JP3519774B2 - Method for producing phenolic resin composition - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a phenol resin composition modified by using polyurethane waste.

[0002]

2. Description of the Related Art Conventionally, as a technique for recycling polyurethane such as polyurethane foam, polyurethane is finely broken into chips, which are then adhesively press-molded into building materials, or polyurethane is finely pulverized and used as a filler. There is a method of recycling, a method of recovering it as a urethane raw material by chemical recycling, a method of burning it and using it as thermal energy.

On the other hand, phenol resin is excellent in various properties such as mechanical properties, heat resistance, electric insulation, dimensional stability, chemical resistance, and moldability, and is inexpensive, so that it can be manufactured from industrial materials to consumer products. Widely used up to. For example, molded products of phenolic resin are used as insulating materials in fields related to telecommunications, and are also in great demand as automobile parts and machine parts. However, the phenol resin has a drawback of being brittle, and improvement of this brittleness is being studied for further expansion of applications. Conventional methods for improving the brittleness of phenolic resins include, for example, a method of increasing the bond distance between phenol nuclei, a method of decreasing the amount of a curing agent to increase the distance between crosslinking points, and natural rubber and acrylonitrile. -A method of adding a plasticizer such as butadiene rubber has been proposed.

[0004]

However, the above-mentioned polyurethane recycling technology has limited industrial application in terms of cost, and it cannot be said that recovery and reuse of polyurethane has been sufficiently satisfied. I want to. Therefore, at present, there is a need for a new technique for recycling waste polyurethane by a simple technique and at low cost.

Although the brittleness of the phenolic resin can be improved by the method proposed above,
On the contrary, the above method has a drawback that the heat resistance of the phenol resin is lowered. That is, it is difficult to simultaneously improve the toughness and the heat resistance of the phenolic resin, and in many cases, there is a problem that if one is improved, the other is lowered.

The present invention has been made in view of the above points, and a phenol resin capable of reusing polyurethane waste easily and at low cost, and improving both toughness and heat resistance. It is intended to provide a method for producing a composition.

[0007]

The method for producing a phenol resin composition according to the present invention is characterized in that a phenol novolac and a polyurethane are melt-kneaded to react with each other .

Further, in the present invention, it is preferable to react the phenol novolac and the polyurethane under the heating condition of 120 to 190 ° C. Further, in the present invention, 1 to 100 parts by weight of phenol novolac is used for polyurethane 1 to
It is preferable to react 50 parts by weight. And the present invention can use waste as polyurethane.

The present invention will be described in detail below. In the present invention, as the polyurethane, it is possible to use wastes produced in the production stage such as defective production and molding burrs, wastes produced in the use stage such as used products, and other wastes. Polyurethane foam is mainly used as polyurethane, but polyurethane elastomer, polyurethane fiber, etc. can also be used.
There is no particular limitation. As the type of polyurethane, either polyether type or polyester type may be used. This polyurethane is preferably crushed and used in the form of powder or particles.

Phenol novolac is a phenol resin intermediate and is not particularly limited.
Phenol, o-cresol, m-cresol, p-cresol, 2,3-xylenol, 2,4-xylenol, 2,5-xylenol, 3,4-xylenol,
Phenols such as 3,5-xylenol, o-ethylphenol, m-ethylphenol, mitol, pt-butylphenol, catechol, pt-amylphenol, resorcinol, p-octylphenol, p-phenylphenol, naphthol, etc. , Soluble and fusible oligomers (initial condensates) obtained by reacting with aldehydes such as formalin, paraformaldehyde, benzaldehyde, and furfural under acidic conditions.

According to the present invention, polyurethane is blended with phenol novolac, and the mixture is heated and melt-kneaded to dissolve the polyurethane in the phenol novolac and to react the phenol novolac with phenol having improved toughness and heat resistance. A resin composition can be prepared. The reason why a phenol resin composition having improved toughness and heat resistance can be obtained by reacting phenol novolac with polyurethane can be speculated as follows. That is, the urethane bond of polyurethane dissociated in phenol novolac reacts with the phenolic hydroxyl group to act as a crosslinking hand, resulting in an increase in crosslinking density and improvement in heat resistance,
It is considered that the soft segment in polyurethane is incorporated into the crosslinked body to improve toughness.

The blending amount of polyurethane with respect to phenol novolac is preferably 1 to 50 parts by weight, more preferably 5 to 30 parts by weight, based on 100 parts by weight of phenol novolac. If the content of polyurethane is less than 1 part by weight, it is difficult to obtain sufficient toughness and heat resistance,
On the other hand, if it exceeds 50 parts by weight, the melt solubility with respect to phenol novolac is deteriorated, making it difficult to carry out a sufficient reaction, and the viscosity of the melt-kneaded product is increased, which may deteriorate the moldability. The heating and kneading temperature (reaction temperature) of polyurethane for phenol novolac is 120.
To 190 ° C is preferable, and more preferably 130 to
It is 150 ° C. The heating and kneading time (reaction time) is 30
To 120 minutes is preferable, and more preferably 30 to 6 minutes.
0 minutes. Reaction temperature less than 120 ° C, reaction time 3
If it is less than 0 minutes, the reaction between the phenol novolac and the polyurethane becomes insufficient. Conversely, if the reaction temperature exceeds 190 ° C and the reaction time exceeds 120 minutes, the cleavage of the molecular chain of polyurethane due to thermal decomposition is remarkable. Therefore, the effect of improving the toughness and the heat resistance may not be sufficiently obtained.

The phenol resin composition obtained by reacting the phenol novolac and the polyurethane as described above is mixed with a curing agent such as hexamethylenetetramine, a lubricant, a filler, a reinforcing material, etc., if necessary. A material can be prepared. This molding material can be molded by any molding method such as injection molding, transfer molding, compression molding, etc., and can be used in various fields as an engineering plastic excellent in toughness and heat resistance.

[0014]

The invention will now be illustrated by the examples. (Example 1) 300 g (3.2 mol) of phenol and oxalic acid in a four-necked flask equipped with a stir bar, a reflux tube and a thermometer.
6 g, 37% formalin 207.6 g (2.56 mol)
After adding, the mixture was refluxed for 1 hour, and then oxalic acid 4.4 was added into the system.
After adding g, the mixture was refluxed again for 1 hour, and then unreacted phenol and water were removed by steam distillation to obtain a phenol novolac. The molecular weight of the obtained phenol novolac was as follows: number average molecular weight Mn = 650, weight average molecular weight Mw =
It was 1600 and the glass transition temperature was 35 ° C.

100 parts by weight of the phenol novolac prepared as described above and 10 parts by weight of polyurethane foam (polyether polyurethane, bulk density 0.037 g / cm ³ ) crushed to an average particle size of 1 mm are biaxially kneaded. The phenol novolac and the polyurethane were reacted by kneading at 150 ° C. for 30 minutes using a machine. Next, to 100 parts by weight of this kneaded material, 12 parts by weight of hexamethylenetetramine as a curing agent, 2 parts by weight of zinc stearate as a lubricant, and 100 parts by weight of wood flour as a filler were added, and this was mixed at 100 to 110 ° C. Use a hot roll heated to about 5
Kneading was carried out for a minute to prepare a molding material.

The molding material thus prepared was transferred to a transfer molding machine at 170 ° C. and 100 kgf / c.
A test piece was prepared by molding under conditions of m ² and 10 minutes. Then, using this test piece, according to JIS K 6911,
The Charpy impact strength and the deflection temperature under load were measured. The results are shown in Table 1. On the other hand, except that wood flour is not blended, a kneaded product of phenol novolac and polyurethane foam, hexamethylenetetramine, and zinc stearate are kneaded with a hot roll to prepare a molding material in the same manner as above, and the molding material is compressed. 170 ℃, 100kgf / c
A test piece was prepared by molding under conditions of m ² and 10 minutes. Then, using this test piece, according to ASTM E399, 3
The critical stress intensity factor was measured by the point bending method to obtain the fracture toughness value (K _IC ). The measurement results are shown in Table 1.

(Example 2) A molding material was used in the same manner as in Example 1 except that the same phenol novolac and polyurethane foam as in Example 1 were used and 100 parts by weight of phenol novolac and 20 parts by weight of polyurethane foam were kneaded. Was prepared, and Charpy impact strength, deflection temperature under load, and fracture toughness were measured in the same manner as in Example 1. The measurement results are shown in Table 1.

(Example 3) A molding material was used in the same manner as in Example 1 except that the same phenol novolac and polyurethane foam as in Example 1 were used and 100 parts by weight of phenol novolac and 30 parts by weight of polyurethane foam were kneaded. Was prepared, and Charpy impact strength, deflection temperature under load, and fracture toughness were measured in the same manner as in Example 1. The measurement results are shown in Table 1.

Comparative Example Without using polyurethane foam, 12 parts by weight of hexamethylenetetramine, 2 parts by weight of zinc stearate and 100 parts by weight of wood flour were added to 100 parts by weight of the same phenol novolak as in Example 1, This was kneaded with a hot roll heated to 100 to 110 ° C. for about 5 minutes until it had an appropriate fluidity at the time of molding to prepare a molding material. This molding material was transfer-molded in the same manner as in Example 1 to prepare a test piece, and the Charpy impact strength and the deflection temperature under load were measured in the same manner as in Example 1. The results are shown in Table 1.

On the other hand, phenol novolac, hexamethylenetetramine, and
A molding material was prepared by kneading zinc stearate with a hot roll, the molding material was compression-molded in the same manner as in Example 1 to prepare a test piece, and the fracture toughness value (K _IC ) was measured. The results are shown in Table 1.

[0021]

[Table 1]

As can be seen from Table 1, the examples obtained by reacting the phenol novolac with the polyurethane foam have higher Charpy impact strength and fracture toughness than those of the comparative example in which the polyurethane foam is not reacted. It is confirmed that the toughness is improved, the deflection temperature under load is high, and the heat resistance is improved.

[0023]

As described above, according to the present invention, the reaction is carried out by melt-kneading the phenol novolac and the polyurethane. Therefore, the polyurethane can increase the crosslink density to improve the heat resistance and the flexibility. It is possible to improve the toughness by introducing segments, and to improve both the toughness and heat resistance. Moreover, by using waste as this polyurethane, the waste of polyurethane can be easily and cheaply manufactured. It can be reused. Also,
React using conventional kneading equipment by melt kneading
Can be equipped with special equipment for reaction
It doesn't have to be like that.

Further, since the phenol novolak and polyurethane to react under heating 120 to 190 ° C., phenol novolak and without reaction becomes insufficient and polyurethane, the effect of improving the toughness and heat resistance You can get enough.

Furthermore, since 1 to 50 parts by weight of polyurethane is made to react with 100 parts by weight of phenol novolac, it is possible to obtain a sufficient reaction without making it difficult to carry out a sufficient reaction or deteriorating moldability. It is possible to obtain excellent toughness and heat resistance.

─────────────────────────────────────────────────── --- Continuation of the front page (72) Inventor Keiko Otsuka 1-1-11-5202 Uenonishi, Toyonaka City, Osaka Prefecture (72) Inventor Akinori Fukuda 6-21 Shinsei Komadai, Ikoma City, Nara Prefecture (72) Invention Person Isamu Ide 1648-15 Kanaoka-cho, Sakai City, Osaka Prefecture (56) References JP-A-52-17597 (JP, A) JP-A-63-23957 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) C08G 18/00-18/87 C08L 75/04-75/16

Claims (4)

(57) [Claims] 1. A phenol novolac and polyurethane
A method for producing a phenol resin composition, which comprises reacting by melt-kneading . 2. The method for producing a phenol resin composition according to claim 1 , wherein the phenol novolac and the polyurethane are reacted under a heating condition of 120 to 190 ° C. 3. The method for producing a phenolic resin composition according to claim 1 or 2, characterized by reacting the polyurethane 50 parts by weight of the phenol novolak 100 parts by weight. 4. The process for producing a phenolic resin composition according to any one of claims 1 to 3, wherein the use of waste as a polyurethane.