JPH07173315A - Production of phenolic resin foam - Google Patents

Abstract

PURPOSE:To obtain a foam, having a good appearance and useful as a material for wall covering or ceiling of building or furniture by expanding and curing a resol type phenolic resin in the presence of a foaming agent, specific two kinds of acidic curing agents and a foam stabilizer. CONSTITUTION:This method for producing the objective phenolic resin foam is to expand and cure a resol type phenolic resin in the presence of a foaming agent (preferably methylene chloride or a carbonate such as barium carbonate), a condensate of naphthalenesulfonic acid with formalin expressed by formula I [(n) is 1-5] and an arylsulfonic acid expressed by formula II {R and R' are each (CH2)m-H [(m) is 1-3], H or OH} at (9/1) to (5/5) ratio of both the components, expressed by formula I to formula II and used in combination and a foam stabilizer (e.g. a polysiloxane-based foam stabilizer or ethylene oxide-propylene oxide copolymer). The components expressed by formulas I and II are used in the total amount of 2-60 pts.wt., preferably 20-40 pts.wt. based on 100 pts.wt. resol type phenolic resin.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention produces a resole-type phenol resin foam having a good appearance, which is useful as a wall material or ceiling material for building materials and a material for furniture, by foaming and curing the resin material in a timely manner. Regarding the method.

[0002]

2. Description of the Related Art Phenolic resin foams are lightweight and superior to thermoplastic foams in flame retardancy, heat resistance and mechanical strength.
It is widely used as a material in the field of building materials and furniture. Generally, a resole-type phenol resin foam is produced by mixing a resole-type phenol resin with a foaming agent, a surfactant and an acid curing agent, and foaming and curing the mixture at room temperature to about 120 ° C. However, in the above-mentioned conventional method, when the blowing agent is a low boiling point solvent having low solubility with a freon-based or resol-type phenol resin, an acidic curing agent can be preferably used, but the solubility with the resol-type phenol resin is good. In the case of a foaming agent or a chemical foaming agent such as carbonate that generates carbon dioxide gas, especially when carbonate is used as a foaming agent, the foaming accompanying the decomposition of carbonate due to the contact between the carbonate and the acidic curing agent Due to the rapid speed, it was difficult to adjust the timing of foaming and curing, and therefore it became difficult to adjust the density of the resol-type phenol resin foam, and it was not possible to obtain a resol-type phenol resin foam having a good appearance. .

In order to solve these drawbacks, attempts have been made to modify the resol type phenolic resin, mix various additives, and use various foaming agents and acid curing agents. However, as a result, a satisfactory resole-type phenol resin foam has not been obtained yet.

[0004]

In the present invention, when various foaming agents are used, the timing of foaming and curing can be easily adjusted, and the density of the resole type phenol resin foam can be adjusted. An object of the present invention is to provide a method for producing a resol-type phenol resin foam which has good cell uniformity and a good appearance with no voids.

[0005]

Means for Solving the Problems As a result of various investigations, the present inventors have found that when producing a resole-type phenol resin foam, a curing reaction with an resole-type phenol resin is relatively slow as an acidic curing agent. A combination of a naphthalene sulfonic acid formalin condensate and an aryl sulfonic acid whose curing reaction is faster than that of the naphthalene sulfonic acid formalin condensate, and selecting a combination ratio of the naphthalene sulfonic acid formalin condensate and the aryl sulfonic acid. By adjusting the timing of foaming and curing, the above object was achieved, and it was found that a resol-type phenol resin foam having a good appearance can be obtained, and the present invention could be completed.

That is, the present invention provides a method for producing a phenol resin foam by foaming and curing a resol-type phenol resin in the presence of a foaming agent, an acid curing agent and a foam stabilizer, and the general formula (I )

[Chemical 3] Naphthalenesulfonic acid formalin condensate (A) represented by the general formula (II)

[Chemical 4] The aryl sulfonic acid (B) represented by the formula (1) is used in combination, and the combined use ratio of (A) and (B) is (A) to (B) =
It is 9: 1 to 5: 5, and the total amount of (A) and (B) used is 2 to 60 parts by weight with respect to 100 parts by weight of the resol-type phenol resin. Manufacturing method.

The present invention will be described in more detail below. Examples of the phenols which are the raw material of the resol type phenol resin used in the present invention include phenol, cresol and xylenol which are usually used as a raw material for producing a phenol resin, and among them, reactivity and curability are preferable. Therefore, phenol and m-cresol are particularly preferable. These phenols may be used not only alone, but also as a mixture of these, or together with O-cresol, P-cresol, bisphenol and the like.

On the other hand, formaldehyde, paraformaldehyde, polyoxymethylene, trioxane and the like can be used as the aldehydes as the raw material. The both are reacted in the presence of a basic catalyst, dehydrated and concentrated to obtain a resol-type phenol resin. 60 as a resin solid
˜90%, viscosity of 1500 to 8000 cps / 25 ° C. is convenient for use, and if the concentration is high, it is also possible to adjust the concentration viscosity by appropriately diluting with alcohol, acetone or the like.

The foaming agent used in the present invention is not particularly limited, and examples thereof include known foaming agents such as methylene chloride, barium carbonate, magnesium carbonate and sodium hydrogen carbonate. The amount of these foaming agents used is 2 with respect to 100 parts by weight of the resol-type phenol resin.
-40 parts by weight is selected.

As the foam stabilizer used in the present invention, a surfactant such as a polysiloxane type, an ethylene oxide-propylene oxide copolymer, a sorbitan, an alkylphenol or a polyoxyalkylene adduct type such as castor oil can be used. These are used alone or as a mixture, and the amount used is 0.5 to 10 parts by weight with respect to 100 parts by weight of the resol type phenol resin.

The acidic curing agent used in the present invention is the naphthalenesulfonic acid formalin condensate (A) represented by the general formula (I) and the arylsulfonic acid (B) represented by the general formula (II).

The naphthalene sulfonic acid formalin condensate (A) is obtained by, for example, melting naphthalene, adding sulfuric acid thereto, and then dropping formalin to form a naphthalene sulfonic acid formalin condensate, and then appropriately diluting with water. Can be manufactured.

Examples of the aryl sulfonic acid (B) include xylene sulfonic acid, benzene sulfonic acid, phenol sulfonic acid and paratoluene sulfonic acid. Among these aryl sulfonic acids (B), the use of xylene sulfonic acid is preferable.

The naphthalene sulfonic acid formalin condensate (A) and the aryl sulfonic acid (B) are used in combination. The combined use ratio of the naphthalene sulfonic acid formalin condensate (A) and the aryl sulfonic acid (B) is (A) to (B) = weight ratio.
9: 1 to 5: 5, preferably (A) to (B) = 8 to 2 to 6: 4. If the combined use ratio of the arylsulfonic acid (B) is less than 1 by weight, the foaming and curing rate is delayed, the timing of foaming and curing cannot be adjusted, and insufficient foaming, shrinkage or uncuring occurs. Further, when the combined use ratio of the arylsulfonic acid (B) is more than 5, the foaming curing rate is remarkably high, the foaming curing cannot be adjusted, and voids are generated, the cells are roughened, and the curing is uneven (gelation). Etc., and it becomes difficult to use. In particular, when carbonate is used as a foaming agent, there is a drawback in that this tendency becomes remarkable.

The total amount of the naphthalene sulfonic acid formaldehyde condensate (A) and the aryl sulfonic acid (B) used in the above combination ratio is 2 to 60 parts by weight, preferably 100 parts by weight of the resol type phenol resin. 20
~ 40 parts by weight. Total usage of (A) and (B) is 2
When the amount is less than the weight part, some foaming occurs, but the curing does not reach to the curing, and the foaming curing becomes insufficient, and a resol type phenol resin foam having a good appearance cannot be obtained. Also,
If the total amount of (A) and (B) used is more than 60 parts by weight, foaming and curing will occur rapidly, mild foaming behavior will not occur, and voids and cell roughness will occur, resulting in a good appearance. A resol-type phenol resin foam having is not obtained.

The resole-type phenol resin foam of the present invention is prepared by mixing a resole-type phenol resin, a foaming agent, a foam stabilizer and an acid curing agent by a conventional mixing method such as a high speed stirring mixing method and a high pressure collision mixing method. It is manufactured by rapidly mixing to obtain a resol-type phenol resin foam mixture, pouring or discharging the foam mixture into a frame or a mold, and foam-curing at room temperature to 120 ° C.

[0017]

In the present invention, the naphthalene sulfonic acid formalin condensate, which has a relatively slow curing reaction with the resole type phenol resin as an acidic curing agent, and the naphthalene sulfonic acid formalin condensate, with the resole type phenol resin, By using aryl sulfonic acid which is comparatively rapid in combination and selecting the combination ratio thereof, it is possible to obtain a phenol resin foam having a good appearance by taking a long time for foam curing and performing sufficient foam curing. It is considered to be a thing. Further, by using naphthalene sulfonic acid formalin condensate and aryl sulfonic acid in combination at a specific ratio as an acidic curing agent, the timing of foaming and curing can be adjusted. It is presumed that the resol-type phenol resin foam having a good appearance can be obtained by exerting the effect also on the carbonate which is one of the foaming agents.

[0018]

The present invention will be described in more detail with reference to examples.

Example 1 2 kg of phenol, 2.93 kg of 37% formaldehyde (formaldehyde / phenol: 1.7 mol ratio) and 60 kg of 20% caustic soda as a catalyst in a four-necked flask.
Was charged, reacted at 80 ° C. for 3 hours, and then pour with 15% sulfuric acid.
H was neutralized to 7.0 and water in the resin was reduced to 5 by dehydration under reduced pressure.
% Or less. The resol type phenolic resin obtained is
The resin solid content was 80%, the viscosity was 2500 cps / 25 ° C, the specific gravity was 1.25 / 25 ° C, and the weight average molecular weight was 430. 4 parts by weight of Tween 40 (polyoxyethylene sorbitan monopalmitate) as a foam stabilizer was mixed with 100 parts by weight of this resol type phenol resin to obtain a foaming resol type phenol resin.

A mixture of 104 parts by weight of the obtained foaming resol-type phenolic resin with 6 parts by weight of methylene chloride as a foaming agent (solution I) and a naphthalenesulfonic acid formalin condensate (general formula (I) as an acid curing agent) Where n
= 4 to 5) 60 parts by weight and 40 parts by weight of xylene sulfonic acid were mixed (solution II). Subsequently, these liquid I and liquid II were treated with a phenol resin foaming machine,
Solution I: Solution II = 100: 20 in a weight ratio of promptly and uniformly mixed and molded (dimensions: length × width × height = 260 × 180
X330 mm), and foamed and cured at room temperature to obtain a phenol resin foam.

The cream time (the time from the end of mixing when the resin foam mixture is prepared to the start of foaming), the rise time and the tack free time of the resol type phenol resin foam mixture are 43 ″ / 1′10 ″ / 1′12, respectively. The results of appearance (cell uniformity, presence or absence of voids) and density are shown in Table 1.

Examples 2 to 8 Resol type phenol resin foams were produced in the same manner as in Example 1 except that the formulation shown in Table 1 was followed. The results are shown in Table 1.

Comparative Examples 1 to 7 Resol type phenol resin foams were produced in the same manner as in Example 1 except that the formulation shown in Table 2 was followed. The results are shown in Table 2.

[0024]

[Table 1]

[0025]

[Table 2]

[0026]

INDUSTRIAL APPLICABILITY When manufacturing a phenol resin foam,
By using naphthalene sulfonic acid formaldehyde condensate and aryl sulfonic acid together as an acidic curing agent, and by specifying the combination ratio and blending amount, the foaming and curing speed can be adjusted and relaxed to produce a phenol resin foam having a good appearance. can do. The acidic curing agent of the present invention can be effectively used even when a carbonate having a rapid foaming rate is used as a foaming agent.

Claims (1)

[Claims] 1. A method for producing a phenol resin foam by foaming and curing a resol-type phenol resin in the presence of a foaming agent, an acidic curing agent and a foam stabilizer, wherein the acidic curing agent is represented by the general formula (I): ] Naphthalenesulfonic acid formalin condensate (A) represented by the general formula (II) The aryl sulfonic acid (B) represented by the formula (1) is used in combination, and the combined use ratio of (A) and (B) is (A) to (B) =
It is 9: 1 to 5: 5, and the total amount of (A) and (B) used is 2 to 60 parts by weight with respect to 100 parts by weight of the resol-type phenol resin. Manufacturing method.