JP2003313349A - Extruded polystyrenic resin foam - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain an extruded styrenic resin foam excellent in heat insulation properties and strength of bond to concrete and useful as a heat insulation and structural material in the fields of construction and civil engineering. <P>SOLUTION: It has been found out that when a foam is used in a position in contact with a placed concrete surface, the foam can develop a high strength of bond to the concrete by giving a specified surface roughness to the outside surface of a styrene resin foam excellent in heat insulation properties. More specifically, the extruded styrene resin foam is one in which the relationships: 15≤Ra≤80 and 100≤Ry≤500 ((Ra) is an arithmetic mean surface roughness representing the surface roughness of the outside surface of the foam, and (Ry) is the maximum height of the surface roughness), and the density is 20-40 kg/m<SP>3</SP>and which is used in a position in contact with a placed concrete surface. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a styrene resin extruded foam used as a heat insulating material / structural material in the field of construction and civil engineering, which has excellent heat insulating properties and good adhesion to concrete.

[0002]

2. Description of the Related Art Extruded styrenic resin foams are preferred for use as heat insulating materials and structural materials in the field of construction and civil engineering because of their excellent heat insulating properties, and the areas of use are expanding due to the recent growing interest in energy conservation. There is a tendency. Under these circumstances, construction methods that use styrene resin extruded foam by adhering it to other materials are widely adopted. Among them, the construction method of adhering to concrete is cheap and easy to use and is therefore preferred. It

However, conventionally, the adhesiveness between the styrene resin extruded foam and the concrete has not always been sufficient. To solve this problem, the diameter of the bubbles forming the foam is increased, and the density of the foam is increased, whereby concrete enters the bubbles and the anchor effect is increased.

However, in particular, in the foams of the three types of extruded polystyrene foam heat insulating plates specified by JIS A9511 which require a high degree of heat insulation, the bubble diameter is generally small, and the adhesiveness of concrete is further increased. It tended to decline. While the surface of the foam is smooth for ordinary use, a method of improving the adhesive strength between the foam and concrete has been carried out by means such as giving unevenness, but it is still not sufficient. Absent.

In JP-A-52-80358, the average cell diameter is 0.08 mm or more and 0.3 mm or less, and the outer surface of the foam has a density 3 formed by providing a grooved surface with a saw or a planer.
Styrenic resin extruded foams of 5-60 kg / m ³ are disclosed. However, the structure of the groove on the outer surface of the foam is not described in detail, and the foam strength having a density lower than 35 kg / m ³ is not described regarding the adhesive strength between the foam and concrete.

As described above, the styrene resin extruded foam having excellent heat insulating property and adhesiveness to concrete has not yet been found.

[0007]

To obtain a styrene resin extruded foam having excellent heat insulating properties and excellent adhesive strength with concrete, which is extremely useful as a heat insulating material / structural material in the field of construction and civil engineering.

[0008]

The present inventors have found that the above-mentioned problems can be solved by roughening the outer surface of a styrene resin extruded foam having an excellent heat insulating property which forms an adhesive surface with concrete to a specific range. The present invention has been completed.

That is, according to the present invention, the arithmetic mean roughness (Ra) indicating the surface roughness of the outer surface of the foam is in the range of 15≤Ra≤80, and the maximum surface roughness (Ry) is 100≤R.
The present invention relates to a styrene-based resin extruded foam having a density of 20 to 40 kg / m ³ with y ≦ 500, which is used at a portion in contact with a concrete placing surface. (Claim 1) The bubbles constituting the foam are mainly 0.25 mm in diameter.
2. The following bubbles and bubbles having a bubble diameter of 0.3 to 1 mm, 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. Of styrene resin extruded foam.
(Claim 2) The styrene resin extruded foam according to claim 1 or 2, wherein the outer surface of the foam is treated with a planar and / or a drum sander. (Claim 3)

Adhesive strength with concrete is 20 N / cm
The styrene-based resin extruded foam according to any one of claims 1 to 3, which is ² or more. (Claim 4) The styrene resin extruded foam according to any one of claims 1 to 4, wherein the foaming agent is a non-CFC type. (Claim 5) The heat conductivity of the foam is three types of extruded polystyrene foam heat insulating plates specified in JIS A9511.
The styrene-based resin extruded foam according to any one of claims 1 to 4. (Claim 6)

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The inventors of the present invention, when the foam is used at a position in contact with a concrete pouring surface, by setting the outer surface of the styrene resin foam excellent in heat insulation to a specific range of surface roughness, It was found that a strong adhesive strength with concrete can be stably expressed.

That is, according to the present invention, the arithmetic mean roughness (Ra) indicating the surface roughness of the outer surface of the foam is in the range of 15≤Ra≤80, and the maximum height of surface roughness (Ry) is 100≤Ry.
The present invention relates to a styrene resin extruded foam having a density of ≤500 and a density of 20 to 40 kg / m ³ , which is used in a portion which comes into contact with a placing surface of concrete.

The styrenic resin extruded foam of the present invention can be produced by adding a styrenic resin, a foaming agent and, if desired, other additives, melt-kneading the mixture in an extruder and discharging the mixture into a low pressure region.

The styrene resin used in the present invention is not particularly limited, and a polystyrene homopolymer obtained only from a styrene monomer, a monomer copolymerizable with a styrene monomer and styrene, or a derivative thereof. Random, block or graft copolymers obtained from
Examples thereof include modified polystyrene such as brominated polystyrene and rubber-reinforced polystyrene. In particular, polystyrene homopolymer is preferable because it can be manufactured at low cost.

The blowing agent used in the present invention is Freon 142.
b, one or more selected from freons represented by freon 134a, aliphatic hydrocarbons having 3 to 4 carbon atoms, water, carbon dioxide, and ethers represented by dimethyl ether. However, a non-Freon type foaming agent which has little influence on the environment is preferable, and one or more kinds selected from aliphatic hydrocarbons having 3 to 4 carbon atoms, water, carbon dioxide, and ethers such as dimethyl ether are preferable.

Examples of the aliphatic hydrocarbon having 3 to 4 carbon atoms include propane, normal butane and isobutane, and examples of the ethers include dimethyl ether, methyl ethyl ether and diethyl ether. Isobutane is the most preferable aliphatic hydrocarbon, and dimethyl ether is the most preferable ether.

Furthermore, in order to produce a foam having a cell structure in which large and small cells are mixed, which will be described later, in addition to a foaming agent such as an aliphatic hydrocarbon having 3 to 4 carbon atoms, carbon dioxide, and dimethyl ether as a foaming agent, This is achieved by using water as a blowing agent.

The density of the extruded styrene resin foam of the present invention is 20 kg / m ³ to 40 kg / m ³ . 2 to give lightweight and excellent heat insulation and mechanical strength
It is preferably 0 kg / m ³ to 40 kg / m ³ ,
More preferably from 20 kg / m ³ to less than 32 kg / m ³ .

The average cell diameter of the foam constituting the styrene resin extruded foam of the present invention is 0.05 to 0.3 mm. Among them, the foam having a characteristic bubble structure in which large and small bubbles are mixed, that is, the bubbles forming the foam are mainly bubbles having a bubble diameter of 0.25 mm or less (small bubbles) and a bubble diameter of 0.3 to 1 mm. Is a foam in which these small bubbles and large bubbles are dispersed in a sea-island shape through a bubble film, and in particular, there are three types of heat insulation specified in JIS A9511 extruded polystyrene foam heat insulating plate. A foam that satisfies the property is preferable. When a foam having a cell structure composed of large and small cells is obtained, small cells having a cell diameter of 0.25 mm or less have an occupied area ratio of 10 to 90% per foam cross-sectional area. The occupying area ratio of the small bubbles is 2 per foam cross-sectional area because it is easily processed into the surface roughness of the present invention.
5 to 50% is preferable.

The adhesive strength between the styrene resin extruded foam of the present invention and concrete is preferably 20 N / cm ² or more. Furthermore, 25 N / cm ² or more is more preferable.

The shape of the styrene resin extruded foam of the present invention is not particularly limited, and may be a cut board or a board with skin. The cut board is more preferable in that the adhesive area with the concrete of the present invention can be easily obtained due to the large adhesive area with the concrete.

The arithmetic mean roughness (R
a) and maximum height (Ry) are JIS B 060
It can be determined by using a surface roughness measuring device according to the surface roughness definition defined in 1-1994.

The arithmetic average roughness (Ra) is obtained by extracting a reference length (l) from the roughness curve in the direction of the average line, and the X-axis in the direction of the average line of the extracted portion is the direction orthogonal to the X-axis. When the Y axis is taken in and the roughness curve is represented by y = f (X), the value obtained by the formula shown in the section of the measurement method described later is represented in micrometers (μm).
Then, an example showing how to perform the measurement is illustrated in FIG.

The maximum height (Ry) is obtained by extracting a reference length from the roughness curve in the direction of its average line, and the interval between the peak line and the valley bottom line of this extracted portion is in the direction orthogonal to the roughness curve. It is measured, and this value is expressed in micrometers (μm). And an example showing how to measure it,
This is illustrated in FIG.

The arithmetic mean roughness (Ra) showing the surface roughness of the outer surface of the styrene resin extruded foam of the present invention is 15 ≦ Ra ≦.
The range is 80. If Ra is less than 20, the effect of the present invention cannot be obtained, and if Ra is more than 80, the commercial value is inferior. Further, Ra is preferably 20 to 50,
More preferably 25-45, most preferably 30-40
Is.

The maximum height (Ry) showing the surface roughness of the outer surface of the styrene resin extruded foam of the present invention is 100≤Ry≤5.
The range is 00. If Ry is less than 100, the effect of the present invention cannot be obtained, and if Ry is more than 500, the commercial value is inferior. Further, Ry is preferably 150 to 500.
And more preferably 250 to 400.

As a method for satisfying the surface roughness of the present invention, the outer surface of the foam can be ground with a hot wire, a slicer, a sharpening stone, a rotary blade, etc.
Further, there is a method of processing the outer surface of the foamed body into a rough surface by using a grinding machine such as a drum sander or a belt sander capable of plane cutting by rotating a cloth file.
Among them, it is easy to adjust the number of revolutions of the rotary blade and the roughness of the cloth file within the range of the surface roughness of the present invention, and the planer and the drum sander are selected from the viewpoint of excellent productivity. Is more preferable.

In particular, when a planar is used, it is preferable to adopt a lower rotary blade speed than in the case of producing an ordinary foam which does not require adhesion to concrete. Can be controlled. Since this rotary blade speed varies depending on the device, it cannot be unconditionally determined, but for example, the normal blade speed is about 3500.
~ About 3500 to about 4500 rpm
It can be realized by reducing the speed to about rpm. More preferably, for example, about 1400 to about 2700 rpm, particularly preferably about 1450 rpm to about 2600 rpm.

The extruded styrene resin foam of the present invention has excellent heat insulating properties and excellent adhesive strength with concrete, and is extremely useful as a heat insulating material / structural material in the field of construction and civil engineering.

[0030]

EXAMPLES Next, the present invention will be described in detail based on examples, but the present invention is not limited to such examples. Physical property evaluation method (1) Foam density (kg / m ³ ) Foam density (g / cm ³ ) = foam weight (g) / foam volume (cm ³ ) /
m ³ ). (2) Foam average cell diameter (mm) Measured according to ASTM D-3576.

(3) Small Cell Occupied Area Ratio (%) The occupied area ratio of cells having a cell diameter of 0.25 mm or less per cross-sectional area of the foam was determined as follows. Here, a bubble having a bubble diameter of 0.25 mm or less has a circle equivalent diameter of 0.25.
Bubbles of mm or less. a) Scanning electron microscope (manufactured by Hitachi, Ltd., product number: S
-450), and a photograph is taken of the vertical cross section of the foamed body at a magnification of 20 to 50 times. b) Place an OHP sheet on top of the photographed image, and place black ink on the portion corresponding to bubbles with a diameter in the thickness direction larger than 7.5 mm (the actual size corresponds to bubbles larger than 0.25 mm). Fill with and copy (primary processing). c) Image processing device (manufactured by Pierce Co., Ltd., product number: PIAS-
The primary processed image is captured in II), and the dark color portion and the light color portion, that is, whether or not the portion is painted with black ink is identified. d) A portion of the dark-colored portion corresponding to the area of a circle having a diameter of 7.5 mm or less, that is, a portion having a long diameter in the thickness direction but having an area of only a circle having a diameter of 7.5 mm or less. Is lightened and the dark part is corrected. e) Using "FACTAREA (area ratio)" in the image analysis / calculation function, the area ratio of the bubble diameter of 7.5 mm or less (light-color portion divided by shading) in the entire image is calculated by the following formula. Small bubble occupying area ratio (%) = (1-area of dark color portion / area of entire image) × 100

(4) Concrete Adhesion Strength Test Concrete is cast on a styrene resin extruded foam having a width of 910 mm, a length of 1820 mm and a thickness of 30 mm, and the concrete is cured and dried outdoors for 2 weeks to adhere the styrene resin extruded foam to the concrete. It was After a disc jig having a diameter of 100 mm and a foam were adhered and cured with an epoxy adhesive, the disc jig was pulled out by a hydraulic press to measure the strength when the adhesive interface between the foam and concrete was peeled off. The adhesive strength was measured at arbitrary 6 points and the average value was taken as the adhesive strength.

(5) Measurement of the surface roughness of the outer surface of the foam Using the ultra-depth shape measuring microscope (VK8500) manufactured by Keyence Corporation, the surface roughness of the cut surface was determined from a photograph of the treated surface of the foam magnified 10 times. The surface roughness was determined according to JIS B 0601-1994 surface roughness definition. The surface roughness was measured in the X direction and the Y direction, and 6 points where a large surface roughness value was obtained were measured and the average value was shown. Arithmetic Average Roughness (Ra) The arithmetic average roughness is extracted from the roughness curve by the reference length (l) in the direction of the average line, and the X axis is orthogonal to the X axis in the direction of the average line of this extracted portion. When the Y axis is taken in the direction and the roughness curve is represented by y = f (X), the value obtained by the following formula is represented in micrometers (μm). Then, an example showing how to perform the measurement is illustrated in FIG.

[0034]

[Equation 1]

Maximum height (Ry) The maximum height is determined by extracting a reference length from the roughness curve in the direction of its average line, and the interval between the peak line and the valley bottom line of this extracted portion is the direction orthogonal to the roughness curve. The value is expressed in micrometers (μm). Then, an example showing how to perform the measurement is shown in FIG.

(Examples 1 to 4) Styrene resin 10
Density 26k extruded and foamed using a mixed blowing agent of 3 parts by weight of propane and 6 parts by weight of methyl chloride to 0 parts by weight.
Styrene resin extruded foam (foam 1) having g / m ³ and an average cell diameter of 0.5 mm (The thermal conductivity specified in JIS A9511 is 0.038 W / mK, and it is compatible with one extruded polystyrene foam heat insulating plate. ); With respect to 100 parts by weight of styrene resin, a density of 31 kg / m ³ produced using a mixed foaming agent of 4 parts by weight of isobutane, 1.5 parts by weight of dimethyl ether, and 0.8 parts by weight of water, and an average cell diameter of 0. 3m
m, styrene resin extruded foam (foam 2) with a small bubble occupying area ratio of 40% (the thermal conductivity specified in JIS A9511 is 0.026 W / mK, and is compatible with three extruded polystyrene foam heat insulating plates) , Feed speed 30m / m
Planar with in (φ300mm, thickness 8mm, number of blades 30)
Sheet) or / and drum sander (process roughness # 4)
In step 0), the outer surface of the foam is ground to obtain a surface roughness Ra of the outer surface.
Is in the range of 15 ≦ Ra ≦ 80, and Ry is 100 ≦
The adhesive strength between the foam of the present invention and concrete in the range of Ry ≦ 500 was evaluated.

(Comparative Examples 1 and 2) Styrene resin 10
A styrene resin extruded foam having a density of 31 kg / m ³ and an average cell diameter of 0.1 mm, which was extruded and foamed using a mixed foaming agent of 4 parts by weight of isobutane and 4 parts by weight of dimethyl ether with respect to 0 part by weight (foam body 3). (The thermal conductivity specified in JIS A9511 is 0.030 W / mK, and it is suitable for two types of extruded polystyrene foam heat insulating plates); Styrene resin 1
Styrene resin extruded foam (foam 4) having a density of 33 kg / m ³ and an average cell diameter of 0.2 mm extruded and foamed using a mixed foaming agent of 4 parts by weight of isobutane and 4 parts by weight of dimethyl ether with respect to 00 parts by weight. Planar (φ300 mm, thickness 8 m) at a feed rate of 30 m / min for (the thermal conductivity specified in JIS A9511 is 0.030 W / mK)
m, the number of blades is 30), the rotation speed of the rotary blade is set to 4000 rpm, the outer surface of the foam is ground, and the surface roughness R of the outer surface is
The adhesive strength between the foam and concrete in which a was 10, 12 and Ry was 95, 200 was evaluated.

[0038]

[Table 1]

The foams shown in the examples of the present invention, in which the outer surface of the foam satisfies the surface roughness of the present invention, have an adhesive strength with concrete of 20 N / cm ² or more and are excellent in concrete adhesive strength as compared with the comparative examples. I understand.

[0040]

EFFECT OF THE INVENTION Density 20 in which the arithmetic mean roughness (Ra) indicating the surface roughness of the outer surface of the foam is 15 ≦ Ra ≦ 80 and the maximum height of surface roughness (Ry) is 100 ≦ Ry ≦ 500. To 40 kg / m ³ of styrene-based resin extruded foam, which is used in a place that comes into contact with a concrete placing surface. The styrene resin extruded foam of the present invention has excellent heat insulating properties and excellent adhesive strength with concrete, and is extremely useful as a heat insulating material / structural material in the field of construction and civil engineering.

[Brief description of drawings]

FIG. 1 shows the arithmetic mean roughness (Ra) calculated from roughness curves.
It is an example of a figure showing how to measure.

FIG. 2 is an example of a diagram showing how to measure a maximum height (Ry) from a roughness curve.

Claims (6)

[Claims] 1. The arithmetic mean roughness (Ra) indicating the surface roughness of the foam outer surface is in the range of 15 ≦ Ra ≦ 80, and the maximum surface roughness height (Ry) is 100 ≦ Ry ≦ 500. A styrene-based resin extruded foam having a certain density of 20 to 40 kg / m ³ , which is used in a portion in contact with a concrete placing surface. 2. The foam constituting the foam is mainly 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, and the bubbles having a bubble diameter of 0.25 mm or less per foam cross-sectional area. The styrene resin extruded foam according to claim 1, having an occupied area ratio of 10 to 90%. 3. The styrene resin extruded foam according to claim 1, wherein the outer surface of the foam is treated with a planar and / or a drum sander. 4. The adhesive strength with concrete is 20 N / c.
styrene resin extruded foam according to any one of claims 1 to 3 m ² or more. 5. The foaming agent is a non-CFC type foaming agent.
The styrene resin extruded foam according to any one of 1. 6. The styrene resin extruded foam according to any one of claims 1 to 5, wherein the foam has three types of heat insulation plates of polystyrene foam extruded according to JIS A9511.