JPS5876407A - Manufacture of rigid polyurethane foam - Google Patents

Abstract

PURPOSE:To obtain titled foam of improved quality useful for insulating material, etc., by carrying out a reaction, in the presence of a catalyst, foaming agent, organo-silcon-based foam stabilizer, and fluorine-based surface active agent, between a polyisocyanate and a polyol having a specific average hydroxyl number. CONSTITUTION:The objective foam can be obtained by carrying out the reaction, in the presence of at least four agents comprising a catalyst, foaming agent, organosilicon-based foam stabilizer, and fluorine-based surfactant, between (A) a polyisocyanate and (B) a polyol high an average hydroxyl number of 300- 700, or a polyol mixture of an average hydroxyl number of 300-700 containing said polyol. For said polyol, an amine-based one prepared by adding an alkylene oxide to an aromatic polyamine is preferably used. Furthermore, it is recommended that said fluorine-based surfactant in anionic, and its amount is 0.01- 5pts.wt. based on 100pts.wt. of the polyol component.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a rigid polyurethane foam with improved heat insulation properties, and in particular, a rigid polyurethane foam with excellent heat insulation properties is produced by using a fluorine thread surfactant in combination with a conventional foam stabilizer. The present invention relates to a method of manufacturing foam.

The most widely used application of rigid polyurethane foam is as a heat insulating material. The most important performance as a heat insulating material is heat insulation, that is, low thermal conductivity. It is well known that the thermal conductivity of rigid polyurethane foam depends on the type and combination of its raw materials. In particular, the type of blowing agent has a great effect on thermal conductivity, and when trichlorofluoromethane is used as a blowing agent, a rigid polyurethane foam with good low thermal conductivity can usually be obtained. However, the blowing agent for rigid polyurethane foam is not limited to trifluorochloromethane, and depending on conditions such as other physical properties and selection of molding method, other) ff
Three foaming agents have been used alone or in combination with trichlorofluoromethane. Other blowing agents include, for example, water, methylene chloride, dichlorodifluoromethane, and other halogenated hydrocarbons. The thermal conductivity of rigid polyurethane foam is greatly influenced by the expander, but also depends on the type and combination of raw materials other than the blowing agent when the same blowing agent is used. Therefore, in order to produce a rigid polyurethane foam with lower thermal conductivity, the selection of raw materials other than the blowing agent is also important.

It is not clear why the selection of raw materials other than the blowing agent affects thermal conductivity, but it may be due to factors such as the size and uniformity of the bubbles, or the ratio of closed cells to total cells (therefore, the thermal conductivity changes). Therefore, when selecting raw materials, it is necessary to consider the effects on these, and it is considered that selection of foam stabilizer and polyol are essential.

Conventionally, in the production of rigid polyurethane foam, various foam stabilizers have been studied in order to adjust the size and uniformity of cells. Foam stabilizers are organosilicon compounds typified by polysiloxanes such as polyoxyT-alkylene-polysiloxane copolymers, and many compounds are commercially available and have been designed as foam stabilizers for polyurethane foams. As a result of examining these commercially available or available organosilicon compound foam stabilizers, the present inventors found that the thermal insulation properties of the rigid polyurethane film obtained are affected to some extent by the type of foam stabilizer. . The effect of foam stabilizers on thermal insulation is thought to be related to the size and uniformity of the bubbles, but when trying to achieve higher thermal insulation, the influence of foam stabilizers also appears in the opposite, unfavorable aspects. I found it. For example, the use of a foam stabilizer that produces fine cells is effective in improving heat insulation, but it also deteriorates the stability of the cells and further deteriorates the dimensional stability of the resulting rigid polyurethane foam. Deterioration of cell stability deteriorates moldability and causes, for example, voids in rigid polyurethane foams. Specifically, by using such a foam stabilizer, a rigid polyurethane foam is obtained which has voids of several diameters on its surface here and there. On the other hand, the stability of the bubbles is good (
Foam stabilizers that can produce hard polyurethane foams with excellent moldability and dimensional stability usually have relatively low insulation properties, and are not suitable for the purpose of producing rigid polyurethane foams with good insulation properties. It's not appropriate.

The present inventor investigated a method of suppressing the adverse effects of the foam stabilizer and improving heat insulation properties, and as a result, found that the use of a fluorine-based surfactant is extremely effective in achieving Er5+. The fluorosurfactant replenishes the above-mentioned foam stabilizer and also reduces the adverse effects caused by it. Although its effect is not clear, it is presumed that the fluorine thread surfactant regulates bubbles by a foam regulating action different from that of the above-mentioned foam stabilizer. The present invention relates to a method for producing rigid polyurethane foam using this fluorosurfactant in combination with an organosilicon compound foam stabilizer. A polyol component consisting of a polyol mixture containing a polyol and a polyisocyanate component are reacted in the presence of at least four additives including a catalytic blowing agent, an organosilicon compound foam stabilizer, and a fluorine surfactant. This is a method for producing a rigid and negative polyurethane foam.

The fluorine-containing surfactant is a surfactant containing fluorine atoms in its constituent components, and particularly preferred is a surfactant containing a polyfluoroalkyl group. The polyfluoroalkyl group-containing fluorine-containing surfactant is not particularly limited, and a wide range of conventionally known and well-known surfactants can be employed, for example. The polyfluoroalkyl group preferably has 4 to 20 carbon atoms, and is usually preferably a perfluoroalkyl group, and has 6 to 18 carbon atoms.
It is desirable that the number of Of course, the polyfluoroalkyl group may be straight or branched, and may partially contain hydrogen atoms, chlorine atoms, etc., or may contain ether bonds. A polyfluoroalkyl group having at least a perfluoroalkyl group at the terminal end is preferably selected. There are various types of fluorine-based surfactants such as anionic, cationic, and nonionic diampholytes.
Can be widely adopted.

Among these fluorine-based surfactants, particularly preferred are anionic surfactants. Carboxylate type is an anionic surfactant.

There are sulfonate type, phosphate type, sulfuric acid ester type and others, but particularly preferred are carboxylate type anionic surfactants.

For example, Rf(Q)m (R)nco
There is something expressed by oM. Rf is a carbon number of 6 to 1°8.
-fluoroalkyl group, Q is -CON(R1)-i or -8o, N(jul), R is an alkylene group having 1 to 10 carbon atoms, 9M, an alkali metal such as sodium or potassium, or NH. Further, R1 is a hydrogen atom or a lower alkyl group having 1 to 4 carbon atoms.

m and nld are each 0 or 1. More specifically, the following anionic surfactants can be used.

RfCOOM, Rf(CH,)pC00M,
RfCON (R') (CH2)pCo0M.

Rf80. N(R') (CH,)p C00M,
Rfso, M, Rf(C:H,)pOEIO8M
.

A: Alkylene group having 1 to 3 carbon atoms Rf + R1 + M’ Same as above Preferred specific examples are the following compounds.

RfCON(CH,), COONa, RfCONH
(CH2), C00NH,, RfCOONH,.

CH.

Various organosilicon compound foam stabilizers are commercially available or have been proposed, but the detailed structures of many of these commercially available foam stabilizers are unknown.

In the present invention, commercially available or available foam stabilizers for polyurethane foams can be used, but those commercially available for rigid polyurethane foams are particularly preferred.

Specific commercially available foam stabilizers include, for example, the following: First, examples of foam stabilizers that can obtain a rigid polyurethane foam with good moldability and excellent dimensional stability include 1. L-5350" (manufactured by Nippon Unicar) and '?-341' (manufactured by Shin-Etsu Kagaku 1), but these usually provide a form with slightly higher thermal conductivity. On the other hand, they have poor formability and dimensional stability. IL-F1420” (Nippon Unicar) is a foam stabilizer that gives a low foam.
(manufactured by Shin-Etsu Chemical), "F'-305" (manufactured by Shin-Etsu Chemical), 5H-
193 (manufactured by Toray Silicone ■). The foam stabilizer suitable for this invention is Nippon Unicar's I
Product names such as 'L-5430'' foam stabilizers in the L-5000 series and product names F'- such as 'F-345' manufactured by Shin-Etsu Chemical ■.
There are foam stabilizers in the 300 range. Of course, the foam stabilizers that can be used in the present invention are not limited to these, and various foam stabilizers for rigid polyurethane foams can be used.

Polyhydric alcohols and polyhydric phenols are used as polyols for manufacturing rigid polyurethane foam.

Preferred are polyamines and polyols obtained by adding alkylene oxide to other initiators having a valence of four or more. For example, dextrose, sucrose, pentaerythritol.

Polyhydric alcohols with a valence of 4 or higher, such as diglycerin.

Suitable initiators include novolacs and other polyamines such as phenol, tolylene diamine, diaminodiphenylmethane, other aromatic polyamines, and ethylene diamine. These initiators can be used alone or in combination, and can also be used in combination with divalent or trivalent initiators. 2-3
Examples of initiators include ethylene glycol and propylene glycol.

Examples include glycerin, trimethylolpropane, jetanolamine, and triethanolamine.

Examples of the alkylene oxide added to the above initiator include ethylene oxide, propylene oxide, butylene oxide, epichlorohydrin, and other alkylene oxides having 6 carbon atoms.
The following alkylene oxides are preferred. Two or more alkylene oxides can be added randomly or in blocks, and alkylene oxides and other epoxides (for example, styrene oxide) can also be used together. Preferred alkylene oxides are propylene oxide alone or a combination of propylene oxide and ethylene oxide. When propylene oxide and ethylene oxide are used together, it may be preferable to first add ethylene oxide and then propylene oxide, or it may be preferable to add them in the reverse order. Of course, both can be added randomly. The amount of alkylene oxide added is such that the hydroxyl value of the resulting polyol is 3.
It is a spear that has an amount of 00 to 700, especially a spear that has a value of 350 to 550.

The polyols having a hydroxyl value of 300 to 700 in the present invention can be used alone, or two or more types of polyols can be used in combination. It can also be used in combination with polyols and polyhydric alcohols other than those mentioned above. Examples of compounds other than those mentioned above that can be used in combination include polyester polyols and low molecular weight polyols. When using two or more polyols, polyhydric alcohols, etc., the average hydroxyl value in the mixture is similarly 300 to 70.
Preferably, it is 0.

From the standpoint of heat insulation, the most preferable polyols are the following amine-based polyols, particularly amine-based polyols using aromatic polyamines as initiators.

These amine polyols can be used not only alone, but also preferably in combination with other polyols, polyester polyols, low molecular weight polyols, etc.

When used in combination with other polyols, the amount of the amine polyol is most preferably 60% by weight or more based on the total polyol.

The amine polyol in the present invention is a compound obtained by adding an alkylene oxide to an amine compound having at least one amino group, imino group, or tertiary nitrogen atom, and is a compound obtained by adding an alkylene oxide to an amine compound having at least one amino group, imino group, or tertiary nitrogen atom. In this case, a functional group to which an alkylene oxide can be attached is required.

Preferred amine compounds are aromatic compounds having at least one amine group, especially aromatic compounds in which at least one amine group is bonded to an aromatic nucleus. - It is a group amine compound. Aromatic amine compounds may have one or more aromatic nuclei, the amino groups may be bonded to the same or different aromatic nuclei, and alkylene or oxide other than the amine group may be added. It may further have a functional group such as a hydroxyl group. Most preferred aromatic amine compound A mononuclear aromatic amine having an amino group of M12 or more, and a mononuclear aromatic amine having at least one amino group alone or a polynuclear aromatic compound condensed with a phenol compound using a methylene group. It is a group amine. An example of the former is
For example, 2.4-) lylene diamine, 2.6-lylene diamine, 12.3-) IJ diamine.

3,4-) Lylene diamine, mixtures thereof, distillation residue of tolylene diamine, diaminobenzene, etc. Examples of presenters include condensation products of aniline and formaldehyde, condensation products of aniline, phenol, and formaldehyde, and 4,4' obtained by purifying these products.
- polynuclear aromatic amines such as diaminodiphenylmethane,
These purification residues are included.

As amine compounds other than aromatic amine compounds,
Alkanolamines, aliphatic amines.

Examples include melamine, urea, guanamine, benzoguanamine, other non-aromatic amine compounds, and their derivatives such as formaldehyde condensates.

Preferred are condensation products of mono- or dialkanolamines, formaldehyde, and amine compounds and/or non-amine compounds, ie, Mannich adducts. For example, there are condensation products of phenol, dialkanolamine and formaldehyde, and condensation products of phenol, aniline, dialkanolamine and formaldehyde, and the latter or one of the above-mentioned aromatic amine compounds can be considered.

Mannich adducts have a secondary or tertiary u atom and at least one b-hydroxyalkyl group attached thereto.

Two or more of these amine compounds may be used in combination, and in particular, the distillation residue is a mixture of various compounds. In addition, it includes purified residues and by-products of isocyanate compounds such as tolylene diisocyanate and diphenylmethane diintzanate, mixtures containing compounds that can be converted into amine-based polyols, and decomposition products of polyurethane. can also be used as one of the amine compounds. Further, these amine compounds can also be used in combination with polyhydric alcohols and the like as an initiator.

The most preferred amine-based polyol is an amine-based polyol obtained by adding propylene oxide or propylene oxide and ethylene oxide to one type of tolylene diamine, a mixture of two or more types of tolylene diamine, or a mixture containing the same as the main component.

The above amine polyols and other hydroxyl values 300 to 700
The polyester polyol that can be used in combination with the polyol mentioned above is obtained by condensing a polyhydric alcohol or its derivative with a polyhydric carboxylic acid or its @conductor, and may have an unsaturated group. In particular, polyester polyols obtained by reacting divalent or trivalent alcohols with dicarboxylic acids, their anhydrides, halogen compounds, and other derivatives are preferred. Two or more types of polyhydric alcohols, polycarboxylic acids, or their derivatives (hereinafter both will be referred to as polycarboxylic acids) may be used in combination; for example, dihydric alcohols and trihydric alcohols may be reacted with dicarboxylic acids. good. The hydroxyl value of polyester polyol is 200-6001, especially 350-55
0 is preferred.

As a low-molecular lid polyol, the molecular weight is 1350 or less, especially 20
Polyols having 0 or less hydroxyl groups and 2 to 4 hydroxyl groups are preferred.

Particularly preferred are polyhydric alcohols and low molecular weight polyether polyols.

It is alkacylamine. As a polyhydric alcohol,
Polyhydric alcohols explained in the above section on polyester polyols with a molecular weight of 1 at 350 or less and a number of hydroxyl groups of 2 to 4, such as ethylene glycol, diethylene glycol, and other polyethylene glycols with a molecular weight of 1350 or less;
Propylene glycol, cyfropylene glycol and other polypropylene glycols with a molecular weight of 350 or less, 1,
4-butanediol and other butanediols, hexamethylene glycol, glycerin, diglycerin, trimethylolpropane.

Examples include pentaerythritol. As the alkanolamine, dialkanolamines such as diethylene glycol and trialkanolamines are preferred. The low molecular weight polyether polyol is preferably a compound obtained by adding a small amount of alkylene oxide to an amine compound such as the above-mentioned polyhydric alcohol or di-alkanolamine, monoalkanolamine, or ethylenediamine. Particularly preferred are low-viscosity, low-molecular-weight polyols, including polyether polyols such as ethylene glycol propylene glycol, butanediol, glycerin, trimethylolpropane, any polyhydric alcohols other than these dimers, and glycerin-alkylene oxide adducts. and so on.

The combination ratio of these polyester polyols or low molecular weight polyols and polyols having a hydroxyl value of 300 to 700 is not particularly limited. However, preferably a polyol of 60% or more and a low molecular weight polyol of 40%!
Combination of T% or less, or polyol 40wt% or more, polyester polyol 2-30%, = %
, and a combination of a low molecular weight polyol of 30 ply or less.

The amount of the fluorosurfactant used is not particularly limited, but the above polyol or polyol mixture 10
0 parts by weight. , 001-5 parts by weight, especially 01-5 parts by weight
A double front is appropriate.

Similarly, the amount of organosilicon compound foam stabilizer used is 0.01~
5 parts by weight, especially 0.5 to 5 parts by weight, is suitable. These 2
It is preferable to use these additives by mixing them into the polyol component in advance, but they can also be added to the polyisocyanate component or mixed at the same time when the polyol component and the polyisocyanate component are mixed. Similarly, catalyst 2
A blowing agent or other nitrifying agent may be added in advance to one or both of the polyol and polyisocyanate components, or may be mixed simultaneously when the polyol and polyisocyanate components are mixed. A tertiary amine catalyst and/or an organometallic compound is suitable as the catalyst. As the blowing agent, reactive blowing agents such as water and non-reactive blowing agents such as halogenated hydrocarbons and inert gases are used alone or in combination. As mentioned above, trichlorofluoromethane is preferred as the halogenated hydrocarbon, and it is preferred to use it alone or in combination with water or other halogenated hydrocarbons.

Other additives include, for example, stabilizers and colorants.

Fillers, crosslinking agents, etc. may be used.

Suitable polyisocyanate components are compounds having at least two incyanate groups, especially aromatic polyisocyanates. Examples include tolylene diisocyanate, diphenylmethane diisocyanate, polymethylene polyphenyl isocyanate, xylylene diisocyanate, other aromatic polyinocyanates, hexamethylene diisocyanate, inborone diisocyanate, and other non-aromatic polyisocyanates. These polyisocyanates may be modified polyisocyanates modified with various treatments or compounds. These polyisocyanates can be used alone, or a mixture of isomers or an unpurified product can be used as polyisocyanate.

EXAMPLES The present invention will be specifically explained below with reference to Examples; however, the present invention is not limited to these Examples.

Examples and Comparative Examples Using the following raw materials, 600 x 900 x 50
mm rigid polyurethane foam panels were produced.

The amount of raw materials used (expressed in parts by weight excluding the isocyanate index) and the formability of this panel.

Table 1 shows the measurement results of thermal conductivity and stability in nine dimensions.

〔material〕

Polyol: A mixture of 60 parts by weight of a podiol obtained by adding ethylene oxide and propylene oxide to a metatolylene diamine mixture and 40 parts by weight of a polyol obtained by adding propylene oxide to a shooter-monoethanolamine mixture initiator. A polyol mixture with an average hydroxyl value of 460.

Foam stabilizer: Indicated by the product name listed above.

S-113: Anionic fluorine-based surfactant (product name manufactured by Asahi Glass ■) Catalyst 1, medium: 2=1 mixture C of tetramethylhexamethylenediamine (product name 1 Kao Riser I61') and pentamethyldiethylenetriamine , MDI: Crude MDI (Kasei Up John 7
”Cracked product name: IPAPI-135I, NCO content: approx. 31.
5%) Formability: Depends on the presence or absence of voids.○: Almost no voids.

3-level evaluation: △: Some voids, ×: Many voids Thermal conductivity (K Guaftar): Anacon Model J16
Measured with ss@1 fixed machine

Claims (1)

[Scope of Claims] 1. A polyol component consisting of a polyol having an average hydroxyl value of 300 to 700 or a polyol mixture containing the polyol and having an average hydroxyl value of 300 to 700 and a polyiscyanate component are combined with a catalyst 9, a blowing agent, and an organosilicon compound. A method for producing rigid polyurethane foam, which comprises reacting in the presence of at least four additives including a foam stabilizer and a fluorosurfactant. 2. The method according to claim 1, wherein the polyol is an amine polyol obtained by adding alkylene oxide to an aromatic polyamine. 3. The method according to claim 1, wherein the fluorine-based surfactant is an anionic fluorine-based thread surfactant. 4. The use of fluorosurfactant is the polyol component 1.
The method according to claim 1, characterized in that the amount is 0.01 to 5 parts by weight per 00 parts by weight.