JP2002363238A - Polyol composition for rigid polyurethane foam and method for producing the rigid polyurethane foam - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a polyol composition for rigid polyurethane foam, wherein the gasification timing of a foaming agent and the foamed gas pressure in the resultant cells are adjusted within specified ranges, respectively, and the components are adjusted by a simple method, and to provide a method for producing a rigid polyurethane foam by using the polyol composition. SOLUTION: The polyol composition comprises a polyol compound, a foaming agent, a foam stabilizer and a catalyst, wherein the foaming agent constitutes a combination of water with a low-boiling organic foaming agent with low coefficient of ozonosphere depletion so as to meet the relationship: y=1.5x+b (-15<=b<=10) (where, (y) is the compounding amount (mol%) of the water based on the total amount of the foaming agent: and (x) is the boiling point of the low-boiling organic foaming agent: deg.C).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a polyol composition for rigid polyurethane foam and a method for producing a rigid polyurethane foam.

[0002]

2. Description of the Related Art Rigid polyurethane foam has heat insulating properties,
It is a material having a great feature of lightness, and is widely used for applications such as heat insulation panels. In addition, since polyurethane has good adhesion to various materials during reaction curing, the heat insulating panel can be formed by foaming with a panel or sheet having a function such as makeup or reinforcement called face material by utilizing such properties. It is manufactured by contacting a stock solution composition and bonding a foam and a face material simultaneously with foaming and curing.

[0003] The above-mentioned foaming stock solution composition is formed by mixing a polyol composition containing a polyol compound, a foaming agent, a catalyst and the like with an isocyanate component. In such a polyol composition, as a blowing agent, at present, mainly HC
FC-141b is used.

[0004] HCFC-141b is a blowing agent having a small ozone depletion potential, but its ozone depletion potential is not zero, and it is decided that HCFC-141b will be completely abolished at the end of 2003.

[0005] As foaming agents replacing HCFC-141b, hydrocarbon compounds such as water, cyclopentane and n-pentane, and hydrocarbon compounds containing fluorine and hydrogen such as HFC-245fa and HFC-365mfc (HFC), especially A system using both water and an organic blowing agent is planned.

[0006]

However, HCFC-1
All of the blowing agents replacing 41b have a different boiling point and solubility in the polyol component from HCFC-141b. As a result, the foaming agent of the polyol composition, which is a component containing the foaming agent of the rigid polyurethane foam stock solution, was mixed with water and the above HF.
In the case of changing to C, the timing of gasification of the foaming agent and the foaming gas pressure in the cells (bubbles) of the foam during the polyurethane foam foam molding change, and the balance with the polymerization of the polyurethane forming the skeleton is lost. Large bubbles (air voids) are generated in the foam. Such air voids cause a decrease in heat insulation and foam strength, a decrease in adhesiveness to the face material, and the like, and in particular, the smoothness of the face material surface of the obtained product is deteriorated, and the appearance characteristics are deteriorated. Problems arise.

In order to avoid such a problem, conventionally, it is necessary to review and conduct experiments on many components such as the ratio of water and the organic blowing agent of the blowing agent, the catalyst composition, the foam stabilizer, and the adjustment of the polyol component. there were. In this component adjustment, the use of a large amount of water as a foaming agent has the advantages of increasing the mechanical strength of the obtained rigid polyurethane foam and improving the flowability of the foaming stock solution composition during foam production. However, when a large amount of an organic foaming agent is used, the heat insulating property is improved, but there may be a problem with the flowability of the foaming stock solution composition. Extensive experiments and evaluations were required to determine the composition of the polyol composition.

The present invention relates to a polyol composition for a rigid polyurethane foam whose components are adjusted by a simple method, wherein the timing of gasification of a foaming agent and the pressure of a foaming gas in a cell are adjusted to predetermined ranges, and the polyol for a rigid polyurethane foam. An object of the present invention is to provide a method for producing a rigid polyurethane foam using the composition.

[0009]

Means for Solving the Problems The present inventors have intensively studied a method for easily determining the blending of a polyol composition, and as a result, only adjusting the molar ratio of water as a blowing agent to a low-boiling organic blowing agent. Thus, the present inventors have found that the compounding can be determined while significantly reducing the man-hour for adjusting other components, and completed the present invention.

The present invention is a polyol composition for a rigid polyurethane foam containing a polyol compound, a foaming agent, a foam stabilizer, and a catalyst, wherein the foaming agent is a low-boiling organic foaming agent having a low water and ozone layer destruction coefficient. When the compounding amount of the water is y mol% of the total amount of the blowing agent and the boiling point of the low-boiling organic blowing agent is x ° C,

## EQU2 ## It is characterized in that water and a low-boiling organic blowing agent are used in combination so as to satisfy y = 1.5x + b (−15 ≦ b ≦ 10).

By adjusting the molar ratio of water and the low-boiling organic blowing agent so as to satisfy the above (Equation 2), it is possible to adjust the polyol component, the foam stabilizer, the catalyst and other multicomponents as in the prior art, Moreover, it is possible to determine the blending of the polyol composition by a simple method without variously examining the ratio of water to the low-boiling organic blowing agent. In addition, the obtained rigid polyurethane foam has no voids, does not reduce the heat insulating property, the strength of the foam, and the adhesiveness to the surface material, and forms a rigid polyurethane foam having excellent surface smoothness of the surface material of the product. A polyol composition is obtained.

This is because, by adjusting the molar ratio between water and the low-boiling organic blowing agent, the generation of carbon dioxide by the reaction of water and isocyanate groups, the foaming of the low-boiling organic blowing agent by vaporization, and the polyurethane formation rate can be balanced. It is presumed to be due to

By such means, the generation of air voids is suppressed, and the surface properties of the polyurethane foam heat insulating panel are improved. In addition, for the purpose of further improving the adhesive strength with the face material and the polyurethane foam strength, etc., it is also a preferable embodiment to finely adjust each component. However, the man-hour required for such fine adjustment is much less than in the past. .

In the above-mentioned polyol composition, the low-boiling organic blowing agent is preferably at least one selected from a hydrocarbon compound having a boiling point at normal pressure of 50 ° C. or lower and a fluorine-containing hydrocarbon compound. And the hydrocarbon compound is selected from cyclopentane and n-pentane, and the fluorine-containing hydrocarbon compound is HF
More preferably, it is selected from C-245fa and HFC-365mfc.

These compounds form a rigid polyurethane foam having an ozone depletion potential of almost zero and excellent heat insulation. When the boiling point of the low-boiling organic blowing agent exceeds 50 ° C., it is not a practical foaming agent for polyurethane foam.

The method for producing a rigid polyurethane foam of the present invention is characterized in that the polyol composition according to any one of claims 1 to 3 and liquid MDI are mixed and foamed to obtain a rigid polyurethane foam.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION As the polyol compound constituting the polyol composition of the present invention, a compound known as a polyol compound for a rigid polyurethane foam can be used. Specifically, aliphatic polyols, aromatic polyols, amine polyols and the like exemplified below are known as polyols for rigid polyurethane foams.

An aliphatic polyol polyfunctional active hydrogen compound, that is, an aliphatic or alicyclic polyfunctional active hydrogen compound as a polyol initiator, and an alkylene oxide, specifically, propylene oxide (P
O), one of cyclic ethers such as ethylene oxide (EO), styrene oxide (SO), and tetrahydrofuran.
Polyfunctional oligomers obtained by ring-opening addition polymerization of one or more species are exemplified.

Examples of the polyol initiator include glycols such as ethylene glycol, propylene glycol, 1,4-butanediol, 1,3-butanediol, 1,6-hexanediol and neopentyl glycol, trimethylolpropane, glycerin and the like. And trifunctional alcohols such as pentaerythritol, polyhydric alcohols such as sorbitol and sucrose, and water.

Instead of the alkylene oxide, or together with the alkylene oxide, a polyol compound obtained by ring-opening polymerization of a lactone such as ε-caprolactone can be used.

Amine-based polyol As a polyol initiator, a primary or secondary amine is used as an alkylene oxide, specifically one or more of propylene oxide (PO), ethylene oxide (EO), styrene oxide (SO), tetrahydrofuran and the like. Is a polyfunctional polyol compound obtained by ring-opening addition polymerization of

Examples of the initiator include amines such as ethylenediamine, toluenediamine and diphenylmethanediamine, and alkanolamines such as monoethanolamine and diethanolamine.

Aromatic polyol A polyol compound obtained by the above-mentioned method of adding an alkylene oxide to a polyfunctional active hydrogen compound having an aromatic ring in the molecule, a polyol compound which is an ester of an aromatic polycarboxylic acid and a polyhydric alcohol Etc. are exemplified.

Polyol compounds obtained by adding the above-described alkylene oxide to a polyfunctional active hydrogen compound include hydroquinone, bisphenol A, etc.
Compounds obtained by ring-opening addition of at least one of O and SO are specifically exemplified.

Examples of the ester of the aromatic polycarboxylic acid and the polyhydric alcohol include ester polyols at the terminal of hydroxyl group of terephthalic acid, phthalic acid, isophthalic acid and the like and ethylene glycol and diethylene glycol.

The above polyol compound has a hydroxyl value of 2
It is preferable that the average number of functional groups is 2 to 6 at 00 to 600 mgKOH / g. The above-mentioned polyol compounds may be used alone or in a combination of two or more kinds to form a foam having more preferable properties.

In producing the rigid polyurethane foam of the present invention, a catalyst, a flame retardant, a coloring agent, an antioxidant and the like well known to those skilled in the art can be used.

As a catalyst, triethylenediamine, N
Tertiary amines such as -methylmorpholine, N, N, N ', N'-tetramethylethylenediamine, N, N, N', N'-tetramethylhexamethylenediamine, DBU, dibutyltin dilaurate, dibutyltindiamine Metal-based catalysts such as acetate and tin octylate are exemplified as urethanization reaction catalysts. In addition, since the polyol composition of the present invention uses water as one component of the blowing agent, the organotin-based catalyst is hydrolyzed and deteriorated. Therefore, the use of a tertiary amine catalyst is preferable.

It is also preferable to use a catalyst which forms an isocyanurate bond which contributes to the improvement of the flame retardancy in the structure of the polyurethane molecule, and examples thereof include potassium acetate and potassium octylate. Some of the above tertiary amine catalysts also promote the isocyanurate ring formation reaction. A catalyst that promotes isocyanurate bond formation and a catalyst that promotes urethane bond formation may be used in combination.

In the present invention, it is also a preferred embodiment to further add a flame retardant.
Metal compounds such as halogen-containing compounds, organic phosphoric esters, antimony trioxide, and aluminum hydroxide are exemplified.

However, in these flame retardants, for example, when an organic phosphoric acid ester is excessively added, the physical properties of the obtained rigid polyurethane foam may be deteriorated, and when a metal compound powder such as antimony trioxide is excessively added. This may cause problems such as affecting the foaming behavior of the foam, and the amount of addition is limited to a range that does not cause such problems.

The rigid polyurethane foam of the present invention includes:
It is preferable to use a plasticizer as needed. Such plasticizers also preferably contribute to flame retardancy, and halogenated alkyl esters of phosphoric acid, alkyl phosphates, aryl phosphates, phosphonates, and the like can be used. Specifically, tris ( β-chloroethyl) phosphate (TCEP, manufactured by Daihachi Chemical),
Tris (β-chloropropyl) phosphate (TMCP
P, manufactured by Daihachi Chemical Co., Ltd.), tributyl phosphate, triethyl phosphate, cresyl phenyl phosphate, dimethyl methyl phosphonate and the like, and one or more of these can be used. The added amount of the plasticizer is preferably 5 to 30 parts by weight based on 100 parts by weight of the polyol component. If the ratio exceeds this range, problems may occur such that a sufficient plasticizing effect cannot be obtained or physical properties of the foam deteriorate.

The polyisocyanate compound to be mixed and reacted with the polyol composition to form a rigid polyurethane foam is excellent in ease of handling, speed of reaction, and physical properties of the obtained rigid polyurethane foam;
Liquid MDI is used because of its low cost.
As liquid MDI, crude MDI (c-MDI)
(44V-10, 44V-20, etc. (manufactured by Sumitomo Bayer Urethane Co., Ltd.)), MDI containing uretonimine (Millionate MTL; manufactured by Nippon Polyurethane Industry) and the like are used. Other polyisocyanate compounds may be used in addition to the liquid MDI. As such a polyisocyanate compound, di- or polyisocyanate compounds known in the technical field of polyurethane can be used without limitation.

The polyol composition for a rigid polyurethane foam of the present invention can be used for production of continuously produced foams such as slab stock foams and sandwich panels, and sandwich panels which are injection molded.

[0035]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments and the like specifically showing the configuration and effects of the present invention will be described below.

(Examples 1 to 5) [Raw material composition] 100 parts by weight of a polyether polyol GR-84 (manufactured by Takeda Chemical Industries) as a polyol compound, 10 parts by weight of TMCPP (manufactured by Daihachi Chemical Industry) as a flame retardant,
3 parts by weight of a foam stabilizer L-5340 (manufactured by Nippon Unicar) were used, and N, N, N ', N'-tetramethylhexamethylenediamine (trade name: Kaolyzer No.
1, Kao) and a polyol composition for a rigid polyurethane foam containing a foaming agent.

The blowing agent was used in combination with a low-boiling organic blowing agent and water so that the foam had a density of 25 kg / m ³ . The use ratio of the low-boiling organic blowing agent to water is shown in Table 1. Table 1 also shows the range of the mole fraction of water in the blowing agent calculated based on the above (Equation 2) using the boiling point of the low boiling organic solvent used.

As the isocyanate component, c-MDI
(Trade name: 44V-20, manufactured by Sumitomo Bayer Urethane) was used.

The polyol composition and the isocyanate component have an NCO / OH equivalent ratio (isocyanate index) of 1.10 and a gel time of 10 including water.
The amount of use was adjusted so as to be 0 seconds, and a foaming stock solution composition in which a polyol composition and an isocyanate component were mixed was injected into the inside of the frame using an injection molding machine (high-pressure foaming machine) of a collision mixing system. To make a rigid polyurethane foam.

[Evaluation] An aluminum decorative plate was used as a surface decorative material, and kraft paper was used as a back surface material.
The foaming stock solution composition described in the above example was injected from an injection port provided at an end of a frame having a space of 0 mm, a width of 400 mm, and a thickness of 40 mm to prepare a heat insulating panel.

Since the voids in the rigid polyurethane foam of the obtained heat insulating panel can be evaluated by the unevenness of the surface of the face material, the panel surface was visually observed to evaluate its smoothness. Table 1 shows the evaluation results.

From the results in Table 1, it can be seen that when water is used in combination with a low-boiling organic blowing agent in the range of (Equation 2), a polyurethane foam panel excellent in surface smoothness can be obtained without adjusting other components. This clearly shows that the generation of air voids in the foam was prevented.

[0043]

[Table 1]

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08L 75:04 (72) Inventor Hiroyuki Koshizaki 1-17-18 Edobori, Nishi-ku, Osaka-shi, Osaka Toyo Tire & Rubber Co., Ltd. Co., Ltd. (72) Inventor Takeo Iwata 1-17-18 Edobori, Nishi-ku, Osaka-shi, Osaka Toyo Tire & Rubber Co., Ltd.F-term (reference) 4F074 AA78M BA34 BA39 BA53 BC05 CA26 CC22Y DA32 4J034 DA01 DB03 DB07 DF16 DF22 DG02 DG03 DG04 DG06 DG08 DG09 DG14 DG16 DG22 DH02 DH06 DH10 KA01 KB02 KC17 KD02 KD12 KE02 NA01 NA02 NA03 NA06 NA08 QB16 QC01 RA15

Claims (4)

[Claims] 1. At least a polyol compound, a foaming agent,
A foam stabilizer, a polyol composition for a rigid polyurethane foam containing a catalyst, wherein the foaming agent comprises water and a low-boiling organic foaming agent having a low ozone layer destruction coefficient. Quantity of y
When the boiling point of the low-boiling organic blowing agent is x ° C., water and a low-boiling organic blowing agent are used in such a manner that y = 1.5x + b (−15 ≦ b ≦ 10) is satisfied. Polyol composition for rigid polyurethane foam. 2. The rigid polyurethane foam according to claim 1, wherein the low-boiling organic blowing agent is at least one selected from a hydrocarbon compound having a boiling point of 50 ° C. or less at normal pressure and a fluorine-containing hydrocarbon compound. Polyol composition. 3. The hydrocarbon compound is selected from cyclopentane and n-pentane, and the fluorine-containing hydrocarbon compound is HFC-245fa, HFC
The polyol composition for a rigid polyurethane foam according to claim 2, which is selected from -365mfc. 4. A method for producing a rigid polyurethane foam by mixing and foaming the polyol composition according to claim 1 and liquid MDI to form a rigid polyurethane foam.