JP2010138244A - Styrene resin extrusion foam with skin and manufacturing method of the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a styrene resin extrusion foam with a skin that is obtained by using an environmentally compatible expanding agent and exhibits excellent heat-insulating properties and strength properties suitable for building material applications and industrial material applications. <P>SOLUTION: The styrene resin extrusion foam with a skin is obtained by heat-melting a styrene resin and adding a non-halogen expanding agent to the styrene resin followed by extrusion expanding molding through a molding mold, where the styrene resin extrusion foam with a skin exhibiting properties above is obtained by controlling the density of a skin layer within 2 mm in the thickness direction from the surface of the extrusion foam to 50-90 kg/m<SP>3</SP>and the density of the whole extrusion foam to 5-30 kg/m<SP>3</SP>lower than the density of the skin layer. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a plate-like styrene-based resin extruded foam with a skin used for building materials, heat insulating materials for industrial materials, and the like. More specifically, the present invention relates to a styrene resin extruded foam with skin having excellent environmental compatibility and good heat insulation and strength properties.

  Conventionally, a styrene resin extruded foam has been widely used as a heat insulating material for buildings because of its workability and suitability for heat insulation. In order to obtain these styrene resin extruded foams, the styrene resin was heated and melted with an extruder, and during the course, a foaming agent was added and kneaded to obtain a fluid gel, and the fluid gel was cooled to a temperature suitable for foaming. Thereafter, a method is generally used in which pressure is released through a die to a low-pressure region and foamed, and simultaneously formed into a plate shape to obtain a foam continuously.

  Conventionally, chlorofluorocarbons and saturated hydrocarbons have been used as foaming agents for styrenic resin foams in order to obtain excellent heat insulation properties. In addition, good mechanical properties, foam dimensional stability and productivity have been achieved. In order to obtain the styrene resin, halogenated hydrocarbons represented by methyl chloride and ethyl chloride, which are easily permeable gases, were used in combination.

  However, in recent years, environmental issues such as ozone layer destruction, global warming, and the influence of chemical substances on the atmosphere and water quality have been highlighted. For example, chlorofluorocarbons are regulated substances as ozone-depleting substances and global warming substances, and their use is difficult. In addition, methyl chloride and ethyl chloride are required to be reported as Class 1 Designated Substances under the PRTR Law, and the amount of emissions is managed. Therefore, it is desirable to use a foaming agent that is as environmentally friendly as possible.

  Under these circumstances, it is very effective in terms of environmental compatibility, and it is also non-flammable in terms of foam flame retardancy. Has been made.

  At the same time, studies have been made on extruded foams with skins excellent in heat insulation performance and strength properties.

  Patent Document 1 discloses the technical content of a styrene resin extruded foam board for building materials that defines the relationship between the skin layer density and the overall foam density and the diffusion rate of the total volatile organic compound. In relation to the overall density of the foam, it is described that there is a limit to increasing the density of the skin layer while maintaining the overall density of the foam.

There has been a demand for a technique for applying a higher density skin layer.
JP 2004-263039 A

  The present invention has been made in view of the prior art, and uses a styrene-based resin with skin having excellent heat insulating performance and strength properties by using a foaming agent that is compatible with the environment and increasing the density of the skin layer. An object is to provide an extruded foam.

  In order to solve the above-mentioned problems, the present inventors have used non-halogen foaming agents as foaming agents, and have mainly studied molding methods. As a result, by setting the mold shape and mold temperature of the extrusion mold for plate-shaped molding placed in close contact with or in contact with the die to an appropriate condition, the density of the foam is extremely high. The present inventors have found that a skin layer density can be imparted and have reached the present invention.

That is, the present invention
[1] A styrene-based resin with skin obtained by heating and melting a styrene-based resin, adding a foaming agent to the styrene-based resin, extrusion foaming through a die, and molding using an extrusion mold connected to the die It is an extruded foam, and the density of the skin layer within 2 mm in the thickness direction from the surface of the extruded foam is 50 to 90 kg / m ³ , and the density of the entire extruded foam plate is 5 than the density of the skin layer. characterized in that 30 kg / ^{m 3} lower, styrene resin extruded foam integral skin,
[2] The styrene-based resin extruded foam with skin according to [1], wherein the density of the skin layer is 55 to 90 kg / m ³ ,
[3] As the blowing agent, (A) at least one selected from saturated hydrocarbons having 3 to 5 carbon atoms, (B) at least one ether selected from the group consisting of dimethyl ether, diethyl ether and methyl ethyl ether, And (C) a styrene-based resin extruded foam with skin according to [1] or [2], wherein other non-halogen-based foaming agent is used,
[4] (C) The styrene resin extruded foam with skin according to [3], wherein the other non-halogen foaming agent is water or carbon dioxide.
[5] The styrene-based resin extruded foam with skin according to any one of [1] to [4], wherein an average diameter of bubbles forming the foam is 0.1 to 0.6 mm.
[6] The bubbles forming the foam are composed of bubbles having a bubble diameter of 0.25 mm or less and bubbles having a bubble diameter of 0.3 to 1 mm, these bubbles are dispersed in a sea-island shape through the cell membrane, and The styrene resin extruded foam with skin according to [4], wherein the bubbles having a bubble diameter of 0.25 mm or less have an occupied area ratio of 10 to 90% per foam cross-sectional area,
[7] The bending strength of the foam is 25 to 150 N / cm ² , and the thermal conductivity is 0.024 to 0.028 W / mK. Any one of [1] to [6] [8] A styrene resin extruded foam with skin, and [8] a styrene resin is heated and melted, a foaming agent is added to the styrene resin, extrusion foamed through a die, and an extrusion mold connected to the die. A method of manufacturing a styrene resin extruded foam with skin obtained by molding using a skin,
The mold temperature T (° C.) of the extrusion mold satisfies the relationship of (t−70) ≦ T ≦ (t + 10) with respect to the Vicat softening temperature t (° C.) of the styrenic resin. The present invention relates to a method for producing a styrene resin extruded foam with skin.

  By using a foaming agent excellent in environmental compatibility according to the present invention, by providing a high-density skin layer, a styrene system with skin excellent in heat insulation and bending strength required for building materials and industrial materials applications A resin extruded foam can be obtained.

In the styrene resin extruded foam with skin of the present invention, the density of the skin layer within 2 mm in the thickness direction from the surface of the extruded foam is 50 to 90 kg in order to give excellent heat insulation performance and bending strength quality. / M ³ is preferable, and 55 to 90 kg / m ³ is more preferable. When the skin layer density is less than 50 kg / m ³ , excellent heat insulating performance and bending strength tend to be difficult to develop, and when the skin layer density is greater than 90 kg / m ³ , the lightness is reduced.

The overall density of the extruded foam with skin of the present invention is preferably 5-30 kg / m ³ lower than the density of the skin layer, more preferably 10-30 kg / m ³ lower. If the density difference between the total density and the skin layer of the foam is less than 5 kg / m ^3, skin easily broken, there is a tendency that problems of cracks generated is generated, the density difference between the total density and the skin layer of the foam If it exceeds 30 kg / m ³ , plate-shaped molding tends to be difficult.

  As a method for producing a styrene resin extruded foam with skin according to the present invention, various additives are mixed into a styrene resin, and then supplied to an extruder, heated and melted, and further pressed into the extruder. At the same time, the mixture is kneaded under high temperature and high pressure to obtain a styrene resin melt composition (fluid gel). The fluid gel is cooled to a resin temperature suitable for extrusion foaming by a cooling extruder, and then extruded and foamed to a low pressure region through a slit die. In addition, a method of obtaining a plate-like foam by molding using an extrusion mold connected to a die is employed.

  As the molding method of the styrene resin extruded foam with skin of the present invention, the foam obtained by releasing the pressure from the slit die having a linear slit shape was placed in close contact with or in contact with the slit die. A method of molding a plate-like foam having a large cross-sectional area using an extrusion mold and a molding roll installed adjacent to the downstream side of the molding mold is used.

  The extrusion mold used in the present invention is constituted by two upper and lower plate-like objects installed so as to expand gently in parallel or from the inlet to the outlet, and if necessary, the above plate Two plate-like objects in the vertical direction may be installed at both ends of the object.

  The extrusion mold used in the present invention has a thickness on the wall surface (resin fluid wall surface) in contact with the extruded foamed resin melt composition from the viewpoint of preventing deterioration of the surface property of the foam (surface property of the skin layer). It is preferable to use one provided with a fluororesin layer of 20 to 3000 μm.

  In the production method of the present invention, the mold shape of the extrusion mold, that is, the length of the region (hereinafter, sometimes referred to as “resin fluid surface”) in contact with the molten resin composition after being extruded and foamed. The desired cross-sectional shape and foam quality of the foam can be obtained by adjusting the shape and the mold temperature.

  The foam with a skin of the present invention has a high-density skin by controlling the mold temperature T (° C.) of the extrusion mold, in particular by controlling in relation to the bigat softening temperature of the styrene resin used. A layer can be applied.

  The mold temperature T (° C.) of the extrusion mold is preferably controlled by (t−70) ≦ T ≦ (t + 10) with respect to the Vicat softening temperature t (° C.) of the styrene resin used. It is more preferable to control by t−60) ≦ T ≦ (t + 10). Furthermore, when the extrusion mold temperature T (° C.) is lower than t-70 (° C.), the skin layer of the foam becomes difficult to extend, and it tends to be difficult to prevent deterioration of the surface property. When the extrusion mold temperature T (° C.) is higher than t + 10 (° C.), the foam skin layer is softened, bubbles (cells) are broken, and it is difficult to prevent deterioration of surface properties. .

  The mold temperature T (° C.) of the extrusion mold is a temperature obtained by measuring the mold surface temperature in the vicinity of the resin flow surface using a contact thermometer. That is, as shown in FIG. 1, the temperature of the extrusion mold is set to 5 cm from the rearmost end of the mold and 5 cm from the left end of the resin flow surface on the lower plate of the mold. It is the value measured after installation.

  The composition of the styrenic resin used in the present invention is not particularly limited, and a styrene homopolymer obtained only from a styrene monomer, a monomer copolymerizable with styrene monomer and styrene, or a derivative thereof. And modified polystyrene such as post-brominated polystyrene and rubber-reinforced polystyrene. These can be used alone or in admixture of two or more.

  Examples of monomers copolymerizable with styrene include methylstyrene, dimethylstyrene, ethylstyrene, diethylstyrene, isopropylstyrene, bromostyrene, dibromostyrene, tribromostyrene, chlorostyrene, dichlorostyrene, and trichlorostyrene. Polyfunctional vinyl compounds such as divinylbenzene, (meth) acrylic compounds such as acrylic acid, methacrylic acid, methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, acrylonitrile, diene compounds such as budadiene or the like Derivatives, unsaturated carboxylic acid anhydrides such as maleic anhydride, itaconic anhydride and the like. These may be used alone or in combination of two or more.

  The styrene resin in the present invention is preferably a styrene homopolymer from the viewpoint of processability.

  As the foaming agent of the present invention, it is possible to use a foaming agent composed of at least one of ether and a saturated hydrocarbon having 3 to 5 carbon atoms. These non-halogen foaming agents can reduce the weight of the obtained foam more stably, and are effective in further improving the foam quality of heat insulation and dimensional stability.

  Examples of the ether in the present invention include dimethyl ether, diethyl ether, methyl ethyl ether and the like, and dimethyl ether is preferable from the viewpoint of foamability, foam moldability, and stability.

  Examples of the saturated hydrocarbon having 3 to 5 carbon atoms in the present invention include propane, n-butane, i-butane, n-pentane, i-pentane, neopentane and the like. Among the saturated hydrocarbons having 3 to 5 carbon atoms, n-butane, i-butane, and a mixture of n-butane and i-butane are preferable, and n-butane is particularly preferable from the viewpoint of foamability and thermal insulation performance of the foam. And i-butane.

  As another non-halogen foaming agent of the present invention, at least one selected from the group consisting of water and carbon dioxide can be used.

The total amount of foaming agent used in the present invention is appropriately changed according to the setting value of the foaming ratio, etc., but when trying to obtain a lightweight foam having a foam density of 20 to 85 kg / m ³ , the styrenic resin 100 0.5-10 weight part is preferable with respect to weight part, and 1-9 weight part is more preferable. When the total amount of the foaming agent used is less than 0.5 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. On the other hand, when the amount exceeds 10 parts by weight, There is a tendency to cause defects such as voids.

  In the present invention, a small amount of a foaming agent as shown below can also be used. For example, ketones such as 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 Alcohols such as methanol, ethanol, propyl alcohol, i-propyl alcohol, butyl alcohol, i-butyl alcohol, t-butyl alcohol; formic acid methyl ester, formic acid ethyl ester, formic acid propyl ester, formic acid butyl ester, formic acid amyl ester Carboxylic acid esters such as methyl propionate and ethyl propionate; inorganic foaming agents such as nitrogen; and chemical foaming agents such as azo compounds.

  The average cell diameter in the styrene resin extruded foam with skin obtained in the present invention is preferably 0.1 to 0.6 mm, preferably 0.15 to 0.5 mm, from the viewpoint of possessing excellent heat insulation and appropriate strength. Is more preferable.

  In the present invention, by using water as the non-halogen-based foaming agent, bubbles having a relatively small bubble diameter (hereinafter referred to as small bubbles) having a bubble diameter of approximately 0.25 mm or less are contained in the styrene resin extruded foam with skin. ) And a bubble having a characteristic bubble structure in which bubbles having a relatively large bubble diameter (hereinafter referred to as large bubbles) having a bubble diameter of approximately 0.3 mm to 1 mm are mixed in a sea-island shape. The heat insulation performance of the foam is improved.

  In a foam having a specific bubble structure in which small bubbles having a bubble diameter of 0.25 mm or less and large bubbles having a bubble diameter of 0.3 to 1 mm are mixed, the ratio of the area of small bubbles to the cross-sectional area of the foam (unit: 5 to 95% is preferable, 10 to 90% is more preferable, 20 to 80% is further preferable, and 25 to 70% is particularly preferable.

  In the present invention, bentonite or zeolite can be used as an adsorbent or dispersant for water and carbon dioxide.

  Examples of bentonite include natural bentonite, purified bentonite, and organic bentonite, and examples of zeolite include natural zeolite and synthetic zeolite.

  The amount of bentonite or zeolite used in the present invention is preferably 0.1 to 20 parts by weight and more preferably 0.15 to 10 parts by weight with respect to 100 parts by weight of the styrene resin.

  In the present invention, it is preferable to use a flame retardant in order to meet the demand in the application.

  As the flame retardant used in the present invention, it is more preferable to use at least one selected from halogen-based flame retardants. Furthermore, a phosphate ester compound, a nitrogen-containing compound, and the like may coexist.

Examples of the halogen-based flame retardant used in the present invention include, as brominated flame retardants, hexabromocyclododecane, tetrabromocyclooctane, dibromoneopentyl glycol, tribromoneopentyl alcohol, and tris (tribromoneopentyl). Phosphate, tris (2,3-dibromopropyl) isocyanurate, bromide of aliphatic or alicyclic hydrocarbon such as tetrabromoethane, hexabromobenzene, ethylenebispentabromodiphenyl, decabromodiphenylethane, decabromodiphenyl ether, Brominated aromatic compounds such as octabromodiphenyl ether and 2,3-dibromopropylpentabromophenyl ether, tetrabromobisphenol A, tetrabromobisphenol A bis (2,3- Bromopropyl ether), tetrabromobisphenol A (2-bromoethyl ether), tetrabromobisphenol A diglycidyl ether, tetrabromobisphenol A bis (allyl ether), adduct of tetrabromobisphenol A diglycidyl ether and tribromophenol Brominated bisphenols and derivatives thereof, tetrabromobisphenol A polycarbonate oligomers, brominated bisphenol derivatives oligomers such as epoxy oligomers of adducts of tetrabromobisphenol A diglycidyl ether and brominated bisphenol, ethylenebistetrabromophthalimide, Brominated aromatic compounds such as bis (2,4,6-tribromophenoxy) ethane, brominated acrylic resins, ethylene-bisdi Etc. Romo norbornane dicarboximide and the like. Examples of the chlorinated flame retardant include chlorinated aliphatic compounds such as chlorinated paraffin, chlorinated naphthalene, and perchloropentadecane, chlorinated aromatic compounds, and chlorinated alicyclic compounds.
Among these, brominated flame retardants are preferable from the viewpoint of flame retardancy, and hexabromocyclododecane, tetrabromocyclooctane, tris (2,3-dibromopropyl) isocyanate are particularly preferable from the viewpoint of compatibility with styrene resins. Nurate, dibromoneopentyl glycol, and tetrabromobisphenol A bis (2,3-dibromopropyl ether) are preferred.

  The amount of the flame retardant used in the present invention is preferably 1.5 to 4 parts by weight and more preferably 1.5 to 2.5 parts by weight with respect to 100 parts by weight of the styrene resin. If the amount of halogenated flame retardant used is less than the above, flame retardancy tends to be difficult to obtain, whereas if it exceeds the above range, the glass transition temperature of the foam tends to decrease and heat resistance tends to decrease. .

  In the present invention, the following processing aids can be used. Specific examples of processing aids include silica, talc, calcium silicate, wollastonite, kaolin, clay, mica, zinc oxide, titanium oxide, calcium carbonate and other inorganic compounds, sodium stearate, magnesium stearate, stearic acid Examples thereof include barium, liquid paraffin, olefin wax, and stearyl amide compound.

  As the stabilizer used in the production method of the present invention, a light-resistant stabilizer such as a phenol-based antioxidant, a phosphorus-based stabilizer, a benzotriazole, or a hindered amine is used.

  Next, although the styrene-type resin extrusion foam with a skin of this invention is demonstrated in detail based on an Example, this invention is not limited only to this Example.

  Bigat softening temperature of styrenic resin, extrusion mold temperature, foam cross-sectional profile, foam overall density, foam skin layer density, average cell diameter, small cell occupation area ratio, foam thermal conductivity, foam bending strength The foam physical properties of foam combustibility were evaluated according to the following methods.

(1) Bigat softening temperature of styrene resin (℃)
The Vicat softening temperature of the styrene resin used was measured according to JIS K7206 (50 N load).

(2) Extrusion mold temperature (℃)
The extrusion mold temperature is 5 cm from the rear end of the mold and 5 cm from the left end of the resin flow surface on the lower plate of the mold. This is the value measured by installing a thermometer.

(3) Foam cross-sectional profile The thickness direction dimension and the width direction dimension of the obtained foam cross section were measured using calipers.
In addition, about the thickness direction dimension, it calculated | required as an average value of the measured value in 3 points | pieces of the width direction both ends and the width direction center part.

(4) Whole foam density (kg / m ³ )
The overall density of the foam was determined based on the following formula, and the unit was expressed in terms of kg / m ³ .
Foam density (g / cm ³ ) = foam weight (g) / foam volume (cm ³ )
In this measurement, a sample of product thickness × width 100 mm × length 100 mm was cut out at the center in the width direction of the foam (thickness: about 25 to 30 mm, width: about 150 mm), the density was measured, and three points were measured. Obtained as an average value.

(5) Foam skin layer density (kg / m ³ )
The foam skin layer density was determined based on the following formula, and the unit was expressed in terms of kg / m ³ .
Foam skin layer density (g / cm ³ ) = skin layer weight (g) / skin layer volume (cm ³ )
In this measurement, a skin layer sample of 2 mm in width × 100 mm in width × 100 mm in length was cut out at the center in the width direction of the foam (thickness: about 25-30 mm, width: about 150 mm), and the density was measured. In addition, it was determined as an average value at 6 points.

(6) Average bubble diameter (mm)
The bubble diameter in each direction of the thickness direction, the width direction, and the extrusion direction in the obtained foam was measured according to ASTM D-3576.
That is, the cross-section in the width direction of the obtained foam is enlarged and projected 50 to 100 times, and the average cell diameter (HD) in the thickness direction and the average cell diameter (TD) in the width direction are measured. Next, the cross section in the extrusion direction was enlarged and projected, and the average cell diameter (MD) in the extrusion direction was measured.
The average bubble diameter was calculated from the following equation as the third root of the product of the average bubble diameter in each direction.
Average bubble diameter = (HD x TD x MD) ^1/3

(7) Small bubble occupation area ratio (%)
When the large and small bubbles constituting the foam are distributed in a sea-island shape, the occupied area ratio per cross-sectional area of the foam for the bubbles smaller than the bubble diameter of 0.25 mm was defined as the small bubble occupied area ratio. Here, the bubble having a bubble diameter smaller than 0.25 mm is a bubble having a circle equivalent diameter smaller than 0.25 mm.

(8) Foam thermal conductivity (W / mK)
The thermal conductivity of the styrene resin extruded foam 7 days after production was measured according to JIS A9511.

(9) Bending strength of foam (N / cm ² )
The foam bending strength was measured for the foam after 7 days of manufacture. A sample size, thickness 25 mm × width 75 mm × length 300 mm was cut out from an arbitrary position of the foam product, measured according to a JIS A9511 extrusion method polystyrene foam heat insulating plate, and obtained as an average value of n = 3.

(10) Foam combustibility Measured according to JIS A9511 extrusion method polystyrene foam heat insulating plate. The measurement was performed on a foam that had passed 7 days after production.
If the flame extinguishes within 3 seconds, there is no residue, and it does not burn beyond the burn-up limit indicator line, it will be ○ (pass), and if this standard is not reached, × (fail) ).

Example 1
As the extrusion process, the first extruder (65 mmφ single screw extruder for melt kneading)-the second extruder (90 mmφ single screw extruder for cooling and mixing)-the third extruder (150 mmφ single screw extruder for cooling and mixing) is used. did.
As a polystyrene resin, Dainippon Ink Chemical Co., Ltd. product name: HP500M (Bigat softening temperature 102 ° C., MFR = 2.8 g / 10 min) is used, and as a water dispersant for 100 parts by weight of the polystyrene resin. 1.0 part by weight of bentonite, 4.0 part by weight of hexabromocyclododecane (hereinafter abbreviated as “HBCD”) as a halogen flame retardant, 0.2 part by weight of talc as a nucleating agent, and barium stearate as a lubricant After dry blending 0.25 parts by weight, these resin mixtures were fed to an extruder. The resin mixture supplied to the first extruder is melted and kneaded by heating to about 200 ° C., and 0.8 parts by weight of water, 3.0 parts by weight of isobutane, 2 parts of dimethyl ether are added to 100 parts by weight of polystyrene resin as a foaming agent. .5 parts by weight were pressed into the resin near the tip of the first extruder. Then, it cools, kneading | mixing with the 2nd extruder connected with the 1st extruder, and the 3rd extruder, and it is air | atmosphere at the foaming resin temperature of about 110-140 degreeC from the slit die provided in the front-end | tip of the 3rd extruder. After extrusion foaming inward, plate molding was performed with an extrusion mold placed in close contact with the slit die and a molding roll placed downstream thereof.
The extrusion mold temperature of the extrusion mold used was set to 70 ° C., and an extruded foam board with skin having a cross-sectional shape having a thickness of 25 mm × width of 200 mm was obtained.
The obtained foam with skin has an overall density of 40 kg / m ³ , a skin layer density of 61 kg / m ³ , and an average cell diameter of 0.24 mm. It had a bubble structure in which large bubbles and small bubbles were mixed, and the occupied area ratio of small bubbles was 35%. The resulting thermal conductivity of the foam 0.027W / mK, bending strength 126N / cm ^2, for flammability met the criteria of JIS A9511.

(Example 2)
The same process as in Example 1 was used for the extrusion process.
As polystyrene resin, PS Japan Co., Ltd. product name: G9401 (Bigat softening temperature 103 ° C., MFR = 2.2 g / 10 min) is used, and bentonite 1.100 parts by weight of polystyrene resin is used as a water dispersant. After dry blending 0 parts by weight, 4.0 parts by weight of HBCD as a halogen flame retardant, 0.2 parts by weight of talc as a nucleating agent, and 0.25 parts by weight of barium stearate as a lubricant, these resin mixtures were extruded. Supplied to the machine. The resin mixture supplied to the first extruder is melted and kneaded by heating to about 200 ° C., and 0.8 parts by weight of water, 3.5 parts by weight of isobutane, 2 parts of dimethyl ether are added to 100 parts by weight of polystyrene resin as a foaming agent. 0.0 part by weight was pressed into the resin near the tip of the first extruder. Then, it cools, kneading | mixing with the 2nd extruder connected with the 1st extruder, and the 3rd extruder, and it is air | atmosphere at the foaming resin temperature of about 110-140 degreeC from the slit die provided in the front-end | tip of the 3rd extruder. After extrusion foaming inward, plate molding was performed with an extrusion mold placed in close contact with the slit die and a molding roll placed downstream thereof.
The extrusion mold temperature of the used extrusion mold was set to 50 ° C., and an extruded foam board with skin having a cross-sectional shape having a thickness of 25 mm × width of 200 mm was obtained.
The obtained foam with skin has an overall density of 44 kg / m ³ , a skin layer density of 71 kg / m ³ , and an average cell diameter of 0.21 mm. It had a bubble structure in which large bubbles and small bubbles were mixed, and the occupied area ratio of small bubbles was 45%. The obtained foam had a thermal conductivity of 0.026 W / mK, a flexural strength of 135 N / cm ² , and a combustibility that met the standards of JIS A9511.

(Example 3)
The same process as in Example 1 was used for the extrusion process.
As polystyrene resin, PS Japan Co., Ltd. product name: G9401 (Bigat softening temperature 103 ° C., MFR = 2.2 g / 10 min) is used, and bentonite 1.100 parts by weight of polystyrene resin is used as a water dispersant. After dry blending 0 parts by weight, 3.0 parts by weight of HBCD as a halogen flame retardant, 0.2 parts by weight of talc as a nucleating agent, and 0.25 parts by weight of barium stearate as a lubricant, these resin mixtures were extruded. Supplied to the machine. The resin mixture supplied to the first extruder is melted and kneaded by heating to about 200 ° C., and 1.0 part by weight of water, 3.0 parts by weight of carbon dioxide, and isobutane with respect to 100 parts by weight of polystyrene resin as a foaming agent. 2.5 parts by weight and 1.5 parts by weight of dimethyl ether were pressed into the resin near the tip of the first extruder. Then, it cools, kneading | mixing with the 2nd extruder connected with the 1st extruder, and the 3rd extruder, and it is air | atmosphere at the foaming resin temperature of about 110-140 degreeC from the slit die provided in the front-end | tip of the 3rd extruder. After extrusion foaming inward, plate molding was performed with an extrusion mold placed in close contact with the slit die and a molding roll placed downstream thereof.
The extrusion mold temperature of the used extrusion mold was set to 80 ° C., and an extruded foam board with skin having a cross-sectional shape having a thickness of 25 mm × width of 200 mm was obtained.
The obtained foam with skin has an overall density of 36 kg / m ³ , a skin layer density of 56 kg / m ³ , and an average cell diameter of 0.26 mm. It had a bubble structure in which large bubbles and small bubbles were mixed, and the occupied area ratio of small bubbles was 25%. The obtained foam had a thermal conductivity of 0.027 W / mK, a flexural strength of 114 N / cm ² , and a combustibility that satisfied the standards of JIS A9511.

Example 4
The same process as in Example 1 was used for the extrusion process.
PS Japan Co., Ltd., trade name: 679 (Bigat softening temperature 87 ° C., MFR = 18 g / 10 min) is used as the polystyrene resin, and 1.0 weight of zeolite as an adsorbent with respect to 100 parts by weight of the polystyrene resin. Parts, HBCD 2.0 parts by weight as a halogen-based flame retardant, 0.2 parts by weight of talc as a nucleating agent, and 0.25 parts by weight of barium stearate as a lubricant are dry blended, and these resin mixtures are fed to an extruder. Supplied. The resin mixture supplied to the first extruder is melt-kneaded by heating to about 200 ° C., and 3.0 parts by weight of carbon dioxide, 1.0 part by weight of isobutane, dimethyl ether with respect to 100 parts by weight of polystyrene resin as a foaming agent. 3.0 parts by weight were pressed into the resin near the tip of the first extruder. Then, it cools, kneading | mixing with the 2nd extruder connected with the 1st extruder, and the 3rd extruder, and it is air | atmosphere at the foaming resin temperature of about 110-140 degreeC from the slit die provided in the front-end | tip of the 3rd extruder. After extrusion foaming inward, plate molding was performed with an extrusion mold placed in close contact with the slit die and a molding roll placed downstream thereof.
The extrusion mold temperature of the used extrusion mold was set to 60 ° C., and an extruded foam board with skin having a cross-sectional shape having a thickness of 25 mm × width of 200 mm was obtained.
The obtained foam with skin has an overall density of 52 kg / m ³ , a skin layer density of 75 kg / m ³ , and an average cell diameter of 0.38 mm. The obtained foam had a thermal conductivity of 0.027 W / mK, a bending strength of 142 N / cm ² , and a combustibility that satisfied the standards of JIS A9511.

(Example 5)
The same process as in Example 1 was used for the extrusion process.
As a polystyrene resin, Dainippon Ink Chemical Co., Ltd. product name: HP500M (Bigat softening temperature 102 ° C., MFR = 2.8 g / 10 minutes) is used, and as an adsorbent for 100 parts by weight of the polystyrene resin. After dry blending 1.0 part by weight of zeolite, 2.0 parts by weight of HBCD as a halogen flame retardant, 0.2 part by weight of talc as a nucleating agent, and 0.25 part by weight of barium stearate as a lubricant, these resins are used. The mixture was fed to the extruder. The resin mixture supplied to the first extruder is melt-kneaded by heating to about 200 ° C., and 3.0 parts by weight of carbon dioxide, 1.0 part by weight of isobutane, dimethyl ether with respect to 100 parts by weight of polystyrene resin as a foaming agent. 3.0 parts by weight were pressed into the resin near the tip of the first extruder. Then, it cools, kneading | mixing with the 2nd extruder connected with the 1st extruder, and the 3rd extruder, and it is air | atmosphere at the foaming resin temperature of about 110-140 degreeC from the slit die provided in the front-end | tip of the 3rd extruder. After extrusion foaming inward, plate molding was performed with an extrusion mold placed in close contact with the slit die and a molding roll placed downstream thereof.
The extrusion mold temperature of the used extrusion mold was set to 60 ° C., and an extruded foam board with skin having a cross-sectional shape having a thickness of 25 mm × width of 200 mm was obtained.
The obtained skins with foam, the whole density of 52kg / ^{m 3,} a skin layer density 75 kg / ^{m 3,} average cell diameter 0.38 mm. The obtained foam had a thermal conductivity of 0.027 W / mK, a bending strength of 142 N / cm ² , and a combustibility that satisfied the standards of JIS A9511.

(Comparative Example 1)
The same process as in Example 1 was used for the extrusion process.
As a polystyrene resin, Dainippon Ink Chemical Co., Ltd. product name: HP500M (Bigat softening temperature 102 ° C., MFR = 2.8 g / 10 min) is used, and as a water dispersant for 100 parts by weight of the polystyrene resin. After dry blending 1.0 parts by weight of bentonite, 4.0 parts by weight of HBCD as a halogen flame retardant, 0.2 parts by weight of talc as a nucleating agent, and 0.25 parts by weight of barium stearate as a lubricant, these resins are used. The mixture was fed to the extruder. The resin mixture supplied to the first extruder is melted and kneaded by heating to about 200 ° C., and 0.8 parts by weight of water, 3.0 parts by weight of isobutane, 2 parts of dimethyl ether are added to 100 parts by weight of polystyrene resin as a foaming agent. .5 parts by weight were pressed into the resin near the tip of the first extruder. Then, it cools, kneading | mixing with the 2nd extruder connected with the 1st extruder, and the 3rd extruder, and it is air | atmosphere at the foaming resin temperature of about 110-140 degreeC from the slit die provided in the front-end | tip of the 3rd extruder. After extrusion foaming inward, plate molding was performed with an extrusion mold placed in close contact with the slit die and a molding roll placed downstream thereof.
The extrusion mold temperature of the used extrusion mold was set to 120 ° C., and an extruded foam board with skin having a cross-sectional shape having a thickness of 25 mm × width of 200 mm was obtained.
The obtained foam with skin has an overall density of 38 kg / m ³ , a skin layer density of 45 kg / m ³ , and an average cell diameter of 0.33 mm. It had a bubble structure in which large bubbles and small bubbles were mixed, and the occupied area ratio of small bubbles was 35%. The obtained foam had a thermal conductivity of 0.029 W / mK, a flexural strength of 126 N / cm ² , and a combustibility that satisfied the standards of JIS A9511.

(Comparative Example 2)
The same process as in Example 1 was used for the extrusion process.
As polystyrene resin, PS Japan Co., Ltd. product name: G9401 (Bigat softening temperature 103 ° C., MFR = 2.2 g / 10 min) is used, and bentonite 1.100 parts by weight of polystyrene resin is used as a water dispersant. After dry blending 0 parts by weight, 4.0 parts by weight of HBCD as a halogen flame retardant, 0.2 parts by weight of talc as a nucleating agent, and 0.25 parts by weight of barium stearate as a lubricant, these resin mixtures were extruded. Supplied to the machine. The resin mixture supplied to the first extruder is melted and kneaded by heating to about 200 ° C., and 0.8 parts by weight of water, 3.5 parts by weight of isobutane, 2 parts of dimethyl ether are added to 100 parts by weight of polystyrene resin as a foaming agent. 0.0 part by weight was pressed into the resin near the tip of the first extruder. Then, it cools, kneading | mixing with the 2nd extruder connected with the 1st extruder, and the 3rd extruder, and it is air | atmosphere at the foaming resin temperature of about 110-140 degreeC from the slit die provided in the front-end | tip of the 3rd extruder. After extrusion foaming inward, plate molding was performed with an extrusion mold placed in close contact with the slit die and a molding roll placed downstream thereof.
The extrusion mold temperature of the used extrusion mold was set to 120 ° C., and an extruded foam board with skin having a cross-sectional shape having a thickness of 25 mm × width of 200 mm was obtained.
The obtained foam with skin has an overall density of 42 kg / m ³ , a skin layer density of 48 kg / m ³ , and an average cell diameter of 0.29 mm. It had a bubble structure in which large bubbles and small bubbles were mixed, and the occupied area ratio of small bubbles was 45%. The obtained foam had a thermal conductivity of 0.028 W / mK, a flexural strength of 96 N / cm ² , and a combustibility that satisfied the standards of JIS A 9511.

  The results obtained in Examples 1-5 and Comparative Examples 1-2 are summarized in Table 1.

It is a schematic diagram which shows the measurement location of mold temperature.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Upper plate of molding die 2 Lower plate of molding die 3 Melting 4 Measurement point with contact thermometer of mold temperature (5 cm from the last end of molding die, 5 cm from the left end of resin flow surface)

Claims (8)

Styrene resin extruded foam with skin obtained by heating and melting a styrene resin, adding a foaming agent to the styrene resin, extrusion foaming through a die, and molding using an extrusion mold connected to the die Because
The density of the skin layer within 2 mm in the thickness direction from the surface of the extruded foam is 50 to 90 kg / m ³ , and the density of the entire extruded foam is 5 to 30 kg / m ³ lower than the density of the skin layer. A styrene-based resin extruded foam with a skin. The styrene-based resin extruded foam with skin according to claim 1, wherein the density of the skin layer is 55 to 90 kg / m ³ .   As the blowing agent, (A) at least one selected from saturated hydrocarbons having 3 to 5 carbon atoms, (B) at least one ether selected from the group consisting of dimethyl ether, diethyl ether and methyl ethyl ether, and (C The styrene resin extruded foam with skin according to claim 1 or 2, wherein other non-halogen foaming agent is used.   The styrene-based resin extruded foam with skin according to claim 3, wherein (C) the other non-halogen-based foaming agent is water or carbon dioxide.   The styrene-based resin extruded foam with skin according to any one of claims 1 to 4, wherein the average diameter of the bubbles forming the foam is 0.1 to 0.6 mm.   The bubbles forming the foam are composed of bubbles having a bubble diameter of 0.25 mm or less and bubbles having a bubble diameter of 0.3 to 1 mm. These bubbles are dispersed in a sea-island shape through the cell membrane, and the bubble diameter is 0. 5. The styrene resin extruded foam with skin according to claim 4, wherein bubbles of 25 mm or less have an occupied area ratio of 10 to 90% per foam cross-sectional area. The skin-attached skin according to any one of claims 1 to 6, wherein the foam has a bending strength of 25 to 150 N / cm ² and a thermal conductivity of 0.024 to 0.028 W / mK. Styrene resin extruded foam. Styrene resin extruded foam with skin obtained by heating and melting a styrene resin, adding a foaming agent to the styrene resin, extrusion foaming through a die, and molding using an extrusion mold connected to the die A manufacturing method of
The mold temperature T (° C.) of the extrusion mold satisfies the relationship of (t−70) ≦ T ≦ (t + 10) with respect to the Vicat softening temperature t (° C.) of the styrenic resin. A method for producing a styrene resin extruded foam with skin.

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