JP3292891B2 - Polyurethane insulation - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyurethane heat insulating material having excellent buffering / compression characteristics and decomposability.

[0002]

2. Description of the Related Art Foamed materials are used in extremely large quantities in the fields of automobiles, electricity, construction materials, foods, furniture, fisheries and agriculture. Among the foam materials used in many of these fields, the dominant plastic material is expanded polystyrene. Recently, environmental pollution caused by plastic waste has become a global problem. The biggest reason is that many plastics, including expanded polystyrene, are not degradable and remain in the soil as they are. It is necessary to secure a safe landfill. Also, even if incinerated, plastics generally have a large amount of heat of combustion, and there are problems with both the quality and quantity of combustion gas. Therefore, it is difficult to cope with such a simple facility as incineration of lignocellulose. On the other hand, polyurethane foam, organic polyisocyanate, polyhydroxy compound,
It is manufactured from a chain extender and a foaming agent as required. Examples of polyhydroxy compounds include polyether polyols, polyester polyols, and alkoxypolyalkylene glycols. Among them, polyester polyols include ethylene glycol, 1,6-hexamethylene glycol, and maleic acid and adipic acid. And polyols obtained by ring-opening polymerization of cyclic esters such as caprolactone and the like have been used. On the other hand, a biodegradable urethane prepolymer (Japanese Unexamined Patent Publication No. 63-278924) or a thermoplastic polyurethane resin (Japanese Unexamined Patent Publication No.
No. 3710), but the compositions described in these documents do not provide a heat insulating material having excellent foaming properties and decomposability, which is the object of the present invention.

[0003]

Generally, conventional polyurethane compounds are disclosed in Appl. Microbio 1., 16 , 900 (1968), etc., it is said to be a moldy material. However, according to the mold resistance test of ASTM G21-70, the conventional polyurethane compound shows the growth of bacteria, but does not reach the point where the weight loss of the test specimen is observed. An object of the present invention is to provide a polyurethane heat insulating material having excellent buffering / compression properties and decomposability.

[0004]

According to the present invention, there is provided a polymethylene polyphenylene polyisocyanate and / or a modified polymethylene polyphenylene polyisocyanate having a --CO--CH (CH ₃ )-O-- group in the molecule. A polyol heat-insulating material obtained by reacting a polyol with a foaming agent, a catalyst and a foam stabilizer, wherein the modified polymethylene polyphenylene polyisocyanate has a molecular weight of 500 to 1500 with polymethylene polyphenylene polyisocyanate. It is an isocyanate group-terminated prepolymer obtained by reacting methoxypolyethylene glycol with an excess of isocyanate groups.

[0005] The polymethylene polyphenylene polyisocyanate used in the present invention is a known one, and any single compound or mixture contained therein can be suitably used. The modified polymethylene polyphenylene polyisocyanate is an isocyanate group-terminated prepolymer obtained by reacting polymethylene polyphenylene polyisocyanate with methoxypolyethylene glycol having a molecular weight of 500 to 1500 in excess of isocyanate. This modified product has good compatibility with polyols and is suitable as an isocyanate component for obtaining a heat insulating material. In the present invention, a polyol having a —CO—CH (CH ₃ ) —O— group in a molecule (hereinafter referred to as a polylactic acid polyol) is obtained by mixing lactic acid or polylactic acid with one or two or more divalent or higher hydroxyl compounds. And, if necessary, one or more hydroxycarboxylic acids. The molecular weight of the polylactic acid polyol is preferably 300 to 7000. Examples of the divalent or higher-valent hydroxy compound include the low-molecular-weight polyols used for modifying polymethylene polyphenylene polyisocyanate. Of these, a combination of polyethylene glycol and glycerin is preferred. Examples of this hydroxycarboxylic acid include glycolic acid, 3
In addition to -hydroxybutyric acid and 3-hydroxyvaleric acid, cyclic esters which generate hydroxycarboxylic acid by hydrolysis of butyrolactone, valerolactone, caprolactone, diglycolide, lactide and the like are included. Among them, lactic acid or polylactic acid and a divalent or higher valent hydroxy compound, or a combination of lactic acid or polylactic acid, a divalent or higher valent hydroxy compound and caprolactone are preferable. If necessary, a di- or more-valent hydroxy compound can be used to improve physical properties during the production of the polyurethane insulating material, but the content of the polylactic acid polyol is 20 to 100 in the total polyol.
%, Preferably 50 to 100% by weight, more preferably 80 to 100% by weight. A divalent or higher valent hydroxy compound commonly used for improving physical properties can be used in combination.

Examples of the foaming agent used in the present invention include:
In addition to water that reacts with isocyanate groups to generate carbon dioxide, low-boiling organic solvents such as butane, n-pentane, iso-pentane, n-hexane, n-heptane, and iso-heptane, or monofluorotrichlorobenzene methane,
Halogenated hydrocarbons represented by difluorodichloromethane, monofluorodichloromethane, dichloromethane, and difluorotetrachloroethane are exemplified. These blowing agents can be used alone or in any combination, but when water is used, it is preferable to use 0.1 to 20 parts by weight with respect to 100 parts by weight of the polyol. In the production of the polyurethane heat insulating material of the present invention, in addition to using a surfactant which is a catalyst and a foam stabilizer, additives such as a filler, a plasticizer, a flame retardant, and a coloring agent may be used as necessary. it can. In the present invention, the mixing ratio of the polymethylene polyphenylene polyisocyanate and / or the modified polymethylene polyphenylene polyisocyanate to the polyol is preferably in the range of 0.6 to 1.4 in terms of the molar ratio of isocyanate groups to active hydrogen groups. More preferably, it is in the range of 0.7 to 1.2. Examples of the method for obtaining the polyurethane heat insulating material of the present invention include a slab foaming method, an injection foaming method, a continuous laminate foaming method, and a spray foaming method.

[0007]

The polyurethane insulation of the present invention has a
In addition to having excellent compression properties, it also has extremely high degradability, so when it is landfilled as waste, it is easily degraded by microorganisms and its shape collapses or disappears. It does not impair the natural environment as in. Polyurethane insulation of the present invention, the type of raw material,
By adjusting the expansion ratio and the like, the hardness, elasticity, feel, and the like can be variously changed, so that application to an extremely wide field is possible. For example, it can be used as a heat insulating material for automobile parts, bedding, furniture, various containers and the like. In particular, it can be widely used as a heat insulating material for keeping heat and cooling, including a heat insulating material for refrigerators. In refrigerators and the like, it is useful for the recent energy-saving and resource-saving era.

[0008]

(Preparation of polylactic acid polyol)

PLA-1: D, L-lactic acid (purity 90%) (105
0 parts), glycerin (46 parts), PEG600 (300 parts)
Part) into a 2 liter four-necked flask,
At 160 ° C. under reduced pressure of 2 mmHg for 8 hours.
After a dehydration condensation reaction for a period of time, a polylactic acid polyol having a molecular weight of 1100 was obtained. PLA-2: D, L-lactic acid (purity 90%) (299
0 parts), glycerin (46 parts), PEG600 (300 parts)
Part) and a molecular weight of 250
0 polylactic acid polyol was obtained. PLA-3: D, L-lactic acid (purity 90%) (570
Parts), ε-caprolactone (650 parts), glycerin (46 parts), PEG600 (300 parts)
A polylactic acid polyol having a molecular weight of 1400 was obtained in the same manner as in A-1. Example 1 PLA-1 (100 parts), water (4 parts), TEDA (0.
5 parts) and a silicone-based surfactant (0.3 parts) were sufficiently stirred and mixed until uniform, and kept at 25 ° C.
Was added, and the mixture was stirred and mixed at 7000 rpm for 5 seconds, and immediately poured into an aluminum mold having an inner size of 100 mm x 100 mm x 50 mm whose temperature was previously adjusted to 50 ° C. After 5 minutes, the polyurethane foam was taken out of the mold. Example 2 PLA-1 (100 parts), water (2 parts), TEDA (0.
3 parts), silicone surfactant (0.3 parts), CFC
A polyurethane foam was obtained in the same manner as in Example 1 using -11 (10 parts) and polymeric MDI (61 parts). Example 3 PLA-1 (100 parts), water (2 parts), TEDA (0.
3 parts), silicone surfactant (0.3 parts), HCF
C-141b (10 parts), polymeric MDI (61 parts)
Part) was used to obtain a polyurethane foam in the same manner as in Example 1. Example 4 PLA-2 (100 parts), water (0.5 parts), TEDA
(0.5 part), silicone surfactant (0.3 part),
Example 1 Using Polymeric MDI (73.7 Parts)
In the same manner as in the above, a polyurethane foam was obtained. Example 5 PLA-2 (100 parts), water (0.2 parts), TEDA
(0.3 parts), silicone surfactant (0.3 parts),
HCFC-141b (10 parts), polymeric MDI
(43.7 parts) to obtain a polyurethane foam in the same manner as in Example 1. Example 6 PLA-3 (100 parts), water (0.2 parts), TEDA
(0.3 parts), silicone surfactant (0.3 parts),
HCFC-141b (10 parts), polymeric MDI
(54.3 parts) to obtain a polyurethane foam in the same manner as in Example 1. Example 7 PLA-1 (100 parts), water (0.2 parts), TEDA
(0.3 parts), silicone surfactant (0.3 parts),
A polyurethane foam was obtained in the same manner as in Example 1 using CFC-11 (10 parts) and a modified product of polymeric MDI (64 parts). Example 8 A polyurethane foam was obtained in the same manner as in Example 2 except that a modified polymer MDI was used in place of the polymer MDI in Example 2 and 0.5 parts of water was used. Comparative Example 1 Glycerin-initiated 3000 molecular weight polypropylene oxide (100 parts), water (2 parts), TEDA
(0.3 parts), silicone surfactant (0.3 parts),
CFC-11 (10 parts), polymeric MDI (43.
7 part) to obtain a polyurethane foam in the same manner as in Example 1. Comparative Example 2 A polyurethane foam was obtained in the same manner as in Comparative Example 1, except that a modified polymer MDI (45.9 parts) was used instead of the polymeric MDI (43.7 parts) in Comparative Example 1. [Performance Test] For Examples 1 to 8 and Comparative Examples 1 and 2, ASTM G2
According to the method described in 1-70, the weight loss rate of the polyurethane foam by the mixed bacteria (5 types) after 20 days was measured.
Table 1 shows various properties of the polyurethane foam.

[Table 1] In the aseptic condition, no weight loss was observed after 20 days in any of Examples and Comparative Examples.

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) C08G 18/00-18/87

Claims (1)

(57) [Claims] 1. A polymethylene polyphenylene polyisocyanate and / or a modified polymethylene polyphenylene polyisocyanate and a compound having —CO—CH (CH
₃ ) A polyurethane heat insulating material obtained by reacting a polyol having an -O- group in the presence of a foaming agent, a catalyst and a foam stabilizer, wherein the modified polymethylene polyphenylene polyisocyanate is polymethylene polyphenylene. The polyurethane heat insulating material, wherein the polyurethane heat insulating material is an isocyanate group-terminated prepolymer obtained by reacting a polyisocyanate with methoxypolyethylene glycol having a molecular weight of 500 to 1500 in an excess of an isocyanate group.