in the bubble film cross-sectional photograph of the extruded foam insulation board.

In the present specification, the streaky copolymer (I) phase confirmed in the cross-sectional photograph of the bubble film refers to the direction along the bubble film in the cross-sectional photograph (the longitudinal direction of the bubble film, the bubble film It means that the copolymer (I) exists in the form of a line or a strip in the direction perpendicular to the thickness direction and forms a phase.
The length of the streaky copolymer (I) phase is preferably 1 μm or more, more preferably 2.5 μm or more, and even more preferably 5 μm or more because an excellent barrier effect can be obtained. It is. Further, a plurality of copolymer (I) phases having the length are preferably present in the thickness direction, and more preferably 3 or more.

  Since the copolymer (I) phase can suppress the intrusion of air into the bubble film and the physical foaming agent such as hydrofluoroolefin can be prevented from escaping into the atmosphere, the heat conduction of the foam insulation board The increase in the rate can be suppressed, and the thermal conductivity can be kept low for a long time. Furthermore, in the foam heat insulating board obtained by this invention, inflow of the air into a bubble is suppressed effectively by forming a specific copolymer (I) phase.

The apparent density of the foam insulation board obtained by the present invention is 20 to 50 kg / m ³ . If the apparent density is too small, it is quite difficult to produce a foam insulation board itself, and depending on the application, the foam insulation board has insufficient mechanical strength. On the other hand, when the apparent density is too high, it is difficult to exert sufficient heat insulation unless the thickness of the foam heat insulating plate is considerably increased, and it is not preferable from the viewpoint of light weight. From this viewpoint, it is preferably 25 to 45 kg / m ³ .

  The thickness of the foam insulation board is 10 to 150 mm. When the thickness is too thin, there is a risk that the heat insulating property required particularly when used as a heat insulating material will be insufficient. On the other hand, although depending on the size of the extruder, foam extrusion may be difficult if the thickness is too thick. The thickness is more preferably 15 mm to 120 mm.

  The average cell diameter in the thickness direction of the foam heat insulating plate is preferably 0.05 to 2 mm, more preferably 0.06 to 0.7 mm, and still more preferably 0.06 to 0.3 mm. When the average cell diameter in the thickness direction is within this range, it becomes a foam heat insulating plate having even higher heat insulating properties for the reason that infrared transmission can be suppressed in combination with the configuration of the apparent density range. There are advantages such as.

The measurement method of the average bubble diameter in this specification is as follows.
The average cell diameter (D _Tav ) in the thickness direction and the average cell diameter (D _Wav ) in the width direction are the number of cells in the photograph at a total of three locations near the center and both ends of the widthwise vertical cross section of the foam insulation board. Enlarged photographs obtained by adjusting the enlargement magnification in the range of about 50 to 200 times so as to be about 200 to 500 pieces are obtained, and on each photograph, using the image processing software NS2K-pro manufactured by Nanosystem Co., Ltd. The bubble diameter in the thickness direction and the bubble diameter in the width direction of each bubble can be measured, and these values can be obtained by arithmetic averaging.

The average cell diameter (D _Lav ) in the extrusion direction is a position that bisects the width direction of the foam heat insulating plate, and is obtained at any three locations in the vertical cross section in the extrusion direction obtained by cutting the foam heat insulating plate in the extrusion direction. Microscopic magnified photographs were obtained, and on each photograph, the bubble diameter in the extrusion direction of each bubble was measured using the image processing software NS2K-pro manufactured by Nanosystem Co., Ltd., and each of these values was arithmetically averaged. Can be sought.
Moreover, let the average bubble diameter _DH of the horizontal direction of a foam heat insulating board be the arithmetic mean value of _DWav and _DLav .

In the foam heat insulating board obtained by this invention, it is preferable that a bubble deformation rate is 0.7-2.0. The cell strain rate, is said value of D _T obtained by the measuring method is calculated by dividing the _{D H (D T / D H} ), bubbles as bubble deformation ratio is less than 1 flat The larger the value is, the longer the image is. If the bubble deformation rate is too small, the compressive strength may decrease because the bubbles are flat, and the flat bubbles tend to return to a spherical shape, so that the dimensional stability of the foam insulation board may also decrease. When the bubble deformation rate is too large, the number of bubbles in the thickness direction is reduced, so that the effect of improving heat insulation by the bubble shape is reduced. From such a viewpoint, the bubble deformation rate is preferably 0.8 to 1.5, and more preferably 0.8 to 1.2. When the bubble deformation rate is within this range, a thermoplastic resin extruded foam heat insulating plate having excellent mechanical strength and further high heat insulating properties is obtained.

  The closed cell ratio of the foam heat insulating board obtained by the present invention is preferably 85% or more, more preferably 90% or more, and further preferably 93% or more. The higher the closed cell ratio, the longer the physical foaming agent such as HFO can stay in the bubbles, and the high heat insulation performance can be maintained over a long period of time. The closed cell ratio S (%) is measured using an air comparison type hydrometer (for example, Toshiba Beckman Co., Ltd., air comparison type hydrometer, model: 930 type) according to the procedure C of ASTM-D2856-70. Is done.

Furthermore, it is desirable that the thermoplastic resin foam insulation board obtained by the present invention satisfies the standard of thermal conductivity defined by JIS A9511 (2006R) 4.2.
Furthermore, the thermal conductivity of the foam insulation board obtained by the present invention is preferably 0.0270 W / (m · K) or less, more preferably 0.0260 W / (m · K) or less, 0 More preferably, it is 0.0250 W / (m · K). If the thermal conductivity is within this range, the foam insulation board is excellent in heat insulation and suitable for building materials. In addition, although heat conductivity is fluctuate | varied from immediately after manufacture, it should just be heat conductivity in this range at the time of use of a foam heat insulating board. Further, the foam heat insulating plate is preferably 0.0248 W / (m · K) or less in terms of thermal conductivity after 100 days from the manufacture in terms of excellent long-term heat insulation, and 0.0245 W. / (M · K) or less is more preferable. The foam insulation board obtained by the present invention comprises, as a thermoplastic resin, a copolymer (I) composed of the polystyrene resin and the copolymer (I), and further having a melt viscosity in a specific range, and the physical foaming agent is used. The copolymer (I) phase is present in the foam film in the above-described morphology that exerts a gas barrier effect, and the HFO dissipates from the foam insulation board and the air into the bubbles. Inflow is effectively prevented. Therefore, even after 100 days have elapsed since manufacture, the thermal conductivity is kept low.

The residual amount of HFO in the foam insulation board obtained by the present invention is preferably 0.18 mol or more per 1 kg of the foam insulation board 100 days after the production. If the remaining amount is within the above range, HFO exhibits an effect of improving heat insulation and is further excellent in heat insulation.
On the other hand, the upper limit of the residual amount of HFO is related to the apparent density of the foam heat insulating plate and the like, but is approximately 0.8 mol, preferably 0.7 mol. The residual amount of HFO varies from immediately after manufacture, but it is sufficient that the residual amount of HFO is within this range when the foam heat insulating board is used.

  The residual amount of HFO in the foam insulation board in this specification is a value measured by an internal standard method using a gas chromatograph. Specifically, an appropriate amount of sample is cut out from the foam insulation board, this sample is placed in a sample bottle with a lid containing an appropriate amount of toluene and an internal standard substance, the lid is closed, and the mixture is thoroughly stirred and placed in the foam insulation board. A gas chromatographic analysis is performed using a solution obtained by dissolving HFO in toluene as a measurement sample, and the residual amount of HFO in the foam insulation board is obtained.

  In the foam insulation board obtained by the production method of the present invention, the air partial pressure in the bubbles after 100 days of production is preferably 1 atm or less. The foam heat insulating plate can suppress the inflow of air into the bubbles, which is a factor for increasing the thermal conductivity of the foam, because the copolymer (I) forms a unique phase structure. Therefore, the air partial pressure in the bubbles is kept low for a longer period than the conventional extruded foam, and the amount of air inflow is reduced. From such a viewpoint, the air partial pressure after 100 days from the production is more preferably 0.7 atm or less, and further preferably less than 0.65 atm.

  Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples. However, the present invention is not limited to these examples.

  The polystyrene resins used in the examples and comparative examples are shown below. In Examples and Comparative Examples, Resin 1 and Resin 2 in which polystyrene 1, polystyrene 2 (polystyrene (a)), and polystyrene 3 shown below were blended in the weight ratio shown below were used.

Resin 1: Polystyrene resin in which polystyrene 1 and polystyrene 2 are mixed at a weight of 67:33.
In addition, when the melt viscosity of the pellet was measured by melting and kneading the resin 1 and measuring the melt viscosity of the pellet, the melt viscosity was (200 ° C., 100 s ⁻¹ ) 920 Pa · s.

Resin 2: A polystyrene resin in which polystyrene 1, polystyrene 2, and polystyrene 3 are mixed at a weight ratio of 67:23:10.
In addition, when the resin 2 was melt-kneaded to form pellets and the melt viscosity of the pellets was measured, the melt viscosity was (200 ° C., 100 s ⁻¹ ) 950 Pa · s.

Polystyrene 1: Grade name 679 manufactured by PS Japan, melt viscosity (temperature 200 ° C., shear rate 100 s ⁻¹ ) = 673 Pa · s, melt tension (200 ° C.) = 3 cN, Mn = 7.3 × 10 ⁴ , Mw = 20 × 10 ⁴ , Mz = 38 × 10 ⁴
Polystyrene 2: Grade name HP780 manufactured by DIC, melt viscosity (temperature 200 ° C., shear rate 100 s ⁻¹ ) = 1946 Pa · s, melt tension (200 ° C.) = 45 cN, Mn = 10 × 10 ⁴ , Mw = 50 × 10 ⁴ , Mz = 190 × 10 ⁴
Polystyrene 3: Grade name GX154 manufactured by PS Japan, melt viscosity (temperature 200 ° C., shear rate 100 s ⁻¹ ) = 1625 Pa · s, melt tension (200 ° C.) = 25 cN, Mn = 10 × 10 ⁴ , Mw = 32 × 10 ⁴ , Mz = 76 × 10 ⁴

  Table 1 shows the copolymer (I) used in Examples and Comparative Examples. In addition, SPET B, C, and D are manufactured by processing SPET A under the heat treatment conditions shown in Table 1 using an extruder, and PETG B is heated as shown in Table 1 using PETG A using an extruder. It manufactured by processing on processing conditions.

Air Conditioning Agent A talc masterbatch containing 60% by weight of talc (manufactured by Matsumura Sangyo Co., Ltd., trade name: High Filler # 12) using polystyrene resin as a base resin was used.

Flame retardant (i) Tetrabromobisphenol-A-bis (2,3-dibromo-2-methylpropyl ether) (Daiichi Kogyo Seiyaku SR130, described as “SR130” in the table)
(Ii) Tetrabromobisphenol-A-bis (2,3-dibromopropyl ether) (Daiichi Kogyo Seiyaku SR720, described as “SR720” in the table)
Was used.

Physical foaming agent The following (1) to (4) were used as physical foaming agents.
(1) C3-C5 saturated hydrocarbon: isobutane (abbreviation "i-Bu")
(2) HFO: trans-1,3,3,3-tetrafluoropropene (HFO-1234ze)
(3) C1-5 aliphatic alcohol: ethanol (4) water

Apparatus A first extruder with an inner diameter of 65 mm and a second extruder with an inner diameter of 90 mm are connected in series, a blowing agent inlet is provided near the end of the first extruder, and the cross section in the width direction is rectangular (gap 1 mm) A flat die having a resin discharge port (die lip) with a width of 115 mm is connected to the outlet of the second extruder, and a pair of upper and lower polytetrafluoroethylenes are parallel to the resin outlet of the flat die. A manufacturing apparatus provided with a shaping apparatus (guider) provided with a plate made of ethylene resin was used.

Examples 1-6, Comparative Examples 1-3
Resins, flame retardants and bubble regulators were supplied to the first extruder so as to have the respective blending amounts shown in Tables 2 and 3. Next, these were heated to 220 ° C., melted and kneaded to obtain a resin melt, and physical foaming of the blending compositions shown in Tables 2 and 3 from the foaming agent inlet provided near the tip of the first extruder. The agent was supplied to the melt at a ratio shown in the table, and melt kneaded to obtain a foamable resin melt. This foamable resin melt was transferred to the subsequent second and third extruders, and the resin temperature was expressed as the foaming suitability temperature as shown in the table (in the table, it was expressed as the extrusion resin temperature. This foaming temperature was the extruder. The temperature of the foamable resin melt is measured at the position of the joint between the die and the die.), And is extruded from the die lip into the guider at a discharge rate of 70 kg / hr. Then, it was molded (shaped) by passing through a guider arranged in parallel to produce a thermoplastic resin extruded foam insulation board. The physical properties and evaluation of the resulting foam insulation board are summarized in Table 2 for Examples 1 to 3 and Comparative Examples 1 and 2, and Table 3 for Examples 4 to 6 and Comparative Example 3.

  In Example 1, a thermoplastic resin composed of 56% by weight of polystyrene resin “Resin 1” and 44% by weight of copolymer (I) “PETG B” is used, and isobutane, HFO, ethanol, What mixed water with the mixing | blending shown in Table 3 was used. When a cross-sectional photograph of the obtained foam insulation board was taken with an electron microscope, as shown in FIG. 1, the copolymer (I) formed a plurality of streak phases in the polystyrene resin in the cross section of the bubble film. Furthermore, it can be confirmed that the polystyrene resin and the copolymer (I) form a co-continuous phase. From Table 2, it can be seen that the obtained foam heat insulating plate has a small change in thermal conductivity with time and is excellent in long-term heat insulation. The heat insulating property is related to the dissipation of the foaming agent in the foam and the inflow of air into the bubbles. However, the heat insulating effect in Example 1 effectively suppresses the inflow of air into the bubbles. It is thought that this is because.

  In Example 2, a foam heat insulating board was produced with the same composition as Example 1 except that “SPET C” was used as copolymer (I). In Example 3, as copolymer (I), “ A foam heat insulating board was produced with the same composition as Example 1 except that “SPET D” was used. 2 and 3 show cross-sectional photographs of the bubble film. Also in Examples 2-3, the copolymer (I) forms a plurality of streak phases in the polystyrene resin, and the copolymer (I) and the polystyrene resin form a co-continuous phase. The foam insulation board excellent in long-term heat insulation was confirmed.

  On the other hand, in Comparative Examples 1 and 2, foamed heat insulating plates were produced using copolymers (I) “SPET A” and “PETG A” having a high melt viscosity. If the melt viscosity of the copolymer (I) is high, the copolymer (I) tends to have an island structure (FIGS. 5 and 6). In addition, when the thermal conductivity after 5 days or 7 days and 100 days after manufacture is compared with the examples, the foam insulation board of the examples has a smaller amount of change with time (thermal conductivity difference), and has a longer thermal insulation. It can be seen that it can be maintained.

  In Example 4, a foam heat insulating board was produced in the same manner as in Example 1 except that the polystyrene resin was changed to the resin 2 and the weight ratio of the polystyrene resin and the copolymer (I) was changed. In Example 5, a foam heat insulating board was manufactured in the same manner as in Example 2 except that the polystyrene resin was changed to the resin 2 and the weight ratio of the polystyrene resin and the copolymer (I) was changed. Moreover, in Example 6, the foamed heat insulating board was manufactured similarly to Example 3 except having changed the polystyrene resin into the resin 2 and changing the weight ratio of the polystyrene resin and the copolymer (I). FIG. 4 shows a cross-sectional photograph of the bubble film. It can be confirmed that the copolymer (I) forms a plurality of streak phases. In Example 4 and Example 5, the same phase state as in Example 6 was observed.

Comparative example 3 is an example using copolymer (I) with high melt viscosity to Examples 4-6. When the melt viscosity of the copolymer (I) is high, the copolymer (I) tends to have an island structure (FIG. 6), and it can be seen that the obtained foam insulation board is inferior in long-term insulation performance.
The copolymer (I) has an effect of suppressing radiant heat conduction in the resin itself. From the comparison of Examples 1 to 3 and Examples 4 to 6, when the blending amount of the copolymer (I) is increased, It can be seen that the heat insulation performance of the foam insulation board is also improved.

  Each physical property in the table was measured as follows.

(Melt viscosity)
The melt viscosity was measured under the conditions of a temperature of 200 ° C. and a shear rate of 100 sec ⁻¹ , and a Capillograph 1D manufactured by Toyo Seiki Seisakusho Co., Ltd. was used. Specifically, a cylinder with a cylinder diameter of 9.55 mm and a length of 350 mm and an orifice with a nozzle diameter of 1.0 mm and a length of 10.0 mm were used. The resin sufficiently dried at a temperature lower by 10 ° C. than the glass transition temperature was placed in the cylinder and measured after standing for 4 minutes, and the melt viscosity (Pa · s) obtained there was adopted. In the measurement, measurement was performed so that bubbles were not mixed in the strand extruded from the orifice as much as possible.
In the case of copolymer (I), drying was performed in a vacuum oven at 80 ° C. for 12 hours before measurement.

(Apparent density)
The apparent density was measured according to JIS K7222: 1999.

(Closed cell rate)
In the present specification, the closed cell ratio of the foam insulation board is determined by measuring the closed cell ratio of each sample according to the procedure C of ASTM-D2856-70 and calculating the measured value as an arithmetic average (5 points or more). Obtained from (1). Cut samples from a total of three locations near the center of the extruded foam insulation board and both ends in the width direction, using each cut sample as a measurement sample, measuring the closed cell rate for each measured sample, and measuring the 3 closed cell rates The arithmetic average value of was adopted. In addition, the cut sample was made into the sample which does not have a foam heat insulation board skin cut | disconnected from the foam heat insulation board to the magnitude | size of length 25mm x width 25mm x thickness 20mm.

S (%) = (Vx−W / ρ) × 100 / (VA−W / ρ) (1)
However, Vx: the true volume (cm ³ ) of the cut sample obtained by measurement with the above air comparison hydrometer (the volume of the resin constituting the cut sample of the foam insulation board, and the total amount of bubbles in the closed cell portion in the cut sample Equivalent to the sum of volume.)
VA: apparent volume (cm ³ ) of the cut sample calculated from the outer dimensions of the cut sample used for measurement
W: Total weight of cut sample used for measurement (g)
ρ: Density (g / cm ³ ) of the base resin constituting the foam insulation board

(Average cell diameter in the thickness direction)
The average cell diameter (D _Tav ) in the thickness direction was measured by the above method. The average bubble diameter (D _Tav ) in the thickness direction was obtained by obtaining magnified photographs with a magnification of 50 times at a total of three locations near the center and both ends of the cross section in the width direction of the extruded foam. Using the image processing software NS2K-pro manufactured by Co., Ltd., the bubble diameter in the thickness direction and the bubble diameter in the width direction of each bubble were measured, and the respective values were obtained by arithmetic averaging.

(MD direction cross-sectional photograph of foam film of foam insulation board)
First, an extruded foam obtained by cutting out the central portion of the foam insulation board to an appropriate size was embedded in an epoxy resin and embedded. After embedding, a surface perpendicular to the thickness direction was cut out with a glass knife or the like, and an ultrathin section of a foam having a thickness of about 0.1 μm was cut out from the cross section with a diamond knife or the like. The cut section (sample) was placed on a Cu mesh and placed in a petri dish with several ml of 2% OsO ₄ aqueous solution, sealed at room temperature, exposed to OsO ₄ vapor, and stained for 30 minutes. Next, the sample was placed in a petri dish together with a solution prepared by mixing several ml of NaClO aqueous solution and a small spatula of RuCl ₃ crystals just before use in a petri dish, exposed to the generated RuO ₄ vapor, and stained for 30 minutes. An ultra-thin section of the stained foam was photographed using a transmission electron microscope. In the photographed electron micrograph, the white part is polystyrene resin and the black part is copolymer (I). As a transmission electron microscope, a transmission electron microscope “JEM-1010” manufactured by JEOL Ltd. was used. Moreover, the length of the phase, the average length (thickness) in the thickness direction, and the number of phases were measured using the photograph. In the present invention, the bubble film part in which the above measurement is performed is a part other than the meeting part where three or more bubble films (cell films) meet in the foam cross section. Although depending on the stretched state of the bubble film, the bubble film part was a part from the thinnest part of one bubble film to a film thickness 1.3 times the thickness.

[Shooting conditions]
Transmission electron microscope: Transmission electron microscope “JEM-1010” manufactured by JEOL Ltd.
Acceleration voltage: 100 kV
Staining: Ruthenium tetroxide Magnification: 20000 times

(Phase state of copolymer (I))
Using the cross-sectional photograph of the foam film of the foam insulation board, the morphology was visually observed and evaluated according to the following criteria. In addition,
On the image observed by the above-mentioned method, a line segment is drawn in the thickness direction of the bubble film to a total of three points, the center in the direction along the bubble film of the image and the point 2.5 μm left and right in the longitudinal direction from the center. The number of intersecting streaks with a length of 5 μm or more was measured. When the phases were branched and merged in the cell membrane, those separated at the point where the line segment intersected were measured as a plurality of phases. The same operation was performed on the enlarged images of a total of three or more points, and the average value was adopted.
○: The copolymer (I) forms a plurality of streak phases.
X: Copolymer (I) forms a bulk phase.

(Thermal conductivity)
The thermal conductivity of the foam insulation board was measured by the following method after storing the foam insulation board immediately after production in an atmosphere of 23 ° C. and 50% humidity for 5 days or 100 days.
A test piece of a foam insulation board having a length of 200 mm, a width of 200 mm, and a thickness of 10 mm, having no epidermis, was cut out from the foam insulation board, and the plate heat flow meter method (heat flow meter 2) described in JIS A1412-2 (1999) was used for the specimen. Sheet type, high temperature side 38 ° C., low temperature side 8 ° C., average temperature 23 ° C.).

(HFO remaining amount)
The HFO residual amount of the foam insulation board was measured by an internal standard method using a gas chromatograph after storing the foam insulation board immediately after production in an atmosphere of 23 ° C. and 50% humidity for 5 days or 100 days. Specifically, an appropriate amount of sample is cut out from the foam insulation board, placed in a sample bottle with a lid containing an appropriate amount of toluene and an internal standard substance, and then the lid is closed. HFO was dissolved in toluene to obtain a measurement sample, and gas chromatographic analysis was performed to determine the amount of HFO remaining in the foam insulation board.

(Foamed state)
The foamed state was evaluated according to the following criteria.
(Double-circle): A foaming state is very favorable.
○: The foamed state is good, but there are irregularities on a part of the surface. Δ: The foamed state is bad and many irregularities are generated on the surface. ×: Cannot be molded into a plate shape.

(Combustion quality)
About the obtained heat insulation board, the combustibility test of the measurement method A of 5.13.1 was performed based on JIS A9511 (2006R) 5.13.1. For the measurement, five test pieces were cut out from one foamed heat insulating board and evaluated according to the following criteria.
○: The flame disappears within 3 seconds in all the test pieces, there is no residual dust, and it does not burn beyond the combustion limit line.
X: The average burning time of 5 test pieces exceeds 3 seconds.

Claims (4)

In a method for producing an extruded foam insulation board having a thickness of 10 to 150 mm and an apparent density of 20 to 50 kg / m ³ , by extruding and foaming a foamable resin melt obtained by kneading a thermoplastic resin and a physical foaming agent,
The thermoplastic resin comprises a polystyrene resin and a polyethylene terephthalate copolymer (I) having a heat of fusion of less than 5 J / g based on JIS K7122 (1987),
The weight ratio of the polystyrene resin and the copolymer (I) is 95: 5 to 50:50,
A method for producing a thermoplastic resin extruded foam heat insulating plate, wherein the copolymer (I) has a melt viscosity (η1) of 1000 to 3000 Pa · s at a measurement temperature of 200 ° C. and a shear rate of 100 sec ⁻¹ .
The polystyrene resin has a melt viscosity (η2) of 800 to 2000 Pa · s at a measurement temperature of 200 ° C. and a shear rate of 100 sec ⁻¹ , and the copolymer (I) has a melt viscosity (η2) of the polystyrene resin of The manufacturing method of the thermoplastic resin extrusion foam heat insulating board of Claim 1 whose ratio ((eta) 1 / (eta) 2) of melt viscosity ((eta) 1) is 1.0-3.5.
The manufacturing method of the thermoplastic resin extrusion foam heat insulating board of Claim 1 or 2 in which the said copolymer (I) contains the glycol component which has cyclic ether frame | skeleton as a diol component.
The physical blowing agent is at least one selected from 1,3,3,3-tetrafluoropropene, 2,3,3,3-tetrafluoropropene, and 1-chloro-3,3,3-trifluoropropene. The manufacturing method of the thermoplastic resin extrusion foam heat insulating board in any one of Claims 1-3 contained.