JP2002088185A - Termite-repelling thermoplastic resin foam and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a termite-repelling thermoplastic resin foam suitable as a heat insulator, underfloor heat insulator or the like without suffering insect damage by termites, wood-borers and the like, and to provide a method for producing the foam. SOLUTION: This termite-repelling thermoplastic resin foam is obtained by melt-kneading a thermoplastic resin composition, a foaming agent suitable for foaming the composition and a termite-repelling agent thermally stable at the melt-kneading temperature and extrusion/expansion molding of the resultant mixture. The other objective method for producing the resin foam comprises above-mentioned melt kneading and extrusion/expansion molding steps.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a termite-resistant thermoplastic resin foam obtained by extrusion foam molding and a method for producing the same. Further, according to the present invention, there is provided a termite-resistant thermoplastic resin foam provided with flame retardancy required as a building material, and such a foam is a heat insulating material which is not affected by termites, bark beetles and the like. Useful for underfloor insulation.

[0002]

2. Description of the Related Art A plate-like thermoplastic resin foam, particularly a polystyrene resin foam, has excellent workability and heat insulation,
Widely used as insulation for building materials. These heat insulating materials are indispensable building materials from the viewpoint of energy saving of indoor cooling and heating.

[0003] On the other hand, with the spread of heating, the habitat of termites is moving northward, and damage to buildings and other buildings has been caused almost all over the country. This termite damage is not an exception not only for wood but also for plate-like polystyrene resin foam used as a heat insulating material for ceilings, walls, floors and the like. In the case where the heat insulating material is used adjacent to the wood, there is a problem in that the damage caused by termites is particularly remarkable, and the heat damage lowers the heat insulating property.

[0004] As a means for solving this problem, a method has been proposed in which a termiticide is added to a resin foam. Examples of termiticides include organochlorine pesticides such as dieldrin, aldrin, DDT, lindane, heptachlor, and chlordane;
Inorganic fixing compounds such as agent A (copper, chromium, arsenic agents) have been used.

However, all of these termiticides are highly toxic to humans and animals and may cause environmental pollution. At present, their use is prohibited or restricted. For example, dieldrin and chlordane are excellent in termite control, but are highly toxic to humans and animals, and are hardly decomposable and have accumulative properties. Therefore, use of them as specific chemical substances is prohibited in Japan. Arsenic compounds also have very high toxicity and cannot be used as termiticides.

Therefore, in recent years, organophosphorus insecticides such as phoxime and chlorpyrifos, carbamate insecticides such as propoxal and bassa, and pyrethrin insecticides such as allesulin and resmethrin, which have relatively low toxicity and are less likely to cause environmental pollution. Agents are used (for example,
-103004). However, even these insecticides remain unsafe in terms of safety.

[0007] Japanese Patent Application Laid-Open No. 11-279321 discloses that pre-foamed expandable styrene resin particles (beads) containing the above insecticide as an anti-termitic agent, and the obtained pre-expanded particles are subjected to in-mold foam molding. There is disclosed a foamable styrene resin having termite resistance obtained as described above. However, the heat resistance temperature of the termite-controlling agent is low, and these termite-controlling agents can be used in the in-mold foaming molding at a temperature of about 100 ° C, but the temperature at the time of kneading and molding is about 200 to 220 ° C. Cannot be used in extrusion foaming. That is, most of the termiticides were thermally degraded (pyrolyzed) in the extruder during extrusion foaming, and an extruded foam having termite-proof properties could not be obtained.

Further, the expandable styrene resin described in the above-mentioned publication is obtained by foaming beads having a termite-inhibiting agent fixed on the surface thereof, and the distribution of the termite-inhibiting agent in the resin molded product tends to be biased. Therefore, further improvement has been desired in terms of the termite control effect. On the other hand, there is an inorganic termite-controlling agent as a heat-resistant termite-controlling agent.
Flame retardancy was not sufficiently obtained.

[0009] Japanese Patent No. 2,610,483 discloses that (4-ethoxyphenyl) [3- (4-fluoro-3-phenoxyphenyl) propyl] (dimethyl) silane (hereinafter referred to as "silafluofen") has high safety. It is described as being effective as a termite control agent. Further, Japanese Unexamined Patent Publication No.
No. 79917 discloses a wood or soil termitic / preservative treating agent containing silafluofen and hinokitiol or essential oils containing the same as active ingredients, and optionally 3-iodo-2-propylbutylcarbamate. ing. However, these publications do not disclose the addition of a termitic / preservative agent to a thermoplastic resin foam and the heat resistance of the termitic / preservative agent during extrusion foaming.

[0010]

DISCLOSURE OF THE INVENTION The present invention provides a termite-resistant thermoplastic resin foam which is more effective as a heat insulating material which is not affected by termites, bark beetles and the like, and a heat insulating material under the floor, and a method for producing the same. The task is to

[0011]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies in view of the above-mentioned problems, and as a result, have used an extrusion foam molding technique. It has been found that by selectively using a small number of termiticides, the termiticide is uniformly distributed in the foam and a highly effective thermoplastic resin foam can be obtained, and the present invention has been completed.

Thus, according to the present invention, a thermoplastic resin composition, a foaming agent suitable for foaming the same, and a melt-kneading agent which is thermally stable at a kneading temperature are melt-kneaded, and extrusion-molding is carried out. An ant thermoplastic foam is provided. The thermoplastic resin composition used here preferably contains a flame retardant.

According to the present invention, (A) a step of heating and melting a thermoplastic resin composition optionally containing a flame retardant,
(B) a step of adding and kneading a foaming agent suitable for foaming to the molten thermoplastic resin composition, and (C) adding and terminating a thermally stable termiticide at a kneading temperature to the molten thermoplastic resin composition. And (D) extrusion foaming of the molten thermoplastic resin composition.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION The termite-controlling thermoplastic resin foam of the present invention is obtained by melt-kneading a thermoplastic resin composition, a foaming agent suitable for foaming the same, and a termite-controlling agent that is thermally stable at a kneading temperature, and is extruded. By foam molding, for example, a foaming agent suitable for foaming is added to the thermoplastic resin composition that is heated and melted, and a thermally stable termiticide is further added at a kneading temperature, and the mixture is kneaded and extrusion foamed. It can be obtained by: The thermoplastic resin composition according to the present invention is composed of at least a thermoplastic resin, and includes a thermoplastic resin composition of 100%.

The "kneading temperature" in the "termitic agent which is thermally stable at the kneading temperature" in the present invention varies depending on the type of the thermoplastic resin used. For example, when the thermoplastic resin is a polystyrene resin The temperature at which the termiticide is added and kneaded is preferably about 220 ° C. or less. Therefore, the termiticide used in the present invention is stable at such a kneading temperature.

Examples of such termiticides include silafluofen, nicotinyl compounds and mixtures thereof. Nicotinyl compounds include 1-
(6-Chloro-3-pyridylmethyl) -N-nitroimidazolidine
-2-ylideneamine (hereinafter referred to as "imidacloprid"), N'-6-chloro-3-pyridylmethyl-N-2-cyano-N '
-Methylacetamidine (also referred to as “acetamipride”) and the like. These termiticides are preferably used particularly when the thermoplastic resin is a polystyrene resin. Among the above termiticides, a mixture with imidacloprid whose main component is silafluofen, for example, silafluofen / imidacloprid = 90-80 / 10-2
A mixture of 0 (% by weight) has a synergistic termite-controlling effect when the thermoplastic resin is a polystyrene resin, and is one of the preferred embodiments of the present invention.

The termiticide may be added as it is to the heat-melted thermoplastic resin composition, but is usually added after being appropriately formulated. Examples of formulations include liquids (eg, organic solvent solutions, emulsions or suspensions) and solids (eg, powders, granules). For formulation, an organic solvent, an emulsifier, a solid diluent or the like which does not hinder the foaming of the thermoplastic resin composition and the effects of the present invention can be appropriately selected and used. The total amount of the termitic active ingredient in the formulated termiticide is 0.1 to
It is about 90% by weight. As such a preparation, those described in JP-A-11-79917 can also be used.

The termiticide is preferably used in an amount of 0.01 to 5.0 parts by weight based on 100 parts by weight of the thermoplastic resin. If the compounding amount of the termiticide is less than 0.01 part by weight, the termiticide is not sufficiently exhibited, which is not preferable. On the other hand, when the compounding amount of the termiticide exceeds 5.0 parts by weight, the flammability of the termiticide itself increases the flammability, and the viscosity of the molten resin decreases in the extruder, resulting in high foaming. This is not preferable because a foam having excellent flame retardancy cannot be obtained. In addition, since the termiticide itself is very expensive, it is preferable that the compounding amount is small.

As the thermoplastic resin in the present invention, known resins such as polystyrene resin, polyethylene resin and polypropylene resin can be mentioned, and among them, polystyrene resin is particularly preferable. Further, these thermoplastic resins have a melt flow index (MFI) of 10
g / 10 min or less is preferable.

As the polystyrene resin, styrene,
Homopolymer of styrene monomer such as methylstyrene, ethylstyrene, isopropylstyrene, dimethylstyrene, chlorostyrene, bromostyrene, vinyltoluene, vinylxylene, and styrene monomer and acrylonitrile, methacrylonitrile, acrylic acid, methacryl Acid, acrylate (eg, ester with methyl, ethyl, etc.), methacrylate (eg, ester with methyl, ethyl, etc.), maleic anhydride, copolymers with vinyl monomers such as butadiene, and These mixtures are mentioned. Specifically, polystyrene resin, styrene-maleic anhydride copolymer, styrene-acrylic acid copolymer, styrene-acrylate copolymer, impact-resistant styrene resin (HIPS), styrene-
An acrylonitrile copolymer, an acrylonitrile-butadiene-styrene terpolymer and the like can be mentioned.

The thermoplastic resin composition to be melted by heating preferably contains a flame retardant, and may further contain other additives as long as the effects of the present invention are not impaired. The flame retardant can be appropriately selected depending on the type of the thermoplastic resin. For example, hexabromocyclododecane (HBCD) is preferable for a polystyrene resin, and ammonium polyphosphate is preferable for a polyethylene resin and a polypropylene resin.

The compounding amount of the flame retardant may be appropriately determined according to the type of the thermoplastic resin or the flame retardant and the required physical properties of the resin foam. For example, when the flame retardant is HBCD, 100 parts by weight of the thermoplastic resin is used. Is preferably 2.0 to 5.0 parts by weight, and particularly preferably 3.0 to 3.5 parts by weight. If the amount of the flame retardant is less than 2.0 parts by weight, it is not preferable because sufficient flame retardancy cannot be obtained. Further, when the compounding amount of the flame retardant exceeds 5.0 parts by weight, the viscosity of the molten resin is reduced in the extruder, and internal foaming is caused in the foamed body, and a good foamed body may not be obtained. Absent. Other additives include a pigment, a bubble nucleating agent (for example, talc), and the like.

The foaming agent in the present invention is not particularly limited as long as it is suitable for foaming a thermoplastic resin. For example, for polystyrene resins, methyl chloride, ethyl chloride, hydrocarbons (eg, propane, butane, pentane), 1,1,1,2-tetrafluoroethane (134a),
Examples include 1,1-difluoroethane (152a), 1,1,1-trifluoroethane, carbon dioxide, and mixtures thereof. For polyethylene-based resins and polypropylene-based resins, hydrocarbons (eg, propane, butane) Pentane), 134a, 152a, 1,1,1-trifluoroethane, carbon dioxide and mixtures thereof.

The compounding amount of the foaming agent is preferably 3.0 to 10.0 parts by weight based on 100 parts by weight of the thermoplastic resin.
Particularly preferred is 0 to 8.0 parts by weight. If the amount of the foaming agent is less than 3.0 parts by weight, a sufficient expansion ratio cannot be obtained, which is not preferable. The amount of the foaming agent is 10.0.
Exceeding the weight part is not preferred because internal foaming occurs.

The termite-resistant thermoplastic resin foam of the present invention preferably satisfies the flammability specified in JIS A9511 in addition to the excellent termite-proof properties. The flame retardant as described above may be blended in the molten resin composition.

The method for measuring flammability specified in JIS A9511 is briefly described below. First, five test pieces having a thickness of about 10 mm, a length of about 200 mm, and a width of about 25 mm are prepared. Each test piece is fixed, and a flame is applied from one end of the test piece to an arbitrary point at a constant speed. After the flame reaches an arbitrary point, the flame is removed and the time from the moment when the flame goes out is measured.
The average value of the time of each test piece is determined. This average value indicates flammability. Here, “satisfying the flammability specified in JIS A9511” means that the above average value is within 3 seconds.

The termite-resistant thermoplastic resin foam of the present invention is obtained by kneading the above-mentioned foaming agent and termite-controlling agent with a heat-melted thermoplastic resin composition and subjecting the mixture to extrusion foam molding. Can be manufactured by the following steps. (A) a step of heating and melting a thermoplastic resin composition optionally containing a flame retardant; (B) a step of adding and kneading a blowing agent suitable for foaming to the molten thermoplastic resin composition; and (C) a step of melting and melting the thermoplastic resin. Adding a thermally stable termiticide at a kneading temperature to the resin composition and kneading, and (D) extruding and forming the molten thermoplastic resin composition.

FIG. 1 is an example of a schematic view of an apparatus which can be used for producing the termite-resistant thermoplastic resin foam of the present invention. This apparatus is a tandem-type extruder composed of a first extruder 2 and a second extruder 4 connected via a connecting pipe 3 and a molding device (only a part is shown) 5 attached thereto. In the figure, reference numeral 1 denotes a hopper serving as a supply port for the thermoplastic resin composition. A cooler, a gear pump, a static mixer, or the like may be appropriately installed and used between the second extruder 4 and the molding device 5 without any problem.

In the method for producing a termite-resistant thermoplastic resin foam of the present invention, when the apparatus used is the apparatus shown in FIG. 1, the steps (A) and (B) are successively and continuously performed by the first extruder. Preferably, the addition and kneading of the termiticide in step (C) are performed in a connecting pipe and a second extruder, respectively.

More specifically, first, a thermoplastic resin composition optionally containing a flame retardant and other additives is supplied from a hopper 1 (raw material supply port A in FIG. 1), and the resin composition is heated and melted. (Step (A)). Next, 2 in the first extruder
Then, the resin composition is kneaded and a foaming agent is added (in the case of a gaseous foaming agent, press-fit, foaming agent supply port B in FIG. 1), and the resin composition and the foaming agent are well kneaded (step).
(B)). The temperature in the first extruder 2 is appropriately set according to the type of the thermoplastic resin. For example, in the case of a polystyrene resin, the set temperature is about 220 to 240 ° C.

In the connecting pipe 3, the temperature of the molten resin composition gradually decreases from the step (B). The termite-controlling agent is added to the resin composition whose temperature has slightly decreased in this way (termite-controlling agent supply port C in FIG. 1). For example, in the case of a polystyrene resin, the temperature at which the termiticide is added is about 200 to 220 ° C. Next, the resin composition and the termiticide are well kneaded in the second extruder 4 (step (C)), and the resin composition is cooled to a resin temperature suitable for foaming. This resin composition is extruded from a mold die attached to the tip (outlet side) of the second extruder 4,
The foamed material having a desired shape is obtained by passing through a molding device 5 attached to the end of the die and cooling at the same time as molding (step (D)).

Extrusion conditions may be appropriately set depending on the type of resin and the like. For example, in the case of a polystyrene resin, the pressure of the die is about 30 to 70 kg / cm ² ,
The resin temperature is about 105 to 125 ° C. The molding device is appropriately selected depending on the shape of the resin foam to be obtained. For example, when a plate-shaped resin foam is to be obtained, a molding device having two plates facing each other may be used.

The termite-resistant thermoplastic resin foam of the present invention comprises:
It has a thickness of 0-100 mm, preferably 25-100 mm, and 20-50 kg / m ³ , preferably 25-4
It can be manufactured as a plate-like foam having a density of 0 kg / m ³ . Such a foam can be suitably used as a heat insulating material when building a rooftop exterior insulation, tatami, wall, soil, roof, foundation building.

[0034]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples, but the present invention is not limited by these Examples. In the examples, “parts” means parts by weight.

The plate-shaped resin foams obtained in Examples and Comparative Examples were evaluated by the following methods. (Average bubble diameter) Based on ASTM D2842-69,
Using a scanning electron microscope (JSM T-300 manufactured by JEOL Ltd.) as a measuring device, three directions of MD (flow direction), TD (width direction) and VD (thickness direction) of a plate-shaped resin foam are used. Were measured, and a value (unit: mm) obtained by arithmetically averaging these cell diameters was defined as “average cell diameter”.

(Termite resistance) The termite resistance as used in the present invention was determined by coexisting a plate-shaped resin foam and a termite for a certain period of time, and determining the weight reduction rate of the resin foam at that time. That is, a plate-like resin foam was cut into a square of 3.0 mm, the sample was weighed, put into a petri dish with 150 termite termites and 15 soldiers, and placed in a dark place where the temperature was controlled at 28 ° C. Days left. However, if termites were found dead during this period, a considerable number of termites were replenished on that day. After 21 days, the weight of the sample was measured, and a sample having a weight reduction rate of 3% or less was regarded as having termite resistance.

(Flammability) As described above, "flammability" in the present invention was measured by the method specified in JIS A9511. .

Example 1 Polystyrene (G-13-30, manufactured by Toyo Styrene Co., Ltd.) as a thermoplastic resin 10
Using 0 part of the resin, 3.0 parts of hexabromocyclododecane (HBCD) as a flame retardant, 0.1 part of a pigment, and 0.5 part of talc as a cell nucleating agent are added to the resin, and the obtained mixture is connected to two units. Tandem type extruder (diameter: first φ50m
m, second φ65 mm).

Next, the mixture was melt-kneaded in a first extruder, and 6.0 parts of methyl chloride (methyl chloride) and butane (70% normal, iso-3
(0%) 3.0 parts were press-fitted. Thereafter, the molten resin and the foaming agent were kneaded well in the first extruder. The temperature of the molten resin in the above step was about 230 ° C. Next, silafluofen / imidacloprid = 90 was added to the connecting pipe of the extruder in which the temperature of the molten resin reached about 200 ° C.
0.3 parts by weight of a termite control agent (hereinafter referred to as “type A”) of / 10 (weight%). Then, the resin composition was cooled to a resin temperature suitable for foaming (about 122 ° C.) while well kneading the molten resin and the termiticide in the second extruder.

This resin composition was applied to a die (lip thickness: 1.4 m) mounted on the tip (outlet side) of the second extruder.
m, lip width: 90 mm), the pressure of the die mouth part is 40
kg / cm ^2, temperature 122 ° C. of resin temperature, and extrusion foaming a discharge rate 37kg per unit time. Then, the extruded foam was closely attached to the tip of the die portion,
The sheets are passed through a molding device facing each other, and cooled at the same time as molding, so that the width is 220 mm and the thickness is 30 m.
m of a plate-like foam was obtained.

The resulting foam had a density of 29.7 kg /
m ³ , average bubble diameter 0.39 mm, JIS A9511
The flammability specified in the above was 1.1 seconds, and the weight reduction rate showing termite resistance was 0.6%, and both termite resistance and flame retardancy were satisfactory. Table 1 summarizes the obtained results.

[0042]

[Table 1]

(Example 2) In the same manner as in Example 1 except that a termiticide of silafluofen / imidacloprid = 80/20 (% by weight) (hereinafter referred to as "type B") was used as an active ingredient for termite control. A plate-like foam was obtained and evaluated. The obtained foam had a width of 215 mm, a thickness of 31 mm, and a density of 2
9.3 kg / m ³ , average bubble diameter 0.56 mm, JI
The flammability specified in SA9511 was 0.5 seconds, and the weight reduction rate showing termite resistance was 0.9%, and both termite resistance and flame retardancy were satisfactory. Table 1 summarizes the obtained results.

(Examples 3 to 8) In the same manner as in Example 1 except that the types and amounts of the foaming agents, the amounts of the flame retardants, and the types of the termiticide were as shown in Table 1, A plate-like foam was obtained and evaluated. Table 1 summarizes the obtained results.

Comparative Example 1 A plate-like foam was obtained in the same manner as in Example 2 except that the compounding amount of the termiticide was changed to 4.0 parts. The viscosity of the molten resin was reduced in the extruder, possibly due to the large amount of the termiticide, and internal foaming was caused in the foamed body. Table 1 summarizes the obtained results.

Comparative Example 2 A plate-like foam was obtained and evaluated in the same manner as in Example 1 except that no termiticide was used. The obtained foam had a width of 220 mm, a thickness of 30 mm, and a density of 29.
kg / m ³ , average bubble diameter 0.34 mm, JIS A
The flammability specified in 9511 was 1.1 seconds, the weight reduction rate showing termite control was 21%, and the termite control was insufficient. Table 1 summarizes the obtained results.

Comparative Example 3 A plate-like foam was obtained in the same manner as in Example 2 except that the amount of the flame retardant was changed to 6.0 parts. Perhaps because the amount of the flame retardant was large, the viscosity of the molten resin was reduced in the extruder, and internal foaming occurred in the foam, and a good foam was not obtained and could not be evaluated. Table 1 summarizes the obtained results.

(Comparative Example 4) The injection temperature of the termiticide was 240 ° C.
A plate-like foam was obtained and evaluated in the same manner as in Example 2 except for the following. The obtained foam had an average cell diameter of 0.6.
0 mm, flammability specified in JIS A9511 is 1.3
The second, the weight reduction rate showing the termite resistance was 5.6%, and the termite resistance was lowered probably because the termiticide was thermally degraded. Table 1 summarizes the obtained results.

Comparative Example 5 A plate-like foam was obtained in the same manner as in Example 1 except that permethrin, a known insecticide, was used as an anti-termitic agent. No foam was obtained. Table 1 summarizes the obtained results.

[0050]

The termite-resistant thermoplastic resin foam of the present invention comprises:
It can be obtained by melt-kneading a thermoplastic resin composition, a foaming agent suitable for foaming the same, and a termiticide that is thermally stable at a kneading temperature, and subjecting the mixture to extrusion foaming. Therefore, since the termiticide is not thermally deteriorated and is uniformly distributed over the entire resin foam, it is possible to provide a resin foam having uniform and reliable termite-prevention properties regardless of which part is used. That is,
In the resin foam of the present invention, a higher termite-controlling effect can be obtained than in the case of foaming beads containing a termite-controlling agent on the surface. Therefore, according to the present invention, it is possible to provide a termite-resistant thermoplastic resin foam highly effective as a heat insulating material which is not affected by termites, bark beetles and the like, a heat insulating material under floor, and the like, and a method for producing the same.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of an apparatus that can be used for producing a termite-resistant thermoplastic resin foam of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Hopper 2 1st extruder 3 Connecting pipe 4 2nd extruder 5 Molding apparatus A Raw material supply port B Blowing agent supply port C Termite control agent supply port

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) C08L 25/00 C08L 101/00 101/00 B29K 101: 12 // B29K 101: 12 // B29K 101: 12 105: 04 105: 04 C08K 5/54 (72) Inventor Teruyoshi Akuzawa 24-18 Gojo Nishi, Nara City, Nara Prefecture F-term (reference) KM14 4J002 AA011 EB097 ES006 EU116 EX006 FD137 FD186

Claims (10)

[Claims] 1. An anti-termite-resistant thermoplastic resin foam obtained by melt-kneading a thermoplastic resin composition, a foaming agent suitable for foaming the same, and a thermally stable termiticide at a kneading temperature and subjecting the mixture to extrusion foam molding. body. 2. The termite-resistant thermoplastic resin foam according to claim 1, further comprising a flame retardant. 3. The termite-controlling heat according to claim 2, wherein the flame retardant is hexabromocyclododecane, and the compounding amount thereof is 2.0 to 5.0 parts by weight based on 100 parts by weight of the thermoplastic resin. Plastic foam. 4. The termite-resistant thermoplastic resin foam is made of JIS
The termite-resistant thermoplastic resin foam according to any one of claims 1 to 3, which satisfies the flammability specified in A9511. 5. The method according to claim 1, wherein the termiticide is a silafluofen and / or a nicotinyl compound.
4. A termite-resistant thermoplastic resin foam as described in (1). 6. The compounding amount of the termiticide is 100 thermoplastic resin.
The amount is from 0.01 to 5.0 parts by weight based on parts by weight.
6. The termite-resistant thermoplastic resin foam according to any one of items 1 to 5. 7. The termite-resistant thermoplastic resin foam according to claim 1, wherein the thermoplastic resin is a polystyrene resin. 8. The termitic-resistant thermoplastic resin foam is preferably 10-1.
It has a thickness of 300 mm, and 20 to 50 kg / anti-termite thermoplastic resin foam according to any one of claims 1 to 7 is a plate-like foam having a density of m ^3. 9. (A) a step of heating and melting a thermoplastic resin composition optionally containing a flame retardant, (B) a step of adding a foaming agent suitable for foaming to the molten thermoplastic resin composition and kneading the mixture. (C) a step of adding and kneading a thermally stable termitic agent at a kneading temperature to the molten thermoplastic resin composition, and (D) a step of extruding and foaming the molten thermoplastic resin composition. A method for producing a thermoplastic resin foam. 10. The apparatus used is a dandem type extruder comprising a first extruder and a second extruder connected via a connecting pipe and a molding apparatus attached to the extruder. The termite-controlling heat according to claim 9, wherein (B) is successively and continuously performed in the first extruder, and the addition and kneading of the termiticide in the step (C) are performed in the connecting pipe and the second extruder, respectively. A method for producing a plastic resin.