JP2002161121A - Flame-retardant foam - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a flame-retardant foam of which the flame retardance can be improved further and which is excellent in rigidity and in other properties. SOLUTION: This flame-retardant foam is continuously formed by reacting an organic polyisocyanate component with a polyol component. A polynuclear phenolic compound obtained from heavy oil or pitch is diluted with a low viscosity polyether polyol in a weight ratio range of 20/80-50/50, the diluted mixture in an amount of 30-60 pts.wt. is blended with 70-40 pts.wt. of an aromatic polyester polyol and the blend is used as the polyol component and an equivalent ratio of isocyanate groups/hydroxyl groups is kept in a range of 3.0-5.0.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flame-retardant foam, and is particularly suitable as a heat insulating material for buildings such as ceilings, floors and walls.

[0002]

2. Description of the Related Art Foams such as rigid urethane foams and polystyrene foams are widely used for heat insulation of ceilings, floors, walls and the like as architectural heat insulating materials because of their excellent heat insulating properties.

However, when a foam such as a rigid urethane foam or a polystyrene foam is used as a heat insulating material, there are the following problems. These foams are easily combustible and their use is restricted in public facilities, fire protection and semi-fire protection areas by building regulations.

[0004] In addition, due to the recent revision of the Building Standard Law, a heat generation test method has been introduced for heat insulating materials, and the evaluation method of flame retardancy has been greatly changed.

Further, in recent years, it is necessary to consider evacuation guidance for vulnerable people such as the elderly living in houses at the time of fire.
Therefore, in order to solve these problems, one of the characteristics required for a foam used as a heat insulating material or the like is to improve the flame retardancy.

For this reason, phenol foams, polyisocyanurate foams, polycarbodiimide foams, polyimide foams and the like have been developed in place of foams such as rigid urethane foams and polystyrene foams.

Japanese Patent Application Laid-Open No. 2000-1599 discloses a highly reactive modified phenol resin obtained based on heavy oils or pitches and obtained from polyols, isocyanates, blowing agents, and catalysts. It is said that a flame-retardant foam can be obtained by the resin.

[0008]

However, although all foams have improved flame retardancy as compared with the conventional foams, they are still insufficient and need to be further improved in flame retardancy. Further, in the case of phenol foam, there are problems of formaldehyde generation and rust generation, and in the case of polyisocyanurate foam, there is a problem that it is brittle and lacks rigidity and breaks during construction. The present invention has been made in view of the problems of the related art, and aims to provide a flame-retardant foam that can further improve the flame retardancy and is excellent in other characteristics such as rigidity. Things.

[0009]

Means for Solving the Problems In order to solve the above-mentioned problems, the present inventors have conducted intensive studies and experiments, and as a result, an organic polyisocyanate component and a polyol component were used as main raw materials, and a foaming agent and a catalyst were used. As a polyol component of a foam produced by blending with, by adjusting and using a phenol polynuclear body mainly composed of a highly reactive modified phenol resin obtained based on heavy oils or pitches,
It has been found that a flame-retardant foam having flame retardancy is obtained by utilizing the rigidity of a rigid polyurethane foam, and the present invention has been completed.

That is, in order to solve the problems of the above prior art, the flame-retardant foam according to claim 1 of the present invention comprises:
A flame-retardant foam which is continuously foamed and formed by a reaction between an organic polyisocyanate component and a polyol component. Dilute the ether polyol in a weight ratio of 20/80 to 50/50, use a mixture of 30 to 60 parts by weight of the diluted product and 70 to 40 parts by weight of an aromatic polyester polyol, and use an isocyanate group / hydroxyl group. Is set in the range of 3.0 to 5.0.

According to the flame-retardant foam, properties such as density, compressive strength, thermal conductivity and brittleness are equal to or higher than those of the rigid polyurethane foam, and a flame penetration test (US Mining Bureau standard) and a heat build-up test (quasi- Cone calorimeter test for noncombustible material test:
(Measured by ISO 5660) and the like, and is excellent in flame retardancy, and particularly suitable as a heat insulating material for buildings.

The flame-retardant foam according to the second aspect of the present invention, in addition to the constitution according to the first aspect, has a viscosity of the low-viscosity polyether polyol of 2000 mPa · s or less and a molecular weight of 200 mPa · s. ~ 400 polyethylene glycol, diethylene glycol, triethylene glycol, glycerin or a mixture thereof.

By diluting the solid phenol polynuclear at room temperature with the polyol component prepared in this manner, the viscosity can be adjusted to an appropriate level, and the flame-retardant property of a conventionally used foam molding line is excellent. A foam can be obtained.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the flame-retardant foam of the present invention will be described in detail below. This flame-retardant foam is a flame-retardant foam which is continuously foam-molded by a reaction between an organic polyisocyanate component and a polyol component, and is obtained based on heavy oil or pitch as the polyol component. The low-viscosity polyether polyol is diluted in the phenol polynuclear obtained in a weight ratio of 20/80 to 50/50, and the diluted product 30 to 60 is diluted.
A mixture of 70 parts by weight and 70 to 40 parts by weight of an aromatic polyester polyol is used, and the equivalent ratio of isocyanate group / hydroxyl group is in the range of 3.0 to 5.0.

In the continuous foam molding of the flame-retardant foam by reaction between an organic polyisocyanate component and a polyol component, the flame-retardant foam contains an organic polyisocyanate component and a polyol component as main components, and further includes a necessary foam stabilizer, foaming agent, and catalyst. Foaming is continuously performed by the reaction in the presence of, for example, a mixed solution is sprayed on one face material by means of an airless spray with a double conveyor device, and at the stage of foam hardening, the other face is formed. A foam having a predetermined thickness is continuously formed by applying the material.

The polyol component used in the flame-retardant foam is obtained by diluting a phenol polynuclear with a specific amount of a low-viscosity polyether polyol, and mixing it with a specific amount of an aromatic polyester polyol.

Among the polyol components used in this flame-retardant foam, those obtained from heavy oils or pitches are used as polyphenols.

As the polynuclear phenol, JP-A-20
What is known as a highly reactive modified phenol resin in JP-A-00-1599 can be used.

This highly reactive modified phenolic resin is composed of heavy oils or pitches, 0.3 to 10 moles of phenols, and 0.2 moles of formaldehyde, based on 1 mole of the starting oil calculated from the average molecular weight. It can be obtained by mixing 〜9 mol of a formaldehyde compound and 0.01-3.0 mol of an acid catalyst, heating and stirring to polycondensate the above components.

As the heavy oils or pitches used as a raw material in the polycondensation reaction of the highly reactive modified phenol resin, any of petroleum-based and coal-based raw oils may be used. Distillation residue, hydrogenolysis residue,
Catalytic cracking residue, catalytic reforming residue, pyrolysis residue of naphtha or LPG and vacuum distillation of these residues, extract or heat treatment by solvent extraction, cracking process such as thermal cracking and catalytic cracking in petroleum refining process Examples of the specific extracted oil or residual oil obtained in the above and reduced-pressure distillates of these residual oils, and the like, in coal systems, specific fractionated components obtained by distilling coal tar in coal dry distillation and heavy oil in coal liquefaction And the like.

Examples of the phenol used as a raw material in the polycondensation reaction of the highly reactive modified phenol resin include a hydroxybenzene compound and a hydroxynaphthalene compound. Examples of the hydroxybenzene compound include phenol, cresol, and the like. Xylenol, resorcin, hydroquinone, catechol, phenylphenol, vinylphenol, nonylphenol, p
-Tert-butylphenol, bisphenol A, bisphenol F and the like. Examples of the hydroxynaphthalene compound include monohydroxynaphthalene compounds such as α-naphthol and β-naphthol, 1,2-dihydroxynaphthalene, 1,3-dihydroxy Naphthalene, 1,4-dihydroxynaphthalene and 2,3-dihydroxynaphthalene, 3,6-dihydroxynaphthalene, 1,5-dihydroxynaphthalene,
1,6-dihydroxynaphthalene, 1,7-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, 2,
A dihydroxynaphthalene compound such as 7-dihydroxynaphthalene, and the above mono- or dihydroxynaphthalene compound having an alkyl group and a substituent such as an aromatic group or a halogen atom, for example, 2-methyl-1-naphthol;
4-phenyl-1-naphthol, 1-bromo-2-naphthol, 6-bromo-2-naphthol and the like can be exemplified. These phenols can be used alone or
A combination of more than one species may be used.

The formaldehyde compound used as a raw material in the polycondensation reaction of the highly reactive modified phenol resin includes, in addition to formaldehyde, linear polymers such as paraformaldehyde and polyoxymethylene (especially oligomers), and trioxane. And the like.

In the polycondensation reaction of the highly reactive modified phenolic resin, an acid catalyst is used to polycondense heavy oils or pitches, formaldehyde compounds and phenols. Sted acids or Lewis acids can be used, but preferably Bronsted acids are used. As Bronsted acids, oxalic acid, toluenesulfonic acid, organic acids such as xylenesulfonic acid and formic acid, inorganic acids such as hydrochloric acid and sulfuric acid,
And solid acids such as acidic cation exchange resins.

Such a specific amount of heavy oils or pitches, a formaldehyde compound, a phenol and an acid catalyst are preliminarily mixed, and then the resulting mixture is heated and stirred to carry out a polycondensation reaction, whereby a highly reactive modification is performed. In a polycondensation reaction in which a phenolic resin is produced or these raw materials and an oxidation catalyst are heated and agitated, heavy oils or pitches, an acid catalyst and at least one of a formaldehyde compound are sequentially added to carry out the polycondensation reaction. Produce highly reactive modified phenolic resin.

Since the phenol polynuclear composed of such a highly reactive modified phenol resin is hard to use at room temperature because it is solid, it is liquefied by heating to 70 to 80 ° C.
Using a low-viscosity polyether polyol, the ratio of phenol polynuclear to polyether polyol (phenol polynuclear / polyether polyol) is 20/80 to 50/5
Use one diluted in a weight ratio range of 0.

The low-viscosity polyether polyol used for diluting the polynuclear phenol is preferably a polyether polyol having a viscosity of not more than 2000 mPa · s at 20 ° C. If the viscosity is higher than 2000 mPa · s, the viscosity of the diluent is increased. Absent.

If the weight ratio of polynuclear phenol to polyether polyol (polynuclear phenol / polyether polyol) is less than 20/80, flame retardancy cannot be improved. If the ratio exceeds 50/50, the viscosity of the diluent is so high that a normal foam cannot be obtained.

The low-viscosity polyether polyol used here is preferably polyethylene glycol having a molecular weight of 200 to 400, or diethylene glycol, triethylene glycol, glycerin or the like, or a mixture thereof, which can be used as a raw material for the polyisocyanurate foam.

As the aromatic polyester polyol to be combined with the diluted phenol polynuclear compound, those having a hydroxyl value of 190 to 300 mgKOH / g obtained by transesterification of waste PET, phthalic anhydride, and DMT residue can be used.

It is preferable to mix 70 to 40 parts by weight of the aromatic polyester polyol with respect to 30 to 60 parts by weight of the phenol polynuclear diluent. If the phenol polynuclear diluent is less than 30 parts by weight, required flame retardancy cannot be obtained, and for example, a quasi-non-combustible grade required as a heat insulating material for buildings cannot be obtained. Conversely, the phenol polynuclear diluent is 6
When the amount exceeds 0 parts by weight, when the foam is used, cell roughness occurs, brittleness and thermal conductivity deteriorate, and good properties as a heat insulating material cannot be obtained.

Next, as the organic polyisocyanate component used in the flame-retardant foam, generally used aromatic polyisocyanate, alicyclic polyisocyanate or aliphatic polyisocyanate can be used. it can.

Specific examples thereof include tolylene 2,4-diisocyanate, tolylene 2,6-diisocyanate and mixtures thereof, diphenylmethane 4,4'-diisocyanate, 3-methyldiphenylmethane 4,4'-diisocyanate and mixtures thereof, Hexamethylene diisocyanate can be used.

Then, the equivalent ratio (NCO / OH index) of the isocyanate group to the hydroxyl group of the mixture of the diluted phenol polynuclear product and the aromatic polyester polyol is 3.0.
To 5.0. If the equivalent ratio of the isocyanate group to the hydroxyl group is less than 3.0, the shrinkage during foam molding is large, the shape cannot be maintained, and a good foam cannot be obtained. On the other hand, if the equivalent ratio exceeds 5.0, the foam becomes brittle, causing a practical problem.

When producing the flame-retardant foam, a foam stabilizer,
A foaming agent, a catalyst and the like can be blended. As the foam stabilizer, conventionally used silicone surfactants are preferable. For example, SH-193 manufactured by Toray Dow, L-5420, L-5421, and SZ-164 manufactured by Nippon Unicar.
2, SZ-1669 and the like.

As a foaming agent, HCFC-141 is used.
b, HFC-245fa, HFC-365mfc, hydrocarbons, for example, cyclopentane, n-pentane, i-pentane or a mixture thereof, or a mixture of water and the like can be used.

Further, examples of the catalyst include tertiary amines such as dimethylmethanolamine, triethylenediamine and tetramethylhexamethylenediamine, and metal catalysts such as potassium acetate and potassium octylate.

As a specific means for producing the flame-retardant foam of the present invention from the above-mentioned raw materials, any apparatus can be used as long as it can uniformly mix the above-mentioned raw materials. The mixture is continuously mixed and sprayed on one face material by means of airless spray or the like, and at the stage of foaming hardening, the other face material is applied and a foam of a predetermined thickness is applied by a double conveyor device. It can be manufactured by continuous molding.

Such a flame-retardant foam has excellent flame retardancy evaluated by a flame penetration test, a heat generation test and the like, and also has excellent properties such as density, compressive strength, thermal conductivity and brittleness. In particular, it is very excellent as a heat insulating material for a building as compared with a conventional heat insulating material.

[0039]

EXAMPLES Hereinafter, examples of the flame-retardant foam of the present invention will be specifically described, but the present invention is not limited to these examples. (Examples 1 to 5) and (Comparative Examples 1 to 6) The phenol polynuclear compound and polyethylene glycol A or polyethylene glycol B were used in Examples 1 to 5 at the weight ratio (% by weight) in Table 1 and Comparative Examples 1 to 5. For 6, a phenol diluent having a weight ratio (% by weight) shown in Table 2 is obtained.

This phenol dilution and polyester polyol A or polyester polyol B were used in Example 1
About 5 to 5 parts by weight shown in Table 1 and Comparative Examples 1 to 6 in the parts by weight shown in Table 2, and a foam stabilizer,
After blending the foaming agent 1 or the foaming agent 2, the catalyst, water, etc., the NCO / OH index is as shown in Table 1 for Examples 1 to 5, and as shown in Table 2 for Comparative Examples 1 to 6. The organic polyisocyanate component was added to the mixture, and the mixture was stirred and mixed, and foamed in a 50 × 300 × 300 mm aluminum mold heated to 80 ° C. to obtain a foam.

After leaving the obtained foam for 2 days, it was cut into a predetermined size, and measured for density, compressive strength, thermal conductivity, brittleness, flame penetration test, heat build-up test and the like. Here, the measurement and the test were performed with a thickness of 25 mm.

The measurement results and the evaluation results are shown in Table 1 for Examples 1 to 5, and Table 2 for Comparative Examples 1 to 6. The following components were used as the components shown in Tables 1 and 2.

Phenol polynuclear (Kashima Sekiyu TSP20)
0, hydroxyl value: 125) polyethylene glycol A (PEG200, manufactured by Sanyo Chemical Industries, Ltd.)
Hydroxyl value: 540, average molecular weight 200) Polyethylene glycol B (PEG400, manufactured by Sanyo Chemical Industries, Ltd.)
Hydroxyl value: 270, average molecular weight 400) Polyester polyol A (aromatic polyester polyol, oxide terol 250, hydroxyl value: 250) Polyester polyol B (aromatic polyester polyol, Hoechst Celanese terate 2541, hydroxyl value: 240) Foaming agent (SH-193 manufactured by Toray Silicone) Foaming agent 1 (water) Foaming agent 2 (HCFC-141b) Catalyst (potassium octylate / triethylenediamine = 2)
/ 1) Organic polyisocyanate component (M-100 manufactured by Mitsui Chemicals, Inc.)
(Crude MDI)) Moreover, the measurement and test of each performance were performed by the following methods.

Density (kg / m ³ ): JIS A9511
Compressive strength (N / cm ² ): Measured according to JIS A9511 Thermal conductivity (mW / mK): Measured according to JIS A1412 Brittleness (%): Measured according to ASTM C421 Flame penetration test: Measured according to US Mining Standards Among them, those satisfying the criteria are indicated by ○, and those not satisfying the criteria are indicated by ×.

Exothermicity test: Cone calorimeter test of quasi-incombustible material test Measurement by ISO5660 The criterion was a maximum heating rate of 200 kW / m ² .
In the table, the case where the condition was not exceeded for more than one second and the condition that the maximum heat generation rate was 8 MJ / m ² or less was evaluated as good, and the case where the condition was not satisfied was evaluated as x.

[0046]

[Table 1]

[0047]

[Table 2]

Comparative Examples 7 and 8 In Comparative Examples 7 and 8, as shown in Table 3, the same performances as those described above were measured and tested for conventional polyisocyanurate foams and phenol foams.

The polyisocyanurate foam of Comparative Example 7 was prepared by mixing a foam stabilizer, a catalyst, a foaming agent, and the like with the above PEG 200, then adding crude MDI so that the NCO / OH index was 4.0, and stirring and mixing. And foamed in a mold heated to 60 ° C. to obtain a foam.

The phenol foam of Comparative Example 8 was prepared by adding a foam stabilizer and a foaming agent to the resole phenol resin, and then adding 20 parts by weight of p-toluenesulfonic acid as an acid catalyst to 100 parts by weight of the phenol resin. The mixture was stirred and mixed, and foamed in a mold heated to 80 ° C. to obtain a foam.

[0051]

[Table 3]

As described above, in each embodiment of the present invention, it can be seen from the results of the flame penetration test and the exothermic test that the flame retardancy is excellent, and the measurement results of the density, compressive strength, thermal conductivity and brittleness were obtained. From this, it can be seen that various properties as a foam are also excellent.

[0053]

According to the flame-retardant foam according to the first aspect of the present invention, as described above, together with the embodiments, the characteristics such as density, compressive strength, thermal conductivity, and brittleness are the same as those of the rigid polyurethane foam. Equal or better, it has excellent flame retardancy by flame penetration test (US Mining Bureau standard) and heat generation test (corn calorimeter test of quasi-incombustible material test: measured by ISO 5660), etc., and is particularly suitable as a heat insulating material for buildings It becomes something.

Further, according to the flame-retardant foam of the second aspect of the present invention, the viscosity can be made appropriate by diluting the solid phenol polynuclear at room temperature, and the foaming material conventionally used can be used. A foam excellent in flame retardancy can be easily obtained in a body molding line.

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Claims (2)

[Claims] 1. A flame-retardant foam which is continuously foam-molded by a reaction between an organic polyisocyanate component and a polyol component, wherein the polyol component is a phenol polynuclear obtained based on heavy oil or pitches. 20/80 to 50/5 low viscosity polyether polyol
0 in a weight ratio range, and the diluted product 3
0 to 60 parts by weight and an aromatic polyester polyol 70 to
A flame-retardant foam using a mixture of 40 parts by weight and an equivalent ratio of isocyanate group / hydroxyl group in the range of 3.0 to 5.0. 2. The low-viscosity polyether polyol has a viscosity of 2000 mPa · s or less, and has a molecular weight of 200 to 400, such as polyethylene glycol, diethylene glycol, triethylene glycol, glycerin, or a mixture thereof. The flame-retardant foam according to claim 1.