KR100982430B1 - Polyol composition for rigid polyurethane foam and process for producing rigid polyurethane foam - Google Patents

Abstract

The present invention provides a polyol composition for hard polyurethane foams using HFC-245fa as a blowing agent and suppressing its vapor pressure, and a method for producing rigid polyurethane foams. The blowing agent component is 1,1,1,3,3-pentafluoropropane (HFC-245fa) and contains diethylene glycol monoethyl ether, and the polyol compound contains a polyol compound containing a tertiary amino group. It is set as the polyol composition for hard polyurethane foams whose nitrogen which originates in the said tertiary amino group is 0.5-9 weight% in a polyol compound. It is also preferable to use HFC-365mfc or HFE-254pc together as a blowing agent component.

Description

Polyol composition for rigid polyurethane foam and process for producing rigid polyurethane foam

The present invention relates to a polyurethane foam polyol composition and HFC-245fa containing 1,1,1,3,3-pentafluoropropane (HFC-245fa) as an essential main component of the foaming agent, as the main component of the foaming agent. The manufacturing method of the used rigid polyurethane foam is related.

As a blowing agent of rigid polyurethane foam which is an excellent heat insulating material, 1,1-dichloro-1-fluoroethane (HCFC-141b) having a small ozone layer destruction coefficient is currently used. HCFC-141b has a small ozone depletion coefficient but is not zero, and it is determined that it will be discontinued at the end of 2003 from the viewpoint of global environmental protection.

As blowing agents to replace HCFC-141b, low boiling point hydrocarbons such as n-pentane or cyclopentane, low boiling point halogenated hydrocarbon compounds containing no chlorine, HFC-245fa or HFC-365mfc, and HFE-254pc having a lower global warming coefficient It is considered.

However, low boiling point hydrocarbons, such as n-pentane or cyclopentane, are highly flammable compounds, the manufacturing process of the polyol composition containing these compounds as a blowing agent, the manufacturing process of the rigid polyurethane foam using the polyol composition, and its hard In the waste treatment process for crushing the polyurethane foam waste, strict fire prevention measures are required, and in the conventional manufacturing process of rigid polyurethane foam, the equipment needs to be renewed. There is a problem. In addition, the flame retardancy of the rigid polyurethane foam using pentane as a blowing agent is lower than that of the conventional HCFC-141b used as a blowing agent, and it is difficult to use it as it is for use as a building material which requires flame retardancy.

Flammability of HFC-365mfc is not confirmed according to the standard of Japanese Fire Law, but the flash point is confirmed at -27 ℃ in German standard, and the polyol composition containing this as a foaming agent is a dangerous substance determined by Fire law by its composition. In the example which corresponds to the 1st petroleum of the 4th class, it handles equally as a dangerous substance with the polyol composition which used HCFC-141b as a blowing agent, and has a problem that storage is not possible. Moreover, HFC-365mfc also has the problem that compatibility with the polyol compound which is a main component of a polyol composition is bad.

In addition, since HFE-254pc is a foaming agent in the development stage, sufficient examination has not been made, but as a dangerous substance, it is similar to HFC-365mfc and has the same problem.

On the other hand, HFC-245fa is a blowing agent which does not have a risk of ignition and does not need to be treated as a dangerous substance, but has a boiling point of 15 ° C. and a high vapor pressure at room temperature. For this reason, when HFC-245fa is used as a blowing agent, the problem that a container, such as a drum tube and an oil pipe which contain a polyol composition, expands especially in summer, and the polyol composition stock solution is taken out by vaporization of a foaming agent when opening a stopper, The foaming agent volatilizes, and the content thereof decreases, resulting in a problem such that a foam having a predetermined density cannot be obtained.

An object of the present invention is to provide a polyol composition for rigid polyurethane foam and a method for producing the rigid polyurethane foam using HFC-245fa as a blowing agent and suppressing the vapor pressure thereof.

The polyol composition for rigid polyurethane foam of the present invention contains at least a polyol compound, a foaming agent, a foam stabilizer, and a catalyst, and is mixed with an isocyanate component containing a polyisocyanate compound to foam-cure the rigid polyurethane foam. Enable formability,

The 1st blowing agent of the main component of the said blowing agent is 1,1,1,3,3- pentafluoropropane (HFC-245fa), contains diethylene glycol monoethyl ether as a vapor pressure reducing agent, The said HFC-245fa / Diethylene glycol monoethyl ether = 95/5 to 60/40 (weight ratio),

The said polyol compound contains the polyol compound containing a tertiary amino group, It is characterized by the nitrogen which originates in the said tertiary amino group is 0.5 to 9 weight% in a polyol compound.

It is possible to achieve the objective of this invention with the polyol composition for hard polyurethane foams of the said structure.

That is, by using HFC-245fa as a blowing agent and adding diethylene glycol monoethyl ether (hereinafter abbreviated as CAc (abbreviation for carbitol acetate)) as a vapor pressure reducing agent, foaming characteristics and obtained hard It is possible to suppress the vapor pressure of HFC-245fa while maintaining the physical properties, heat insulation and the like of the polyurethane foam.

When the HFC-245fa / CAc weight ratio exceeds 95/5, the vapor pressure lowering effect is not sufficiently exhibited, and the vapor pressure of the polyol composition for hard polyurethane foam is high. In addition, when HFC-245fa / CAc weight ratio is less than 60/40, the ratio of CAc will become large too much and the physical property of foam may fall.

In addition, since a polyol compound containing a tertiary amino group is superior to other polyol compounds having compatibility with HFC-245fa, by using a tertiary amino group-containing polyol compound in combination, further excellent vapor pressure lowering effect of HFC-245fa is achieved. Is obtained. By using a tertiary amino-group containing polyol compound together, the reaction activity of a polyol composition becomes high further, the uniformity of the bubble of the obtained rigid polyurethane foam becomes high, and the material facing each other (face material) In addition, the effect of increasing the adhesive strength with and is also obtained. In case where nitrogen based on the tertiary amino group is less than 0.5 in the polyol compound, the effect of lowering the vapor pressure, the uniformity of the bubbles, and the adhesive strength with the face member are not sufficiently improved. Stability is lowered.

As for nitrogen based on a tertiary amino group, it is more preferable that it is 1.5 to 8.5 weight% in a polyol compound.

The polyol composition for hard polyurethane foam further includes 1,1,1,3,3-pentafluorobutane (HFC-365mfc) as a second blowing agent, and HFC-245fa / HFC-365mfc≥60 / 40, It is preferable that it is (HFC-245fa + HFC-365mfc) / CAc = 95/5-60/40 (weight ratio).

HFC-365mfc is a compound having better compatibility with HFC-245fa and having a higher boiling point (40.2 ° C) than HFC-245fa, and by using HFC-365mfc in combination, the physical properties of the foamed or obtained rigid polyurethane foam, It is possible to further suppress the vapor pressure of HFC-245fa while maintaining heat insulation and the like.

When the weight ratio of HFC-245fa / HFC-365mfc is less than 60/40, the content of HFC-365mfc is increased, resulting in a lower flash point and the case where the polyol composition is recognized as a highly flammable petroleum among the dangerous substances. . If the (HFC-245fa + HFC-365mfc) / CAc weight ratio exceeds 95/5, the ratio of CAc becomes too small and its addition effect is not sufficiently exhibited. If the weight ratio is less than 60/40, the ratio of CAc The ratio becomes too large and the physical properties of the foam may deteriorate.

As for (HFC-245fa + HFC-365mfc) / CAc weight ratio, it is more preferable that it is 93/7-70/30.

The polyol composition for rigid polyurethane foam further contains methoxy ethane tetrafluoride (HFE-254pc) as a third blowing agent, HFC-245fa / HFE-254pc ≧ 50/50, (HFC-245fa + HFE-254pc) It is preferable that it is / CAc = 95/5-60/40 (weight ratio).

The compatibility with HFC-245fa is good, and by using HFE-254pc, which has a higher boiling point than HFC-245fa, the vapor pressure of HFC-245fa is further maintained while maintaining the foaming properties, the physical properties of the obtained rigid polyurethane foam, heat insulation, and the like. Can be suppressed and effective for preventing global warming.

When the weight ratio of HFC-245fa / HFE-254pc is less than 50/50, the content of HFE-254pc is increased, resulting in a lower flash point and the case where the polyol composition is recognized as highly flammable petroleum among the dangerous substances.

Further, when the weight ratio of (HFC-245fa + HFE-254pc) / CAc exceeds 95/5, the ratio of CAc becomes too small so that the effect of addition thereof is not sufficiently exhibited, and when the weight ratio becomes less than 60/40, If the ratio of CAc becomes too large, the physical properties of the foam may decrease.

The (HFC-245fa + HFE-254pc) / CAc weight ratio is more preferably 93/7 to 70/30.

CAc may be mixed with HFC-245fa and HFC-365mfc or HFE-254pc in advance, and mixed with a polyol compound as a foaming agent composition, and each component may be added and mixed separately, and as a result, if it coexists in a polyol composition, The order of addition and form do not matter.

By using CAc as one component of the polyol composition, it has been found that the adhesive strength of the rigid polyurethane foam and the face member is also improved. The reason for this is not clear. However, when only HFC-245fa or HFC-245fa and HFC-365mfc or HFE-254pc are used as the blowing agent, compatibility between the blowing agent and the polyol component is not good. Thus, the isocyanate component and the polyol composition When the mixed solution of the mixed solution is brought into contact with a face member or the like, the temperature at the contact surface decreases, HFC-245fa blooms until the curing reaction starts, and then a foaming reaction occurs, whereby the foam cells near the interface are roughened. As a result, it is estimated that adhesiveness with a face material falls. Since CAc has an effect of improving compatibility between HFC-245fa and a polyol compound, it is considered that the adhesive strength of the rigid polyurethane foam and the face plate is improved.

 Still another aspect of the present invention is a method for producing a rigid polyurethane foam in which a isocyanate component and a polyol composition are mixed, foamed and cured to form a rigid polyurethane foam, and the polyol composition for rigid polyurethane foam according to any one of claims 1-3 as the polyol composition. It characterized in that to use.

According to the related production method, a rigid polyurethane foam can be produced by using the same production apparatus as the case where HCFC-141b is used as the foaming agent without significantly improving the fire prevention measures.

Best Mode for Carrying Out the Invention

The polyol composition for hard polyurethanes of the present invention contains at least a polyol compound, a foam stabilizer, and a catalyst in addition to the blowing agent. The polyol compound contains a tertiary amino group-containing polyol compound.

As the polyol compound, a known polyol compound for hard polyurethane foam can be used without limitation. As a related polyol compound, tertiary amino-group containing polyol compound, aliphatic polyol, aromatic polyol, etc. are illustrated.

The tertiary amino group-containing polyol compound is an alkylene oxide such as a primary or secondary amine, specifically propylene oxide (PO), ethylene oxide (EO), styrene oxide (SO), tetrahydrofuran or the like. It is a polyfunctional polyol compound obtained by ring-opening addition polymerization of one or more kinds.

As a primary or secondary amine initiator which is an initiator of a tertiary amino-group containing polyol compound, aliphatic primary or secondary monoamines, such as ammonia, methylamine, and ethylamine, ethylenediamine, hexamethylenediamine, N, Aliphatic primary or secondary polyamines such as N'-dimethylethylenediamine, aromatic primary or secondary mono or poly such as aniline, diphenylamine, toluenediamine, diphenylmethanediamine and N-methylaniline Alkanolamines, such as amines, monoethanolamine, and diethanolamine, are illustrated.

Aliphatic polyols are aliphatic or cycloaliphatic polyfunctional active hydrogen compounds as the polyol initiators, and cyclic ethers such as alkylene oxides, specifically propylene oxide (PO), ethylene oxide (EO), styrene oxide (SO) and tetrahydrofuran. It is a polyfunctional oligomer obtained by ring-opening addition polymerization of 1 or more types.

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

Examples of the aromatic polyol include a polyol compound obtained by the method of adding the above-described alkylene oxide to a polyfunctional active hydrogen compound having an aromatic ring in its molecule, a polyol compound which is an ester of an aromatic polycarboxylic acid and a polyhydric alcohol, and the like.

As a polyol compound obtained by adding the above-mentioned alkylene oxide to a polyfunctional active hydrogen compound, the compound which ring-opened at least 1 sort (s) of PO, EO, SO etc. to hydroquinone, bisphenol A etc. is specifically illustrated.

As ester of an aromatic polycarboxylic acid and a polyhydric alcohol, ester polyol of the hydroxyl terminal terminal, such as terephthalic acid, phthalic acid, isophthalic acid, etc., and ethylene glycol, diethylene glycol, etc. is specifically illustrated.

It is preferable that a hydroxyl value of the said polyol compound is 200-600 mgKOH / g. Also in these polyol compounds, when a tertiary amine group containing polyol compound and aliphatic polyol are used, the effect of reducing the viscosity of a polyol composition is acquired.

As the catalyst used in the polyol composition for hard polyurethane foam of the present invention, a known catalyst for hard polyurethane foam can be used without limitation. Specifically, 3rd such as triethylenediamine, N-methylmorpholine, N, N, N ', N'- tetramethylethylenediamine, N, N, N', N'-tetramethylhexamethylenediamine, DBU, etc. Metal-type catalysts, such as a tertiary amine, dibutyltin dilaurate, dibutyltin diacetate, and octylic acid tin, are illustrated as a urethanation reaction catalyst.

As for the rigid polyurethane foam, the isocyanate group which forms a polymer may be only a urethane bond, and a urea bond or an isocyanurate bond may exist.

It is a preferable aspect to improve the characteristic of the rigid polyurethane foam obtained using a small amount of water as a foaming agent.

The use of a catalyst which forms an isocyanurate bond, which contributes to the improvement of flame retardancy in the structure of the polyurethane molecule, is also preferable. For example, potassium acetate and potassium octylate can be exemplified. Some of the above-mentioned tertiary amine catalysts also promote isocyanurate ring formation reaction. You may use together the catalyst which promotes isocyanurate bond formation and the catalyst which promotes urethane bond formation.

As the foam stabilizer, a known foam stabilizer for hard polyurethane foam can be used without limitation. As the foam stabilizer, graft copolymers or block copolymers of polydimethylsiloxane and polydimethylsiloxane and polyalkylene oxide are usually used. As the polyalkylene oxide, a polyethylene or polypropylene oxide having a mean molecular weight of 5000 to 8000, a random copolymer or a block copolymer of ethylene oxide and propylene oxide is used.

In the polyol composition for hard polyurethane foam of the present invention, flame retardants, colorants, antioxidants, anti-scorch agents and the like that are well known to those skilled in the art can be used.

Examples of the flame retardant include metal compounds such as halogen-containing compounds, organophosphate esters, antimony trioxide, and aluminum hydroxide.

These flame retardants may decrease the physical properties of the rigid polyurethane foam obtained when the organophosphate ester is added in excess, for example, and the foaming behavior of the foam may be affected by excessive addition of metal compound powder such as antimony trioxide. In some cases, such a problem may occur, and the amount of addition thereof is limited to a range that does not cause a related problem.

It is suitable for the rigid polyurethane foam of this invention to use a plasticizer as needed. It is preferable that related plasticizers also contribute to flame retardancy, and halogenated alkyl esters, alkyl phosphate esters or aryl phosphate esters of phosphoric acid, phosphonic acid esters and the like can be used, and specifically, tris (2-chloroethyl) phosphate (CLP, Large chemicals, tris (β-chloropropyl) phosphate (TMCPP), tributoxyethyl phosphate (TBXP), tributyl phosphate, triethyl phosphate, cresyl phenyl phosphate, Dimethylmethylphosphonate and the like can be exemplified, and one or more of these can be used. It is preferable that the addition amount of a plasticizer is 5-30 weight part with respect to 100 weight part of polyol components. If this range is exceeded, the plasticizing effect will not be obtained sufficiently, and a problem, such as a decrease in the physical properties of a foam, will occur.

As a polyisocyanate compound which mixes and reacts with a polyol composition to form a rigid polyurethane foam, liquid MDI is used because of its ease of handling, reaction speed, excellent physical properties of the obtained rigid polyurethane foam, and low cost. do. Examples of the liquid MDI include crude MDI (c-MDI) (44V-10, 44V-20, etc.) and uretonimine-containing MDI (millionate MTL; Nippon Polyurethane Co., Ltd.). Etc. are used. Among these polyisocyanate compounds, the use of crude MDI is particularly preferable in view of excellent physical properties such as mechanical strength of the formed rigid polyurethane foam and low price.

In addition to the liquid MDI, other polyisocyanate compounds may be used in combination. As the related polyisocyanate compound, di or polyisocyanate compounds known in the art of polyurethane can be used without limitation.

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

Hereinafter will be described embodiments and the like showing the configuration and effects of the present invention in detail.

The constituent materials of the polyol composition are shown in Table 1.

The addition amount (weight ratio) of the composition of a polyol composition and a foaming agent composition was described in Tables 2-4. The addition amount of a foaming agent composition is adjusted so that the density of the rigid polyurethane foam at the time of prefoaming may be 25 kg / m <3>. The blowing agent composition is obtained by previously adding carbitol acetate (CAc), which is an additive that lowers the vapor pressure of the blowing agent, to HFC-245fa, HFC-365mfc, and HFE-254pc, which are blowing agents.

Rigid polyurethane foam was manufactured by a conventional method. That is, in the composition shown in Table 1, the component except the isocyanate component and the blowing agent composition were mixed and stirred to adjust the polyol composition, the temperature was adjusted to 20 ° C., and then the polyol component and the isocyanate component adjusted to temperature at 20 ° C. were prescribed. The mixture was stirred and mixed at a ratio, followed by foaming and curing to obtain a rigid polyurethane foam.

<evaluation>

Steam Pressure Assessment

50 g of the polyol composition stock solution adjusted to the predetermined mixing ratio was injected into a 100 ml SUS container, and the container was completely sealed, freeze-degassed with liquid nitrogen, and then allowed to stand in a constant temperature bath at 40 ° C. to measure absolute vapor pressure P. It was. The decompression rate was calculated by the following formula. PO is a vapor pressure of only 245fa (comparative example 2) of a blowing agent.

Decompression rate (%) = 100 (PO-P) / PO

(Compressive strength)

The cube of 50 mm x 50 mm x 50 mm was cut out from the foam | foam freely foamed in the container, and it measured according to JIS A 9511 (foamed plastic insulation).

Dimensional stability

The cube of 100 mm x 100 mm x 100 mm was cut out from the free-foamed foam in the container, and it was left to stand for 24 hours in the atmosphere of -30 degreeC, and the dimension change amount was measured. The evaluation result was expressed as a dimensional change rate (Δ%).

(Adhesiveness)

Create a free-foamed foam on top of the graft paper faceplate, cut off the end of the cutout that has been bonded to the foam from the back side with a 5 cm wide cut, and pull it out using a banner Intensity (gf / 5 cm) was measured.

(Bubble stability)

Free-foamed foam in the container was visually observed. The evaluation results are indicated by the following criteria.

○: The cell is uniformly dense and equivalent to HCFC-141b foamed product.

(Triangle | delta): There exists a roughness of a cell, and is slightly inferior to HCFC-141b foamed product.

X: The roughness of the cell is severe and poor foaming.

<Evaluation results>

The evaluation result was shown to the bottom of Tables 2-4. The foaming agent composition shown in Table 2 is a composition which previously mixed HFC-245fa and CAc which is a vapor pressure reducing agent, and the foaming agent composition shown in Table 3 is three components of HFC-245fa, HFC-356mfa, and CAc, the foaming agent shown in Table 4 The composition is a three-component composition in which HFC-245fa, HFE-254pc, and CAc are mixed in advance. From the results of these tables, by setting it as the foaming agent composition of the present invention, the vapor pressure of the foaming agent is greatly reduced, and handling with the polyol composition using the conventional HCFC-141b becomes possible. Stability also improved. However, in the comparative example, the following knowledge was acquired. In dimensional stability, the foam which used HCFC-141b as a foaming agent was -17.0%, and it judged based on this.

a) When HFC-245fa / CAc is 55/45, as a result of too much CAc, the dimensional stability is lower than the foam which used HCFC-141b as a foaming agent (comparative example 3).

b) When HFC-245fa / HFC-365mfc is 50/50 (Comparative Example 4), and when HFC-245fa / HFE-254pc is 40/60 (Comparative Example 7), the amount of HFC-365mfc or HFE-254pc added As a result of this excessive increase, the dimensional stability is lower than that of the foam using HCFC-1451b as a blowing agent.

c) Even if the blowing agent composition is within the scope of the present invention, when the nitrogen concentration attributable to the tertiary amino group in the total polyol compound is less than 0.5 wt%, the bubble stability is lowered and the adhesive strength with the face member is also lowered (comparatively). Example 5,8). When the nitrogen concentration attributable to the tertiary amino group exceeds 9 wt%, the dimensional stability of the obtained rigid polyurethane foam is lowered (Comparative Examples 6 and 9).

As explained above, according to the structure of this invention, it is possible to provide the polyol composition for hard polyurethane foams and the manufacturing method of hard polyurethane foam which used HFC-245fa as a foaming agent, and suppressed the vapor pressure. Therefore, the industrial significance of this invention is large.

Claims (4)

In the polyol composition for hard polyurethane foam containing at least a polyol compound, a foaming agent, a foam stabilizer, and a catalyst, and mixed with an isocyanate component containing a polyisocyanate compound and foamed and cured to form a rigid polyurethane foam, The first blowing agent of the blowing agent is 1,1,1,3,3-pentafluoropropane (HFC-245fa), and as the second blowing agent, 1,1,1,3,3-pentafluorobutane (HFC- 365 mfc), HFC-245fa / HFC-365mfc ≥ 60/40, containing diethylene glycol monoethyl ether as a vapor pressure reducing agent, (HFC-245fa + HFC-365mfc) / diethylene glycol monoethyl ether = 93/7 to 60/40 (weight ratio), The polyol compound includes a polyol compound containing a tertiary amino group, and the nitrogen resulting from the tertiary amino group is 0.5 to 9% by weight of the polyol compound. delete In the polyol composition for hard polyurethane foam containing at least a polyol compound, a foaming agent, a foam stabilizer, and a catalyst, and mixed with an isocyanate component containing a polyisocyanate compound and foamed and cured to form a rigid polyurethane foam, The first blowing agent of the blowing agent is 1,1,1,3,3-pentafluoropropane (HFC-245fa), contains methoxy ethane fluoride (HFE-254pc) as the third blowing agent, and HFC-245fa / HFE-254pc ≧ 50/50, containing diethylene glycol monoethyl ether acetate as a vapor pressure reducing agent, (HFC-245fa + HFE-254pc) / diethylene glycol monoethyl ether = 93/7 to 60/40 ( Weight ratio), The polyol compound includes a polyol compound containing a tertiary amino group, and the nitrogen resulting from the tertiary amino group is 0.5 to 9% by weight of the polyol compound. In the method for producing a rigid polyurethane foam in which the isocyanate component and the polyol composition are mixed, foamed and cured to form a rigid polyurethane foam, the polyol composition for hard polyurethane foam according to claim 1 or 3 is used as the polyol composition. Method for producing a rigid polyurethane foam characterized in that.