JP2007211069A - POLYMER COMPOSITION, PROCESS FOR PRODUCING THE SAME, AND MOLDED ARTICLE THEREOF - Google Patents

Abstract

[PROBLEMS] To provide a polymer composition in which a borate salt having an anti-ant / anti-mite effect is uniformly dispersed in a polymer compound so that the effect is exerted to the maximum and its characteristics are not permanently lost. And a method for producing the same, and a molded article thereof.
A polymer composition is obtained by melt-kneading a condensate of a borate and a polyhydric alcohol with a polymer compound. Using this polymer composition as a raw material, or once forming the polymer composition into pellets and using the pellets as raw materials, foams and woven fabrics can be produced by various molding methods such as melt injection, melt extrusion, and melt spinning. To obtain a desired molded article such as a nonwoven fabric, a sheet, and a film.
[Selection figure] None

Description

  The present invention relates to a polymer composition that is less susceptible to damage by insects such as termites, a method for producing the same, and a molded article thereof.

  Synthetic polymers are widely used in the construction field and the like as materials with high functionality. Synthetic polymers themselves cannot be a nutrient source for termites and other pests, but can be devoured for several reasons.

  For example, polystyrene foam is widely used as a heat insulating material for houses, but termites may penetrate the heat insulating material to build an ant road, which may damage a xylem at a remote location. Moreover, in order to utilize the heat insulation effect of a heat insulating material, a hole may be made in the heat insulating material to make a nest.

  In another example, in order to damage the cellulose insulating material of the power transmission cable, the synthetic polymer coating on the outer layer may be eroded.

  Conventionally, as a means of protecting synthetic polymer moldings from insect damage such as termites, methods of adding an insecticide directly to synthetic polymer moldings or applying insecticides to synthetic polymer moldings are known. It has been. Here, as the insecticide, there are an organic synthetic insecticide and an inorganic insecticide. In particular, the inorganic insecticide has an advantage that it is chemically stable and has a long-term effect. Inorganic pesticides include boron compounds because of their low toxicity to mammals, low environmental impact, strong toxicity to all lower animals without blood purification functions, etc. Often used.

  In addition, as a method for dispersing borate in a synthetic polymer, there are methods proposed in Patent Documents 1 and 2, for example. In the methods proposed in Patent Documents 1 and 2, after the sodium borate is fixedly attached to the surface of the raw polystyrene beads, the treated beads are heated in a mold to form a foamed polystyrene block. It is designed to be molded.

Japanese Patent Laid-Open No. 2001-200088 JP 2003-3003 A

  However, in the conventional method in which an inorganic insecticide is added directly to a synthetic polymer molded body, the inorganic insecticide aggregates in the synthetic polymer molded body, and the dispersibility tends to decrease. If the dispersibility is poor, the pests can avoid inorganic pesticides and selectively damage only the matrix synthetic polymer. For this reason, there exists a problem that an anti-ant and a tick-proof effect cannot fully be acquired.

  On the other hand, in the conventional method of applying an insecticide to a synthetic polymer molded body, it is necessary to provide a step of applying an insecticide to the molded body after molding a polymer substance, which increases the number of steps. There is a problem. In addition, the insecticide applied to the molded product will peel off with long-term use, and termites will invade from the missing parts and mites will be generated, so that sufficient anti-anticide / acaricide effect can be permanently obtained. There is a problem that can not be.

  Further, the methods proposed in Patent Documents 1 and 2 have a problem that the distribution of borate depends on the particle size of the raw material beads.

  The present invention has been made to solve such problems, borate having an anti-ant and anti-mite effect is uniformly dispersed in the polymer compound, and the effect is maximized, It is another object of the present invention to provide a polymer composition, a method for producing the polymer composition, and a molded body thereof in which the characteristics are not permanently lost.

In order to achieve the above object, the polymer composition according to the first invention comprises:
It is characterized by melting and kneading a condensate of borate and polyhydric alcohol with a polymer compound.

  In the first invention, the borate is preferably disodium octaborate tetrahydrate (second invention).

Next, the method for producing the polymer composition according to the third invention comprises:
The polymer compound is characterized by melting and kneading a condensate of a borate and a polyhydric alcohol.

The molded product according to the fourth invention is
It is formed by molding the polymer composition according to the first invention or the second invention.

  In the present invention, a high boiling viscosity liquid (condensate) obtained by condensing borate and polyhydric alcohol is melt-kneaded with a polymer compound using a melt-kneader (extruder, kneader, etc.). Thus, a polymer composition in which borate is dispersed in a polymer compound is obtained. Then, for example, by using the polymer composition obtained in this melt-kneading step as a raw material, the polymer composition is injected into a mold or extruded from a nozzle, whereby a target molded body is obtained. In addition, for example, the polymer composition obtained in the melt-kneading step is extruded from a nozzle, and then rapidly cooled, cut, and once formed into a pellet shape. Using the pellet as a raw material, melt injection, melt extrusion, melt spinning, etc. By using these various molding methods, a desired molded article can be obtained.

  According to the present invention, since the borate is melt-kneaded while being in a liquid state, the borate is uniformly dispersed substantially at the molecular level in the polymer composition. For this reason, termites, mites and other pests cannot eat only high-molecular compounds without ingesting borate, ant and mite-proofing effects are maximized, and their characteristics are almost permanent. Will be maintained. In addition, it is thought that borate finally causes metabolic inhibition in the form of orthoboric acid in the body of the pest that ingested it, leading to death of the pest. Here, the borate has characteristics such as low toxicity to mammals such as human beings, but excellent ant-proofing and mite-proofing effects, and also facilitates the condensation reaction with polyhydric alcohols. The disodium octaborate tetrahydrate is preferably used.

  In addition, since the borate is uniformly dispersed at the molecular level in the polymer composition of the present invention, there is no need for a post-treatment step after molding, and conventional melt injection, melt extrusion, There is an advantage that various molding methods such as melt spinning can be applied as they are.

  Further, the polymer composition of the present invention is suitable for producing an anti-antically injection-molded article, synthetic fiber, film, sheet, etc. by melt molding, and these molded articles are used for housing construction. It is used as a reinforcement for foundations and can protect houses from the invasion of underground termites. In addition, as the molded article of the present invention, for example, the expanded polystyrene molding material can be used for burying in the ground such as a heat insulating material of a wooden house in a termite-inhabiting area, a synthetic tatami mat material, or an EPS civil engineering method. Will not suffer.

  Next, specific embodiments of the polymer composition according to the present invention, the production method thereof, and the molded body thereof will be described.

The borate in the present invention is a generic term for boron oxoacids and salts thereof. In particular, disodium octaborate tetrahydrate (Na ₂ B ₈ O ₁₃ · 4H ₂ O: commonly called DOT) or A mixture of these borates is preferably used.

  Examples of the polyhydric alcohol in the present invention include glycols such as ethylene glycol, propylene glycol, and diethylene glycol, polyhydric alcohols having three or more hydroxyl groups such as glycerin and diglycerin, and mixtures thereof. Here, ethylene glycol is preferable because a large amount of borate can be converted into a viscous liquid. For synthetic polymers having a high molding temperature, diethylene glycol or glycerin is preferably used.

  In the present invention, the condensate of borate and polyhydric alcohol can be obtained, for example, by mixing and heating borate and polyhydric alcohol and removing the reaction product water from the reaction system. In the reaction, it is desirable to completely remove water. If the reaction is incomplete, for example, when a synthetic polymer melt and a high-viscosity condensate are mixed with an extruder, a large amount of water vapor is generated, which tends to cause trouble. When the condensation reaction proceeds extremely, the viscosity of the condensate is too high, making it difficult to supply. In addition, the mixing ratio of borate to polyhydric alcohol used in this reaction is not particularly specified, but when the mixing ratio is low, the resulting polymer composition has an appropriate anti-ant / anti-mite effect. In order to obtain this condensate, it is necessary to melt and knead a large amount of the condensate into the polymer compound, and the physical properties of the polymer compound itself are impaired. Therefore, the mixing ratio should be as high as possible, preferably 0.3 or more It is.

  As the polymer compound in the present invention, for example, a thermoplastic polymer compound that can be heated and melted is suitably used. Specific examples include nylon, polyester, polycarbonate, polyethylene, polystyrene, polypropylene, ABS resin, AS resin, polymethyl methacrylate, polyvinyl alcohol, eval (ethylene, vinyl alcohol copolymer), polyvinylidene fluoride, biodegradation And polyester resins, and polymer alloys thereof.

  In the present invention, as a method of melt-kneading a high-boiling viscous liquid obtained by condensing borate and polyhydric alcohol into a polymer compound, for example, when the polymer compound is melted with a vented extruder, A continuous production method in which a condensate liquid of borate and polyhydric alcohol is directly pumped into an appropriate place in a pump or a polymer compound in a batch type pressure kneader, heated and kneaded, and polymer Examples thereof include a batch-type production method in which a compound is melted and a condensate liquid of borate and polyhydric alcohol is added thereto and melt kneaded for an appropriate time.

  Instead of adding a condensate of borate and polyhydric alcohol to the polymer compound, for example, supplying a mixture of polymer compound and boric anhydride (fine powder) to the extruder, A polyhydric alcohol may be injected into this to cause a condensation reaction in the extruder.

  In the present invention, the amount of addition of the condensate of borate and polyhydric alcohol to the polymer compound is not particularly defined, but it is the lowest that an anti-ant / anti-mite effect of borate can be obtained. Addition amount of the condensate is increased, and the properties such as mechanical properties of the polymer compound itself are lost or adversely affect the subsequent molding process, so 50% or less is preferable. .

  The final molded product of the polymer composition of the present invention is not particularly defined as long as it is melt-molded. For example, a foamed molded product (such as polystyrene foam) or a fibrous (nonwoven fabric also) Include), sheet-like, film-like molded bodies, and the like. Such a molded body is widely used as a house building foundation material, a tatami mat, an agricultural material, an industrial landfill material, and the like.

  Next, specific examples of the polymer composition according to the present invention, the production method thereof, and the molded body thereof will be described below. In addition, this invention is not limited to the Example described below.

  The condensate liquid of borate and polyhydric alcohol used in this example was prepared by the following method. First, 1350 g of disodium 8-borate tetrahydrate, 1650 g of ethylene glycol, and 300 g of water were heated in a 5-liter stainless steel three-necked flask equipped with a stirring blade and a Liebig condenser. At this time, heating was continued while condensing the generated water vapor with a cooler. Then, the reaction was stopped at a temperature around 150 ° C., the contents were naturally cooled, and a condensate to be used was obtained. The amount of sodium borate in the resulting condensate liquid was 50% by weight.

(Production Example 1)
A polystyrene resin and the condensate liquid were melt-kneaded using a biaxial extruder (axial length (L) / screw diameter (D) = 35) having a diameter of 30 mm. In this melt-kneading step, when the polystyrene resin was in a molten state at a cylinder set temperature of 200 ° C., the condensate liquid was injected with a plunger pump from a nozzle hole provided in the middle of the cylinder. Here, the injection amount of the plunger pump was adjusted so that the injection amount of the condensate liquid was 10% by weight with respect to the total amount. The kneaded product was extruded as a strand at a discharge rate of 10 kg / hr, cooled with water, then cut into an appropriate length with a cutter and pelletized. The sodium borate content in the polystyrene composition thus obtained was 5% by weight based on the total amount.

(Production Example 2)
The conditions of the polymer compound and the biaxial extruder used are the same as in Production Example 1, but the plunger pump is injected so that the amount of the condensate liquid injected is 1% by weight with respect to the total amount. The amount was adjusted and kneaded, and the kneaded product was extruded as a strand at a discharge rate of 8 kg / hr. Here, the extrusion conditions and the number of nozzles were adjusted so that the diameter of the strand was about 0.5 mm. Further, when this strand is cut with a cutter, the strand is cut so that its length is about 0.5 mm, and finally the polystyrene micro-containing 0.5 wt% of disodium 8 borate tetrahydrate. A pellet was prepared.

(Production Example 3)
A nylon 6 composition pellet was obtained by performing melt kneading with the condensate liquid in the same manner as in Production Example 1 except that the polymer compound used was nylon 6 and the cylinder set temperature was 240 ° C. .

(Production Example 4)
The polymer compound used was polyethylene terephthalate, and melt-kneading with the condensate liquid was performed in the same manner as in Production Example 1 except that the cylinder set temperature was 260 ° C. to obtain polyethylene terephthalate composition pellets. .

Example 1
The polystyrene composition pellets obtained in Production Example 1 were diluted with the raw polystyrene resin so that the final sodium borate content was 0.5% by weight, and mixed well with a tumbler for about 20 minutes. Thereafter, a chemical foaming agent such as sodium hydrogen carbonate was further added and mixed, and then foamed and extruded about 5 times with an extruder to obtain a foamed sheet.

(Example 2)
The polystyrene micropellets obtained in Production Example 2 were impregnated with foaming gas, and foamed by about 50 times by a known method to obtain a foamed sheet.

(Example 3)
The nylon 6 composition pellets obtained in Production Example 3 were diluted with the raw material nylon 6 resin so that the final sodium borate content was 1% by weight, and mixed well with a tumbler for about 20 minutes. As a result of melt spinning and drawing, good long fibers could be obtained. The obtained long fiber was used as a woven fabric.

Example 4
The polyethylene terephthalate composition pellets obtained in Production Example 4 were diluted with the raw material polyethylene terephthalate resin so that the sodium borate content was finally 0.7% by weight, and mixed well with a tumbler for about 20 minutes. When a nonwoven fabric was produced by the jet spin method, jet spinning could be performed stably and a good nonwoven fabric could be obtained.

(Production Comparative Example 1)
The same biaxial extruder as that used in Production Example 1 was used, the production conditions were the same, and the powder of polystyrene resin and disodium 8-borate tetrahydrate was 5% by weight with a tumbler. The mixture was mixed and melt-kneaded, but disodium octaborate tetrahydrate was gradually dissolved at the raw material hopper port of the biaxial extruder, and the hopper port had to be cleaned every few tens of minutes. . In addition, large aggregates thought to be sodium borate were deposited on the filter of the discharge part of the biaxial extruder, the resin pressure in the discharge part increased abnormally, and the pellets could not be collected stably.

(Comparative Example 1)
A foaming sheet such as sodium bicarbonate was mixed with polystyrene resin as a raw material, and foamed and extruded at a magnification of about 5 times by a known method to prepare a foamed sheet. Then, disodium octaborate tetrahydrate dissolved in water was sprayed on the foam sheet.

(Comparative Example 2)
A polystyrene microbead was impregnated with a foaming gas, and foamed by about 50 times by a known method to produce a foamed sheet. Then, disodium octaborate tetrahydrate dissolved in water was sprayed on the foam sheet.

(Comparative Example 3)
A woven fabric was prepared using nylon 6 long fibers, and disodium 8 borate tetrahydrate dissolved in water was sprayed on the woven fabric.

(Comparative Example 4)
A nonwoven fabric was prepared by a known method using polyethylene terephthalate as a raw material, and disodium 8 borate tetrahydrate dissolved in water was sprayed on the nonwoven fabric.

For each of Examples 1 and 2 and Comparative Examples 1 and 2, the ant-proof effect was evaluated by the following method, and for each of Examples 3 and 4 and Comparative Examples 3 and 4, the mite-proof effect was evaluated by the following method. It was evaluated with.
[Anti-ant effect]
A disc having a thickness of 40 mm and a diameter of 56 mm is cut out from each of the produced foamed sheets to obtain a test piece. On the other hand, 14 parts of ion-exchanged water was added to and mixed with 75 parts of sterilized sand and 11 parts of vermiculite. 30 g of this mixture was uniformly laid on the bottom of a plastic cylindrical container having an inner diameter of 56 mm and a height of 100 mm, and a 20 × 20 × 30 mm red pine square piece was placed thereon. Further, the test piece was placed on this red pine square piece, and the same red pine square piece as described above was placed thereon. Then, put 100 termite ants and 10 soldier ants in such a cylindrical container, seal it with a packaging film, put this cylindrical container in a wooden box with a lid, and store it in a room at 25-30 ° C for one month. The inside was observed.
[Anti-mite effect]
Each of the produced nylon woven fabric and each polyester nonwoven fabric was cut into 100 mm squares to form test pieces. The test piece is laid on the bottom of a polyethylene container having an inner dimension of 100 mm square and a depth of 50 mm, and about 100 goby leopard mites and about 2 g mite food are placed in the center, and stored at a humidity of 70-80% and a temperature of about 28 ° C. The total number of surviving ticks after 3 months was counted.
The above results are summarized in Table 1.

  As is clear from Table 1, it can be seen that the examples 1 and 2 have an extremely superior ant protection effect as compared with the comparative examples 1 and 2. Moreover, it turns out that the thing of Examples 3 and 4 is very excellent in the mite prevention effect compared with the thing of Comparative Examples 3 and 4. Therefore, it can be said that the polymer composition of the present invention and the molded product thereof are extremely excellent in the ant-proof and mite-proof effects.

Claims (4)

  A polymer composition obtained by melting and kneading a condensate of a borate and a polyhydric alcohol with a polymer compound.   The polymer composition according to claim 1, wherein the borate is disodium octaborate tetrahydrate.   A method for producing a polymer composition, comprising melt-kneading a condensate of a borate and a polyhydric alcohol with a polymer compound.   A molded article obtained by molding the polymer composition according to claim 1.