JPS62138536A - Phenolic foam - Google Patents

Abstract

PURPOSE:Phenolic foam having improved corrosive properties, obtained by expanding a mixture containing a phenol-formaldehyde resin, a polyisocyanate compound, an aromatic sulfonic acid compound, a boron compound and water. CONSTITUTION:The aimed foam comprising (A) 100pts.wt. phenol-formaldehyde resin obtained be blending benzilic ether type phenol-formaldehyde resin with a resol type phenol-formaldehyde resin in a weight ratio of 10/0-5/5, (B) 1-50pts.wt. polyiscoyanate compound, preferably tolyene diisocyanate, etc., (C) 1-65pts.wt. aromatic sulfonic acid compound (preferably used as aqueous solution) in an amount to give gram equivalent ratio (NCO)/(SO3H) of the components. B/C of 0.1-1, (D) 0.1-50pts.wt. boron compound, (E) 0.1-100pts.wt. water, a blowing agent and a foam stabilizer; obtained by adding a mixed solution of the components B and D and a mixed aqueous solution of the component C to a mixed solution consisting of the component A, the foam stabilizer and the blowing agent, blending them vigorously, casting the blend into a mold and heating preferably at 60-100 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to phenol foam. Specifically, it is a phenol foam prepared by mixing and foaming a phenol-formaldehyde resin, a -liisocyanate compound, an aromatic sulfonic acid compound, a boron compound, and other foaming agents and foam stabilizers necessary for foaming.

<Prior art> Although phenol foam has excellent properties such as heat resistance, flame retardance, and low smoke emission, it is very poor compared to other plastic foams such as urethane foam and colystyrene foam. It is difficult to use because it is brittle and loose. Furthermore, in addition to these physical property disadvantages, resol type phenolic resins have problems with the storage stability of the resin itself, and novolac type phenolic resins are solid, making handling inconvenient. There is also.

On the other hand, benzylic ether type phenol 4*f Jl
The phenol foam itself has good storage stability, but when a curing agent is added to it, it generates intense heat and turns into a resin with foaming.

The foam formed has a very low density and is brittle, making it impossible to use it as a thermal insulator. Regarding foams using benzylic ether type phenolic resin, a method of producing urethane foam by reacting with an irisocyanate compound is also known, for example, in Japanese Patent Publication No. 55-27093, but it is not flame retardant and has low smoke emission. etc. are inferior to phenol form.

Furthermore, the present inventors have already filed an application regarding a method for producing phenol foam using a benzylic ether type phenol resin. (Unexamined Japanese Patent Publication No. 59-45332) <Problems to be Solved by the Invention> In JP-A No. 59-45332, the present inventors solved the problems of low resolution and brittleness, and the invention can be fully utilized in industry. A novel method for producing phenolic foam has been disclosed. However, there are problems that have not been fully resolved, such as the problem of metal plate corrosion when manufacturing composite boards for heat-insulating building materials, and the problem of foam peeling due to vibration during handling of siding boards.

An object of the present invention is to provide a phenolic foam with improved corrosion resistance to metals.

<Means for Solving the Problems> The present invention provides a phenol foam forming mixture comprising a phenol-formaldehyde resin, a pyriisocyanate compound, an aromatic sulfonic acid compound, water, a blowing agent, and a foam stabilizer, and further contains a boron compound. This relates to a phenol foam whose corrosivity to metals has been improved by adding and foaming.

Used in the present invention. Phenol formaldehyde resin is
Weight ratio of benzylic ether type and resol type is 1010
It was mixed at a ratio of ~515.

Benzylic ether type phenol (4
The fat is known from, for example, Japanese Patent Publication No. 47-50873, and is represented by the general formula (R is a hydrogen atom, a hydrocarbon group, an oxyhydrocarbon group, or a halogen atom, n = 1 to 3). phenol and an aldehyde represented by the following general formula R' CHO (R' represents a hydrogen atom or a hydrocarbon group having 1 to 8 carbon atoms) in a ratio of 1:1 to 1:3. It is obtained by reacting in the presence of a salt catalyst.

The resol-type phenol resin used in the present invention is composed of a phenol represented by the general formula (R is a hydrogen atom, a hydrocarbon group, an oxyhydrocarbon group, or a halogen atom, n = 1 to 3) and the following general formula R'CHO (R ' indicates a hydrogen atom or a hydrocarbon group having 1 to 8 carbon atoms.) in the presence of a basic catalyst in a ratio of 1:1 to 1:3. It is something that can be done.

The purpose of adding resol type phenolic resin is to improve the formability when creating a composite board with phenol foam as the core material.
and to improve the workability of the finished composite plate.

The pyriisocyanate compound used in the present invention is methylene pyrifhenyl isocyanate (so-called crude 4,4
'-diphenylmethane diisocyanate), tolylene diisocyanate, hexamethylene diisocyanate, etc. are preferable, but pyramidyl diisocyanate and polyhydric alcohol such as glycol, glycerin, trimethylolzolono Isocyanate compound, or polyisocyanate and noriether-based or polyester-based juice? A prepolymer type polyisocyanate compound having an incyanate group at the end obtained by reaction with lyol can also be used.

The pyriisocyanate compound may be used in an amount of 1 to 50 parts by weight, preferably 3 to 25 parts by weight, based on 100 parts by weight of the phenol-formaldehyde resin. If the amount of the hylyisocyanate compound is 1 part by weight or less, the resulting foam will be very brittle and have a low density, resulting in large shrinkage of the foam after molding.

If the amount of the IJ isocyanate compound used exceeds 50 parts by weight, the foaming state will become significantly non-uniform, and as a result,
A practical foam cannot be obtained.

Aromatic sulfonic acid compounds used in the present invention include benzenesulfonic acid, biluenesulfonic acid, xylene sulfonic acid,
Typical examples include phenolsulfonic acid, but phosphoric acid, sulfuric acid,
Inorganic acids such as hydrochloric acid can also be used in combination. The aromatic sulfonic acid compound is preferably used as an aqueous solution with an appropriate amount of water.

The aromatic sulfonic acid compound can be used in an amount of 1 to 65 parts by weight, preferably 5 to 30 parts by weight, based on 100 parts by weight of the phenol-polmaldehyde resin.

The 41J isocyanate compound and the aromatic sulfonic acid compound are used in an [NCO]/[5o3H] equivalent ratio of 0.1 to 1.0, preferably 0.3 to 09. (Here, (NGO) refers to the isocyanate group, and t: 5o3H) refers to the gram difference of the sulfone group. ) If the (NCO)/(SO3H) equivalent ratio is less than 0.1, the resulting foam will be very bulky and have a low density, resulting in large shrinkage of the foam after molding. [NCO] /
If the equivalent ratio (C5O3H) exceeds 1.0, the foam will be extremely non-uniform and no practical foam will be obtained.

Examples of boron compounds used in the present invention include boric acid esters such as trimethylboric acid and triethylboric acid, boric anhydride, boron oxide compounds such as boric acid, sodium borate,
Examples include borates such as ammonium borate, and fluoroboron compounds such as hydrofluoroboric acid, ammonium fluoroborate, and boron trifluoride. In addition, complexes of boron fluoride compounds, such as complexes of boron trifluoride with ethers, phenols, amines, pizzeridine, acetic acid, etc., are also preferred boron compounds. The amount of boron compound used is phenol-formaldehyde resin 10
01 to 50 parts by weight, preferably 0.2 parts by weight
It is used in a range of 30 parts by weight.

The boron compound is preferably used by being mixed into a phenol-formaldehyde resin or a boli incyanate compound.

If the amount of the boron compound used is too small, corrosion of the metal will occur and the objective effect of the present invention will not be achieved, while if it is too large, it will cause a decrease in the strength of the foam.

The addition of water used in the present invention can be achieved by any method, for example by using an aromatic sulfonic acid compound as an aqueous solution as described above. The amount of water is effective if it is in the range of 0.1 to 100 parts by weight, preferably 4 to 45 parts by weight, based on 100 parts by weight of the phenol-formaldehyde resin. Excessive water in excess of 100 parts by weight causes sagging properties, while water below 901 parts by weight makes it impossible to control foaming.

The blowing agent used in the present invention is a low-boiling aliphatic hydrocarbon or its halide, and examples thereof include petroleum ether, n-hexane, n-hezotane, methylene chloride, and trichlorofluoromethane.

The foam stabilizer used in the present invention is a silicone-based nonionic surfactant and/or a nonionic surfactant, such as an ethylene oxide adduct of sorbitan fatty acid ester, alkylphenol, or the like.

The amount of foam stabilizer used is phenol formaldehyde resin 1
It is preferably 1 to 5 parts by weight per 00 parts by weight.

In addition, in the present invention, polyhydric hydroxy compounds such as ethylene glycol, propylene glycol, glycerin, or l-lyoxyalkylene polyols such as pyrioxy are used as additives to improve the mechanical properties of the foam. It is also possible to add ethylene glycol, polyoxypropylene glycol, or nitrogen-containing compounds such as jetanolamine, triethanolamine, jetanoltriamine, urea, etc. to improve heat resistance, flame retardancy, and low smoke emission. In order to increase the strength, flame retardants, inorganic powders, etc. can be added as appropriate.

The foam according to the invention is produced as follows.

Mix the phenol-formaldehyde resin, foam stabilizer, blowing agent, and optionally other additives. Next, a mixed solution of a polyisocyanate compound and a boron compound and an aqueous mixed solution of an aromatic sulfonic acid compound are added to this mixed solution, mixed vigorously at room temperature, and poured into a mold. Although a foam can be obtained without heating, heating at 60 to 100°C is preferable in order to obtain a good foam in a short time. It is also possible to mix the polyisocyanate compound and the curing agent in advance and add them to the above mixture.

Moreover, it is also possible to continuously manufacture the mixed liquid by a molding method in which it is flowed out onto an endless conveyor.

<Effects of the Invention> The foam thus obtained is non-corrosive and has excellent mechanical strength, so its main uses include asbestos paper, glass bean paste, aluminum foil, and various heat-resistant and flame-resistant materials. We manufacture composite boards with laminated paper, five-arm boards, various metal facing materials, etc., and can be used widely as insulation building materials.

The method of the present invention will be explained in more detail below with reference to Examples and Comparative Examples.

Example Synthesis of benzylic ether type phenolic resin Diphenol 357f, Noraformaldehyde 174F
, 1.5 parts of lead naphthenate, and 3.0 parts of zinc naphthenate were stirred and mixed, and reacted at 110 to 114°C for 3 hours. Rapidly dehydrated under reduced pressure to obtain a viscosity of 3QOOOcps (a
A benzylic ether type phenol resin with a temperature of t25°C was obtained.

Phenol 4709 137% Formalin 730v1 Sodium hydroxide 99% Mixed with stirring, reacted at 80°C for 3 hours, adjusted to pH 7 with oxalic acid, quickly dehydrated under reduced pressure, viscosity 2000cps (at 25°C), water content A resol type phenol resin having a yield of 15% or less was obtained.

Example 1 The above benzylic ether type phenolic resin 1002
, foam stabilizer 3 ft (Tween-40° manufactured by Kao Atlas Co., Ltd.), foaming agent 102 (Freon R-11: manufactured by Mitsui Fluorochemical Co., Ltd.), and boron oxide 10F were thoroughly mixed, and to this, 30 t of curing agent (p- Toluene sulfo/acid 64% aqueous solution) and crude diphenylmethane diisocyanate (Millionate MR-200: manufactured by Nipponbori Urethane Co., Ltd.) 5f
After stirring vigorously for 10 seconds, a colored galvanized iron plate was placed in a mold prepared as a face material, and foaming was performed. The foam obtained after heating the foam in a constant temperature bath at 80 to 90°C for 2 to 5 minutes has no brittleness, no looseness, and no shrinkage.
The mechanical properties were also good, and the foam had excellent corrosion resistance. Semi-noncombustible material test (JIS A-
1321 and additional tests) are shown in Table 1.

Table-1 *(1) Test piece 30 x 220 x 220% *(2) According to the model box test method specified in Section 5 of Ministry of Construction Notification No. 1231 of 1976.

Examples 2 to 7 and Comparative Examples 1 to 3 Foams were made in the same manner as in Example 1 using the benzylic ether type phenolic resin and resol type phenolic resin described in Examples. Mixing prescription and molding results,
Corrosion test results are shown in Table 2. (Numbers in the table represent heavy chain parts.) (1) Benzylic ether type phenol resin described in Examples.

(2) Phenol-formaldehyde resin mixed in a benzylic type/resol type ratio of 7/3.

(3) T-40: Foam stabilizer Tween-40 manufactured by Kao Atlas Co., Ltd.

(4) Curing agent: p-) 64% aqueous solution of luenesulfonic acid.

(5) Corrosion resistance test: The composite was tested in a 70°C x 95% RH humidity atmosphere using a colored galvanized iron plate as a face material.

◎: No white rust formation after 30 days or more ×: ゛White rust forms within 7 days.

As described above, in Examples 2 to 7, foams with excellent corrosion resistance were obtained.

Hodogaya Chemical Industry Co., Ltd.

Claims (1)

[Claims] 1. (A) 1-50 parts by weight of polyisocyanate compound (B) per 100 parts by weight of phenol-formaldehyde resin
) Aromatic sulfonic acid compound 1-65 (C) Boron compound 0.1-50 (D) Water
A phenol foam characterized by foaming a mixture containing 0.1-100.