JP3341116B2 - Biodegradable tubing material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a biodegradable tubing material.

[0002]

2. Description of the Related Art It is known to use a synthetic resin foam as a washing pipe material for washing the inside of various pipes.
However, conventional synthetic resin foams are difficult to dispose after use because they do not have biodegradability, and are difficult to landfill from the viewpoint of environmental protection, and are treated exclusively by incineration. Also, a biodegradable tubing material made of a flexible polyurethane foam is known (Japanese Patent Laid-Open No. 2000-2000).
-536 publication). However, this tube-washing material is unsatisfactory in the effect of removing deposits in the tube.

[0003]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a biodegradable tubing material which is a flexible foam and has an enhanced effect of removing deposits in the tubing.

[0004]

Means for Solving the Problems The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, have completed the present invention. That is, according to the present invention, the polylactic acid solution containing a molasses and / or a sugar compound, a polyisocyanate, and an inorganic fine powder are made of a flexible polyurethane foam obtained by a polycondensation reaction in the presence of water. The biodegradation is characterized in that the powder comprises a high specific gravity fine powder having a specific gravity of 3.5 or more and / or a high hardness fine powder having a Mohs hardness of 3 or more, and the content of the inorganic fine powder is 0.5 to 500%. A flush tubing material is provided.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION As molasses used in the present invention, molasses can be used, but in view of the cost, molasses is preferably used. The saccharide compounds used in the present invention include monosaccharides, oligosaccharides, polysaccharides, sugar alcohols and the like, and any compounds can be used as long as they are soluble in polyhydric alcohols. Such sugar compounds include, for example, glucose, galactose, xylose, lactose, mannose, talose, rhamnose, arabinose, glucosyl mannose, lyxose, allose, altrose, growth, idose, ribose, erythrose, threose,
Psicose, fructose, sorbose, tagatose,
Pentzulose, tetrose, sucrose, maltose,
Isomaltose, cellobiose, lactose, trehalose, kojibiose, sophorose, nigerose, laminaribiose, isomaltose, gentiobiose, melibiose, blanteobiose, turanose, vicianose, agarobiose, silaviose, rutinose,
Primemeose, Xylobiose, Losimenabio,
Erythritol, mesoerythritol, maltitol,
In addition to lactitol, D-threitol, D-arabinitol, ribitol, xylitol, sorbitol, galactitol, D-mannitol, allitol, higher alditol, etc., lignin, starch, dextran, mannan, pectin, pectic acid, alginic acid, chitosan, etc. No. In the present invention, lignin is preferably used, and as the lignin in this case, lignin by-produced during pulp production or a modified product thereof is used.

The polyhydric alcohol used in the present invention includes:
For example, ethylene glycol, diethylene glycol,
1,4-butanediol, 1,6-hexanediol,
Low molecular weight polyols such as neopentyl glycol, trimethylolpropane, glycerin, triethanolamine, and sorbitol: polyether polyols such as polyethylene glycol, polypropylene glycol, polytetramethylene glycol, ethylene oxide / propylene oxide copolymer: polycaprolactone, poly- β-
Methyl-δ-butyrolactone, polyesters from diols and dibasic acids, and the like. Other examples include a hydroxyl group-containing liquid polybutadiene, polycarbonate diol, and acrylic polyol.

The polyisocyanate used in the present invention includes aliphatic polyisocyanates, alicyclic polyisocyanates, aromatic polyisocyanates, and modified products thereof. Examples of the aliphatic polyisocyanate include hexamethylene diisocyanate, and examples of the alicyclic polyisocyanate include isophorone diisocyanate. Examples of the aromatic polyisocyanate include tolylene diisocyanate, xylylene diisocyanate, diphenylmethane diisocyanate, polymeric diphenylmethane diisocyanate, triphenylmethane triisocyanate, and tris (isocyanatephenyl) thiophosphate. Examples of the modified polyisocyanate include urethane prepolymer, hexamethylene diisocyanate buret, hexamethylene diisocyanate, trimer, and isophorone diisocyanate trimer. In the present invention, it is preferable to use an aliphatic polyisocyanate from the viewpoint of obtaining a tube-washing material having enhanced biodegradability.

In order to produce the tube-washing material of the present invention, molasses and / or a sugar compound are mixed with a polyhydric alcohol to obtain a homogeneous solution. In addition, an inorganic fine powder, a foam stabilizer, water and a catalyst are added to this solution, and after stirring, a polyisocyanate is mixed and stirred, and a polycondensation reaction is performed to obtain a flexible polyurethane foam. As the catalyst, a conventionally known catalyst for a urethane reaction is used, and as such a catalyst, a tin-based or amine-based catalyst is used.

In the present invention, an inorganic fine powder is used as a foam additive, and those having a high specific gravity and / or a high hardness are used as such an inorganic fine powder. As a material having a high specific gravity, its specific gravity is 3.5 or more, preferably 4
The above, for example, titanium oxide (rutile type, specific gravity 4.
2), titanium oxide (TiO ₂ 25%, BaSO ₄ 75
%) (Specific gravity 4.3), lithopone (ZnS 30%, Ba)
SO ₄ 70%) (specific gravity 4.3), zinc sulfide (specific gravity 4.0)
4.1), zirconium oxide (specific gravity 5.69), barite (BaSO ₄ ) (specific gravity 4.45), precipitated barium sulfate (specific gravity 4.3), barium carbonate (BaCO ₃ ) (specific gravity 4.33) , red iron oxide (Fe ₂ O ₃₎ (specific gravity 4.6 to
5.0), cuprous oxide (Cu ₂ O) (specific gravity 5.79), iron _{(FeO · Fe 2 O 3)} ( specific gravity 4.24 to 5.21), and the like. The upper limit of the specific gravity is usually about 6. On the other hand, high hardness materials having a Mohs hardness of 3 or more, preferably 4 or more, such as calcite (hardness 3), fluorite (hardness 4), apatite (hardness 5), and feldspar (hardness 6) ), Quartz (hardness 7), corundum (hardness 9), quartz (hardness 7) and the like.

The inorganic fine powder is preferably as fine as possible, and has an average particle size of 1000 μm or less, preferably 300 μm or less, and the lower limit is not particularly limited, but is usually about 1 μm. . The content of the inorganic fine powder is 5% or more, preferably 10%, in all the washing tube materials.
Above, more preferably 15% or more. The upper limit is about 30%.

The inorganic fine powder used in the present invention provides a tube-washing material having an improved effect of removing deposits in the tube. That is, when a high specific gravity is used as the inorganic fine powder, the compressive strength and the compressive elastic modulus of the tube-washing material are increased, and the effect of removing the deposits in the tube is improved. In addition, when a high hardness inorganic fine powder is used, the compressive strength and the compressive elastic modulus of the tube washing material are increased, and the high hardness inorganic fine powder has a high effect of removing deposits by friction. Therefore, as a result, the friction removal effect of the deposits in the pipe is improved.

The usage ratio of polyisocyanate and polyhydric alcohol containing molasses and / or sugar compounds (hereinafter also referred to as hydroxyl group component) is shown as follows. The usage ratio of polyisocyanate is the total hydroxyl content contained in the hydroxyl group component. The isocyanate group equivalent number is 0.8 to 2 equivalents, preferably 1 to 1.5 equivalents, based on the equivalent number of the group. Molasses and / or sugar compounds are used in an amount of 0.1 to 50% by weight, preferably 1
-20% by weight. By using such a polyhydric alcohol containing molasses and / or a sugar compound as a reaction component, a flexible polyurethane foam having excellent biodegradability and improved compressive strength and compressive modulus can be obtained.

[0013] The apparent density (volume / weight) of the flexible polyurethane foam obtained as described above can be adjusted by the amount of water (blowing agent) added to the reaction raw material. 0.01 to 1 mol of isocyanate
It is about 0.1 mol, preferably about 0.02 to 0.09 mol.

The tube-washing material of the present invention comprises the soft polyurethane foam obtained as described above, and has an apparent density (volume / weight of polyurethane foam) of 0.1 to 0.3 g / cm. ³ , preferably from 0.2 to 0.1.
3 g / cm ³ . When the apparent density is lower than the above range, there is a problem that mechanical properties required as a tube washing material cannot be obtained, and when the apparent density is higher than the above range,
Problems such as an increase in the transfer energy of the washing material in the tube and an increase in the material cost arise.

The tube washing material of the present invention has a relatively small apparent density, is lightweight, and has high compressive strength and compressive elasticity. Therefore, the tube washing material of the present invention
In addition to being easy to handle, it absorbs the cleaning solution into it and inserts it into the pipe with strong force. (Dirt) can be efficiently removed. In the case of the tube washing material of the present invention, since it is a foam (foam) having a large number of micropores, it is also excellent in liquid absorbability. Further, since the tube washing material of the present invention is excellent in biodegradability, even if it is buried in the ground, no environmental problem occurs. The tube-washing material of the present invention may have any shape as long as it can be inserted into a tube, and is used in various shapes. In general, it is used in a shape such as a sphere or a column. The tube washing material of the present invention can be applied to various pipes (pipes). Such pipes include various metal pipes, plastic pipes, and ceramic pipes. The inner diameter of the tube is usually 5 to 200 cm, especially 1
0-100 cm. The ratio A / B of the diameter A of the pipe washing material of the present invention to the pipe inner diameter B is 0.1 to 0.9, preferably 0.2 to 0.8.

[0016]

Next, the present invention will be described in more detail with reference to examples.

Example 1 Molasses and polyethylene glycol (molecular weight: 200) were mixed (weight ratio = 1: 2) to prepare a polyol mixture having a molasses concentration of 33%. Ethylene adipate polyol was added to 20 parts by weight of the mixture. (Molecular weight 2200) 70 parts by weight, silicon-based foam stabilizer 0.3 parts by weight, tin-based urethanization catalyst (dibutyltin dilaurate) 0.25 parts by weight, dichloromethane 1 part by weight, water 0.35 parts by weight, and barium sulfate ( An appropriate amount (average particle size: 300 μm) was added and stirred. While the mixture was vigorously stirred at room temperature, 39 parts by weight of lysine diisocyanate was added, and stirring was continued to obtain a foam.

The physical properties of the foam obtained as described above are shown in the following table in relation to the amount of barium sulfate added.
The ethylene adipate polyol is represented by the following formula (1).

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[0019]

[Table 1]

The contents of the description shown in Table 1 are supplemented as follows. (1) Glass transition temperature (° C.) Measured by a differential scanning calorimeter (heating rate: 10 ° C. /
(Min) (2) Decomposition temperature (° C) Measured by thermogravimetry (in nitrogen, heating rate: 10 ° C)
(3) Apparent density (g / cm ³ ) The value obtained by dividing the weight (g) of the foam by the volume (cm ³ ) (4) Strength (kPa) Compressive strength at a compressibility of 10% (5) Strength / Density (kPa / g · cm ⁻³ ) Ratio of strength of (4) to density of (3) (6) Modulus of elasticity (MPa) Measured by tensile / compression tester (7) Modulus of elasticity / density ( MPa / g · cm ⁻³ ) Ratio between the elastic modulus of (6) and the density of (3) (8) Amount of barium sulfate (%) Mass ratio of barium sulfate in foam

Example 2 A foam was obtained in the same manner as in Example 1, except that 1.3 parts of quartz powder (average particle size: 50 μm) was used instead of barium sulfate. In this case, the foam contained high-hardness quartz powder, and thus was excellent in the effect of removing friction on the deposits in the tube.

[0022]

The tube-washing material of the present invention has a high compressive strength and an elastic modulus because it contains inorganic fine powder while being light in weight, and is excellent in the effect of removing friction of the deposits in the tube. Those containing high hardness as the inorganic fine powder show an enhanced effect on removal of deposits in the tube.

────────────────────────────────────────────────── ─── Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI C09K 3/14 C09K 3/14 550L B08B 9/02 E (72) Inventor Shigeo Hirose 205 Shimoyagiri, Matsudo-shi, Chiba (56) References JP-A-2000-536 (JP, A) JP-A-10-130634 (JP, A) JP-A-59-176400 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C08L 75 / 04-75/12 B08B 9/02 C08G 18/65-18/87 C08K 3/00-3/40 C08K 3/14

Claims (1)

(57) [Claims] 1. A flexible polyurethane foam obtained by a polycondensation reaction of a polyhydric alcohol solution containing molasses and / or a sugar compound, a polyisocyanate and an inorganic fine powder in the presence of water, wherein the inorganic fine powder has a specific gravity. A biodegradable tubing material comprising a high specific gravity fine powder of 3.5 or more and / or a high hardness fine powder of Mohs hardness of 3 or more, wherein the content of the inorganic fine powder is 5% or more.