JP2003137954A - Method for producing phenol-modified polyurethane foam for heat insulating/cushioning material for shipping container - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing phenol-modified polyurethane foam for heat-insulating/cushioning material for a shipping container which has excellent high-temperature heat resistance, is flame-retardant, can reduce foaming pressure in foaming in a mold, control inferior foaming conditions (mainly crack) and raise compression strength. SOLUTION: This method for producing phenol-modified polyurethane foam for heat-insulating/cushioning material for a shipping container comprises a process for preparing a composition composed of a polyol component containing a novolak phenol resin as an essential component, a polypropylene glycol and a blowing agent and reacting the composition with an isocyanate component. The average molecular weight of the polypropylene glycol is 100-5,000 and the ratio of the polypropylene glycol mixed is 0.5-25 parts wt. based on 100 parts wt. of the polyol component.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention
The present invention relates to a method for producing a phenol-modified polyurethane foam for a cushioning material, specifically, excellent in high temperature heat resistance,
It is flame-retardant, can reduce the foaming pressure at the time of foaming the mold, and can suppress the occurrence of foaming defects (mainly cracks) and increase the compression strength. The present invention relates to a method for producing a polyurethane foam.

[0002]

2. Description of the Related Art Wood has been mainly used as a heat insulating material and a cushioning material for transportation containers. However, due to environmental problems and deterioration of strength due to corrosion over time, polyurethane foam is used instead. It became so. However, the use of polyurethane foam has been required to have safety such as fire safety and thermal stability at high temperatures for a long period of time. To meet these demands, use of heat-resistant polyols, isocyanurate conversion, and the like have been generally performed as a method for increasing the heat resistance of polyurethane foams.

However, for example, when the above-mentioned isocyanurate conversion is performed, the flame retardancy against ignition and flame is improved, but there is a problem that a large amount of smoke is generated during combustion. Further, the isocyanurate conversion has a problem that since a large amount of isocyanurate is used during blending of the polyurethane foam, the foam tends to be brittle and the compressive strength becomes low. Further, in the isocyanurate formation, since the foaming pressure at the time of foaming the mold is high and it takes a long time until the mold is released, productivity is poor, and foaming defects such as cracks occur, and sufficient compressive strength is imparted as a cushioning material. There is also a problem that you cannot do it.

[0004]

SUMMARY OF THE INVENTION Therefore, the object of the present invention is excellent in high temperature heat resistance, flame retardancy, capable of reducing the foaming pressure at the time of foaming a mold, and further foaming defects (mainly cracks). It is an object of the present invention to provide a method for producing a phenol-modified polyurethane foam for a heat insulating / buffering material of a transportation container, which is capable of suppressing the occurrence of heat generation and increasing the compressive strength.

[0005]

The present invention provides a polyol component containing a novolac type phenolic resin as an essential component,
A method for producing a phenol-modified polyurethane foam for a heat insulating / buffering material for a transportation container, comprising the steps of preparing a composition containing polypropylene glycol and a foaming agent, and adding an isocyanate component to the composition and reacting the composition. Average molecular weight is 100-50
And the polypropylene glycol is added to the composition in a proportion of 0.5 to 25 parts by weight with respect to 100 parts by weight of the polyol component. Further, the present invention is characterized in that aluminum hydroxide having an average particle size of 5 to 100 μm is added to the composition in a ratio of 0.5 to 25 parts by weight with respect to 100 parts by weight of the polyol component. The present invention provides a method for producing a phenol-modified polyurethane foam for a heat insulating / buffering material.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be further described below.
The polyol component in the present invention uses a novolac type phenol resin as an essential component. In addition, the polyol component in the present invention does not include the polyacetylene glycol described below. Generally, examples of the phenol resin include a resol type phenol resin, a benzylic ether type phenol resin, and a novolac type phenol resin. Resole type phenolic resin has phenolic hydroxyl group and methylol group, but the stability of the resin is poor because it is self-crosslinking type, and it is difficult to control the reaction with isocyanate component due to the presence of free monomer, so it was manufactured. Good foam appearance and physical properties cannot be obtained. In addition, the benzylic ether type phenolic resin is
Although the stability is better than that of the resol type phenol resin, the reaction of the phenolic hydroxyl group and the methylol group occurs randomly, and it is difficult to control the reaction with isocyanate. Furthermore, since both the resole type and benzylic ether type phenolic resins have a methylol group, formaldehyde is generated during the condensation and there is a problem with odor. However, since the novolac type phenol resin does not have a methylol group, it becomes easy to control the reaction between the phenolic hydroxyl group and the isocyanate. As a result, flame resistance and heat resistance, which are the characteristics of the phenol resin, are imparted, and the crosslink density is increased due to the molecular structure in which the aromatic rings are dense, and a foam having high strength can be manufactured.

Examples of the phenols used as the raw material of the novolac type phenol resin include phenol, cresol and xylenol. These phenols may be used alone or in combination. Formaldehyde, paraformaldehyde, polyoxymethylene, trioxane, etc. can be used as aldehydes,
Particularly, an aqueous formaldehyde solution (formalin) is preferably used. These aldehydes may be used alone or may be mixed. Also, hydrochloric acid as a novolak catalyst,
Examples thereof include inorganic acids such as sulfuric acid and organic acids such as acetic acid and oxalic acid. These catalysts may be used alone or may be mixed. The novolac type phenol resin has a number average molecular weight of 300 to
1000 is preferred.

As the polyol component in the present invention,
Other polyols other than the above novolac type phenol resin can be used in combination. Examples of other polyols include conventional polyester polyols and polyether polyols for urethane production. However, when other polyols are used in combination, the amount used is preferably 40% by weight or less based on the entire polyol component.

According to the present invention, the use of polypropylene glycol makes it possible to reduce the foaming pressure at the time of foaming the mold, suppress foaming defects (mainly cracks) occurring during foaming, and The compressive strength can be increased. Also, the compatibility with the isocyanate component is improved. Among them, the average molecular weight (number average, the same applies hereinafter) 10
0 to 5000 polypropylene glycol is preferred.
If the average molecular weight is less than 100, the effect of addition is small,
If it exceeds 00, the compatibility with the isocyanate component is deteriorated and the foam may be deformed. The mixing ratio of polypropylene glycol is 0.5 to 25 parts by weight, preferably 2 to 10 parts by weight, based on 100 parts by weight of the polyol component. When polyethylene glycol is used instead of the polypropylene glycol, the compatibility with the isocyanate component is deteriorated and the foam may be deformed, which is not preferable.

According to the present invention, the average particle size is 5-10.
Aluminum hydroxide of 0 μm was added to the polyol component 100
It is preferable to use 0.5 to 25 parts by weight with respect to parts by weight because the foaming pressure at the time of foaming the mold can be further reduced. Aluminum hydroxide also contributes to the improvement of flame retardancy. If the average particle size is less than 5 μm, the physical properties of the foam, particularly the compression strength, are deteriorated, which is not preferable. On the contrary, when it exceeds 100 μm, the appearance of the foam is deteriorated, which is not preferable.

As the foaming agent used in the present invention, the use of specific freons such as trichlorofluoromethane (R-11) and trichlorotrifluoroethane (R-113) which have been conventionally used due to the problem of ozone depletion is prohibited. As a substitute for these, HCFC-141b, H
Alternative CFCs such as CFC-123 and HFC, halogenated hydrocarbons such as methylene chloride, petroleum hydrocarbons such as cyclohexane and normal pentane, low boiling point compounds such as isopropyl ether and water can be used. The amount of the foaming agent used is preferably 1 to 50 parts by weight with respect to 100 parts by weight of the polyol component. The foam stabilizer used in the present invention,
A polysiloxane alkylene oxide adduct type so-called silicone type is suitable and is selected according to the physical properties of the foam. The addition amount is 0.1 to 5 parts by weight, preferably 1 to 2 parts by weight, based on 100 parts by weight of the polyol component.

The isocyanate component used in the present invention is
2,4- or 2,6-tolylene diisocyanate (T
DI) or a mixture thereof, p-phenylene diisocyanate, xylylene diisocyanate, diphenylmethane diisocyanate (MDI) and a polynuclear mixture of polymeric MDI and the like, and among them, polymeric MDI is particularly suitable. The amount of the isocyanate component to be blended is 0.7 to OH / NCO equivalent ratio.
A range of 1.5 is suitable. As a urethanization catalyst,
Triethylenediamine, tetramethylguanidine, N,
N, N ', N'-tetramethylhexane-1,6-diamine, dimethyl ether amine, N, N, N',
Amine-based catalysts such as N ″, N ″ -pentamethyldipropylene-triamine, N-methylmorpholine, bis (2-dimethylaminoethyl) ether, dimethylaminoethoxyethanol, triethylamine; dibutyltin diacetate, dibutyltin dilaurate Examples thereof include organotin catalysts such as dibutyltin thiocarboxylate and dibutyltin dimaleate, and the combined use of an amine catalyst and an organotin catalyst is particularly advantageous. These urethanization catalysts can be used in various foaming methods such as injection and continuous board by obtaining the required foaming speed and curing speed by adjusting the type and amount used. The amount of the urethanization catalyst used varies depending on the required foaming rate and curing rate, but is generally 0.0 per 100 parts by weight of the polyol component.
1 to 10 parts by weight is preferable.

[0013]

The present invention will be further described below with reference to Examples and Comparative Examples. (Example 1) 100 kg of phenol, 45 kg of 37% formalin Charged in the presence of 1 kg of oxalic acid as a reaction catalyst at 100 ° C. for 5 hours, and then dehydrated under reduced pressure until the water content becomes 0.5% and the unreacted phenol content becomes 1% or less. Then, a novolac type phenol resin A was obtained. The obtained novolac type phenol resin A had a hydroxyl value of 450 mgKOH / g, a number average molecular weight of 400, and a semisolid state (viscous state) at room temperature. To 100 parts by weight of this novolac type phenol resin A, silicone (Toray Dow ring:
SH-193) 1 part by weight, triethylenediamine (Kao: KL-No31) 1 part by weight as a urethanization catalyst, potassium octylate (Japan Chemical Industry: Pcat 15G) 1 part by weight, HCFC-141b 10 parts by weight as a foaming agent. It melt | dissolved and it was set as the polyol system liquid a. To 100 parts by weight of this polyol system liquid a, 2 parts by weight of polypropylene glycol (average molecular weight 400) was added, and further 2 parts by weight of aluminum hydroxide having an average particle diameter of 50 μm was added. Furthermore, as an isocyanate component, polymeric MD
I (Sumitomo Bayer Urethane: 44V20-NCO = 3
1.5%) was added to the polyol system liquid a so that the -OH / -NCO equivalent ratio was 1.05, and the diameter was 1200
A foamed panel was obtained by heating to 70 ° C. with a semicircular mold having a thickness of 100 mm and a thickness of 100 mm. The properties of the foamed panel obtained are shown in Table 1.

(Example 2) Polyol system liquid a10
Polypropylene glycol (average molecular weight 10
00) and 5 parts by weight of aluminum hydroxide having an average particle diameter of 50 μm were mixed and foamed under the same conditions as in Example 1 to obtain a foamed panel. The properties of the foamed panel obtained are shown in Table 1.

(Example 3) Polyol system liquid a10
Polypropylene glycol (average molecular weight 30
No. 00) and 7 parts by weight of aluminum hydroxide having an average particle diameter of 50 μm were mixed and foamed under the same conditions as in Example 1 to obtain a foamed panel. The properties of the foamed panel obtained are shown in Table 1.

(Example 4) Polyol system liquid a10
Polypropylene glycol (average molecular weight 10
No. 00) and 5 parts by weight of aluminum hydroxide having an average particle size of 10 μm were mixed and foamed under the same conditions as in Example 1 to obtain a foamed panel. The properties of the foamed panel obtained are shown in Table 1.

(Example 5) Polyol system liquid a10
Polypropylene glycol (average molecular weight 30
No. 00) was blended and 7 parts by weight of aluminum hydroxide having an average particle diameter of 75 μm was blended under the same conditions as in Example 1 and foamed to obtain a foamed panel. The properties of the foamed panel obtained are shown in Table 1.

(Comparative Example 1) Polyol system liquid a10
A foam panel was obtained by mixing and foaming under the same conditions as in Example 1 except that 0 parts by weight of polypropylene glycol and aluminum hydroxide were not mixed. The properties of the foamed panel obtained are shown in Table 2.

(Comparative Example 2) Polyol system liquid a10
Polypropylene glycol (average molecular weight 9
2) was mixed in 2 parts by weight and 7 parts by weight of aluminum hydroxide having an average particle diameter of 50 μm was mixed, and the mixture was mixed and foamed under the same conditions as in Example 1 to obtain a foamed panel. The properties of the foamed panel obtained are shown in Table 2.

(Comparative Example 3) Polyol system liquid a10
Polypropylene glycol (average molecular weight 70
No. 00) was mixed in 2 parts by weight, and 7 parts by weight of aluminum hydroxide having an average particle size of 50 μm was mixed, and mixed and foamed under the same conditions as in Example 1 to obtain a foamed panel. The properties of the foamed panel obtained are shown in Table 2.

(Comparative Example 4) Polyol system liquid a10
0 parts by weight of polypropylene glycol (average molecular weight 40
0) was blended in an amount of 25 parts by weight, and 12 parts by weight of aluminum hydroxide having an average particle diameter of 5 μm was blended under the same conditions as in Example 1 and foamed to obtain a foamed panel. The properties of the foamed panel obtained are shown in Table 2.

(Evaluation method) <Foaming pressure> A strain gauge was attached to the mold to measure the foaming pressure. If the value of the foaming pressure after 3 hours from foaming was less than 0.1 g / cm ² , there was no foaming pressure. Regarded <Crack> The center of the foam was cut and the presence or absence of cracks in the cross section was observed. <Productivity> The value of foaming pressure for 3 hours after foaming is 0.1 g / c.
If it is less than m ² , the mold release is possible and the productivity is ◯, and if it exceeds it, the mold release is not possible and the productivity is x. <Compressive strength> Based on JIS A-9514, it was determined from the strength at 10% compression with respect to the thickness. As a standard, density (kg / m ³ ) × 0.057-11 = compressive strength (N / m
m ² ) ± 2 (N / mm ² ). <Combustibility> In accordance with ISO5660, measurement was performed under the following conditions, and the presence or absence of a quasi-incombustible material was confirmed. Equipment used Tone Seiki Co., Ltd. CONE3 Radiant heat 50KW Measurement time 10 minutes Specimen size 100mm × 100mm Surface material 1mm thickness SUS plate <Heat resistance change> Atmosphere temperature 120 ° C Specimen size 100mm × 100mm × 25mm (t) Measurement period 1 month

[0023]

[Table 1]

[0024]

[Table 2]

[0025]

As is apparent from Tables 1 and 2, according to the present invention, it is excellent in high temperature heat resistance and flame retardant, and it is possible to reduce the foaming pressure at the time of foaming the mold, and further it is a foaming defect. Provided is a method for producing a phenol-modified polyurethane foam for a heat insulating / buffer material for a transportation container, which is capable of suppressing (mainly cracking) generation and increasing the compressive strength.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) C08L 75/04 C08G 101: 00 // (C08G 18/48 B65D 81/04 101: 00) (72) Invention Yoichi Tezuka 1-325 Koishikawa, Bunkyo-ku, Tokyo Mitsubishi Materials Corporation (72) Inventor Osamu Shimoda 1-3-25 Koishikawa, Bunkyo-ku, Tokyo Mitsubishi Materials Corporation F-term (reference) 3E066 AA01 CA01 DA01 MA01 3E067 BA05A BB17A CA18 FA01 FC01 GA11 GD03 4J002 CK021 DE146 GG00 GG02 4J034 BA05 BA07 DA01 DC02 DC42 DF01 DG00 DG01 DG04 DJ01 DJ08 HA00 HA01 HA06 HA06 Q16 Q17B06Q17 Q16 Q17B06Q17 Q17 Q17 Q17AQ17 HC17 HC12 HC12 HC17 HC71 HC17 HC71 HC17 HC71 HC12 HC12 HC17 HC12 HC17 HC17 HC12 HC12

Claims (2)

[Claims] 1. A heat insulating / buffering for a transportation container, which comprises a step of preparing a composition containing a polyol component containing a novolac type phenol resin as an essential component, a polypropylene glycol, and a foaming agent, and reacting the composition with an isocyanate component. A method for producing a phenol-modified polyurethane foam for wood, wherein the polypropylene glycol has an average molecular weight of 100 to 5,000, and the polypropylene glycol is added in an amount of 0.5 to 25 parts by weight based on 100 parts by weight of the polyol component. The said manufacturing method characterized by mix | blending with a composition. 2. Aluminum hydroxide having an average particle size of 5 to 100 μm is added to 100 parts by weight of the polyol component.
The method for producing a phenol-modified polyurethane foam for a heat insulating / buffering material of a transport container according to claim 1, wherein the composition is mixed in an amount of 5 to 25 parts by weight.