JP2018100352A - Styrenic resin extrusion foam and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily obtain a styrenic resin extrusion foam which has excellent heat insulation property and flame retardancy, is beautiful in appearance, is usable for use and has sufficient thickness.SOLUTION: A styrenic resin extrusion foam contains 0.5 pts.wt. or more and 8.0 pts.wt. or less of a flame retardant and 1.0 pts.wt. or more and 5.0 pts.wt. or less of graphite with respect to 100 pts.wt. of a styrenic resin, and contains saturated hydrocarbon having 3 to 5 carbon atoms and hydrochlorofluoroolefin as foaming agents, where a residual amount of the foaming agent in the extrusion foam of the styrenic resin extrusion foam is a specific amount.SELECTED DRAWING: None

Description

  The present invention relates to a styrene resin extruded foam obtained by extrusion foaming using a styrene resin and a foaming agent, and a method for producing the same.

  Styrenic resin extruded foam is generally produced by heating and melting a styrene resin composition using an extruder or the like, then adding a foaming agent under high pressure conditions, cooling to a predetermined resin temperature, Manufactured continuously by extruding into a zone.

  The styrene resin extruded foam is used as a heat insulating material for a structure because of good workability and heat insulation. In recent years, demands for energy saving of houses, buildings, and the like have increased, and technical development of highly heat-insulating foams more than before has been desired.

  Proposed methods for producing highly heat-insulating foams include a method of controlling the bubble diameter of an extruded foam within a predetermined range, a method of adding a heat radiation inhibitor, and a method of using a foaming agent with low thermal conductivity. Has been.

  For example, Patent Document 1 proposes a manufacturing method in which fine bubbles having an average cell diameter in the thickness direction of an extruded foam of 0.05 to 0.18 mm are formed and the bubble deformation rate of the extruded foam is controlled.

  Patent Document 2 proposes a production method in which graphite or titanium oxide is added in a predetermined range as a heat ray radiation inhibitor.

  Furthermore, a method for producing a styrene-based resin extruded foam using an environmentally friendly fluorinated olefin (also referred to as hydrofluoroolefin or HFO) having an ozone depletion coefficient of 0 (zero) and a low global warming potential Has been proposed (see, for example, Patent Documents 3 to 5).

JP 2004-59595 A JP2013-221110A Special table 2008-546892 WO15 / 093195 JP2013-194101A

  However, the techniques described in Patent Documents 1 to 5 have excellent heat insulating properties and flame retardancy, and further provide a styrenic resin extruded foam having a beautiful appearance and a sufficient thickness suitable for use. That was not enough.

  An object of the present invention is to easily obtain an extruded foam of a styrene resin having excellent heat insulating properties and flame retardancy, and having a beautiful appearance and a sufficient thickness suitable for use.

  As a result of intensive studies to solve the above problems, the present inventors have completed the present invention.

  That is, one embodiment of the present invention has the following configuration.

[1] Styrenic resin extrusion foaming containing 0.5 to 8.0 parts by weight flame retardant and 1.0 to 5.0 parts by weight of graphite with respect to 100 parts by weight of styrene resin And containing a saturated hydrocarbon having 3 to 5 carbon atoms and hydrochlorofluoroolefin as a foaming agent,
(I) The residual amount of hydrochlorofluoroolefin in the extruded foam of the styrene-based resin extruded foam is 0.05 mol or more and 0.50 mol or less per kg of the extruded foam,
(II) The residual amount of the saturated hydrocarbon having 3 to 5 carbon atoms in the extruded foam of the styrenic resin extruded foam is 0.10 mol or more and 0.50 mol or less per kg of the extruded foam,
(III) The total amount of the residual amount of saturated hydrocarbons having 3 to 5 carbon atoms and the residual amount of hydrochlorofluoroolefin in the extruded foam of the styrenic resin extruded foam is 0.000 per kg of the extruded foam. A styrene-based resin extruded foam characterized by being 30 mol or more and 0.90 mol or less.

  [2] The residual amount of the hydrochlorofluoroolefin and the residual amount of the saturated hydrocarbon having 3 to 5 carbon atoms are residual amounts after 7 days from the production of the extruded styrene resin foam. The styrene resin extruded foam according to [1].

  [3] The styrene resin extruded foam according to [1] or [2], wherein the hydrochlorofluoroolefin is trans-1-chloro-3,3,3-trifluoropropene.

  [4] The method according to any one of [1] to [3], wherein the method has passed the flammability measurement method A defined in JIS A9521 and has a fire spread length of 10 mm or less. Styrene resin extruded foam.

[5] The styrenic resin according to any one of [1] to [4], wherein the apparent density is 20 kg / m ³ or more and 45 kg / m ³ or less, and the closed cell ratio is 90% or more. Extruded foam.

  [6] The foaming agent is characterized in that at least one member selected from the group consisting of dimethyl ether, ethyl chloride, and methyl chloride is added in an amount of 0.5 to 15 parts by weight based on 100 parts by weight of the styrenic resin. The styrene resin extruded foam according to any one of [1] to [5].

  [7] The extruded styrenic resin foam according to any one of [1] to [6], wherein the saturated hydrocarbon having 3 to 5 carbon atoms is isobutane.

  [8] The styrene resin extruded foam according to any one of [1] to [7], wherein the thickness is 10 mm or more and 150 mm or less.

  [9] The flame retardant is a bromine-based flame retardant, and is contained in an amount of 0.5 part by weight or more and 5.0 parts by weight or less based on 100 parts by weight of the styrene resin. [1] to [8] The styrene resin extruded foam according to any one of the above.

  [10] The method for producing an extruded foam of styrene resin according to any one of [1] to [9].

  According to the present invention, it is possible to easily obtain an extruded foam of a styrene resin having excellent heat insulation and flame retardancy, and having a beautiful appearance and a sufficient thickness suitable for use.

  An embodiment of the present invention will be described below, but the present invention is not limited to this. The present invention is not limited to each configuration described below, and various modifications can be made within the scope shown in the claims. Further, embodiments and / or examples obtained by appropriately combining technical means disclosed in different embodiments and / or examples are also included in the technical scope of the present invention. Moreover, all the academic literatures and patent literatures described in this specification are used as references in this specification. Unless otherwise specified in this specification, “A to B” representing a numerical range is intended to be “A or more (including A and greater than A) and B or less (including B and less than B)”.

  As a result of intensive studies by the present inventors, it has been found that Patent Documents 1 to 5 described above have the following problems. Specifically, first, in the technique described in Patent Document 1, when the average bubble diameter is set to a fine range, the distance between the bubble walls of the foam is shortened, so that the bubbles when the foam is shaped by extrusion foaming. There was a problem that the movable range was narrow and deformation was difficult, and it was not easy to give a beautiful surface to the extruded foam and to obtain the thickness of the extruded foam.

  Next, in the technique described in Patent Document 2, when a large amount of a solid additive is used, the nucleation point increases, so that bubbles of the foam are refined, and there is a problem similar to the technique described in Patent Document 1. It was. In addition, the elongation of the resin itself deteriorates, and there is a problem that it becomes more difficult to give a beautiful surface to the extruded foam and to obtain the thickness of the extruded foam.

  Moreover, in the techniques described in Patent Documents 3 to 4, the hydrofluoroolefin used in these conventional techniques has low solubility in the styrene resin, and the separation from the styrene resin at the time of extrusion foaming is fast, The separated hydrofluoroolefin becomes a nucleation point and the bubble diameter becomes finer, and the resin is cooled and solidified by the latent heat of vaporization of the hydrofluoroolefin (the elongation of the resin becomes worse), which is the same as the technique described in Patent Document 1. There was a problem.

  In the technique described in Patent Document 5, hydrofluoroolefin and saturated hydrocarbon, and water or carbon dioxide are used in combination in order to achieve both heat insulation and moldability. When the amount of the foaming agent used is large, especially when graphite is used as the heat ray radiation inhibitor, it is impossible to impart flame retardancy suitable for the extruded foam. Since hydrofluoroolefin is not completely non-flammable, unless a suitable range is selected in combination with the foaming agent used in combination, the amount, and the combination with the heat ray radiation suppressor, when the styrene resin extruded foam is obtained It had the problem of impairing flame retardancy.

  As described above, all of the conventional techniques for producing a highly heat-insulating foam are the bubble deformation rate of the foam and / or the elongation of the resin itself when the extruded foam is extruded and foamed. There were problems in exacerbating and imparting a beautiful surface to the extruded foam and increasing the thickness of the extruded foam. Therefore, the prior art for producing a highly heat-insulating foam has an excellent heat insulating property and flame retardancy, and further facilitates a styrenic resin extruded foam having a beautiful appearance and / or a sufficient thickness. However, it still has a problem.

  The present inventor has completed the present invention in order to solve such problems. Embodiments of the present invention will be described below.

[1. Styrene resin extruded foam)
The extruded styrenic resin foam according to an embodiment of the present invention is 0.5 to 8.0 parts by weight flame retardant and 1.0 to 5 parts by weight with respect to 100 parts by weight of styrene resin. It is a styrene resin extruded foam containing not more than 0 parts by weight of graphite, and contains a saturated hydrocarbon having 3 to 5 carbon atoms and hydrochlorofluoroolefin as a foaming agent. Further, if necessary, a styrenic resin composition containing an appropriate amount of other additives is heated and melted using an extruder or the like, and then a foaming agent is added under high-pressure conditions and cooled to a predetermined resin temperature. This is continuously produced by extruding it into a low pressure region.

(1-1. Component)
The styrenic resin used in one embodiment of the present invention is not particularly limited. (I) Styrene such as styrene, methylstyrene, ethylstyrene, isopropylstyrene, dimethylstyrene, bromostyrene, chlorostyrene, vinyltoluene, and vinylxylene (Ii) the styrene monomer and divinylbenzene, butadiene, acrylic acid, methacrylic acid, methyl acrylate And a copolymer obtained by copolymerizing one or more monomers such as methyl methacrylate, acrylonitrile, maleic anhydride, and itaconic anhydride. Monomers such as acrylic acid, methacrylic acid, methyl acrylate, methyl methacrylate, maleic anhydride, and itaconic anhydride to be copolymerized with styrenic monomers are the compression strength of the styrene resin extrusion foam produced The amount can be used so as not to deteriorate the physical properties. Further, the styrene resin used in one embodiment of the present invention is not limited to the homopolymer or copolymer of the styrene monomer, and the homopolymer or copolymer of the styrene monomer, It may be a blend of another monomer with a homopolymer or copolymer. For example, the styrene resin used in an embodiment of the present invention may be a blend of the styrene monomer homopolymer or copolymer and diene rubber reinforced polystyrene or acrylic rubber reinforced polystyrene. Good. Furthermore, the styrene resin used in one embodiment of the present invention is a styrene resin having a branched structure for the purpose of adjusting the melt flow rate (hereinafter referred to as MFR), the melt viscosity at the time of molding, the melt tension, and the like. There may be.

  As the styrenic resin in an embodiment of the present invention, it is preferable to use a resin having an MFR of 0.1 to 50 g / 10 min. (I) The molding processability in extrusion foam molding is excellent. (Ii) Molding The point of easy adjustment of the discharge amount during processing, the thickness, width, apparent density, and closed cell ratio of the obtained styrene resin extruded foam to desired values, (iii) foamability (foam thickness, width, (Iv) It is easy to adjust the apparent density, closed cell ratio, surface properties, etc. to a desired situation), (iv) a styrene resin extruded foam excellent in appearance, etc., and (v) This is preferable from the viewpoint of obtaining a styrene-based resin extruded foam having balanced properties (for example, mechanical strength such as compressive strength, bending strength or bending deflection, and toughness). Further, the MFR of the styrenic resin is more preferably 0.3 to 30 g / 10 minutes, and preferably 0.5 to 25 g / 10 minutes in terms of the balance between moldability and foamability, mechanical strength and toughness. Particularly preferred. In one embodiment of the present invention, MFR is measured according to method A of JIS K7210 (1999) and test condition H.

  In one embodiment of the present invention, among the styrene resins described above, a polystyrene resin is particularly suitable from the viewpoint of economy and workability. Moreover, when higher heat resistance is required for the extruded foam, it is preferable to use a styrene-acrylonitrile copolymer, (meth) acrylic acid copolymer polystyrene, or maleic anhydride-modified polystyrene. Moreover, when higher impact resistance is required for the extruded foam, it is preferable to use rubber-reinforced polystyrene. These styrenic resins may be used alone, or two or more different styrenic resins such as copolymerization component, molecular weight and molecular weight distribution, branched structure, and / or MFR may be mixed and used. .

(1-2. Foaming agent)
As a C3-C5 saturated hydrocarbon used by one Embodiment of this invention, a propane, n-butane, i-butane, n-pentane, i-pentane, neopentane etc. are mentioned, for example. Among these saturated hydrocarbons having 3 to 5 carbon atoms, propane, n-butane, i-butane, or a mixture thereof is preferable from the viewpoint of foamability. Further, n-butane, i-butane (hereinafter sometimes referred to as “isobutane”), or a mixture thereof is preferred from the viewpoint of the heat insulating performance of the foam, and i-butane is particularly preferred.

  The hydrochlorofluoroolefin used in one embodiment of the present invention is not particularly limited, but is specifically trans-1-chloro-3,3,3-trimethyl from the viewpoint of low gas thermal conductivity and safety. Fluoropropene (trans-HCFO-1233zd) is preferred. Etc. These hydrochlorofluoroolefins may be used alone or in combination of two or more.

  Depending on various properties of the foam, such as the desired foaming ratio and flame retardancy, the amount of the saturated hydrocarbon having 3 to 5 carbon atoms or the amount of the hydrochlorofluoroolefin added may be limited. Formability may not be sufficient.

  In one embodiment of the present invention, by using another foaming agent, a plasticizing effect and an auxiliary foaming effect at the time of foam production can be obtained, the extrusion pressure can be reduced, and the foam can be stably produced. It becomes.

  Examples of other foaming agents include ethers such as dimethyl ether, diethyl ether, methyl ethyl ether, isopropyl ether, n-butyl ether, diisopropyl ether, furan, furfural, 2-methyl furan, tetrahydrofuran, and tetrahydropyran; dimethyl ketone, methyl ethyl ketone , Diethyl ketone, methyl n-propyl ketone, methyl-n-butyl ketone, methyl-i-butyl ketone, methyl-n-amyl ketone, methyl-n-hexyl ketone, ethyl-n-propyl ketone, ethyl-n-butyl ketone, etc. A saturated alcohol having 1 to 4 carbon atoms such as methanol, ethanol, propyl alcohol, i-propyl alcohol, butyl alcohol, i-butyl alcohol, t-butyl alcohol; Carboxylic acid esters such as acid methyl ester, formic acid ethyl ester, formic acid propyl ester, formic acid butyl ester, formic acid amyl ester, propionic acid methyl ester, propionic acid ethyl ester; organic foams such as alkyl halides such as methyl chloride and ethyl chloride Agents, inorganic foaming agents such as water and carbon dioxide, and chemical foaming agents such as azo compounds and tetrazole can be used. These other blowing agents may be used alone or in combination of two or more.

  Among other foaming agents, saturated alcohols having 1 to 4 carbon atoms, dimethyl ether, diethyl ether, methyl ethyl ether, methyl chloride, ethyl chloride and the like are preferable from the viewpoint of foamability and foam moldability. From the viewpoint of flame retardancy or heat insulation, water and carbon dioxide are preferred. Among these, dimethyl ether, methyl chloride, and ethyl chloride are particularly preferable from the viewpoint of the plasticizing effect, and water is particularly preferable from the viewpoint of the cost and the effect of improving the heat insulation by controlling the bubble diameter.

  In one embodiment of the present invention, when dimethyl ether, methyl chloride, or ethyl chloride is used as the other foaming agent, the addition amount thereof is 0.5 to 15 parts by weight with respect to 100 parts by weight of the styrenic resin. Is preferable, 1.0 part by weight or more and 10 parts by weight or less is more preferable, and 2.0 parts by weight or more and 8.0 parts by weight or less is particularly preferable. If the addition amount of dimethyl ether, methyl chloride, or ethyl chloride is less than 0.5 parts by weight with respect to 100 parts by weight of the styrene resin, the addition amount is too small and it is difficult to obtain the effect of improving the foamability and moldability of the extruded foam. . When the addition amount of dimethyl ether, methyl chloride, and ethyl chloride exceeds 15 parts by weight with respect to 100 parts by weight of the styrene resin, the amount remaining in the obtained extruded foam is too much, and the flame retardancy is deteriorated. There is a risk of causing.

  The amount of the foaming agent added in one embodiment of the present invention is preferably 2.0 parts by weight or more and 20 parts by weight or less, and more preferably 2.0 parts by weight or more and 15 parts by weight or less with respect to 100 parts by weight of the styrene resin. . If the amount of the foaming agent added is less than 2.0 parts by weight, the foaming ratio is low, and the characteristics such as light weight and heat insulation as the resin foam may be difficult to be exhibited. Due to the amount, defects such as voids may occur in the foam.

In one embodiment of the present invention, the foaming agent includes a saturated hydrocarbon having 3 to 5 carbon atoms and hydrochlorofluoroolefin,
(I) The residual amount of hydrochlorofluoroolefin in the extruded foam of the styrene resin extruded foam is 0.05 mol or more and 0.50 mol or less per kg of the extruded foam,
(II) The residual amount of the saturated hydrocarbon having 3 to 5 carbon atoms in the extruded foam of the styrenic resin extruded foam is 0.10 mol or more and 0.50 mol or less per kg of the extruded foam,
(III) The total amount of the residual amount of saturated hydrocarbons having 3 to 5 carbon atoms and the residual amount of hydrochlorofluoroolefin in the extruded foam of the styrenic resin extruded foam is 0.000 per kg of the extruded foam. 30 mol or more and 0.90 mol or less.

  Moreover, in one Embodiment of this invention, the residual amount of a C3-C5 saturated hydrocarbon in this extrusion foam of the said styrene resin extrusion foam is 0.10 mol or more and 0.50 mol or less per kg of this extrusion foam. Yes, 0.15 mol or more and 0.40 mol or less is preferable, and 0.15 mol or more and 0.30 mol or less is more preferable. When the residual amount of the saturated hydrocarbon having 3 to 5 carbon atoms in the extruded foam of the styrenic resin extruded foam is less than 0.10 mol per kg of the extruded foam, the number of carbon atoms in the foam is 3 to 3. Since the amount of the saturated hydrocarbon of 5 is too small, the desired heat insulating property cannot be obtained. When the residual amount of saturated hydrocarbons having 3 to 5 carbon atoms in the extruded foam of the styrenic resin extruded foam exceeds 0.50 mol per kg of the extruded foam, a combustible gas is contained in the foam. Since there is too much quantity of a certain C3-C5 saturated hydrocarbon, desired flame retardance cannot be provided, and the fire spread length in a JIS combustion test becomes long exceeding 10 mm.

  Improving the gas surface combustion of the foam cannot be solved by increasing the flame retardant alone. The mechanism of the gas surface combustion is not limited to this, but as the fire source ignites the foam, the bubbles are destroyed and the foaming agent (combustible gas) present in the bubble structure is returned to the atmosphere. By being released, it is considered that gas combustion occurs together with oxygen in the air. Therefore, if the foam has a structure that is weak against heat, it is considered that the gas release from the foam is facilitated and gas combustion is promoted. Furthermore, for the purpose of imparting excellent heat insulating properties, such as graphite of the present invention, a foam containing a heat ray radiation inhibitor having a heat ray radiation absorption effect is absorbed by the heat ray radiation inhibitor. However, since the foam collapses at a high temperature and releases a large amount of foaming agent from the foam, there is a problem that gas surface combustion is more likely to occur compared to a foam that does not contain a heat ray radiation inhibitor. Gas combustion generally occurs only in the surface layer portion of the JIS combustion test piece, and the fire spread of the fire source may reach the top in an instant.

  According to one embodiment of the present invention, the residual amount of saturated hydrocarbons having 3 to 5 carbon atoms, the residual amount of hydrochlorofluoroolefin, and the residual amount thereof in the extruded foam of the styrene resin extruded foam By controlling the total amount, gas surface fire spread is improved while imparting excellent heat insulation to the foam, and the fire spread length can be 10 mm or less.

  In one embodiment of the present invention, the residual amount of hydrochlorofluoroolefin in the extruded foam of the styrenic resin extruded foam is 0.05 mol or more and 0.50 mol or less, and 0.10 mol or more per kg of the extruded foam. 0.45 mol or less is preferable, and 0.10 mol or more and 0.40 mol or less is more preferable. When the residual amount of hydrochlorofluoroolefin in the extruded foam of the styrenic resin extruded foam is less than 0.05 mol per kg of the extruded foam, the amount of hydrochlorofluoroolefin in the foam is too small. The desired heat insulating property cannot be obtained. When the residual amount of hydrochlorofluoroolefin in the extruded foam of the styrene resin extruded foam exceeds 0.50 mol per kg of the extruded foam, the amount of hydrochlorofluoroolefin in the foam is too large. The moldability deteriorates and an extruded foam having a desired appearance cannot be obtained.

  Hydrochlorofluoroolefin is an environmentally friendly foaming agent that has zero or extremely low ozone depletion potential, a very low global warming potential, and is environmentally friendly. Moreover, since the hydrochlorofluoroolefin has a low thermal conductivity in the gaseous state and is nonflammable, it can be used as a foaming agent for styrene-based resin extruded foam, and can provide excellent heat insulation properties. It is easy to impart flame retardancy superior to the case where a combustible gas is used.

  In one embodiment of the present invention, the total amount of the residual amount of saturated hydrocarbons having 3 to 5 carbon atoms and the residual amount of hydrochlorofluoroolefin in the extruded foam of the styrene resin extruded foam is the extruded foam. It is 0.30 mol or more and 0.90 mol or less, preferably 0.35 mol or more and 0.80 mol or less, more preferably 0.35 mol or more and 0.70 mol or less per 1 kg of the body. When the total amount of the residual amount of saturated hydrocarbons having 3 to 5 carbon atoms and the residual amount of hydrochlorofluoroolefin in the extruded foam of the styrene resin extruded foam is less than 0.30 mol, the foam Since there is too little amount of foaming agents in it, desired heat insulation is not obtained. When the total amount of the residual amount of saturated hydrocarbons having 3 to 5 carbon atoms and the residual amount of hydrochlorofluoroolefin in the extruded foam of the styrenic resin extruded foam exceeds 0.90 mol, the extrusion Since the amount of the foaming agent during foaming is too large, the moldability deteriorates, and an extruded foam having a desired appearance cannot be obtained.

  In one embodiment of the present invention, as described above, in the extruded foam of a saturated hydrocarbon having 3 to 5 carbon atoms and hydrochlorofluoroolefin used as a foaming agent, and a styrene resin extruded foam obtained by adding them together By making the residual amount of the product a predetermined amount, the surface property and thickness-thickening property of the extruded foam (that is, the moldability of the extruded foam) deteriorated when hydrochlorofluoroolefin is used as the foaming agent is excellent. A styrene resin extruded foam having excellent heat insulation and flame retardancy can be obtained. If a large amount of hydrochlorofluoroolefin is used to improve heat insulation, the moldability of the extruded foam deteriorates. Therefore, the residual amount of hydrochlorofluoroolefin is suppressed to the above amount, and further, the number of carbon atoms is 3 to 5. By including the saturated hydrocarbon, good moldability of the extruded foam can be secured. On the other hand, when the residual amount of hydrochlorofluoroolefin is set to the above amount, the hydrochlorofluoroolefin alone has too little foaming agent residual amount in the foam and the effect of improving the heat insulation is small. 5 saturated hydrocarbons are included in a residual amount that does not deteriorate the flame retardancy. By making hydrochlorofluoroolefin and saturated hydrocarbon having 3 to 5 carbon atoms into the above-mentioned residual amount, a desired foam structure is obtained while imparting excellent heat insulation and suitable flame retardancy to the extruded foam. be able to.

  The residual amount of saturated hydrocarbons having 3 to 5 carbon atoms and the residual amount of hydrochlorofluoroolefin in the extruded foam of the styrenic resin extruded foam are within the predetermined range specified in the present invention as described above. In order to control, what is necessary is just to adjust the compounding quantity, extrusion temperature, foaming pressure, etc. of a C3-C5 saturated hydrocarbon and hydrochlorofluoroolefin. In order to increase the residual amount of C3-C5 saturated hydrocarbon and hydrochlorofluoroolefin by adjusting the extrusion temperature and foaming pressure, the extrusion temperature should be kept low and the foaming pressure kept high. In order to reduce the residual amount of the saturated hydrocarbon having 3 to 5 carbon atoms and the hydrofluoroolefin, the extrusion temperature is increased and the foaming pressure is decreased.

  In one embodiment of the present invention, the residual amount of hydrochlorofluoroolefin and the residual amount of saturated hydrocarbon having 3 to 5 carbon atoms are the residual amount after 7 days from the production of the styrene resin extruded foam. preferable. Hydrochlorofluoroolefin and saturated hydrocarbons having 3 to 5 carbon atoms have a very slow dissipation rate from the foam, and if the remaining amount after 7 days from production is known, the change in the remaining amount is small.

  In one embodiment of the present invention, when water and / or alcohols are used as the other foaming agent, it is preferable to add a water-absorbing substance in order to stably perform extrusion foam molding. Specific examples of the water-absorbing substance used in one embodiment of the present invention include polyacrylate polymers, starch-acrylic acid graft copolymers, polyvinyl alcohol polymers, vinyl alcohol-acrylate copolymers. In addition to water-absorbing polymers such as polymers, ethylene-vinyl alcohol copolymers, acrylonitrile-methyl methacrylate-butadiene copolymers, polyethylene oxide copolymers and derivatives thereof, anhydrous silica having silanol groups on the surface (Silicon oxide) [For example, AEROSIL manufactured by Nippon Aerosil Co., Ltd. is commercially available] etc. Fine powder having a hydroxyl group on the surface and a particle diameter of 1000 nm or less; Water absorption or water such as smectite, swellable fluoromica Swellable layered silicates and their organic products: zeolite, activity , Alumina, silica gel, porous glass, activated clay, diatomaceous earth, porous material or the like, such as bentonite. The addition amount of the water-absorbing substance is appropriately adjusted depending on the addition amount of water and the like, but is preferably 0.01 to 5 parts by weight, preferably 0.1 to 3 parts by weight with respect to 100 parts by weight of the styrenic resin. Part is more preferred.

  In the method for producing a styrene resin extruded foam according to an embodiment of the present invention, the pressure when adding or injecting a foaming agent is not particularly limited, and may be a pressure higher than the internal pressure of an extruder or the like. That's fine.

(1-3. Flame retardant)
In one embodiment of the present invention, in a styrene resin extruded foam, a styrene resin obtained by containing a flame retardant in an amount of 0.5 to 8.0 parts by weight with respect to 100 parts by weight of a styrene resin. Flame resistance can be imparted to the extruded foam. If the content of the flame retardant is less than 0.5 parts by weight, good properties as a foam such as flame retardancy tend to be difficult to obtain. On the other hand, if the content exceeds 8.0 parts by weight, the foam is produced. The stability and surface properties of the time may be impaired. However, the content of the flame retardant is such as the amount of foaming agent added, the apparent density of the foam, and the additive having a flame retardant synergistic effect so that the flame retardancy specified in JIS A 9521 measurement method A can be obtained. Or it is more preferable to adjust suitably according to content etc.

  In one embodiment of the present invention, it is preferable that the flammability measurement method A specified in JIS A9521 is passed and the fire spread length is 10 mm or less.

  A brominated flame retardant is preferably used as the flame retardant. Specific examples of the brominated flame retardant in one embodiment of the present invention include hexabromocyclododecane, tetrabromobisphenol A-bis (2,3-dibromo-2-methylpropyl) ether, tetrabromobisphenol A-bis. Aliphatic bromine-containing polymers such as (2,3-dibromopropyl) ether, tris (2,3-dibromopropyl) isocyanurate, and brominated styrene-butadiene block copolymers. These may be used alone or in combination of two or more.

  Of these, a mixed brominated flame retardant comprising bromide and tetrabromobisphenol A-bis (2,3-dibromo-2-methylpropyl) ether and tetrabromobisphenol A-bis (2,3-dibromopropyl) ether Styrene-butadiene block copolymer and hexabromocyclododecane are desirably used because they have good extrusion operation and do not adversely affect the heat resistance of the foam. These substances may be used alone or as a mixture.

  The content of the brominated flame retardant in the styrene resin extruded foam according to an embodiment of the present invention is preferably 0.5 parts by weight or more and 5.0 parts by weight or less with respect to 100 parts by weight of the styrene resin. 1.0 to 5.0 parts by weight is more preferable with respect to 100 parts by weight of the resin, and 1.5 to 5.0 parts by weight is even more preferable. If the brominated flame retardant content is less than 0.5 parts by weight, good properties such as flame retardancy tend to be difficult to obtain. On the other hand, if the content exceeds 5.0 parts by weight, It may impair the stability and surface properties during body production.

  In one embodiment of the present invention, a radical generator can be used in combination for the purpose of improving the flame retardancy of the styrene resin extruded foam. Specific examples of the radical generator include 2,3-dimethyl-2,3-diphenylbutane, poly-1,4-diisopropylbenzene, 2,3-diethyl-2,3-diphenylbutane, 3,4- Dimethyl-3,4-diphenylhexane, 3,4-diethyl-3,4-diphenylhexane, 2,4-diphenyl-4-methyl-1-pentene, 2,4-diphenyl-4-ethyl-1-pentene, etc. Is mentioned. Peroxides such as dicumyl peroxide are also used. Among them, those that are stable under the resin processing temperature conditions are preferable, specifically 2,3-dimethyl-2,3-diphenylbutane and poly-1,4-diisopropylbenzene are preferable. A preferable addition amount is 0.05 to 0.5 parts by weight with respect to 100 parts by weight of the styrene resin.

  Furthermore, for the purpose of improving the flame retardancy, in other words, as a flame retardant aid, a phosphorus flame retardant such as phosphate ester and phosphine oxide can be used in combination as long as the thermal stability performance is not impaired. Examples of phosphate esters include triphenyl phosphate, tris (tributylbromoneopentyl) phosphate, tricresyl phosphate, trixylylenyl phosphate, cresyl diphenyl phosphate, 2-ethylhexyl diphenyl phosphate, trimethyl phosphate, triethyl phosphate, tributyl phosphate, Examples thereof include tris (2-ethylhexyl) phosphate, tris (butoxyethyl) phosphate, and condensed phosphate ester. Triphenyl phosphate or tris (tributylbromoneopentyl) phosphate is particularly preferable. As the phosphine oxide-type phosphorus flame retardant, triphenylphosphine oxide is preferable. These phosphate esters and phosphine oxides may be used alone or in combination of two or more. A preferable addition amount of the phosphorus flame retardant is 0.1 to 2 parts by weight with respect to 100 parts by weight of the styrene resin.

(1-4. Stabilizer)
In one embodiment of the present invention, a resin and / or a flame retardant stabilizer can be used as necessary. Although not particularly limited, specific examples of the stabilizer include (i) epoxy compounds such as (i) bisphenol A diglycidyl ether type epoxy resin, cresol novolac type epoxy resin, and phenol novolac type epoxy resin, ii) A reaction product of a polyhydric alcohol such as pentaerythritol, dipentaerythritol or tripentaerythritol and a monovalent carboxylic acid such as acetic acid or propionic acid, or a divalent carboxylic acid such as adipic acid or glutamic acid. A polyhydric alcohol ester which is a mixture of esters having one or more hydroxyl groups in the molecule and may contain a small amount of a starting polyhydric alcohol; (iii) triethylene glycol-bis-3- (3-tert-butyl-4-hydroxy-5-methylpheny ) Propionate, pentaerythritol tetrakis [3- (3 ′, 5′-di-tert-butyl-4′-hydroxyphenyl) propionate], and octadecyl 3- (3,5-di-tert-butyl-4-hydroxyphenyl) ) Phenolic stabilizers such as propionate, (iv) 3,9-bis (2,4-di-tert-butylphenoxy) -2,4,8,10-tetraoxa-3,9-diphosphaspiro [5.5 ] Undecane, 3,9-bis (2,6-di-tert-butyl-4-methylphenoxy) -2,4,8,10-tetraoxa-3,9-diphosphaspiro [5.5] undecane, and tetrakis ( 2,4-di-tert-butyl-5-methylphenyl) -4,4′-biphenylenediphosphonite) Agents, etc. without reducing the flame retardancy of the foam, and, since it improves the thermal stability of the foam, is preferably used.

(1-5. Heat radiation inhibitor)
The styrene resin extruded foam according to an embodiment of the present invention contains graphite as a heat ray radiation suppressor for improving heat insulation. Examples of the graphite used in the embodiment of the present invention include scale-like graphite, earthy graphite, spherical graphite, and artificial graphite. Among these, it is preferable to use the one whose main component is scale-like graphite from the viewpoint of a high heat ray radiation suppressing effect. The graphite preferably has a fixed carbon content of 80% or more, and more preferably 85% or more. The foam which has high heat insulation is obtained by making fixed carbon content into the said range.

  The dispersed particle diameter of graphite is preferably 15 μm or less, and more preferably 10 μm or less. By setting the particle size within the above range, the specific surface area of graphite is increased, and the probability of collision with heat radiation is increased, so that the effect of suppressing heat radiation is enhanced. In order to make the dispersed particle diameter within the above range, a particle having a primary particle diameter of 15 μm or less may be selected.

  The dispersed particle diameter is an arithmetic average value based on the number of particle diameters of the respective particles dispersed in the foam, and the particle diameter is measured by enlarging the foam cross section with a microscope or the like. The primary particle size means a volume average particle size (d50).

  In one embodiment of the present invention, the graphite content is 1.0 to 5.0 parts by weight with respect to 100 parts by weight of the styrene resin, and 1.5 to 3.0 parts by weight. preferable. When the content is less than 1.0 part by weight, a sufficient heat ray radiation suppressing effect cannot be obtained. If the content exceeds 5.0 parts by weight, the effect of suppressing heat radiation corresponding to the content cannot be obtained, and there is no cost merit.

  The said heat ray radiation inhibitor means the substance which has the characteristic to reflect, scatter, and absorb the light of near infrared or infrared region (for example, wavelength range of about 800-3000 nm). By containing a heat ray radiation inhibitor, a foam having high heat insulation can be obtained. As a heat ray radiation inhibitor that can be used in the present invention, white particles such as titanium oxide, barium sulfate, zinc oxide, aluminum oxide, and antimony oxide can be used in combination with graphite. These may be used alone or in combination of two or more. Among these, titanium oxide or barium sulfate is preferable, and titanium oxide is more preferable from the viewpoint of a great effect of suppressing radiation radiation. The dispersed particle diameter of the white particles is not particularly limited, but is preferably 0.1 μm to 10 μm, for example, in the case of titanium oxide, in view of effectively reflecting infrared rays and considering color developability to the resin. 0.15 μm to 5 μm is more preferable.

  The content of the white particles in an embodiment of the present invention is preferably 1.0 part by weight or more and 3.0 parts by weight or less, and 1.5 parts by weight or more and 2.5 parts by weight or less with respect to 100 parts by weight of the styrene resin. More preferred are parts by weight or less. The white particles have a smaller heat ray radiation suppressing effect than graphite, and if the white particle content is less than 1.0 part by weight, even if the white particles are contained, there is almost no heat ray radiation suppressing effect. When the content of the white particles exceeds 3.0 parts by weight, the heat ray radiation suppressing effect corresponding to the content cannot be obtained, while the flame retardancy of the foam tends to deteriorate.

  In one embodiment of the present invention, the total content of the heat ray radiation inhibitor is preferably 1.0 part by weight or more and 6.0 parts by weight or less, and 2.0 parts by weight or more and 5.5 parts by weight or less with respect to 100 parts by weight of the styrene resin. 0 parts by weight or less is more preferable. If the total content of the heat ray radiation inhibitor is less than 1.0 part by weight, it is difficult to obtain heat insulation, whereas the nucleation point increases as the content of the solid additive such as the heat ray radiation inhibitor increases. However, it tends to be difficult to impart a beautiful surface to the extruded foam and to increase the thickness of the extruded foam by making the foam bubbles finer or the elongation of the resin itself worsening. In addition, when the total content of the heat ray radiation inhibitor exceeds 6.0 parts by weight, it is particularly inferior to impart a beautiful surface to the extruded foam and to give a thickness of the extruded foam, There is a tendency to impair extrusion stability and flame retardancy.

(1-6. Additive)
In one embodiment of the present invention, if necessary, for example, silica, calcium silicate, wollastonite, kaolin, clay, mica, carbonic acid, as long as the effects according to one embodiment of the present invention are not inhibited. Inorganic compounds such as calcium, processing aids such as sodium stearate, calcium stearate, magnesium stearate, barium stearate, liquid paraffin, olefin waxes, stearylamide compounds, phenolic antioxidants, phosphorus stabilizers, nitrogen System stabilizers, sulfur stabilizers, light-resistant stabilizers such as benzotriazoles and hindered amines, cell diameter regulators such as talc, flame retardants other than those mentioned above, antistatic agents, colorants such as pigments, plasticizers, etc. An additive may be contained in the styrenic resin.

  As a method and procedure for blending various additives into the styrene resin, for example, a method of adding various additives to the styrene resin and mixing them by dry blending, melting from a supply unit provided in the middle of the extruder A method for adding various additives to the styrenic resin, a masterbatch containing various additives at a high concentration in the styrenic resin using an extruder, kneader, Banbury mixer, roll, etc. in advance, Examples thereof include a method of mixing a styrene resin by dry blending, or a method of supplying various additives to an extruder by a supply facility different from the styrene resin. For example, a procedure in which various additives are added to and mixed with a styrenic resin, then supplied to an extruder, melted by heating, and a foaming agent is further added and mixed. There is no particular limitation on the timing and kneading time for adding the styrene resin.

(2. Physical properties)
The thermal conductivity of the styrene-based resin extruded foam according to one embodiment of the present invention is not particularly limited, but for example, it has been considered that it functions as a heat insulating material for a building, or a heat insulating material for a cold storage or a cold car. From the viewpoint of heat insulation, the thermal conductivity after one week of production measured at an average temperature of 23 ° C. is preferably 0.0285 W / mK or less, more preferably 0.0245 W / mK or less, and 0.0225 W. / MK or less is particularly preferable.

The apparent density of the styrene-based resin extruded foam according to one embodiment of the present invention is, for example, heat insulating properties and light weight considering that it functions as a heat insulating material for buildings, or a heat insulating material for a cold storage or a cold car. In view of the above, it is preferably 20 kg / m ³ or more and 45 kg / m ³ or less, more preferably 25 kg / m ³ or more and 40 kg / m ³ or less.

  The closed cell ratio of the styrene resin extruded foam according to an embodiment of the present invention is preferably 90% or more, and more preferably 95% or more. When the closed cell ratio is less than 90%, the foaming agent dissipates from the extruded foam at an early stage, and the heat insulating property is lowered.

  The average cell diameter in the thickness direction of the styrene resin extruded foam according to an embodiment of the present invention is preferably 0.05 mm or more and 0.5 mm or less, more preferably 0.05 mm or more and 0.4 mm or less, and 0.05 mm or more. 0.3 mm or less is particularly preferable. In general, the smaller the average cell diameter, the shorter the distance between the cell walls of the foam, so the range of movement of the foam in the extruded foam is narrow when shaping the extruded foam during extrusion foaming, making deformation difficult Therefore, it tends to be difficult to impart a beautiful surface to the extruded foam and to increase the thickness of the extruded foam. When the average cell diameter in the thickness direction of the styrene resin extruded foam is smaller than 0.05 mm, it tends to be difficult to give a beautiful surface to the extruded foam and to obtain the thickness of the extruded foam. It will be something. On the other hand, when the average cell diameter in the thickness direction of the styrene resin extruded foam is more than 0.3 mm, sufficient heat insulation may not be obtained.

  In addition, the average cell diameter of the styrene resin extruded foam according to an embodiment of the present invention was evaluated as described below using a microscope [manufactured by KEYENCE, DIGITAL MICROSCOPE VHX-900].

  The width direction vertical cross section of the thickness direction center part of a total of three places of the width direction center part of the obtained styrene-type resin extrusion foam and the place of 150 mm from the end of the width direction to the opposite end direction (the same place about both ends of the width direction). Was observed with the microscope from the extrusion direction and the width direction, and a 100 times magnified photograph was taken. Three straight lines of 2 mm are arbitrarily drawn in the thickness direction of the enlarged photograph (three for each observation location and each observation direction), and the number of bubbles a in contact with the straight line is measured. From the measured number of bubbles a, the average bubble diameter A in the thickness direction for each observation location was determined by the following equation (1). The average value of three locations (each in two directions) was defined as the average cell diameter A (average value) in the thickness direction of the styrene resin extruded foam.

Average bubble diameter A (mm) in the thickness direction for each observation location = 2 × 3 / number of bubbles a
(1).

  The cross-section in the width direction of the obtained styrene-based resin extruded foam, and the vertical cross section in the thickness direction at the central part in the thickness direction of a total of three places: 150 mm in the opposite direction from one end in the width direction (the same place for both ends in the width direction) Was observed with the microscope from the width direction, and a 100 times magnified photograph was taken. Arbitrarily draw 3 straight lines of 2 mm in the extruding direction of the enlarged photograph (3 for each observation location), and measure the number b of bubbles in contact with the straight line. From the measured number b of bubbles, the average bubble diameter B in the extrusion direction for each observation location was determined by the following equation (2). The average value at three locations was defined as the average cell diameter B (average value) in the extrusion direction of the styrene resin extruded foam.

Average bubble diameter B (mm) in the extrusion direction for each observation location = 2 × 3 / number of bubbles b
(2).

  The width direction vertical cross section of the thickness direction center part of a total of three places of the width direction center part of the obtained styrene-type resin extrusion foam and the place of 150 mm from the end of the width direction to the opposite end direction (the same place about both ends of the width direction). Was observed with the microscope from the direction of extrusion, and a 100 times magnified photograph was taken. Three straight lines of 2 mm are arbitrarily drawn in the width direction of the enlarged photograph (three at each observation point), and the number c of bubbles in contact with the straight line is measured. From the measured number c of bubbles, the average bubble diameter C in the width direction for each observation location was determined by the following equation (3). The average value at three locations was defined as the average cell diameter C (average value) in the width direction of the styrene resin extruded foam.

Average bubble diameter C (mm) in the width direction for each observation location = 2 × 3 / number of bubbles c
(3).

  The cell deformation rate of the styrene resin extruded foam according to an embodiment of the present invention is preferably 0.7 or more and 2.0 or less, more preferably 0.8 or more and 1.5 or less, and 0.8 or more and 1.2 or less. The following is more preferable. When the bubble deformation rate is smaller than 0.7, the compressive strength becomes low, and the extruded foam may not be able to ensure the strength suitable for the application. Further, since the bubbles try to return to a spherical shape, there is a tendency that the dimension (shape) maintainability of the extruded foam is inferior. On the other hand, when the bubble deformation rate is more than 2.0, the number of bubbles in the thickness direction of the extruded foam is reduced, so that the effect of improving the heat insulation property by the bubble shape is reduced.

  In addition, the bubble deformation rate of the styrene resin extruded foam according to an embodiment of the present invention can be obtained from the above-described average cell diameter by the following equation (4).

  Bubble deformation rate (no unit) = A (average value) / {[B (average value) + C (average value)] / 2} (4).

  The thickness of the styrene-based resin extruded foam according to an embodiment of the present invention is, for example, thermal insulation, bending strength, and compressive strength in consideration of functioning as a thermal insulation for a building, or a thermal insulation for a cold box or a cold car. In view of the above, it is preferably 10 mm or more and 150 mm or less, more preferably 20 mm or more and 130 mm or less, and particularly preferably 30 mm or more and 120 mm or less.

  In addition, in the styrene resin extruded foam, as described in the examples of the present invention and comparative examples, after forming by extrusion foam molding, both surfaces of the plane perpendicular to the thickness direction are on one side in the thickness direction. Although it may be cut to a depth of about 5 mm to obtain the product thickness, unless otherwise stated, the thickness in the styrene resin extruded foam according to one embodiment of the present invention gives the shape by extrusion foam molding. It is the thickness which is not cut as it is.

  The shape of the styrene-based resin extruded foam according to an embodiment of the present invention is, for example, a heat insulating material for buildings, or a heat insulating material for a cold storage or a cold car, for example, an extrusion direction, a width direction, and a thickness. It must be plate-shaped with no undulations in any direction. As described above, for example, when hydrofluoroolefin is used, when a heat ray radiation inhibitor is used, or when the average cell system is refined as a styrene-based extruded foam, the elongation of the resin itself deteriorates. When the foam foam is shaped by extrusion foaming, the movable range of bubbles in the extruded foam is narrow and deformation is difficult, so it can be shaped when trying to adjust the thickness by extrusion foam molding. In some cases, one or more of the extrusion direction, the width direction, and the thickness direction of the extruded foam is wavy and does not have a plate shape.

  The surface property of the styrene resin extruded foam according to one embodiment of the present invention is to ensure stability during production, and when used as a product while leaving both surfaces of the plane perpendicular to the thickness direction. Since it becomes particularly important, there is no need for flow marks, cracks, mess, etc., and it needs to be beautiful. As described above, for example, when hydrofluoroolefin is used, when a heat ray radiation inhibitor is used, or when the average cell system is refined as a styrene-based extruded foam, the elongation of the resin itself deteriorates. Or when the foam is extruded and shaped to give a narrow range of movement of the foam bubbles, difficult to deform, flow marks, cracks, rashes, etc. occur on the surface of the extruded foam. The surface property may be impaired. A flow mark is a flow mark of a resin melt, and is generated on both surfaces of a plane perpendicular to the thickness direction when the resin itself is hard and poorly stretched. A crack is a crack that occurs when an excessive force is applied to an extruded foam, and is particularly likely to occur when the thickness of an extruded foam is forcibly molded to increase its thickness. . It may occur on both surfaces of the plane perpendicular to the thickness direction, or may occur at the end (side part) in the width direction. In severe cases, cracks may be the starting point, and the continuously produced extruded foam may be broken. In addition, scouring means that a part of the foamed resin melt is excessively solidified, etc., and is caught on the molding die and rolled up, so that both surfaces of the plane perpendicular to the thickness direction and the end in the width direction (side Part) may occur locally or entirely.

  Thus, according to an embodiment of the present invention, it is possible to easily obtain a styrene resin extruded foam having excellent heat insulating properties and flame retardancy, and having a beautiful appearance and a sufficient thickness suitable for use. it can.

[2. Styrene resin extruded foam manufacturing method]
The manufacturing method of the styrene-type resin extrusion foam which concerns on one Embodiment of this invention was described above [1. It is a manufacturing method used in order to manufacture the styrene resin extrusion foam as described in [Styrene resin extrusion foam]. Among the configurations used in the method for producing a styrene resin extruded foam according to an embodiment of the present invention, [1. The description of the configuration already described in [Styrenic resin extruded foam] is omitted here.

  As a method for producing a styrene resin extruded foam according to an embodiment of the present invention, a styrene resin and, if necessary, a flame retardant, a stabilizer, a heat radiation inhibitor, or other additives are extruded. To the heating and melting section of the machine. At this time, hydrochlorofluoroolefin, saturated hydrocarbon having 3 to 5 carbon atoms, and, if necessary, other blowing agent can be added to the styrenic resin under high pressure conditions at any stage. A mixture of a styrene-based resin, a hydrochlorofluoroolefin, a saturated hydrocarbon having 3 to 5 carbon atoms, and other additives and / or other blowing agents is fluidized gel (in other words, a resin melt). After cooling to a temperature suitable for extrusion foaming, the fluid gel is extruded and foamed into a low pressure region through a die to form a foam.

  The heating temperature in the heating and melting part may be equal to or higher than the temperature at which the styrene-based resin used melts, but the temperature at which molecular degradation of the resin due to the influence of additives and the like is suppressed as much as possible, for example, 150 ° C. to 260 ° C. The degree is preferred. The melt kneading time in the heating and melting part is uniquely defined because it varies depending on the amount of styrene resin extruded per unit time and / or the type of the extruder used as the heating and melting part and used as the melt kneading part. The time required for uniformly dispersing and mixing the styrenic resin, the foaming agent, and the additive is appropriately set.

  Examples of the melt-kneading part include a screw type extruder, but are not particularly limited as long as they are used for normal extrusion foaming.

  The foam molding method according to an embodiment of the present invention is an extruded foam obtained by opening from a high-pressure region to a low-pressure region through a slit die in which an opening used for extrusion molding has a linear slit shape, for example. A plate-like foam having a large cross-sectional area using a molding die placed in close contact with or in contact with a slit die, and a molding roll placed adjacent to the downstream side of the molding die Is used. By adjusting the flow surface shape of the molding die and the mold temperature, the desired cross-sectional shape of the foam, the surface property of the foam, and the quality of the foam can be obtained.

  The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope shown in the claims, and embodiments obtained by appropriately combining technical means disclosed in different embodiments. Is also included in the technical scope of the present invention. Furthermore, a new technical feature can be formed by combining the technical means disclosed in each embodiment.

  Examples of the present invention will be described below. Needless to say, the present invention is not limited to the following examples.

  The raw materials used in the examples and comparative examples are as follows.

○ Base resin / styrene resin A [manufactured by PS Japan, G9401; MFR 2.2 g / 10 min]
Styrene resin B [manufactured by PS Japan Co., Ltd., 680; MFR 7.0 g / 10 min].

○ Heat radiation inhibitor / graphite [manufactured by Maruhyo Casting Mfg. Co., Ltd., M-885; scale-like graphite, primary particle size 5.5 μm, fixed carbon content 89%]
Titanium oxide [manufactured by Sakai Chemical Industry Co., Ltd., R-7E; primary particle size 0.23 μm].

○ Flame retardants ・ Bromo flame retardant mixed with tetrabromobisphenol A-bis (2,3-dibromo-2-methylpropyl) ether and tetrabromobisphenol A-bis (2,3-dibromopropyl) ether [Daiichi Kogyo] Manufactured by Pharmaceutical Co., Ltd., GR-125P]
-Brominated styrene-butadiene block polymer [Emeral Innovation # 3000, manufactured by Chemtura].

○ Flame retardant aid, triphenylphosphine oxide [Sumitomo Corporation Chemical].

A radical generator, poly-1,4-diisopropylbenzene [manufactured by UNITED INITIATORS, CCPIB].

O Stabilizer / bisphenol-A-glycidyl ether [manufactured by ADEKA, EP-13].
-Cresol novolac epoxy resin [manufactured by Huntsman Japan, ECN-1280]
-Dipentaerythritol-adipic acid reaction mixture [Ajinomoto Fine Techno Co., Ltd., Pleniser ST210]
Pentaerythritol tetrakis [3- (3 ′, 5′-di-tert-butyl-4′-hydroxyphenyl) propionate] [manufactured by Chemtura, ANOX20]
・ 3,9-bis (2,4-di-tert-butylphenoxy) -2,4,8,10-tetraoxa-3,9-diphosphaspiro [5.5] undecane [manufactured by Chemtura, Ultranox 626]
Triethylene glycol-bis-3- (3-tert-butyl-4-hydroxy-5-methylphenyl) propionate [Songwon Japan Co., Ltd., Sonnox 2450FF].

○ Other additives
・ Talc [Hayashi Kasei Co., Ltd., Talcan powder PK-Z]
・ Calcium stearate [manufactured by Sakai Chemical Industry Co., Ltd., SC-P]
Bentonite [Hogel Jungle, Wengel Bright K11]
Silica [Evonik Degussa Japan Co., Ltd., Carplex BS-304F]
-Ethylene bis-stearic acid amide [NOF Corporation, Alflow H-50S].

○ Foaming agent / HCFO-1233zd [Honeywell Japan Co., Ltd.]
・ Dimethyl ether [Made by Iwatani Corporation]
・ Isobutane [Mitsui Chemicals, Inc.]
・ Ethyl chloride [Nippon Specialty Chemicals Co., Ltd.]
・ Water [Tapzu City, Osaka Prefecture].

  About Examples and Comparative Examples, the thickness of the styrene resin extruded foam (before cutting), the residual amount of HCFO-1233zd per 1 kg of the foam, the residual amount of isobutane, the apparent density, the closed cell ratio, the average cell diameter, according to the following method The bubble deformation rate, thermal conductivity, JIS flammability and fire spread length, and foam appearance were evaluated.

(1) Thickness of styrene resin extruded foam (before cutting)
Using a caliper [M-type standard caliper N30 manufactured by Mitutoyo Corporation], the thickness of the central part in the width direction and a place 150 mm from the one end in the width direction to the opposite end direction (the same place for both ends in the width direction), a total of three points Was measured. The average value of the three points was taken as the thickness of the styrene resin extruded foam.

(2) Residual amount of HCFO-1233zd per 1 kg of foam, residual amount of isobutane The obtained styrene-based resin extruded foam was classified into standard temperature class 3 (23 ° C. ± 5 ° C.) and standard humidity defined in JIS K 7100 The mixture was allowed to stand under the condition of state 3 (50 ^{+ 20, −10} % RH), and the residual amount of HCFO-1233zd and the residual amount of isobutane after 7 days from the production were evaluated by the following equipment and procedure.
a) Equipment used: Gas chromatograph GC-2014 [manufactured by Shimadzu Corporation]
b) Column used: G-Column G-950 25UM [Chemicals Evaluation and Research Institute]
c) Measurement conditions;
・ Inlet temperature: 65 ℃
-Column temperature: 80 ° C
-Detector temperature: 100 ° C
Carry gas: High purity helium Carry gas flow rate: 30 mL / min Detector: TCD
・ Current: 120mA
Put about 1.2g of test piece into an approximately 130cc sealable glass container (hereinafter referred to as "sealed container"), depending on the apparent density cut out from the foam, and evacuate the sealed container with a vacuum pump. It was. Thereafter, the sealed container was heated at 170 ° C. for 10 minutes, and the foaming agent in the foam was taken out into the sealed container. After the airtight container returns to room temperature, helium is introduced into the airtight container to return to atmospheric pressure, and then 40 μL of HCFO-1233zd and a mixed gas containing isobutane are taken out using a microsyringe, and the above a) to c) are used. Evaluation was carried out using equipment and measurement conditions.

(3) Apparent density (kg / m ³ )
While measuring the weight of the obtained styrene resin extruded foam, the length dimension, the width dimension, and the thickness dimension were measured.

From the measured weight and each dimension, the foam density was calculated | required based on the following formula | equation (5), and the unit was converted into kg / m < ³ >.
Apparent density (g / cm ³ ) = foam weight (g) / foam volume (cm ³ ) (5)
(4) Closed cell ratio 40 mm in thickness from a total of three locations, the central portion in the width direction of the obtained styrene-based resin extruded foam, and a location 150 mm in the opposite direction from one end in the width direction (the same location for both ends in the width direction). × Using a test piece cut into a length (extrusion direction) of 25 mm × a width of 25 mm, measured according to the procedure C of ASTM-D2856-70, and obtaining the closed cell ratio of each test piece with the following calculation formula (6), The average value of 3 places was made into the closed cell rate of a styrene-type resin extrusion foam.
Closed cell ratio (%) = (V1−W / ρ) × 100 / (V2−W / ρ) (6)
Here, V1 (cm ³ ) is the true volume of the test piece measured using an air-comparing hydrometer [Tokyo Science Co., Ltd., air-comparing hydrometer, model 1000 type] Is removed.) V2 (cm ³ ) is an apparent volume calculated from the outer dimensions of the test piece measured using a caliper [manufactured by Mitutoyo Corporation, M-type standard caliper N30]. W (g) is the total weight of the test piece. Moreover, (rho) (g / cm < ³ >) is the density of the styrene resin which comprises an extrusion foam, and was 1.05 (g / cm < ³ >).

(5) Average cell diameter in the thickness direction and cell deformation rate The obtained styrene resin extruded foam was evaluated as described above.

(6) Thermal conductivity In accordance with JIS A 9521, using a test piece cut into a thickness product thickness × length (extrusion direction) 300 mm × width 300 mm, a thermal conductivity measuring device [Eihiro Seiki Co., Ltd., HC- 074], the thermal conductivity at an average temperature of 23 ° C. was measured. Measurements were made after manufacturing a styrene-based resin extruded foam, and cut into a test piece having the above dimensions, and the standard temperature state class 3 (23 ° C. ± 5 ° C.) and standard humidity state class 3 (50 ^{+20, −10} % RH), and one week after production. The thermal conductivity value obtained by the measurement was determined according to the following criteria.
○ (Pass): Thermal conductivity is 0.024 (0.0245) W / mK or less.
X (failure): Thermal conductivity is larger than 0.024 (0.0245) W / mK.

(7) JIS combustibility In accordance with JIS A 9521, a test piece having a thickness of 10 mm, a length of 200 mm, and a width of 25 mm was used, and evaluation was performed according to the following criteria. Measurements were made after manufacturing a styrene-based resin extruded foam, and cut into a test piece having the above dimensions, and the standard temperature state class 3 (23 ° C. ± 5 ° C.) and standard humidity state class 3 (50 ^{+20, −10} % RH), and one week after production.
○: Satisfies the criteria that the flame disappears within 3 seconds, there is no residue, and the combustion limit indicator line is not exceeded.
X: The above criteria are not satisfied.

  In addition, regarding the gas surface combustion, which is a phenomenon in which only the foam surface is spread by the combustible gas contained in the foam (in the bubbles), the length (mm) of the flame spread beyond the combustion limit indicating line is expressed as “fire spread length”. Was measured. The measurement of the “fire spread length” was also an average value obtained by measuring five test pieces as in the case of the JIS combustibility. When the fire was extinguished without exceeding the combustion limit instruction line (without reaching the combustion limit instruction line), the remaining distance from the combustion limit instruction was obtained as a negative value. In general, this minus amount is regarded as zero, but in order to clarify the effect of the present invention, it is described in the minus direction.

(8) Foam appearance From the evaluation results of the shape and surface properties described in (8) -1 and (8) -2 below, determination was made according to the following evaluation criteria.
Pass: Both the shape and surface property evaluation results are ◯.
Fail: At least one of the evaluation result of the shape and the surface property is Δ or ×.

(8) -1. Shape The extruded foam after the forming roll and before cutting was visually observed and evaluated according to the following evaluation criteria.
◯: There is no corrugation in any of the extrusion direction, the width direction, and the thickness direction of the extruded foam, and it is plate-shaped.
X: Any one or more of the extrusion direction, the width direction, and the thickness direction of the extruded foam is corrugated and is not plate-shaped.

(8) -2. Surface property Before and after the cut, the extruded foam was visually observed and evaluated according to the following evaluation criteria. In addition, the surface refers to a surface perpendicular to the thickness direction, and after cutting, both surfaces were cut at a depth of 5 mm on one side in the thickness direction based on the thickness of the styrene resin extruded foam (three-point average value). Refers to the state.
○: A surface having no surface abnormality such as a flow mark, a crack, and a rash, and a beautiful surface.
Δ: Although there are surface abnormalities such as flow marks, cracks, and whips, no marks remain on the surface after cutting.
X: There are surface abnormalities such as flow marks, cracks, and rashes, and those marks remain on the surface after cutting.

  About an Example and a comparative example, the graphite and the titanium oxide were added with the masterbatch produced according to the following methods.

[Production of graphite masterbatch A]
For the Banbury mixer, 100 parts by weight of styrene resin A [PS Japan Co., Ltd., G9401] as a base resin, and 100 parts by weight of styrene resin A, graphite [manufactured by Marufyo Casting Co., Ltd. , M-885] and 102 parts by weight of ethylene bis-stearic acid amide [manufactured by NOF Corporation, Alflow H-50S], and heated under a load of 5 kgf / cm ^2. The mixture was melt kneaded for 20 minutes without cooling. At this time, the resin temperature was measured and found to be 190 ° C. The strand-shaped resin extruded at a discharge rate of 250 kg / hr through a die having a small hole attached to the tip by being supplied to the ruder was cooled and solidified in a 30 ° C. water tank, and then cut to obtain a master batch.

[Preparation of graphite masterbatch B]
In the Banbury mixer, 100 parts by weight of styrene resin B [PS Japan Co., Ltd., 680] as a base resin, and 100 parts by weight of styrene resin B graphite [manufactured by Marufyo Casting Co., Ltd. , M-885] and 102 parts by weight of ethylene bis-stearic acid amide [manufactured by NOF Corporation, Alflow H-50S], and heated under a load of 5 kgf / cm ^2. The mixture was melt kneaded for 20 minutes without cooling. At this time, the resin temperature was measured and found to be 180 ° C. The strand-shaped resin extruded at a discharge rate of 250 kg / hr through a die having a small hole attached to the tip by being supplied to the ruder was cooled and solidified in a 30 ° C. water tank, and then cut to obtain a master batch.

[Preparation of titanium oxide master batch A]
To a Banbury mixer, 100 parts by weight of styrene resin A [PS Japan Co., Ltd., G9401] as a base resin, and 100 parts by weight of styrene resin A, titanium oxide [manufactured by Sakai Chemical Industry Co., Ltd., R-7E] 154 parts by weight and 2.6 parts by weight of ethylene bis-stearic acid amide [manufactured by NOF Corporation, Alflow H-50S] were charged and heated and cooled under a load of 5 kgf / cm ^2. And kneading for 20 minutes. At this time, the resin temperature was measured and found to be 190 ° C. The strand-shaped resin extruded at a discharge rate of 250 kg / hr through a die having a small hole attached to the tip by being supplied to the ruder was cooled and solidified in a 30 ° C. water tank, and then cut to obtain a master batch.

[Preparation of titanium oxide master batch B]
To the Banbury mixer, 100 parts by weight of styrene resin B [PS Japan Co., Ltd., 680] as a base resin, and 100 parts by weight of styrene resin B, titanium oxide [manufactured by Sakai Chemical Industry Co., Ltd., R-7E] 154 parts by weight and 2.6 parts by weight of ethylene bis-stearic acid amide [manufactured by NOF Corporation, Alflow H-50S] were charged and heated and cooled under a load of 5 kgf / cm ^2. And kneading for 20 minutes. At this time, the resin temperature was measured and found to be 180 ° C. The strand-shaped resin extruded at a discharge rate of 250 kg / hr through a die having a small hole attached to the tip by being supplied to the ruder was cooled and solidified in a 30 ° C. water tank, and then cut to obtain a master batch.

Example 1
[Preparation of resin mixture]
Styrenic resin A [PS Japan Co., Ltd., G9401] 96.5 parts by weight as a base resin, and graphite masterbatch A 5.0 parts by weight as a heat ray radiation inhibitor for 100 parts by weight of styrene resin A 2.5 parts by weight of titanium oxide master batch A, tetrabromobisphenol A-bis (2,3-dibromo-2-methylpropyl) ether as a flame retardant, and tetrabromobisphenol A-bis (2,3-dibromopropyl) Bromine flame retardant mixed with ether [Daiichi Kogyo Seiyaku Co., Ltd., GR-125P] 3.0 parts by weight, triphenylphosphine oxide [Sumitomo Shoji Chemical] 1.0 part by weight as a flame retardant aid, cell diameter 0.50 parts by weight of talc [manufactured by Hayashi Kasei Co., Ltd., Talcan powder PK-Z] as a regulator, bisphenol as a stabilizer -Glycidyl ether [manufactured by ADEKA, EP-13] 0.20 parts by weight, triethylene glycol-bis-3- (3-t-butyl-4-hydroxy-5-methylphenyl) propionate [Songwon Japan, Ltd. ), Sonnox 2450FF] 0.20 parts by weight, dipentaerythritol-adipic acid reaction mixture [manufactured by Ajinomoto Finetechno, Plenizer ST210] 0.10 parts by weight, calcium stearate [manufactured by Sakai Chemical Industry Co., Ltd., SC-P] 0.20 parts by weight, bentonite as a water-absorbing medium [manufactured by Hojun Co., Ltd., Bengelbright K11] 0.40 parts by weight, and silica [Evonik Degussa Japan Co., Ltd., Carplex BS-304F] 0 40 parts by weight were dry blended.

[Production of extruded foam]
About 950 kg / hr to the obtained resin mixture, a single screw extruder (first extruder) with a diameter of 150 mm, a single screw extruder (second extruder) with a diameter of 200 mm, and an extruder connected in series with a cooler Supplied with.

  The resin mixture supplied to the first extruder was heated to a resin temperature of 240 ° C. to be melted or plasticized and kneaded, and a foaming agent (HCFO-1233zd 1.5 parts by weight, isobutane 2 with respect to 100 parts by weight of the base resin) 0.0 parts by weight, 2.5 parts by weight of dimethyl ether, and 0.9 parts by weight of water) were pressed into the resin near the tip of the first extruder. Thereafter, in the second extruder and the cooler connected to the first extruder, the resin temperature is cooled to 121 ° C., and a die having a rectangular cross section (slit die) having a thickness of 6 mm and a width of 400 mm provided at the tip of the cooler. ), After being extruded and foamed into the atmosphere at a foaming pressure of 3.0 MPa, a cross-sectional shape having a thickness of 60 mm × width of 1000 mm is formed by a molding die placed in close contact with the die and a molding roll placed downstream thereof. An extruded foam plate was obtained and cut with a cutter into a thickness of 50 mm, a width of 910 mm, and a length of 1820 mm. The evaluation results of the obtained foam are shown in Table 1.

(Examples 2 to 8)
As shown in Table 1, an extruded foam was obtained in the same manner as in Example 1, except that various types of blending, addition amount, and / or production conditions were changed. Table 1 shows the physical properties of the obtained extruded foam. As described above, graphite and titanium oxide were added in advance in the form of a styrene-based resin master batch at the time of preparing the resin mixture. When the master batch was used, the base resin was 100 parts by weight in total with the base resin contained in the master batch.

(Comparative Examples 1-5)
As shown in Table 2, an extruded foam was obtained in the same manner as in Example 1, except that various types of blending, addition amount, and / or production conditions were changed. Table 2 shows the physical properties of the obtained extruded foam. As described above, graphite and titanium oxide were added in advance in the form of a styrene-based resin master batch at the time of preparing the resin mixture. When the master batch was used, the base resin was 100 parts by weight in total with the base resin contained in the master batch.

  As can be seen from Comparative Examples 1-2, when the residual amount of the saturated hydrocarbon having 3 to 5 carbon atoms in the extruded foam of the styrene resin extruded foam is larger than a predetermined amount, the fire spread length exceeds 10 mm. Getting worse.

  As can be seen from Comparative Example 3, when the residual amount of hydrochlorofluoroolefin in the extruded foam of the styrene-based resin extruded foam is less than a predetermined amount, the thermal conductivity deteriorates exceeding 0.024 W / mK.

  As can be seen from Comparative Example 4, when the total amount of the residual amount of saturated hydrocarbons having 3 to 5 carbon atoms and the residual amount of hydrochlorofluoroolefin in the extruded foam of the styrene-based resin extruded foam is larger than a predetermined amount. The moldability of the extruded foam deteriorates, and an extruded foam having a desired foam appearance cannot be obtained.

  As can be seen from Comparative Example 5, when the residual amount of hydrochlorofluoroolefin in the extruded foam of the styrene resin extruded foam is larger than a predetermined amount, the moldability of the extruded foam deteriorates and the desired foam appearance is obtained. An extruded foam having the following cannot be obtained.

  As can be seen from Examples 1 to 8, the styrene resin extruded foam of the present invention has excellent heat insulation with a thermal conductivity of 0.024 W / mK or less and excellent flame retardancy with a fire spread length of 10 mm or less. In addition, a styrene resin extruded foam having a beautiful surface and a sufficient thickness suitable for use is obtained.

  From the viewpoint of heat insulation expressed by thermal conductivity, preferred examples of Examples 1 to 8 are Examples 2 to 8.

  The present invention is a styrene resin extruded foam having excellent heat insulation and flame retardancy, and having a beautiful surface and sufficient thickness suitable for use. The resin extruded foam can be suitably used as a heat insulating material for a house or a structure.

Claims (10)

A styrene resin extruded foam containing a flame retardant of 0.5 to 8.0 parts by weight and a graphite of 1.0 to 5.0 parts by weight with respect to 100 parts by weight of a styrene resin. And containing a C3-C5 saturated hydrocarbon and hydrochlorofluoroolefin as a foaming agent,
(I) The residual amount of hydrochlorofluoroolefin in the extruded foam of the styrene-based resin extruded foam is 0.05 mol or more and 0.50 mol or less per kg of the extruded foam,
(II) The residual amount of the saturated hydrocarbon having 3 to 5 carbon atoms in the extruded foam of the styrenic resin extruded foam is 0.10 mol or more and 0.50 mol or less per kg of the extruded foam,
(III) The total amount of the residual amount of saturated hydrocarbons having 3 to 5 carbon atoms and the residual amount of hydrochlorofluoroolefin in the extruded foam of the styrenic resin extruded foam is 0.000 per kg of the extruded foam. A styrene-based resin extruded foam characterized by being 30 mol or more and 0.90 mol or less. The residual amount of the hydrochlorofluoroolefin and the residual amount of the saturated hydrocarbon having 3 to 5 carbon atoms are residual amounts after 7 days from the production of the styrene resin extruded foam. 1. A styrene resin extruded foam according to 1. The styrenic resin extruded foam according to claim 1 or 2, wherein the hydrochlorofluoroolefin is trans-1-chloro-3,3,3-trifluoropropene. The styrenic resin according to any one of claims 1 to 3, wherein the flammability measurement method A defined in JIS A9521 is passed and the fire spread length is 10 mm or less. Extruded foam. The styrene resin extruded foam according to any one of claims 1 to 4, wherein an apparent density is 20 kg / m ³ or more and 45 kg / m ³ or less, and a closed cell ratio is 90% or more. . The foaming agent is further characterized in that at least one member selected from the group consisting of dimethyl ether, ethyl chloride and methyl chloride is added in an amount of 0.5 to 15 parts by weight based on 100 parts by weight of the styrenic resin. The styrene resin extruded foam according to any one of claims 5 to 6. The styrene resin extruded foam according to any one of claims 1 to 6, wherein the saturated hydrocarbon having 3 to 5 carbon atoms is isobutane. The styrene resin extruded foam according to any one of claims 1 to 7, wherein the thickness is 10 mm or more and 150 mm or less. The flame retardant is a brominated flame retardant, and is contained in an amount of 0.5 to 5.0 parts by weight with respect to 100 parts by weight of a styrene resin. 2. A styrene resin extruded foam according to item 1. The manufacturing method of the styrene resin extrusion foam of any one of Claims 1-9.