JP2001247645A - Rigid polyurethane foam and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rigid (isocyanurate-modified) polyurethane foam which is produced by using a polyester polyol compound which is obtained by the esterification of phthalic acid or a phthalic acid derivative; as a polyol component and a hydrofluorocarbon(HFC) as the foaming agent; is flame-retardant; has no problem or ozonosphere destruction; has no problem of the increasing inner pressure of a mixing solution to foam as described below; and has a density decreased by mixing a relatively large amount of HFC. SOLUTION: The rigid polyurethane foam can be produced by mixing the polyisocyanate component, the polyol component, the foaming agent, a catalyst and the other auxiliaries to foam, wherein said polyol component includes the polyester polyol compound synthesized by the esterification of phthalic acid and/or a phthalic acid derivative and said foaming agent contains two or more HFCs including 1,1,1,3,3-pentafluorobutane.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rigid polyurethane foam and a method for producing the same, and more particularly, to mixing a polyisocyanate component with a compounded liquid obtained by mixing a polyol component, a foaming agent, a catalyst and other auxiliaries with a mixing head. The present invention relates to a rigid polyurethane foam suitable for airless spray foaming, which uses hydrofluorocarbon (HFC) having no problem of destruction of the ozone layer as a foaming agent and has excellent flame retardancy.

[0002]

2. Description of the Related Art Rigid polyurethane foams are widely used as heat insulating materials for houses, refrigerators and the like because of their excellent heat insulating properties and self-adhesive properties.

[0003] Rigid polyurethane foams used in these applications are generally foamed by mixing a polyisocyanate component and a compounded liquid obtained by mixing a polyol component, a foaming agent, a catalyst, a foam stabilizer and other auxiliaries with a mixing head. In this method, a good heat-insulating layer of a rigid polyurethane foam can be formed by a simple operation of directly spraying and applying to an object to be applied.

In rigid polyurethane foams, dichloromonofluoroethane (HCFC-141b), which is currently used as a main blowing agent, has a problem of ozone layer destruction. For this reason, hydrofluorocarbons (HFCs) that do not destroy the ozone layer have been proposed as candidates for next-generation blowing agents that can be used instead. HFCs include tetrafluoroethane (HFC134a), 1,
1,1,3,3-pentafluoropropane (HFC24
5fa), 1,1,1,3,3-pentafluorobutane (HFC365mfc) and the like. Among these, there are compounds which have no ozone destructive property and are considered to be promising as a foaming agent after HCFC is completely abolished.

[0005]

However, since all HFCs have a property that they are difficult to dissolve in the polyol component and the isocyanate component, when used alone, the internal pressure of the compounded liquid increases and the container ruptures. There is a drawback that the safety of handling cannot be ensured due to the fact that some liquids may cause boiling or the liquid may be flammable. In particular, in order to make the foam flame-retardant, it is essential to apply a polyester polyol compound obtained by subjecting phthalic acid or a phthalic acid derivative to an esterification reaction as a polyol component. In this case, the solubility of HFC is particularly high. Low,
The internal pressure of the compounded liquid was easily increased.

For this reason, the amount of HFC to be charged is naturally limited, and as a result, there is a problem that the density of the obtained foam increases.

The present invention solves the above-mentioned conventional problems, and uses a polyester polyol compound obtained by subjecting a phthalic acid or a phthalic acid derivative to an esterification reaction with a polyol component, and using HFC as a foaming agent. Moreover, it is an isocyanurate-modified rigid polyurethane foam having no problem of ozone destruction, and has no problem of an increase in the internal pressure of a blended liquid, and a relatively large amount of HFC can be blended to reduce the foam density. The purpose is to provide.

[0008]

The rigid polyurethane foam of the present invention is a rigid polyurethane foam obtained by mixing and foaming a polyisocyanate component, a polyol component, a foaming agent, a catalyst, and other auxiliaries. In an isocyanurate-modified rigid polyurethane foam using a polyol component containing a polyester polyol compound obtained by subjecting phthalic acid and / or a phthalic acid derivative to an esterification reaction, 1,1,1,3,3 is used as a foaming agent. -Two or more types of hydrofluorocarbons including pentafluorobutane are used.

According to the present invention, 1,1,
Two or more types of H containing 1,3,3-pentafluorobutane
By using FC, a foam can be efficiently foamed to produce a rigid polyurethane foam having low density and excellent flame retardancy.

That is, the rigid polyurethane foam of the present invention is an isocyanurate-modified rigid polyurethane foam using a polyester polyol compound obtained by subjecting phthalic acid or a phthalic acid derivative to an esterification reaction as a polyol component. Excellent.

In such an isocyanurate-modified rigid polyurethane foam, 1,1,1,1 is used as a foaming agent.
When 3,3-pentafluorobutane is used alone,
Since 1,1,1,3,3-pentafluorobutane is flammable, it may reduce the flame retardancy of the obtained foam. In addition, 1,1,1,3,3-pentafluorobutane has a molecular weight of 1,1,1,3,3-pentafluorobutane. Is large, the weight required for obtaining a predetermined foam density is large. For this reason, 1,1,
It is not preferable to use 1,3,3-pentafluorobutane alone from the viewpoint of safety and economy.

In the present invention, such 1,1,1,3,1
By using 3-pentafluorobutane and an HFC other than 1,1,1,3,3-pentafluorobutane in combination,
It is possible to suppress an increase in the internal pressure of a liquid mixture containing a foaming agent and obtain a low-density rigid polyurethane foam having high flame retardancy and low cost.

In the present invention, as the foaming agent, 1,
By using 1,1,3,3-pentafluorobutane, a foam having fine bubbles and excellent heat insulating performance can be obtained. And, 1,1, which is such an excellent foaming agent,
1,1,3-pentafluorobutane and 1,1,1,
By using an HFC other than 3,3-pentafluorobutane in combination, the effect of suppressing an increase in the internal pressure of the blended liquid is as follows: 1,1,1,3 used as a foaming agent
HFCs other than 3-pentafluorobutane have a relatively low boiling point, whereas 1,1,1,3,3-pentafluorobutane has a relatively high boiling point and a mixture of both forms an azeotropic component. It is considered something.

In the present invention, the content of the polyester polyol compound obtained by esterifying phthalic acid or a phthalic acid derivative in the polyol component is 5 to 8%.
It is preferably 0% by weight.

HFCs used in combination with 1,1,1,3,3-pentafluorobutane include 1,1,1,3,3
3-pentafluoropropane or 1,1,1,2-tetrafluoroethane, among which 1,1,1,1
When using 3,3-pentafluoropropane,
5 to 9 of 1,1,1,3,3-pentafluoropropane
5% by weight, 95-5% by weight of 1,1,1,3,3-pentafluorobutane, especially 20-80% by weight of 1,1,1,3,3-pentafluoropropane, 1,1,1 , 3,
The content of 3-pentafluorobutane is preferably 80 to 20% by weight. When 1,1,1,2-tetrafluoroethane is used, 1,1,1,2-tetrafluoroethane is used in an amount of 2 to 12% by weight. %, 1,1,1,3,3-pentafluorobutane at 98 to 88% by weight, especially 1,1,1,2,3.
5-10% by weight of tetrafluoroethane, 1,1,
95,90% by weight of 1,3,3-pentafluorobutane
It is preferred that

The HFC is contained in an amount of 1 to 20% by weight, especially 5 to 15% by weight, based on a reactive polyurethane raw material comprising a polyisocyanate component, a polyol component, a blowing agent, a catalyst and other auxiliaries. Is preferred.

The rigid polyurethane foam of the present invention can be obtained by airless spray foaming, in which a polyisocyanate component and a compounded liquid obtained by mixing a polyol component, a foaming agent, a catalyst and other auxiliaries are mixed by a mixing head and foamed. Suitable for rigid polyurethane foam.

The process for producing a rigid polyurethane foam according to the present invention comprises a low boiling point H having a boiling point of 0 ° C. or less at room temperature and normal pressure as a blowing agent other than 1,1,1,3,3-pentafluorobutane.
A method for producing a rigid polyurethane foam by airless spray foaming using FC, wherein the low-boiling HFC is directly injected into a mixing head or into a conduit for introducing other components into the mixing head. Low boiling point HFC with a boiling point of 0 ° C or less at normal temperature and normal pressure
Can be efficiently injected to obtain a high-quality rigid polyurethane foam.

In this method, the amount of the low boiling point HFC used is 0.5 to 10% by weight based on the amount of the reactive polyurethane raw material comprising the polyisocyanate component, the polyol component, the blowing agent, the catalyst and other auxiliaries. Is preferred. As the low boiling point HFC, 1,1,1,2-tetrafluoroethane is preferable.

[0020]

Embodiments of the present invention will be described below in detail.

First, the raw material components used in the present invention will be described.

Polyisocyanate Component The polyisocyanate component includes aromatic polyisocyanate compounds such as diphenylmethane diisocyanate and tolylene diisocyanate, alicyclic polyisocyanates such as isophorone diisocyanate, and aliphatic polyisocyanates such as hexamethylene diisocyanate. One or more of these can be used. In addition,
The isocyanate index of the polyisocyanate component is 100
It is preferably from 200 to 200. That is, it is preferable to obtain an isocyanurate foam in the presence of a trimerization catalyst.

Polyol Component As the polyol component, one or more phthalic acids or derivatives thereof selected from the group consisting of o-phthalic acid, m-phthalic acid, p-phthalic acid and derivatives thereof are subjected to an esterification reaction. The phthalic acid-based polyester polyol obtained by this is used. By using such a phthalic acid-based polyester polyol compound containing an aromatic ring as the polyol component, stable flame retardancy can be obtained.

Examples of the hydroxy compound forming the phthalic acid-based polyester polyol include ethylene glycol, diethylene glycol, phenol and derivatives thereof, and examples of the phthalic acid derivative include diethyl phthalate and dimethyl phthalate. The preferred hydroxyl value of the polyester polyol is 150 to 450.
It is.

If the proportion of such a phthalic acid-based polyester polyol in the polyol component is too small, sufficient flame retardancy cannot be obtained, and if it is too large, the degree of the foam is reduced. It is preferably contained at 80% by weight.

As the polyol component, in addition to the above-mentioned phthalic acid-based polyester polyol, a polyether polyol obtained by subjecting phenol and / or a derivative thereof to Mannich modification (hereinafter referred to as “Mannich-modified polyol”), that is, phenol, or Nonylphenol,
A polyether polyol obtained by subjecting a phenol derivative such as an alkylphenol to a Mannich modification using a secondary amine such as formaldehyde and diethanolamine, ammonia, or a primary amine, and subjecting an alkylene oxide such as ethylene oxide or propylene oxide to ring-opening addition polymerization is obtained. May be used. Since such a Mannich-modified polyol has a high self-reaction activity and a relatively high flame retardancy, by using the Mannich-modified polyol,
For example, in the case of an airless spray foaming type rigid polyurethane foam, the reaction can proceed promptly without significantly impairing the flame retardant performance at the time of spray foaming. However, when the Mannich-modified polyol in the polyol component is 8
If the content exceeds 0% by weight, the flame retardancy deteriorates. Therefore, when a Mannich-modified polyol is used, the proportion in the polyol component is 70% by weight or less, particularly 20 to 50% by weight.
It is preferred that

Further, in addition to the phthalic polyester polyol and the Mannich-modified polyol, ethylenediamine, tolylenediamine,
A polyol compound of an initiator different from the Mannich-modified polyol such as sucrose, amino alcohol and diethylene glycol may be used in combination within a range of 30% by weight or less in the polyol component.

Catalysts Examples of the catalyst include amine catalysts such as triethylenediamine, pentamethyldiethylenetriamine and tetramethylhexamethylenediamine, dibutyltin dilaurate, lead octylate, stannas octoate, potassium octylate (potassium 2-ethylhexylate), One or more kinds of organometallic catalysts such as potassium acetate can be used.

Blowing agent As the blowing agent, two or more types of HFCs including 1,1,1,3,3-pentafluorobutane are used. 1,1,1,
HFCs other than 3,3-pentafluorobutane include:
1,1,1,3,3-pentafluoropropane, 1,
1,1,2-tetrafluoroethane, 1,1,1,2,2
3,3-hexafluoropropane, 1,1,1,4
4,4-hexafluorobutane and the like, among which 1,1,1,3,3-pentafluoropropane,
1,1,1,2-tetrafluoroethane is preferably used.

When 1,1,1,3,3-pentafluoropropane is used, 5-1,95% by weight of 1,1,1,3,3-pentafluoropropane, 1,1,1,3,3 3
95 to 5% by weight of pentafluorobutane, in particular 1,
1,1,3,3-pentafluoropropane is 20 to 80
%, 1,1,1,3,3-pentafluorobutane is preferably 80 to 20% by weight.
When using 2-tetrafluoroethane, 1,1,
2 to 12% by weight of 1,2-tetrafluoroethane,
98,88% by weight of 1,1,3,3-pentafluorobutane, especially 5,1,1,1,2-tetrafluoroethane
Preferably, the content of 1,1,1,3,3-pentafluorobutane is 95 to 90% by weight. When the amount of 1,1,1,3,3-pentafluorobutane is larger than the above range, there are problems such as a decrease in flame retardancy, a rise in price, and a rise in boiling point as an azeotropic component. When the amount of 1,3,3-pentafluorobutane is small, an increase in the internal pressure of the blended liquid and an increase in the viscosity of the blended liquid due to an increase in the concentration of the low boiling point blowing agent are observed. Also, 1,1,1,2-tetrafluoroethane is
It may be mixed with 1,1,1,3,3-pentafluorobutane and introduced into the liquid mixture, or may be directly mixed as a third component into a mixing head or the like.

As a foam stabilizer, any foam stabilizer that is effective for producing a rigid polyurethane foam can be used. For example, a silicone-based material such as polyoxyalkylene alkyl ether can be used.

In the present invention, optional components other than those described above, for example, a flame retardant, a filler and the like can be used as long as the object of the present invention is not hindered.

When the rigid polyurethane foam of the present invention is produced by airless spray foaming using a mixing head, the above-mentioned polyisocyanate component is mixed with a mixture of a polyol component, a foaming agent, a catalyst and other auxiliaries in an amount of 30%. It can be manufactured by mixing using a mixing head at ５０50 ° C., spraying the mixture at a discharge pressure of 3.9 to 7.8 × 10 ⁶ Pa on the surface to be processed, and repeatedly blowing to foam to a predetermined thickness. it can.

In the production of the rigid polyurethane foam of the present invention, 1,1,1,3,3-
The amount of HFC containing pentafluorobutane is from 1 to 20% by weight, especially from 5 to 15% by weight, based on the reactive polyurethane raw material comprising the polyisocyanate component, polyol component, blowing agent, catalyst and other auxiliaries. Is preferred. If the amount of the HFC used is less than the above range, foaming is insufficient and the density of the foam cannot be sufficiently reduced. If the amount is more than the above range, bumping of the liquid and remarkable bubbling occur, resulting in handling problems. Happens.

Also, in the present invention, 1,1,1,
The use of an HFC other than 3,3-pentafluorobutane having a boiling point of 0 ° C. or less at normal temperature and normal pressure has the effect of further lowering the density of the obtained foam and being excellent in economical efficiency. , This low boiling HFC
It is preferable to directly inject the other components into the mixing head or to the mixing head to the mixing head in order to secure workability at the time of spraying, particularly in airless spray foaming.

In this case, the amount of the low-boiling HFC used is determined by the polyisocyanate component, the polyol component,
The content is preferably 0.5 to 10% by weight with respect to the reactive polyurethane raw material comprising a blowing agent, a catalyst and other auxiliaries. If the amount is less than the above range, the effect of reducing the density of the foam and improving the workability cannot be sufficiently obtained,
If the amount is too large, the vaporizing power of the low boiling point foaming agent is too strong and the bubbles are not stable.

The low boiling point HFC has a boiling point of -26 ° C.
1,1,1,2-tetrafluoroethane is preferably used.

[0038]

The present invention will be described more specifically below with reference to examples and comparative examples.

Examples 1 to 5 and Comparative Examples 1 to 4 According to the formulation shown in Table 1, formulation A was prepared and polyisocyanate was prepared. The raw materials used for the polyisocyanate and the mixture A are as follows.

Polyisocyanate: Crude diphenylmethane diisocyanate (NCO%: 30.5) manufactured by Nippon Polyurethane Industry Co., Ltd. Polyol A: Mannich-modified polyol manufactured by Daiichi Kogyo Seiyaku Co., Ltd. Hydroxyl value: 700 mg-KOH / g Polyol B: Takeda Ethylenediamine-based polyether polyol manufactured by Yakuhin Kogyo Co., Ltd. Hydroxyl value: 685 mg-KOH / g Polyol C: phthalic acid-based polyester polyol manufactured by Toho Rika Co., Ltd. Hydroxyl value: 240 mg-KOH / g Polyol D: manufactured by Asahi Glass Co., Ltd. Ethylenediamine sucrose-based polyether polyol Hydroxyl value: 440 mg-KOH / g Flame retardant: "TCPP (Trismonochloropropyl propyl phosphate)" manufactured by Daihachi Chemical Co., Ltd. Foam stabilizer: "L" manufactured by Nippon Unicar Co., Ltd. 5420 "(block copolymer of dimethylsiloxane and polyether) Catalyst A: Tetramethylhexamethylenediamine manufactured by Kao Corporation Catalyst B: Potassium octylate solution manufactured by Nippon Kagaku Sangyo Co., Ltd. Blowing agent A: manufactured by Central Glass Co., Ltd. , 1,1,3,3-pentafluoropropane (HFC245fa) Blowing agent B: Solvay Co., Ltd. 1,1,1,3,3-pentafluorobutane (HFC365mfc) Blowing agent C: Asahi Glass Co., Ltd. 1,1,1-Dichloromonofluoroethane (HCFC141b) Blowing agent D: 1,1,1,2-tetrafluoroethane (HFC134a) manufactured by Mitsui Fluorochemicals Co., Ltd. An isocyanate was provided. The weight ratio of the blended liquid A and the polyisocyanate is determined so as to have a predetermined isocyanate index.
The mixture was foamed by stirring at rpm for 5 seconds to produce a rigid polyurethane foam.

In manufacturing this rigid polyurethane foam, the internal pressure of the blended liquid was measured by filling a glass autoclave having a capacity of 200 cc with 120 cc of the blended liquid adjusted to a liquid temperature of 20 ° C. The results are shown in Table 1.

The isocyanate index used as an evaluation standard for flame retardancy was as shown in Table 1.

With respect to the obtained rigid polyurethane foam, the core density was measured for a piece cut to a size of 30 mm × 50 mm × 50 mm, and the results are shown in Table 1.

From Table 1, it can be seen that the rigid polyurethane foam of the present invention is a low-density foam having a small increase in the internal pressure of the liquid mixture and excellent flame retardancy.

[0045]

[Table 1]

[0046]

As described in detail above, according to the present invention,
In an isocyanurate-modified rigid polyurethane foam having excellent flame retardancy using a polyester polyol compound obtained by subjecting phthalic acid or a phthalic acid derivative to an esterification reaction as a polyol component, HFC having no problem of ozone layer destruction is used as a foaming agent. Thus, a low-density rigid polyurethane foam can be obtained at low cost.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (reference) C08L 75:06 C08L 75:06 75:12 75:12 F term (reference) 4F074 AA81 AA85 BA53 BB08 BB12 BC05 CA25 DA02 DA18 DA32 4J034 BA03 DA01 DB03 DB07 DF01 DF16 DF22 DG03 DG04 DG16 HA01 HA08 HC12 HC17 HC22 HC26 HC35 HC46 HC52 HC61 HC65 HC67 HC71 HC73 KA01 KB02 KB05 KC02 KC17 KC18 KD02 KD03 KD12 KE05 KE03 NA02

Claims (14)

[Claims] A rigid polyurethane foam obtained by mixing and foaming a polyisocyanate component, a polyol component, a foaming agent, a catalyst, and other auxiliaries, wherein phthalic acid and / or a phthalic acid derivative are used as the polyol component. In an isocyanurate-modified rigid polyurethane foam using a polyol component containing a polyester polyol compound obtained by an esterification reaction, two or more types of hydrofluorocarbons containing 1,1,1,3,3-pentafluorobutane as a blowing agent Rigid polyurethane foam characterized by using. 2. The method according to claim 1, wherein the content of the polyester polyol compound in the polyol component is 5 to 80.
Rigid polyurethane foam, characterized in that it is a percentage by weight. 3. The method according to claim 1, wherein the hydrofluorocarbon contains 1,1,1,3,3-pentafluoropropane and 1,1,1,3,3-pentafluorobutane. Rigid polyurethane foam. 4. The method of claim 3, wherein the hydrofluorocarbon comprises 5 to 95% by weight of 1,1,1,3,3-pentafluoropropane and 95 to 5% by weight of 1,1,1,1.
Rigid polyurethane foam containing 3,3-pentafluorobutane. 5. The method of claim 4, wherein the hydrofluorocarbon comprises 20 to 80% by weight of 1,1,1,3,3-pentafluoropropane and 80 to 20% by weight of 1,1,
Rigid polyurethane foam containing 1,3,3-pentafluorobutane. 6. The method according to claim 1, wherein the hydrofluorocarbon contains 1,1,1,2-tetrafluoroethane and 1,1,1,3,3-pentafluorobutane. Rigid polyurethane foam. 7. The method of claim 6, wherein the hydrofluorocarbon comprises 2 to 12% by weight of 1,1,1,2-tetrafluoroethane and 98 to 88% by weight of 1,1,1,3,3.
-A rigid polyurethane foam containing pentafluorobutane. 8. The method of claim 7, wherein the hydrofluorocarbon comprises 5 to 10% by weight of 1,1,1,2-tetrafluoroethane and 95 to 90% by weight of 1,1,1,3,3.
-A rigid polyurethane foam containing pentafluorobutane. 9. The reactive polyurethane raw material comprising a polyisocyanate component, a polyol component, a foaming agent, a catalyst and other auxiliaries according to claim 1, wherein the content of the hydrofluorocarbon is 1 to 20.
Rigid polyurethane foam, characterized in that it is a percentage by weight. 10. The reactive polyurethane raw material comprising a polyisocyanate component, a polyol component, a foaming agent, a catalyst and other auxiliaries according to claim 9, wherein the content of hydrofluorocarbon is 5 to 15% by weight. Rigid polyurethane foam. 11. The method according to claim 1, wherein a polyisocyanate component, a polyol component,
A rigid polyurethane foam obtained by airless spray foaming in which a mixing liquid in which a foaming agent, a catalyst and other auxiliaries are mixed is mixed by a mixing head and foamed. 12. A low-boiling hydrofluorocarbon having a boiling point of 0 ° C. or less at ordinary temperature and normal pressure is used as a blowing agent other than 1,1,1,3,3-pentafluorobutane.
In a method for producing a rigid polyurethane foam of
A method for producing a rigid polyurethane foam, comprising injecting the low-boiling-point hydrofluorocarbon directly into a mixing head or into a conduit for introducing other components into the mixing head. 13. The method according to claim 12, wherein the amount of the low-boiling-point hydrofluorocarbon directly injected into the mixing head or into a conduit for introducing other components into the mixing head is a polyisocyanate component, a polyol component, a foaming agent, a catalyst and other components. Characterized in that the amount is from 0.5 to 10% by weight based on the amount of the reactive polyurethane raw material comprising the auxiliary agent. 14. The method according to claim 12, wherein the low-boiling hydrofluorocarbon is 1,2.
A method for producing a rigid polyurethane foam, which is 1,1,2-tetrafluoroethane.