JPH0859985A - Phenolic resin composition - Google Patents

Abstract

PURPOSE: To obtain the subject composition retaining the excellent characteristics of polyamides as one of its component, also excellent in flame retardancy, heat resistance and water resistance, useful for fibers, etc., by melt mixing a powdered phenolic resin cured product with a polyamide in specific proportions. CONSTITUTION: This resin composition is obtained by melt mixing (A) 100 pts.wt. of a polyamide with (B) 5-50 pts.wt. of a powdered phenolic resin cured product (pref. with an acetone extraction rate of <=10% and a particle diameter of 1-100μm). It is preferable that the component B be obtained by blending a novolak-type phenolic resin with a curing agent followed by curing under heating, or by curing a resol-type phenolic resin under heating or using an acid.

Description

Detailed Description of the Invention

[0001]

[Field of Industrial Application] The present invention does not impair the properties of polyamide as a thermoplastic resin, and makes good use of the excellent characteristics of phenol resin, and has good flame resistance, water resistance, and heat resistance. The present invention also relates to a phenol resin composition that gives impact resistance and the like, and is useful for various molded articles obtained by injection molding and the like, and applications obtained by extrusion molding and the like.

[0002]

2. Description of the Related Art Generally, polyamide is superior to other thermoplastic resins in mechanical properties, thermal properties and chemical properties, and is used for fibers, automobile parts, electric / communication equipment parts, general mechanical parts. It is also used in a wide range of fields such as sundries and sporting goods. In particular, it has a very high impact resistance as compared with other thermoplastic resins, and has excellent abrasion resistance as compared with phenolic resins and mild steel.
However, since polyamide is a crystalline resin, it has a large molding shrinkage, and since it has a large water absorption, it cannot be said that it has particularly excellent electrical properties, and there are problems in flame retardancy and heat resistance.

Therefore, for example, glass fibers are blended to improve flame retardancy, heat resistance and molding shrinkage, and studies are conducted with chlorinated paraffins, antimony trioxide, aromatic halogen compounds, etc. for the purpose of improving flame retardancy. Has also been done. However, there are still problems such as high price of flame retardant and safety and health.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a phenol resin composition having excellent flame retardancy, heat resistance and water resistance, with almost no deterioration of the excellent characteristics of polyamide.

[0005]

[Means for Solving the Problems] The present inventors have been engaged in research on phenolic resins for many years, and as a result of examination, they have added the characteristics of phenolic resins such as heat resistance, flame retardancy, electrostatic properties and abrasion resistance, A phenol resin composition obtained by melt-kneading a polyamide and a powdered phenol resin cured product could be obtained. As a result of further intensive study, the above-mentioned characteristics were obtained by using a powdery phenolic resin cured product having an acetone extraction rate of less than 10% in the powdery phenolic resin cured product and a powder particle size of 1 to 100 μm. In addition to this, they have found that impact resistance, tensile strength, bending strength and the like are improved, and have completed the present invention.

That is, the present invention relates to a phenol resin composition obtained by melt-kneading 100 parts by weight of polyamide and 5 to 50 parts by weight of a powdered phenol resin cured product, preferably 100 parts by weight of polyamide and powdered phenol resin. A phenol resin composition obtained by melt-kneading 5 to 30 parts by weight of a cured product, and more preferably a phenol resin composition obtained by melt-kneading 100 parts by weight of polyamide and 10 to 25 parts by weight of a powdery phenol resin cured product. is there. Here, when the compounding amount of the powdery phenolic resin cured product with respect to 100 parts by weight of polyamide is less than 5 parts by weight, the excellent characteristics of the phenolic resin are not exhibited. Further, when the amount of the powdered phenolic resin cured product blended exceeds 50 parts by weight with respect to 100 parts by weight of polyamide, the moldability of the polyamide and the appearance of the molded product are impaired.

The phenol resin cured product used in the present invention is pulverized and powdered, and the particle size of the powder is 1 to 100.
One of the features is that it is μm. Here, if the particle size of the powder is less than 1 μm, the workability at the time of melt-kneading is deteriorated because it is extremely fine, and if the particle size of the powder exceeds 100 μm, the appearance of the molded product is impaired.

[0008]

The amide used in the present invention is not particularly limited and is commercially available.
Various polyamides such as 66 nylon and 610 nylon can be used.

Examples of the phenol resin used for producing the powdery phenol resin cured product used in the present invention include novolac type phenol resin, resol type phenol resin and benzylic ether type phenol resin. These may be used alone or in combination of two or more. Further, various modified phenolic resins such as rubber modified and alkylbenzene modified can also be used. Preferably, a powdered phenol resin cured product obtained by mixing a novolac type phenol resin and a curing agent and curing by heating and / or a cured product obtained by curing a resol type phenol resin by heating or an acid.

The novolak type phenolic resin used in the present invention includes phenols (P) and aldehydes (F).
Was charged into a reaction kettle at a blending ratio such that the blending molar ratio (F / P) was 0.5 to 1.0, and hydrochloric acid was used as a resinification catalyst.
Add one or more selected from sulfuric acid, phosphoric acid, p-toluenesulfonic acid, benzenesulfonic acid, oxalic acid, maleic acid, formic acid, acetic acid, etc., and if a modified resin is to be obtained, add a modifier and then heat. After carrying out a reflux reaction for an appropriate time, vacuum dehydration or atmospheric pressure dehydration for removing the condensed water produced by the reaction, and further removing remaining water and unreacted phenols can be obtained.

The resol type phenolic resin used in the present invention is a mixture of phenols (P) and aldehydes (F) in a molar ratio (F / P) of 1.0 to 2.0. Proportionately charged into a reaction kettle, and as a resinification catalyst, hydroxides or oxides of alkali metals and alkaline earth metals such as sodium hydroxide, potassium hydroxide, barium hydroxide and calcium hydroxide, ammonia, triethylamine, etc. 1 or 2 or more selected from the amines mentioned above are added, and when a modified resin is obtained, a modifier is added and then heated and refluxed for an appropriate time, and then condensed water produced by the reaction It can be obtained by vacuum dehydration or atmospheric dehydration.

The phenols used as raw materials for the phenolic resin used in the present invention include phenol, orthocresol, metacresol, paracresol and bisphenol.
A, bisphenol F, catechol, resorcin, hydroquinone, propylphenol, butylphenol
And one or more selected from nonylphenol, octylphenol, nonylphenol and the like. Examples of the aldehydes include formaldehyde, paraformaldehyde, trioxane, acetaldehyde and the like, and one or two or more kinds are appropriately selected from these. As the modifier species, alkylbenzene (xylene-based resin), cashew oil, terpenes such as rosin, and boric acid are used.

As a curing method for producing the powdery phenolic resin cured product used in the present invention, a method of curing with heat and an acid is typically mentioned, and a curing method with heat is particularly preferable. In the case of a novolac type phenol resin, 1 to 20 parts by weight of a curing agent such as hexamethylenetetramine is added and mixed with 100 parts by weight of the novolac type phenol resin in accordance with the target degree of the cross-linking structure to cure.

In the present invention, the degree of curing of the powdery phenolic resin cured product is indicated by the numerical value of the acetone extraction rate measured by the acetone extraction test method. The acetone extraction test is a method of extracting the uncured portion of the phenol resin with a Soxhlet extractor using acetone as a solvent. Normally, uncured phenolic resin dissolves in acetone,
It does not dissolve as the curing progresses. A completely cured powdery phenol resin cured product does not dissolve in acetone at all. That is, the phenol resin has an acetone extraction rate of 100.
%, The completely cured phenol resin cured product has an acetone extraction rate of 0%.

The temperature at which the mixture of the novolac type phenol resin and hexamethylenetetramine and the resol type phenol resin are heat-cured is set according to the target degree of curing. That is, when a powdery phenolic resin cured product having a cured structure with an acetone extraction rate of less than 10% is produced, the heating temperature is preferably 100 to 180 ° C.

A hammer mill, a free mill, a pulverizer, a turbo mill, a jet mill or the like can be used for pulverizing the powdery phenol resin cured product. The particle size of the powder can be adjusted by the crusher used. In order to obtain a resin powder having a particle size in a specific range, it can be easily obtained by pulverizing and then sieving. At this time, the feed rate of the raw material to the crusher, the rotation speed of the crusher, and the particle size obtained depend on the mesh of the screen of the crusher.

[0017]

EXAMPLES The present invention will be described in detail below with reference to examples, but the present invention is not limited to the examples.
In addition, "parts" and "%" described in Examples and Comparative Examples indicate "parts by weight" and "% by weight".

<< Synthesis of phenol resin >> [Synthesis example 1] 1,000 parts of phenol and 10.0 parts of oxalic acid were charged into a reactor equipped with a stirrer, a heat exchanger and a thermometer. Thereafter, the temperature of the mixed solution was raised to 90 ± 2 ° C., and while maintaining the same temperature and controlling the vacuum degree to 440 Torr, 690 parts of the 37% aqueous formaldehyde solution placed in the aldehyde tank was added to 2.5%. It was added to the mixed solution over a period of time, and after the addition, the former aldehyde-catalyzed reaction was carried out for 3.0 hours under the same conditions. Then, after raising the temperature of the reaction solution in the previous stage to 150 ° C under normal pressure, the temperature of the solution was raised to 250 ° C while maintaining the vacuum degree at 60 Torr to remove residual water and free monomers. A novolac type phenol resin (B1) having a melting point of 95 ° C. and a free monomer amount of 0.5% was obtained.

[Synthesis Example 2] 1,000 parts of phenol, 1,380 parts of 37% aqueous formaldehyde solution and 120 parts of 28% ammonia water were charged in the same reactor as in Synthesis Example 1. After that, the temperature of the mixed solution was gradually raised, and the mixture was refluxed under reduced pressure at 80 ° C. for 15 minutes. After cooling to an internal temperature of 50 ° C., the mixture was allowed to stand, the separated water was removed, and the mixture was dehydrated under reduced pressure at 60 ° C. to obtain a resol-type phenol resin (B2) having a melting point of 70 ° C. and a free monomer amount of 2.5%.

<Preparation of Phenolic Resin Cured Product> [Preparation Example 1] 1,000 parts of the novolac-type phenol resin (B1) prepared in Synthesis Example 1 and 100 parts of hexamethylenetetramine were mixed and pulverized, and then the mixture was crushed at 120 ° C. for 60 minutes. Minutes Further heated at 160 ° C. for 60 minutes. The obtained cured novolak resin was roughly pulverized with a hammer mill and then finely pulverized with a palpelizer. The obtained powdery novolac resin cured product (D1) had an average particle size of 40 μm and an acetone extraction rate of 7%.

[Production Example 2] 1,000 parts of the novolac type phenol resin (B1) synthesized in Synthesis Example 1 and 100 parts of hexamethylenetetramine were mixed and pulverized, and then 110 ° C.
Heated for 2 hours at 140 ° C. for 90 minutes. The obtained cured novolak resin was roughly pulverized with a hammer mill and then finely pulverized with a palpelizer. The obtained powdery novolac resin cured product (D2) had an average particle size of 60 μm and an acetone extraction rate of 9%.

[Production Example 3] The resol-type phenol resin (B2) synthesized in Synthesis Example 2 was heated at 150 ° C for 1 hour. The obtained resole resin cured product was roughly pulverized with a hammer mill and then finely pulverized with a palpelizer. The average particle size of the obtained powdery resol resin cured product (D3) is 45.
μm, and the acetone extraction rate was 0.6%.

[Production Example 4] The resol-type phenol resin (B2) synthesized in Synthesis Example 2 was heated at 130 ° C for 90 minutes. The obtained resol resin cured product was roughly pulverized with a hammer mill and then finely pulverized with a jet mill. The average particle diameter of the obtained powdery resol resin cured product (D4) is 15μ.
m, and the acetone extraction rate was 1.5%.

[Production Example 5] 1,000 parts of the novolac type phenol resin (B1) synthesized in Synthesis Example 1 and 100 parts of hexamethylenetetramine were mixed and pulverized, and then 120 ° C.
It was heated for 30 minutes at 160 ° C. for 60 minutes. The obtained novolak resin cured product was roughly pulverized with a hammer mill and then finely pulverized with a pulverizer and a jet mill.
The obtained powdery novolac resin cured product (D5) had an average particle size of 0.8 μm and an acetone extraction rate of 9%.

[Production Example 6] The resol-type phenol resin (B2) synthesized in Synthesis Example 2 was heated at 140 ° C for 60 minutes. The obtained resole resin cured product was roughly pulverized with a hammer mill and then finely pulverized with a palpelizer. The average particle diameter of the obtained powdery resol resin cured product (D6) is 15
It was 0 μm, and the acetone extraction rate was 6%.

[Examples 1 to 4] Polyamide and Preparation Example 1
4 powdered novolac resin cured product (D1 to D
4) was blended as shown in Table 1 with a twin-screw extruder and melt-kneaded at 280 ° C. for 1 minute, and the obtained phenol resin composition was molded by injection molding to prepare each test piece.

Comparative Examples 1 to 4 Polyamide and Preparation Example 1,
Powdery novolac resin cured product (D) obtained in 3, 5, and 6
1, D3, D5, D6) were melt-kneaded in a twin-screw extruder at 280 ° C. for 1 minute with the composition shown in Table 1, and the obtained phenol resin composition was molded by injection molding to prepare each test piece. .

[Comparative Example 5] 100 parts by weight of polyamide were molded by injection molding to prepare test pieces.

Comparative Example 6 100 parts by weight of polyamide and 20 parts by weight of glass fiber are melt-kneaded for 1 minute at 280 ° C. in a twin-screw extruder. The obtained composition was molded by injection molding to prepare each test piece.

(Evaluation method of test piece) Tensile strength is ASTM
D638, flexural strength ASTM D790, Izod impact strength ASTM D256, heat distortion temperature AST
M D648, heat distortion temperature is ASTM D648, combustion test is Underwriters Laborato
It was measured according to safety standard UL94 (○: burning time within 10 seconds, Δ: burning for 10 seconds or more, x: burnt down) manufactured by ries. The formulations and the evaluation results are shown in Table 1.

[0031]

[Table 1]

The phenol resin compositions obtained by melt-kneading the polyamides obtained in Examples 1 to 4 and the powdery phenolic resin cured products were compared with those obtained in Comparative Examples 1 to 6,
Mechanical properties such as water absorption, heat distortion temperature, bending strength, flame retardancy, etc.
It was confirmed that the physical properties were improved.

[0033]

EFFECTS OF THE INVENTION According to the present invention, a phenol resin having flame resistance, heat resistance, water resistance, etc., can be used without impairing the excellent characteristics such as impact resistance and abrasion resistance of conventional polyamides. You can also add the features you have. Therefore, it can be applied not only in the fields where polyamides have been conventionally used but also in the fields where flame retardancy and heat resistance are required.

Claims (4)

[Claims] 1. A phenol resin composition obtained by melt-kneading 100 parts by weight of polyamide and 5 to 50 parts by weight of a powdered phenol resin cured product. 2. A powdery phenolic resin cured product is obtained by mixing a novolac type phenolic resin and a curing agent and curing the powdery phenolic resin cured product and / or a resol type phenolic resin by heating or acid. The phenol resin composition according to claim 1, which is a powdered phenol resin cured product obtained by the above. 3. The phenol resin composition according to claim 1, wherein the powdery phenolic resin cured product has an acetone extraction rate of less than 10%. 4. The phenol resin composition according to claim 1, 2 or 3, wherein the powder of the powdered phenol resin cured product has a particle size of 1 to 100 μm.