JPH07188446A - Production of phenol resin foam - Google Patents

Abstract

PURPOSE:To obtain a phenol resin foam which has a good appearance, a controlled density, and stable mechanical strengths by controlling and moderating the foaming and curing rates. CONSTITUTION:A phenol resin foam is produced by foaming and curing 100 pts.wt. resole phenol resin by using 1-30 pts.wt. carbonate as the blowing agent and 2-80 pts.wt. acidic curative which comprises a naphthalenesulfonic acid- formalin condensate (A), an arylsulfonic acid (B), and at least one acid (C) selected from the group consisting of formic acid, phosphoric acid, and lactic acid in an amt. of C of 2-80wt.% of the sum of A and B.

Description

Detailed Description of the Invention

[0001]

INDUSTRIAL APPLICABILITY The present invention has heat resistance, heat insulation, flame retardancy and water resistance, which are useful as materials for building materials such as wall materials and ceiling materials, and furniture, and has excellent mechanical strength. The present invention relates to a method for producing a phenol resin foam.

[0002]

2. Description of the Related Art Phenolic resin foams are lightweight and excellent in flame retardancy, heat resistance and mechanical strength as compared with thermoplastic resin foams, and are widely used as materials for building materials, furniture and the like. As a manufacturing method, a resol type phenol resin was used as a raw material, and trichloromonofluoromethane (CFC-11), trichlorotrifluoroethane (CFC-113) and the like were mainly used as a foam. However, CFC-11 and CFC-113 have extremely excellent properties as a foaming agent, are harmless to the human body, have no flammability and ignitability, and are a process-safe foaming agent. It has been found that the substances destroy the ozone layer surrounding the earth and promote the environmental destruction of the earth, and the demand for a gradual decrease in the amount of use and the prohibition of use have been exclaimed. The search for is urgent.

Further, conventionally known blowing agents such as methylene chloride, pentane, hexane, physical blowing agents such as nitrogen gas and carbon dioxide, or chemical blowing agents such as carbonate accompanied with generation of carbon dioxide are also positively active. Is being researched. Particularly, carbonate foaming has been carefully studied. However, when a carbonate is used as the foaming agent, it is difficult to adjust the density of the foam because the foaming rate accompanying the decomposition of the carbonate is rapid due to the contact between the carbonate and the acidic curing agent, and therefore the cell density is There is a problem with uniformity, voids, etc., and the appearance is not good, and a foam having improved uniform stability of mechanical strength cannot be obtained.

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

[0005]

DISCLOSURE OF THE INVENTION The present invention provides a method for producing a phenol resin foam excellent in stability of appearance, density adjustment and mechanical strength by adjusting and relaxing foaming and curing rates. To aim.

[0006]

Means for Solving the Problems As a result of various studies, the present inventors have used a carbonate as a foaming agent and a formic acid or phosphorus as an acidic curing agent when producing a resole-type phenol resin foam. A mixture of a naphthalenesulfonic acid formalin condensate containing at least one acid selected from the group consisting of acids and lactic acids and an arylsulfonic acid is used, and the ratio of each component of the acidic curing agent is specified, and a foaming agent is used. By specifying the amount of the acidic curing agent used and the amount of the acidic curing agent used, the decomposition reaction of the carbonate at the time of foaming becomes mild and the foam curing time can be taken longer.
The inventors have completed the present invention, knowing that a foam having excellent density control and stable mechanical strength can be obtained and the above-mentioned object can be achieved.

That is, the present invention is 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. Resin 1
1 to 30 parts by weight per 100 parts by weight, composed of a naphthalenesulfonic acid formalin condensate (A) and an arylsulfonic acid (B) as an acidic curing agent, and a total amount of (A) and (B) 100 parts by weight 2 to at least one acid selected from the group consisting of formic acid, phosphoric acid, and lactic acid for 2 parts.
The present invention relates to a method for producing a phenol resin foam, characterized in that 80 parts by weight of a mixture is used in an amount of 2 to 80 parts by weight based on 100 parts by weight of a resol type phenol resin.

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 in a mixture of them, or in combination with O-cresol, P-cresol or bisphenol.

On the other hand, formaldehyde, paraformaldehyde, polyoxymethylene, trioxane or the like can be used as the aldehyde 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 1,500〜8,000cps / 25 ℃ is convenient to use, and if the concentration is high, it is possible to adjust the concentration viscosity by diluting with alcohol, acetone, etc. is there.

The foaming agent used in the present invention is a carbonate accompanied by the generation of carbon dioxide gas when decomposed, and specific examples thereof include sodium hydrogen carbonate, calcium carbonate, magnesium carbonate, barium carbonate and the like. These carbonates may be used alone or in combination of two or more, and the amount of the carbonate used may be 1 part with respect to 100 parts by weight of the resol type phenol resin.
-30 parts by weight is selected. Of the carbonates, the use of barium carbonate is especially preferred.

As the foam stabilizer used in the present invention, a surfactant such as polysiloxane type, ethylene oxide-propylene oxide copolymer, sorbitan, alkylphenol or 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 an acid obtained by combining the naphthalene sulfonic acid formalin condensate (A) and the aryl sulfonic acid (B) together with at least a formic acid, a phosphoric acid and a lactic acid. It is a mixture of one type of acid.

The naphthalenesulfonic acid formalin condensate (A) can be produced, for example, by melting naphthalene, adding sulfuric acid thereto, and then dropping formalin. The obtained naphthalenesulfonic acid formalin condensate (A) is represented by the following general formula (I).

[Chemical 1]

The aryl sulfonic acid (B) has the general formula (II)

[Chemical 2] Is represented by.

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 weight ratio of the naphthalenesulfonic acid formalin condensate (A) to the arylsulfonic acid (B) is (A) to (B) = 9: 1 to 5: 5, preferably (A) to ( It is preferable that B) = 8: 2 to 6: 4. When the weight ratio of the arylsulfonic acid (B) is less than 1, the foaming rate is delayed, the timing of foaming and curing cannot be adjusted, and insufficient foaming, shrinkage or uncuring occurs. Further, when the use ratio of the arylsulfonic acid (B) is more than 5, the decomposition of the carbonate occurs rapidly, so that the foam hardening rate is remarkably fast, the foam hardening cannot be adjusted, and the occurrence of voids and the cell coarseness As a result, uneven curing (spot gelation) occurs, making it difficult to use.

In the present invention, the total amount of the naphthalenesulfonic acid formalin condensate (A) and the arylsulfonic acid (B) blended within the above range is 100 parts by weight,
Further, 2 to 80 parts by weight, preferably 3 to 50 parts by weight of at least one acid selected from the group consisting of formic acid, phosphoric acid and lactic acid.
A mixture blended by weight is used as an acidic curing agent. At least 1 selected from the group consisting of formic acid, phosphoric acid and lactic acid
When the blending amount of the seed acid is less than 2 parts by weight, the carbonate is decomposed quickly, it is difficult to sufficiently foam and cure, and it is difficult to have good appearance and uniform strength. On the other hand, when the amount is more than 80 parts by weight, the decomposition of carbonate is mild, but the curing is delayed, the balance of foam curing is lost, the shrinkage,
It causes uncured, etc., and it becomes difficult to have good appearance and uniform strength.

A mixture of naphthalene sulfonic acid formalin condensate (A), aryl sulfonic acid (B) and at least one acid selected from the group consisting of formic acid, phosphoric acid and lactic acid within the above range is acid-cured. When used as an agent, the amount used is 2 to 80 parts by weight, preferably 30 to 60 parts by weight, relative to 100 parts by weight of the resol type phenol resin.
Parts by weight. When the amount of the acidic curing agent used is less than 2 parts by weight, the acid curing agent is insufficient, so that it has a function of decomposing carbonate, but the balance between foaming and curing is disturbed, or the resol-type phenol resin is completely cured. However, the foam does not form uniform cells due to uncured or shrinkage. Further, when the amount of the acidic curing agent used is more than 80 parts by weight, foaming and curing occur rapidly, mild foaming behavior is not achieved, and the foam causes voids, cell roughness, etc. (decomposition of carbonate Mechanical strength is reduced).

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

[0020]

The strong acid has been used for foaming and curing the resol type phenol resin. When the foaming agent is a freon-based solvent or other low boiling point solvent, strong acid can be preferably used, but when carbonate is used as the foaming agent, the carbonate is rapidly decomposed by contact with carbonate and strong acid. Therefore, the timing of foaming and curing cannot be adjusted, and it is difficult to obtain a good phenol resin foam.

In the present invention, a carbonate is used as a foaming agent, and an acid using a combination of a naphthalenesulfonic acid formalin condensate and an arylsulfonic acid as an acidic curing agent is added to formic acid having different carbonate decomposition rates and curing rates. At least one acid selected from the group consisting of phosphoric acid and lactic acid was used in combination, and by adjusting the compounding ratio, the foaming and curing times were adjusted and alleviated, resulting in appearance, density adjustment, and mechanical strength. It is presumed that a resol-type phenol resin foam having improved stability can be obtained.

[0022]

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

Example 1 In a four-necked flask, 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.
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 2,500 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 10 parts by weight of barium carbonate as a foaming agent (104 parts by weight) with 104 parts by weight of the obtained resol-type phenol resin for foaming and 60 parts by weight of a naphthalenesulfonic acid formalin condensate as an acidic curing agent, aryl 40 parts by weight of xylene sulfonic acid and 9 as sulfonic acid
A mixture of 20 parts by weight of 0% formic acid (solution II) was prepared. Next, these I liquid and II liquid were rapidly and uniformly mixed with a phenol resin foaming machine at a weight ratio of I liquid: II liquid = 114: 45, and were discharged onto a panel on which a lower surface material having a surface temperature of 90 ° C. was set. It was Then cover with the top material,
After pressing with a panel thickness of 25 mm for 4 to 5 minutes, a resol-type phenol resin foam was taken out.

The cream time (the time from the end of mixing to the start of foaming when adjusting the resin foaming mixture) and the rise time of the resole type phenolic resin foaming mixture are 5 respectively.
It was 0 "/ 1'30". Density, appearance (cell uniformity,
Table 1 shows the measurement results of presence / absence of voids, pH, and mechanical strength. In addition, regarding the confirmation of uniform mechanical strength stability, the prepared phenol resin foam was subjected to
Points, 3 points indiscriminately near the edge, 6 points in total, 50 mm each
The test piece was cut into a size of x50 mm x 25 mm, and a compressive strength test was performed at a crosshead speed of 1 mm / min in an amount of 10% of the thickness of the test piece, and the average values of the central portion and the end portion were shown.

Examples 2 to 13 and Comparative Examples 1 to 6 Resol type phenol resin foams were produced in the same manner as in Example 1 except that the formulations shown in Tables 1 and 2 were followed. The results are shown in Tables 1 and 2.

[0027]

[Table 1]

[0028]

[Table 2]

[0029]

INDUSTRIAL APPLICABILITY When manufacturing a phenol resin foam,
Carbonate is used as a foaming agent, and a mixture of naphthalenesulfonic acid formalin condensate, arylsulfonic acid and at least one acid selected from the group consisting of formic acid, phosphoric acid and lactic acid is used as an acidic curing agent. Then, by specifying the mixing ratio and blending amount, the foaming and curing speed is adjusted,
It is possible to produce a phenol resin foam which is relaxed and has an appearance, density adjustment, and stable mechanical strength.

Claims (2)

[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 acid curing agent and a foam stabilizer, wherein a carbonate is used as a foaming agent in an amount of 100 parts by weight of the resol-type phenol resin. 1 to 30 parts by weight per part, consisting of naphthalenesulfonic acid formalin condensate (A) and arylsulfonic acid (B) as an acidic curing agent, and a total amount of (A) and (B) of 100 parts by weight. On the other hand, a mixture containing 2 to 80 parts by weight of at least one acid selected from the group consisting of formic acid, phosphoric acid and lactic acid is used in an amount of 2 to 100 parts by weight of the resol type phenol resin.
A method for producing a phenol resin foam, which comprises using 80 parts by weight. 2. The use ratio of the naphthalenesulfonic acid formalin condensate (A) and the arylsulfonic acid (B) is (A) to (B) = 9: 1 to 5: 5 by weight. A method for producing a phenolic resin foam.