JP3167159B2 - Production method of spray type rigid polyurethane foam - Google Patents

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 spray-type rigid polyurethane foam. More specifically, the present invention relates to a method for producing a spray-type rigid polyurethane foam which allows a reaction between a polyol and an isocyanate to sufficiently proceed even at a low temperature and has excellent mechanical properties and adhesiveness.

[0002]

2. Description of the Related Art Rigid polyurethane foams are used for various purposes because of their excellent heat insulating properties, self-adhesiveness, simplicity of production and versatility. In general, rigid polyurethane foam is often used for inner walls and ceilings. On the other hand, the spray-type rigid polyurethane foam can be used particularly for on-site construction, and is therefore used for heat insulation in houses, tanks, and the like. A special foaming machine is used for foaming the spray-type rigid polyurethane foam. The air spray foaming machine is a system in which compressed air is introduced into a mixing gun, and the airless foaming machine is a foaming machine in which an undiluted solution is introduced into a mixing gun using a compression lightweight pump and sprayed. Using these foaming machines, a mixture of a polyol component and an isocyanate component is sprayed on the surface to be sprayed, and the property of rapidly increasing viscosity, foaming, and increasing the molecular weight is used to insulate the rigid polyurethane foam on the surface to be sprayed. Form a layer. Such useful spray-type rigid polyurethane foams have also been used in various applications, and various problems have occurred as the amount of the polyurethane foam increases. One of them is that the bonding strength with the surface material to be bonded is low. After the application, peeling or falling off due to low adhesive strength with the surface material tends to cause a decrease in thermal conductivity and dew condensation. In recent years, starting from the problem of global environmental pollution, the amount of water used as a blowing agent tends to increase due to the restriction on the use of fluorocarbons such as trichlorofluoromethane, and this problem has been exacerbated. In other words, when the amount of water is increased to reduce the amount of regulated CFCs, aggregation due to the urea bond generated by the reaction between water and isocyanate occurs violently, and the heat of reaction occurs at the boundary between the urethane foam and the surface to be adhered or at the surface of the foam. The fact that it is difficult to accumulate also overlaps, and reveals the disadvantage that the self-adhesive strength, which is the most important physical property of the spray-type rigid polyurethane foam, is insufficient or the brittleness is increased. Further, this tendency becomes remarkable when spraying is performed at a relatively low temperature of 5 ° C. or less.

[0003]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems, and as a result, in producing a spray-type rigid polyurethane foam, a polyol having a catalytic action in a molecular skeleton as a polyol component has been found. By using a tertiary amino alcohol having a tertiary amino group and having a hydroxyl group capable of reacting with an isocyanate group at both molecular terminals and using a specific amount of water as a blowing agent, the low temperature of the spray type rigid polyurethane foam can be reduced. The present inventors have found that the self-adhesion strength underneath is improved and arrived at the present invention.

That is, in the present invention, when a polyisocyanate component and a polyol component are reacted to produce a spray-type rigid polyurethane foam, water as a blowing agent is added in an amount of 2 to 8 parts by weight based on 100 parts by weight of the total amount of the polyol component. The following general formula (I) is used for part or all of the polyol component used.

[0005]

Embedded image

Wherein R ₁ is the same or different and has 2 to 2 carbon atoms.
Straight or branched chain alkylene group of 20, alicyclic alkylene group, an Rarukiren group or _{- (CH 2 CH 2 O)} p - (CH 2 CH 2) q -
(Where p is 0 or a positive number and q is a positive number), and R ₂ represents the same or different linear or branched alkyl or aralkyl group having 1 to 20 carbon atoms. And the average degree of polymerization n is a positive number of 2 to 50. ] The use of one or more tertiary amino alcohols represented by the formula:

[0007] The tertiary amino alcohol represented by the general formula (I) used in the present invention has a tertiary amino group in the molecule, and therefore has a catalytic performance for the reaction between the polyisocyanate compound and the active hydrogen compound. It also has a terminal hydroxyl group, and itself reacts with isocyanate groups, is incorporated into the polyurethane skeleton, and because it is a diol type, it does not inhibit the increase in the molecular weight of the polyurethane resin and does not lower the final physical properties It has the feature of. Therefore, the reaction between the polyol component containing the tertiary amino alcohol represented by the general formula (I) and the isocyanate can complete the reaction speed early in proportion to the compounding amount, and the reaction temperature of 5 ° C. or less The reaction can proceed even at a low temperature. Thus, the reaction proceeds sufficiently even at a low temperature, so that the required mechanical properties and adhesive strength are maintained, and the heat insulating layer does not peel off or fall off from the surface to be bonded after spraying. Furthermore, reducing the amount of regulated CFCs such as trichlorofluoromethane, the desired adhesive strength is obtained even with a polyol component using a large amount of water as a blowing agent, and the heat insulating layer is peeled off even at a low temperature of 5 ° C. or less. It did not fall off. Also,
Compared with a normal tertiary amine catalyst, the tertiary amino alcohol represented by the general formula (I) according to the present invention has a terminal hydroxyl group and has a certain molecular weight, so that it has no odor of its own. In addition, there is an advantage that a favorable working environment is provided because there is no scattering of catalyst components and no generation of offensive odor in the spraying operation.

The tertiary amino alcohol represented by the general formula (I) used in the present invention can have various structures and molecular weights by changing the types of diols and primary amines as raw materials. be able to. As the diol, a linear or branched one having 2 to 24 carbon atoms is used. For example, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexane Diol, 1,9-nonanediol, 1,10-decanediol, diethylene glycol, triethylene glycol, tetraethylene glycol, 1,4-cyclohexanedimethanol, 1,4-hydroquinone, and the like, and a mixture thereof is used. You can also. Also,
Examples of the primary amine include a linear or branched primary or aromatic amine having 1 to 24 carbon atoms having two active hydrogens, such as methylamine, propylamine, isopropylamine, butylamine, and the like. Examples thereof include 2-ethylhexylamine, heptylamine, octylamine, decylamine, dodecylamine, cetylamine, stearylamine, docosylamine, oleylamine, benzylamine, phenethylamine, and aniline, and a mixture thereof.

The method for producing a tertiary amino alcohol according to the present invention will be described in more detail. The above diol and the first
When producing a tertiary amino alcohol by reacting with a tertiary amine, a catalyst containing copper-noble metal as a main component, for example, copper-
Nickel-group 8 platinum group element, copper-chromium-group 8 platinum group element, copper-zinc-group 8 platinum group element, copper-manganese-
Using a catalyst having a composition of a group VIII platinum group element, copper-iron-group VIII platinum group element, copper-cobalt-group VIII platinum group element, etc., water generated by a reaction in the presence of these catalysts is used. The object is achieved by stirring the mixture at a temperature of 150 to 250 ° C. under atmospheric pressure or pressure while continuously or intermittently removing the mixture from the reaction system. At this time, the diol may be added continuously during the reaction, charged from the beginning, or may be charged in a fixed amount. When the primary amine is a gas, it may be blown continuously or intermittently during the reaction, or may be charged at a time under a predetermined pressure. When the primary amine is a liquid, it may be charged continuously or a predetermined amount may be charged from the beginning. Here, the molar ratio of the amine to the diol needs to be 0.7 times or more, preferably 1 time, and in the case of a gaseous amine, the gas charged in excess with hydrogen may be recovered and recycled.

In the method for producing a tertiary amino alcohol according to the present invention, it is preferable that water generated by the reaction between the diol and the primary amine is taken out of the reaction system. If the produced water is not taken out of the system, the catalytic activity and selectivity often decrease. For example, when the reaction is carried out without removing the produced water, the disproportionate of the amine increases and the yield of the desired tertiary amino alcohol may decrease. However, the disproportionate of the amine is usually represented by the following general formula (II)

[0011]

Embedded image

Wherein R ₃ is the same or different and has 2 to 2 carbon atoms.
Straight or branched chain alkylene group of 20, alicyclic alkylene group, an Rarukiren group or _{- (CH 2 CH 2 O)} p - (CH 2 CH 2) q -
(Where p is 0 or a positive number and q is a positive number), and R ₄ is the same or different, a linear or branched alkyl group or aralkyl group having 1 to 20 carbon atoms. The average polymerization degree m is a positive number of 2 to 50. And a tertiary amino alcohol represented by the general formula (II):
Since a mixture comprising in tertiary amino alcohol represented may be used, if the amount of disproportionation product range polyurethane of interest is obtained, it may not be particularly performed the removal of water. The removal of water may be carried out continuously or continuously, and the produced water may be removed as appropriate without being present in the reaction system for a long time. It is desirable to do. Specifically, it is common to introduce an appropriate amount of hydrogen gas into the reaction system during the reaction and distill off the generated water together with the hydrogen gas.The hydrogen gas is circulated by concentrating and separating the generated water with a condenser. Can also be used. Further, a suitable solvent may be added during the reaction, and the produced water may be distilled off by azeotropic distillation with this solvent, or an inert solvent may be added for the purpose of lowering the viscosity of the product.

In the process for producing the tertiary amino alcohol represented by the general formula (I) according to the present invention, a catalyst which has been separately reduced in advance with hydrogen gas may be used. The catalyst before reduction is put into a reactor, and when the hydrogen gas or the amine to be reacted is a gaseous amine, the catalyst is reduced by raising the temperature to the reaction temperature while introducing a mixed gas of the hydrogen gas and the gaseous amine. Is preferred.

The tertiary amino alcohol used in the present invention has the structure represented by the general formula (I), wherein R ₁ is the same or different and is a straight or branched chain having 2 to 20 carbon atoms. alkylene group, an alicyclic alkylene group, an Rarukire <br/> emissions group or _{- (CH 2 CH 2 O)} p - (CH 2 CH 2) q - ( where, p is 0 or a positive number, preferably Is a positive number from 0 to 15, more preferably a positive number from 0 to 10. q is a positive number, preferably a positive number from 1 to 15), and is preferably the same or different carbon. It is a linear or branched alkylene group of the formulas 6 to 9 . Also, R ₂ are identical or different straight-chain or branched-chain alkyl group or an aralkyl group having a carbon number of 1 to 20, wherein the benzyl group and aralkyl group, an alkyl group having an aromatic ring such as a phenethyl group Say. The aralkylene group for R ₁ is a divalent group obtained by removing one hydrogen atom from an aralkyl group. R ₂ is preferably the same or different linear or branched alkyl group having 1 to 4 carbon atoms, particularly preferably a methyl group. The average degree of polymerization n is a positive number of 2 to 50, preferably 2 to 30, and particularly preferably 2 to 18.
Is a positive number. If the carbon number of R ₁ is larger than 20 and the average degree of polymerization n is larger than 50, the molecular weight of the obtained tertiary amino alcohol increases, and the viscosity increases due to the carbon number and structure of R ₂ , making it difficult to use. On the other hand, when the carbon number of R ₁ is smaller than 2 and the average degree of polymerization n is smaller than 2 , the content of the tertiary amino group in the molecular skeleton becomes too small and the expected catalytic performance cannot be obtained.

[0015] Examples of the tertiary amino alcohol represented by the general formula (I) used in the present invention, one general formula (I)
Wherein R ₁ is the same or different linear or branched alkylene group having 6 to 9 carbon atoms, R ₂ is the same or different linear or branched alkyl group having 1 to 4 carbon atoms, and the average degree of polymerization n is 2 ~ 18 positive
A tertiary amino alcohol which is a number , R ₁ in the general formula (I)
Are the same or different, linear or branched alkylene groups having 6 to 9 carbon atoms, R ₂ is the same or different linear or branched alkyl groups having 1 to 4 carbon atoms, and the average degree of polymerization n is 2 to 30, And tertiary amino alcohols.

As described above, a tertiary amino alcohol represented by the general formula (II) may be produced depending on the reaction conditions. In the present invention, one or more tertiary amino alcohols represented by the general formula (II) are used in combination with the tertiary amino alcohol represented by the general formula (I) as a third component. You can also. The third component represented by the general formula (II) accounts for 30% of the total amount of the tertiary amino alcohol represented by the general formula (I) and the tertiary amino alcohol represented by the general formula (II). It is preferable to use it in the range of not more than weight%. In the tertiary amino alcohol represented by the general formula (II), R ₃ in the general formula (II) is R ₁ in the general formula (I), and R ₄ in the general formula (II) is a general formula ( R _{2 in} I) and the average degree of polymerization m in general formula (II) may be different from n in general formula (I), but those in the same range are preferable.

Thus, by selecting the tertiary amino group content and molecular weight in the molecular skeleton, the molecular weight of the side chain, and the structure within a range satisfying the performance as a polyol,
Tertiary amino alcohols having various catalytic performances corresponding to the required reactivity can be obtained, and a rigid polyurethane foam can be produced by a spray method without substantially using a catalyst component.

In the present invention, the tertiary amino alcohol represented by the general formula (I) is used as a part or all of the polyol component and can be used in an arbitrary ratio with other polyols. When the tertiary amino alcohol represented by the formula (II) is used in combination, the total amount thereof is 1 to 50% by weight, preferably 10 to 30% by weight, based on the total amount of the polyol component. As other polyols, generally known polyester polyols, polyether polyols and the like used for producing rigid polyurethane foams can be used. For example, polyester polyols produced from ordinary dibasic acids and polyhydric alcohols, glycols, glycerin, pentaerythritol,
Examples include polyether polyols obtained by adding ethylene oxide and / or propylene oxide to polyhydric alcohols such as trimethylolpropane and sucrose and polyhydric amines such as triethylenediamine, 1,3 propanediamine and isophoronediamine. it can. These polyols can be used alone or as a mixture of two or more.

As the polyisocyanate compound used in the present invention, an aromatic, aliphatic or alicyclic polyisocyanate having two or more isocyanate groups, a mixture of two or more thereof, There is a modified polyisocyanate obtained. For example, polyisocyanates such as tolylene diisocyanate, diphenylmethane diisocyanate, polymethylene polyphenyl polyisocyanate (crude MDI), xylylene diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate and modified polyisocyanates thereof, for example, carbodiimide modified products, buret modified products And dimer and trimer, and further include prepolymers of terminal isocyanate groups of these polyisocyanates and active hydrogen compounds.

Further, in the production method of the present invention, water is used as a blowing agent, and the amount of water used is the total amount of the polyol component.
It is 2 to 8 parts by weight based on 100 parts by weight. In addition, it is preferable to use commonly used trichlorofluoromethane or another blowing agent. Other foaming agents include
Difluorochloromethane (F-22), 1,1-difluoroethane
(F-152a), 1,1,1,2-tetrafluoroethane (F-134a),
1,1,1,2,2-pentafluoroethane (F-125), 1,1-dic
Rollo-2,2,2-trifluoroethane (R-123), 2,2-di
Chloro-2-fluoroethane (R-141b), 1-chloro-1,
1-difluoroethane (R-142b) and the like.

In the present invention, in addition to the polyisocyanate component and the polyol component, a catalyst, if necessary,
Surfactants and / or foam stabilizers, coloring agents, flame retardants, stabilizers and the like can be used. The types and amounts of these additives can be sufficiently used within the types and usage ranges usually used.

By using the tertiary amino alcohol represented by the general formula (I) according to the present invention as all or at least a part of the polyol component, it is substantially unnecessary to use a catalyst component. When the amount is small, a metal catalyst can be used in combination for controlling the reaction at a low temperature. Depending on the application, the use of a catalyst is also possible. Such a catalyst is not particularly limited, but a conventionally known amine catalyst or metal catalyst can be used.
As the amine catalyst, N, N-dimethylcyclohexyla
Min, N, N-dimethylbenzylamine, triethylamido
, N-methylmorpholine, N-ethylmorpholine, N,
N, N ', N'-tetramethylethylenediamine, N, N, N', N '
-Tetramethyl-1,3-propanediamine, N, N, N ', N'
-Tetramethylhexanediamine, bis-2-dimethyl
Aminoethyl ether, N, N, N ', N', N ''-pentamethyl
Diethylene triamine, tetramethyl guanidine, tri
Ethylenediamine, N, N'-dimethylpiperazine, N-meth
Tyl-N′-dimethylaminoethyl-piperazine, N −
(2-dimethylaminoethyl) morpholine, 1-methyl
Imidazole, 1,2-dimethylimidazole, N, N-di
Methylaminoethanol, N, N, N'-trimethylamino
Tylethanolamine, N-methyl-N '-(2-hydro
Xylethyl) piperazine, N- (2-hydroxyethyl)
G) morpholine, 1- (2-hydroxypropyl) imi
Dazole, 2,4,6-tris (dimethylaminomethyl) phenyl
Enol, N, N-dimethylaminohexanol, N, N-
Dimethylaminoethoxyethoxyethanol, 1,4-bi
(2-hydroxypropyl) -2-methylpiperazine
, Triethanolamine, N, N ', N''-tris (3-di
Methylaminopropyl) hexahydro-S-triazine
And the like. Octane is a metal-based catalyst.
Stannate, dibutyltin dilaurate, lead octoate,
And dibutyl lead butylate. These catalysts can be used alone or in combination with a tertiary amino alcohol as a mixture of two or more.

[0023]

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to these examples. In the examples, “parts” are based on weight unless otherwise specified.

Reference Example A 600 g of 1,6-hexanediol and Cu were placed in a 1-liter flask equipped with a condenser and a separator for separating produced water.
/ Ni / Pd catalyst 36 g (based on diol 6% by weight)
The system was replaced with nitrogen while stirring, and the temperature was raised. When the temperature in the system reaches 100 ° C, hydrogen gas is
It was blown into the system at a flow rate of 10 liter / Hr, and the temperature was raised to 180 ° C. At this temperature, a mixed gas of monomethylamine and hydrogen gas was blown into the reaction system at a flow rate of 40 L / Hr, and the reaction was monitored by amine value and hydroxyl value. The reaction was performed for about 4 hours. After completion of the reaction, the catalyst was separated by filtration to obtain a pale brown viscous liquid.

Reference Example B The reaction was carried out for 4 hours under the same conditions as in Reference Example A, except that the flow rate of hydrogen gas was 5 L / Hr, and the flow rate of a mixed gas of monomethylamine and hydrogen gas was 35 L / Hr.

The analytical values of the tertiary amino alcohols A and B obtained in the above Reference Examples are shown in Table 1.

[0027]

[Table 1]

Comparative Example 1 A conventional spray-type rigid polyurethane foam as shown in Table 2 was foamed by the following method. That is, Table 2
Of the ingredients in the mixture, the raw materials excluding crude MDI were premixed and kept at 5 ° C., and then a specified amount of the polyol component preliminarily mixed with crude MDI brought to 5 ° C. was reacted by hand-mixing foaming. The mechanical properties of the foam were measured. The self-adhesion strength was measured by a method according to JIS 9526. That is, the sample preparation is crude MD
The raw materials except for I are premixed and kept at 5 ° C. Next, a prescribed amount of the polyol component preliminarily mixed with crude MDI at 5 ° C. was hand-mixed, and the mixture was sprayed on a plywood kept at 5 ° C. to foam and harden. The environmental temperature during the foaming process was kept at 5 ° C. Table 3 shows the results.

Examples 1 to 4 Tertiary amino alcohols A of the present invention obtained in Reference Examples,
Using B, foaming was carried out in the same manner as in the comparative example with a composition as shown in Table 2, and each physical property of the polyurethane foam was measured.
Table 3 shows the results.

Example 5 and Comparative Example 3 A foaming test was conducted at a low temperature (0 ° C.). The operation was carried out under the same conditions as in Comparative Example 1 and Example 1. However,
The raw material temperature was kept at 0 ° C., and the temperature and room temperature of the test piece of self-adhesion strength were also kept at 0 ° C. Table 3 shows the results.

[0031]

[Table 2]

[0032]

[Table 3]

[0033]

As is clear from the examples, when the tertiary amino alcohol according to the present invention is used, a normal amine catalyst is not required, and especially the reaction rate at 0 ° C. is greatly delayed in the conventional compounding. On the other hand, when the tertiary amino alcohol of the present invention is blended, the reaction rate delay is small,
Since the increase in the free form density is small, it is considered that the reaction at a low temperature is proceeding smoothly. Also JIS 9
It is also evident that the self-adhesion strength of 526 is greatly improved, which makes it possible to carry out construction at low temperatures, which was difficult to carry out by spraying in the past, and is effective even in a formulation containing a large amount of water.

──────────────────────────────────────────────────続 き Continuation of the front page (72) Shoichiro Harada, Inventor 727-96, Zenmyoji Temple, Wakayama City (56) References Japanese Patent Publication No. 32-6748 (JP, B1) Japanese Patent Publication No. Sho 61-501327 (JP, A) (58) ) Surveyed field (Int.Cl. ⁷ , DB name) C08G 18/00-18/87

Claims (6)

(57) [Claims] When a polyisocyanate component and a polyol component are reacted with each other to produce a spray-type rigid polyurethane foam, 2 to 8 parts by weight of water is used as a foaming agent based on 100 parts by weight of the total amount of the polyol component. Some or all of the components have the following general formula (I): Wherein, R ₁ represents identical or different straight-chain or branched-chain alkylene group having a carbon number of 2-20, an alicyclic alkylene group, an Raruki <br/> alkylene group or _{- (CH 2 CH 2 O)} p — (CH ₂ CH ₂ ) _q — (where p is 0 or a positive number and q is a positive number), and R ₂ is the same or different linear or branched alkyl having 1 to 20 carbon atoms Base
Or an aralkyl group, and the average degree of polymerization n is a positive number of 2 to 50. ] A method for producing a spray-type rigid polyurethane foam, characterized by using one or more tertiary amino alcohols represented by the following formula: 2. In the formula (I), R ₁ is the same or different and is a straight-chain or branched alkylene group having 6 to 9 carbon atoms, and R ₂ is the same or different and is a straight-chain or branched chain having 1 to 4 carbon atoms. alkyl group, the average polymerization degree n is the preparation of spray type rigid polyurethane foam according to claim 1, wherein a positive number of 2 to 18. 3. A straight-chain or branched alkylene group having 6 to 9 carbon atoms, wherein R ₁ is the same or different, and a straight-chain or branched chain having 1 to 4 carbon atoms, wherein R ₂ is the same or different. The method for producing a spray-type rigid polyurethane foam according to claim 1, wherein the alkyl group has an average degree of polymerization n of 2 to 30 and is a positive number. 4. In addition to the tertiary amino alcohol represented by the general formula (I), a tertiary amino alcohol represented by the general formula (II): Wherein, R ₃ is identical or different straight-chain or branched-chain alkylene group having a carbon number of 2-20, an alicyclic alkylene group, an Raruki <br/> alkylene group or _{- (CH 2 CH 2 O)} p — (CH ₂ CH ₂ ) _q — (where p is 0 or a positive number and q is a positive number), and R ₄ is the same or different linear or branched alkyl having 1 to 20 carbon atoms Base
Or an aralkyl group, and the average degree of polymerization m is a positive number of 2 to 50. The method for producing a rigid polyurethane foam according to any one of claims 1 to 3 , wherein at least one tertiary amino alcohol represented by the formula (1) is used. 5. A tertiary amino alcohol represented by the general formula (I) and a tertiary amino acid represented by the general formula (II), wherein the third component represented by the general formula (II) is The method for producing a spray-type rigid polyurethane foam according to claim 4, wherein the foam is used in an amount of 30% by weight or less of the total amount with the alcohol. 6. A linear or branched alkylene group having 6 to 9 carbon atoms, wherein R ₁ in the general formula (I) and / or R ₃ in the general formula (II) are the same or different. In the formula (I)
R ₂ and / or R ₄ in the general formula (II) are the same or different linear or branched alkyl groups having 1 to 4 carbon atoms, and the average polymerization degree n in the general formula (I) and / Or the general formula
The method for producing a rigid polyurethane foam according to claim 4 or 5 , wherein the average degree of polymerization m in (II) is a positive number of 2 to 30.