JPH11222950A - Heat insulating plate for wooden building - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat insulating plate for a wooden building excellent in chemical resistance and heat insulating effect per unit weight and unit thickness. SOLUTION: A heat insulating plate used being fitted between support frame bodies of a wooden building is formed of a foam grain in-die molding comprising a polypropylene resin/styrene graft polymer obtained by graft-polymerizing a styrene monomer with polypropylene resin (the ratio of polypropylene resin content/styrene resin content is 95-65 wt.%/5-35 wt.%), as base material resin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat insulating board for a wooden building which is used by being fitted between support frames to insulate the floor and walls of the wooden building.

[0002]

2. Description of the Related Art Conventionally, as a heat insulating plate for a wooden building, which is used by being fitted between a floor and a supporting frame of a wall of the wooden building,
What consists of a molded article in a foaming particle type | mold which uses a polypropylene resin as a base resin is known. Although such a heat insulating board shows good chemical resistance to chemicals such as termiticides applied to its surface and preservatives applied to wood to protect it from pests such as termites, The problem was that the heat insulating effect per unit weight and unit thickness was still low. In order to obtain a heat insulating plate having a high heat insulating effect when the heat insulating effect per unit weight and unit thickness is low, it is necessary to increase the thickness of the heat insulating plate,
There are problems such as the lightness of the heat insulating plate being impaired and the cost of the heat insulating plate being increased.

[0003]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a heat insulating board for a wooden building having excellent chemical resistance and heat insulating effect per unit weight and unit thickness.

[0004]

Means for Solving the Problems The present inventors have made intensive studies to solve the above-mentioned problems, and as a result, completed the present invention. That is, according to the present invention, an insulating plate used by being fitted between support frames of a wooden building, the insulating plate being obtained by graft-polymerizing a styrene-based monomer to a polypropylene-based resin, [Polypropylene resin content]
/ [Styrene resin content] ratio is 95 to 65% by weight /
There is provided a heat insulating board for a wooden building, comprising a molded article in a foamed particle mold containing 5 to 35% by weight of a polypropylene resin / styrene graft copolymer as a base resin.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The insulating plate for a wooden building of the present invention
[Polypropylene resin content] obtained by graft polymerization of styrene monomer to polypropylene resin, [Polypropylene resin content] /
The ratio of [styrene resin content] is 95 to 65% by weight / 5.
It is formed of a foamed particle-type molded product having a base resin of a polypropylene resin / styrene graft copolymer (hereinafter, also simply referred to as a modified polypropylene resin) of about 35% by weight. As the polypropylene resin used in the present invention, propylene homopolymer, propylene / ethylene (ethylene component 0.5 to 8% by weight) random copolymer, propylene / ethylene (ethylene component 3 to
18% by weight) block copolymer, propylene / butene
1 (butene-1 component 2 to 15% by weight) random copolymer, propylene / ethylene (ethylene component 0.3 to 5% by weight) / butene-1 (butene-1 component 0.5 to 20% by weight) random copolymer Polymer, propylene / hexene-1 (hexene-1 component 2 to 6% by weight) random copolymer, propylene / 4-methylpentene-1 (4-methylpentene-1 component 1 to 8% by weight) random copolymer Blends of these polymers; blends of these polymers with other polymers, for example, polyethylene resins, ethylene-propylene rubber, etc. at a ratio of 50% by weight or less. In addition, it is good to use a polypropylene resin in the form of particles, and the particle size is usually 0.1 to 3.0 mm, preferably 0.5 to 3.0 mm.
It is good to use 2.0 mm, or the thing whose particle weight is 0.1-20.0 mg, Preferably it is 0.4-4.0 mg.

Examples of the styrene monomer include styrene, chlorostyrene, bromostyrene, vinyltoluene, vinylxylene, p-methylstyrene and α-methylstyrene.

The modified polypropylene-based resin is obtained by impregnating the polypropylene-based resin particles with the styrene-based monomer and performing graft polymerization. As an example of its production, first, an aqueous medium such as water, a polypropylene-based resin particle, a styrene-based monomer and a dispersant are charged into an autoclave, heated after stirring the contents of the autoclave while stirring, and then closed. The styrene monomer is sufficiently impregnated in the resin particles. The heating temperature at this time is usually about 70 to 120 ° C. As the dispersant, for example, polyvinyl alcohol, methyl cellulose, tricalcium phosphate, magnesium pyrophosphate, calcium carbonate, sodium dodecylbenzenesulfonate and the like are used. These dispersants are generally added in an amount of 0.01 to 50% by weight based on water as an aqueous medium.
Next, the content of the autoclave is cooled down to 50 ° C. or less. After cooling, a radical polymerization initiator is added into the autoclave, and after sealing, the mixture is heated again to cause graft polymerization.

In this case, it is preferable to use a radical polymerization initiator having a 10-hour half-life temperature of 70 ° C. or less, and specific examples thereof include the following organic peroxides. Bis (4-t-butylcyclohexyl) peroxydicarbonate; 1-cyclohexyl-1-methylethylperoxy neodecanoate; di (2-ethoxyhexylperoxy) dicarbonate; dimethoxybutyl peroxydicarbonate; Butyl peroxy neodecanoate; t-hexyl peroxy pivalate; t-butyl peroxy pivalate; octanoyl peroxide; lauroyl peroxide; stearoyl peroxide; isobutyryl peroxide; α, α'bis (neodeca Noyl peroxy) diisopropylbenzene; cumyl peroxy neodecanoate; di-n-propyl peroxy dicarbonate; 1,1,3,3-tetramethylbutyl peroxy neodecanoate; di-2-
Ethoxyethyl peroxy dicarbonate; di (3-methyl-3-methoxybutyl peroxy) dicarbonate; t-butyl peroxy neodecanoate; 2,4-
Dichlorobenzoyl peroxide; 3,5,5-trimethylhexanoyl peroxide; 1,1,3,3-
Tetramethylbutylperoxy 2-ethylhexanoate; succinic peroxide; 2,5-dimethyl-
2,5-di (2-ethylhexanoylperoxy) hexane; 1-cyclohexyl-1-methylethylperoxy 2-ethylhexanoate; t-hexylperoxy-2-ethylhexanoate.

The amount of the polymerization initiator to be used is 2.0 to 10 parts by weight, preferably 3.0 to 7.0 parts by weight, based on 100 parts by weight of the styrene monomer. The temperature of the polymerization reaction is
It is less than 90 ° C, more preferably 50 ° C to 89 ° C. 9
If the temperature exceeds 0 ° C., bubbles are undesirably reduced. The reaction time is 3 to 12 hours, more preferably 3.5 to 8 hours. As described above, the graft-modified polypropylene resin particles with the styrene monomer are obtained. The modified polypropylene resin particles thus obtained are non-crosslinked.

In the present invention, the ratio of [polypropylene resin content] / [styrene resin content] in the modified polypropylene resin obtained by the graft polymerization reaction is 95 to 65% by weight to 5 to 35% by weight. More preferably, it is required to be (90-80) / (10-20).
If the styrene resin content is less than the above ratio, the heat insulating performance of the heat insulating plate is reduced (at the same thickness and the same density). Therefore, in order to obtain the desired heat insulating performance, the thickness must be increased. However, this increases the manufacturing cost, and increases the transportation cost and storage cost associated with the increase in weight and volume. In addition, when the heat insulating plate is used between the floor of the building and the floor of the building or between the floor of the floor and the floor of the building, the weight of the heat insulating plate becomes heavy and the construction becomes difficult. On the other hand, if the styrene-based resin content is higher than the above ratio, the chemical resistance is significantly deteriorated, and when the termiticide or the preservative is sprayed on or near the heat insulating plate construction part, the chemical touches the heat insulating plate. Insulation plate greatly reduces the volume, significantly lowering the insulation performance,
Also, the heat insulating plate may come off from between the support frames. This means that maintenance such as termite extermination and antiseptic treatment at the heat insulating board construction site cannot be performed thoroughly, which eventually leads to a decrease in durability of a wooden building or the like.
The ratio between the content of the polypropylene-based resin and the content of the styrene-based resin is adjusted by adjusting the amounts of the polypropylene-based resin and the styrene monomer used as raw materials.

Next, the modified polypropylene resin particles (hereinafter, also simply referred to as modified particles) are foamed by a conventional method to obtain modified polypropylene resin expanded particles (hereinafter, also simply referred to as expanded particles). That is, the modified particles, a dispersion medium such as water, a foaming agent, a dispersant, and the like are placed in a closed container, heated to a temperature equal to or higher than the softening temperature of the modified particles to impregnate the modified particles with the foaming agent, and then sealed. One end of the container is opened to release the modified particles and water to the low-pressure section to form expanded particles. The resin softening temperature is a softening temperature measured under a load of 4.6 kg / cm ² specified in ASTM-D-648.

Examples of the blowing agent include propane, butane, pentane, hexane, cyclobutane, cyclohexane, chlorofluoromethane, trifluoromethane, 1,1-difluoroethane, 1-chloro-1,1-difluoroethane,
2,2,2-tetrafluoroethane, 1-chloro-1,
Volatile foaming agents such as 2,2,2-tetrafluoroethane or inorganic gas-based foaming agents such as nitrogen, air, carbon dioxide, and argon are used, but they are environmentally friendly and inexpensive carbon dioxide and air. And the like are preferable. The amount of the foaming agent used is generally 2 to 50 parts by weight, more preferably 3 to 10 parts by weight, based on 100 parts by weight of the modified particles, and may be appropriately determined within the above range in consideration of the expansion ratio and the expansion temperature. .

The dispersion medium is a liquid such as water, ethylene glycol, glycerin, methanol, ethanol or the like which does not dissolve the modified particles. The amount of the dispersion medium is generally 1.5 to 10 times, preferably 2 to 5 times the total weight of the modified particles. Double it. Usually, water is used as a dispersion medium.

When dispersing the modified particles in a dispersion medium and impregnating the modified particles with a foaming agent under heating, it is preferable to use an anti-fusing agent to prevent mutual fusion of the modified particles. As the anti-fusing agent, a fine powder having an average particle diameter of 0.001 to 70 μm, more preferably 0.001 to 30 μm, which is an inorganic or organic high-melting substance insoluble in the dispersion medium is used. Usually, inorganic anti-fusing agents such as kaolin, talc, mica, alumina, titania, and aluminum hydroxide are used. The addition amount of the anti-fusing agent is 0.01 to 10% by weight, more preferably 2 to 7% by weight, based on the amount of the modified particles used.

When the anti-fusing agent is added, an anionic surfactant such as sodium dodecylbenzenesulfonate or sodium oleate is preferably used as a dispersing aid. .001-
5.0% by weight, especially 0.1 to 1.0% is desirable.

The range of the bulk density of the expanded particles produced as described above is usually 0.015 to 0.18 g / cm ³ . However, in the present invention, the bulk density is 0.0
It is desirably 45 g / cm ³ or less. because,
This is because foamed particles having a high bulk density exceeding 0.045 g / cm ³ do not significantly contribute to shortening of the cooling time during in-mold molding. Since foamed particles having a lower bulk density contribute more to shortening the cooling time, the bulk density is desirably 0.030 g / cm ³ or less from such a viewpoint. In order to manufacture a heat insulating board having a density of 0.02 g / cm ³ or less as described later, the bulk density of the expanded particles is 0.019 g.
/ Cm ³ or less. However, since extremely low bulk density expanded particles may cause a large shrinkage in the obtained in-mold molded product, the lower limit may be limited to 0.006 g / cm ³ . In addition, when the bulk density of the foamed particles produced first exceeds 0.045 g / cm ³ ,
g / cm ³ or less, when further lowering the density is necessary, by applying an increased internal pressure with air or the like and heating with steam or the like to further expand the foamed particles of the bulk density or from the beginning In addition, foamed particles having a reduced density can be obtained. Further, in the present invention, the average cell diameter of the expanded particles is preferably 200 μm or more. The bulk density is 0.045 g /
cm ³ or less, particularly 0.030 g / cm ³ or less, when the average cell diameter is less than 200 μm, for example,
Unless the air pressure in the expanded foam cells is increased to 2.3 atmospheres or more, an in-mold molded article having few surface voids cannot be obtained. In this case, on the contrary, the cooling time during the in-mold molding becomes extremely long, and as a result, there arises a problem that the productivity is reduced. From such a viewpoint, the preferable lower limit of the average bubble diameter is 250 μm. However, the upper limit of the average bubble diameter is desirably 600 μm which does not cause deterioration of the appearance. Such expanded particles having relatively large cells can be easily produced by using the above-mentioned modified polypropylene resin particles obtained by graft polymerization at a low temperature as a raw material of the expanded particles.

Further, in the present invention, the DSC curve (condition: expanded particle 1) obtained by differential scanning calorimetry of the expanded particles is used.
Up to 3 mg with a differential scanning calorimeter
/ Min), and the peak calorie at the highest temperature is (1) the melting point of the base resin constituting the foamed particles is 150 ° C. or less. Is preferably 2 to 25 J / g, and (2) the melting point of the base resin constituting the expanded beads is preferably 5 to 40 J / g when the melting point exceeds 150 ° C. In both cases (1) and (2), if the peak calorific value is below the lower limit, the molded article in the mold tends to shrink, and if the peak caloric value exceeds the upper limit, the superheated steam pressure during molding in the mold is reduced. It has to be kept high, which tends to be disadvantageous in terms of energy costs. In addition, it is preferable that the melting point of the base resin constituting the expanded particles is 150 ° C. or less, because the superheated steam pressure during in-mold molding can be further reduced.

The peak present on the highest temperature side is, for example, when the above-mentioned foaming method in which heated modified particles containing an inorganic gas-based blowing agent and water are released to the low-pressure portion is employed, the heating temperature is determined prior to the release. Is the melting point of modified particles (base resin constituting foamed particles) and the extrapolative melting end temperature (JIS K
(Temperature specified in 7121) for 5 to 90 minutes, preferably 15 to 60 minutes, and then release. The size of the peak is adjusted mainly by the heating temperature, the heating holding time, the type and amount of the foaming agent.

The peak calorie existing on the highest temperature side is a straight line from 80 ° C. on the DSC curve obtained by differential scanning calorimetry of the expanded particles to the melting end temperature of the endothermic peak located on the highest temperature side. (A),
A straight line (B) is drawn from the center of the valley formed by the endothermic peak on the highest temperature side and the endothermic peak existing on the lower temperature side so as to intersect the straight line perpendicularly to the straight line, and the DSC curve minus the straight line above the straight line (B) (A) means the amount of heat corresponding to the area surrounded by the straight line (B). Further, the melting point of the modified particles means that in the above differential scanning calorimetry, after the temperature was raised to 220 ° C., the temperature was immediately lowered to 40 ° C. at a temperature lowering rate of 10 ° C./min. Means the peak of the highest temperature peak obtained when the temperature is raised to This melting point is preferably 125 ° C. or higher, more preferably 130 ° C. or higher, so as not to lose the characteristics of the polypropylene resin.

Next, using the foamed particles obtained as described above, a foamed particle molded body is produced by a conventionally known in-mold molding method. That is, the foamed particles are filled in a mold, a heating medium such as superheated steam is introduced, and the foamed particles are heated and fused to form a foamed particle molded body.

The heat insulating board for a wooden building of the present invention comprises the foamed particle molded product itself obtained as described above, or a product obtained by cutting it into appropriate dimensions, or a product obtained by appropriately joining them. In the present invention, the density of the heat insulating plate is 0.02 g / cm ³ or less (however, 0 is not included),
More preferably 0.009 to 0.018 g / cm ³ ,
And the thermal conductivity of the heat insulating plate is 0.042 kcal / mh ° C.
The following (however, 0 is not included), more preferably 0.02
When the temperature is set to 0.04 kcal / mh ° C., the weight per one heat insulating plate can be reduced, and the fitting work and the like can be easily performed. The density of the heat insulating plate can be adjusted mainly by adjusting the bulk density of the foamed particles used and the state of compression of the foamed particles in the mold during in-mold molding. In addition, the thermal conductivity of the heat insulating plate generally shows a smaller value as the density of the heat insulating plate is smaller, the average cell diameter is smaller, and the closed cell ratio is higher.
Regarding the density of the heat insulating plate, the decrease in thermal conductivity reaches a plateau when the density decreases to a certain extent, and the thermal conductivity tends to increase when the density further decreases), so it should be adjusted mainly considering these points. Can be.

The heat insulating plate of the present invention is excellent in both lightness and heat insulating properties, and is inexpensive, easy to handle, and excellent in durability. In addition, despite being modified with styrene, they exhibit chemical resistance to termiticides and preservatives themselves and organic solvents such as toluene, which are their solvents, and are substantially reduced by contact with these agents. Therefore, the spraying and application of various chemicals for maintenance and preservation of the wooden building can be easily performed without any particular restrictions due to the presence of the heat insulating plate.

In particular, in the case where the heat insulating board for a wooden building of the present invention is used by being press-fitted as a heat insulating underfloor material between the floor and the base or between the floor and the floor of the floor of the wooden building, the termite is used. At the time of pest control, etc., or at the time of preservation treatment on the base, etc., during maintenance, chemicals sprayed on the wood or the ground, such as the base or the base, sprinkle on or come into contact with the heat insulating plate of the present invention. Even if the heat insulating plate does not substantially reduce the volume, the spraying of the medicine can be performed smoothly without any particular restrictions. This greatly contributes to the improvement of the durability of the wooden building.

[0024]

Next, the present invention will be described in more detail with reference to Production Examples and Examples. Production Examples 1-2 and Comparative Production Example 1 4.1% by weight of ethylene component, melting point 138 ° C., melt flow rate (condition 14 in Table 1 of JIS K7210) 8 g
Aluminum hydroxide (foaming nucleating agent) per 100 parts by weight of propylene-ethylene random copolymer resin / 10 minutes
0.05 parts by weight was supplied to an extruder, melt-kneaded at 220 ° C., extruded into a strand from a die having a diameter of 2 mm, cut with water, and cut to produce mini-pellets having an average particle weight of about 2 mg.

In Production Examples 1 and 2, the obtained mini-pellets (M), parts by weight of styrene monomer (S),
0 parts by weight, 10 parts by weight of a 10% suspension of calcium triphosphate (dispersant) and 0.1 part by weight of sodium dodecylbenzenesulfonate were charged in an autoclave, sealed, and then stirred at 2 ° C./min. The temperature was raised to 95 ° C at a speed of 2 hours, and the temperature was maintained for 2 hours to impregnate the styrene monomer into the mini-pellet, then cooled to 50 ° C, and then placed in the autoclave in the type and amount shown in Table 1 (mini-pellet). Of a radical polymerization initiator (refer to <List of used radical polymerization initiators> for the type thereof) when the sum of styrene monomer and styrene monomer is 100 parts by weight. The temperature was raised to [GT] ° C. at a rate of 2 ° C./min, maintained at that temperature for 5 hours, cooled to 40 ° C., taken out the contents of the autoclave, and filtered off the solid components. Washing the solid component at a constant hydrochloric acid solution, and dried 24 hours in a drier to about 60 ° C. setting. Table 1 shows the physical properties of the modified particles thus obtained.

Next, 100 parts by weight of modified particles (Preparation Examples 1 and 2) or the unmodified mini-pellet (Comparative Preparation Example 1), 300 parts by weight of water, 0.3 parts by weight of kaolin (dispersant), dodecyl Sodium benzenesulfonate 0.02
Parts by weight and 8 parts by weight of dry ice (foaming agent) were charged in an autoclave, sealed, and then stirred at 2 ° C.
/ Min at a rate of 2 ° C / min and hold at that temperature for 15 minutes, then raise to [FT] ° C at a rate of 2 ° C / min and hold at that temperature for 15 minutes, At that temperature, the inside of the autoclave is supplied with pressurized air at 45 kg / c.
While maintaining the m ² G, the contents of the autoclave were discharged into the atmosphere to produce expanded particles (A). Table 2 shows the physical properties of the obtained expanded particles (A).

Next, the internal pressure shown in Table 2 was given by keeping the expanded particles (A) at room temperature under pressurized air. Superheated steam of 0.7 kg / cm ² G was sprayed on the foamed particles (B) having an increased internal pressure in a container to produce foamed particles (C) having physical properties shown in Table 2.

The foamed particles (C) were kept at room temperature under pressurized air to give an internal pressure shown in Table 3, and then a molding die (1867 mm × 84 in Production Example 1 and Comparative Production Example 1).
Using a molding die with an inner dimension of 4 mm x 82 mm,
In Production Example 2, a molding die having an inner dimension of 1867 mm x 844 mm x 77 mm was used, and preheating was performed with superheated steam, and then superheated steam having a pressure shown in Table 3 was supplied into the mold. And perform main heating, then water cooling,
Mold release and molded article of expanded particles (hereinafter simply referred to as molded article)
I got The internal pressure applied to the foamed particles (C) is set under such a condition that voids on the surface of the molded body are substantially eliminated.
As the water cooling time, the minimum time during which tertiary foaming did not occur in the molded product was adopted. The obtained molded body was dried in an oven at 60 ° C. for 24 hours, and then allowed to cool at room temperature for 3 days, and then the density was measured. The results are shown in Table 3.

Examples 1 and 2, Comparative Examples 1 and 2 The molded articles obtained in the above Production Examples 1 and 2 and Comparative Production Example 1 and a commercially available in-mold foam molded article made of HIPS (high impact polystyrene) were used for wooden building. Insulation board for goods. Table 4 shows the physical property values and the evaluation results.

In Tables 1 to 4, the measurement of various physical properties and the evaluation of the heat insulating plate were performed as follows. (1) Measurement of Bulk Density (D) of Expanded Particles The apparent volume (V) of the expanded particles placed in a measuring cylinder
Measure cm ³ . Next, the weight (W) g of the expanded particles at that time is measured. The bulk density (D) g / cm ³ is determined by the following equation. D = W / V

(2) Measurement of Average Cell Diameter (D) of Expanded Particles A randomly selected expanded particle is cut at almost the center, and the cut surface is straightened on a screen or a micrograph taken by a microscope. The number (N) of bubbles existing on a straight line having an arbitrary length (L) from an arbitrary arbitrary bubble wall to another arbitrary bubble wall is counted, and is calculated by the following equation. However, the start point of the straight line is an arbitrary bubble wall, and the end point is another arbitrary bubble wall, so that at least 10 bubbles exist between the start point and the end point. D = 1.62 × (L ÷ N)

(3) Measurement of Density of Insulating Board The volume and weight of one insulating board were measured and calculated.

(4) Measurement of Thermal Resistance and Thermal Conductivity of Insulating Plate The thermal resistance of the insulating plate was measured by a flat plate heat flow method described in JIS A1412-1994. The thermal conductivity was calculated from the thickness of the heat insulating plate and the thermal resistance value.

(5) Measurement of Thickness of Insulating Plate 0.1 m at a measuring element area of 10 cm ² and a measuring element pressure of 2 g / cm ²
The thickness of the central part of the heat insulating plate was measured using a dial gauge having an accuracy of m or more.

(6) Measurement of Weight of Insulating Board The weight of one insulating board was measured.

(7) Evaluation of Toluene Resistance of Insulating Plate Using a cut sample from a 100 mm × 10 mm × 10 mm insulating plate, the sample was immersed in toluene at 23 ° C. for 60 minutes, taken out, and the surface of the sample was observed. The evaluation was based on the following criteria. ○ No change △ At least one of swelling and deformation was observed × Dissolution was observed

(8) Evaluation of resistance to termite-proofing agent application to heat-insulating plate Using a cut sample from a heat-insulating plate of 100 mm × 10 mm × 10 mm, a stock solution of a termite-proofing agent (“Sankyo Lentrec oil” manufactured by Sankyo Co., Ltd.) was brushed. Was used to observe the entire surface of one side surface of the cut sample, and evaluated according to the following criteria. ○ No change △ At least one of swelling and deformation was observed × Dissolution was observed

<List of Radical Polymerization Initiators Used> Parloyl L: trade name of “Lauroyl peroxide (10-hour half-life temperature: 61.6 ° C.)” of Nippon Yushi Co., Ltd. "Bis (4-t-butylcyclohexyl) peroxydicarbonate (10 hour half-life temperature 40.8 ° C)"

[0039]

[Table 1] * 1 See <List of used radical polymerization initiators>

[0040]

[Table 2]

[0041]

[Table 3]

[0042]

[Table 4]

The following can be seen from the results of the examples and comparative examples. (1) Compared with the heat insulating plate of Example 1, the heat insulating plate of Example 2, and the heat insulating plate of Comparative Example 1 having the same thermal resistance value, the heat insulating plate of the present invention (the heat insulating plate of the present invention) has a larger thickness. It can be made thinner and lighter. (2) Although the heat insulating plate of Comparative Example 2 is excellent in heat insulating performance, it cannot withstand a termiticide or a solvent, while the heat insulating plate of the example shows excellent resistance to a termiticide or a solvent. .

[0044]

The heat insulating board for a wooden building according to the present invention is excellent in both lightness and heat insulating property, has good chemical resistance, is inexpensive, has excellent handleability, and can be used for a long time. In particular, when the heat insulating board is used between a barbecue and a base or a barbecue and a barge of a wooden building, the heat insulating board has excellent chemical resistance against spraying or contact of chemicals such as termiticides and preservatives. As shown, maintenance of the wooden building with the chemicals or the like can be performed at any time, which can contribute to improvement of the durability of the wooden building.

Continuing on the front page (72) Inventor Toshio 282-1 Togami-cho, Utsunomiya-city, Tochigi Pref.

Claims (3)

[Claims] 1. A heat insulating plate used by being fitted between support frames of a wooden building, wherein the heat insulating plate is obtained by graft-polymerizing a styrene monomer to a polypropylene resin. Resin content] / [styrene resin content] ratio is 95 to 65% by weight / 5 to 35% by weight from a molded article in a foamed particle mold using a polypropylene resin / styrene graft copolymer as a base resin. A heat insulating board for a wooden building, comprising: 2. The heat insulating board for a wooden building according to claim 1, which has a density of 0.02 g / cm ³ or less and a thermal conductivity of 0.042 kcal / mh ° C. or less. 3. The heat insulating board for a wooden building according to claim 1, which is used between a base and a base of a wooden building.