JPH0859986A - 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 semi-cured product with a polyamide in specific properties. 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 semi- cured product (pref. with an acetone extraction rate of 10-90% 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 semi- curing under heating, or by semi-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 excellent in flame retardancy, heat resistance and water resistance, with almost no deterioration in the excellent properties 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, It was possible to obtain a phenol resin composition obtained by melt-kneading a polyamide and a powdery phenol resin semi-cured product. As a result of further diligent study, by using a powdery phenolic resin semi-cured product having an acetone extraction rate of 10 to 90% in the powdery phenolic resin semi-cured product and a powder particle size of 1 to 100 μm, In addition to the above characteristics, it was found that impact resistance, tensile strength, bending strength, etc. were improved, and the present invention was completed.

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

The semi-cured phenol resin used in the present invention is pulverized and powdered, and the powder has a particle size of 1-10.
One of the features is that it is 0 μm. If the particle size of the powder is less than 1 μm, the workability during 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 preparing the powdery phenol resin semi-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 novolac type phenolic resin and a curing agent are mixed, and a powdery phenolic resin semi-cured product obtained by semi-curing by heating and / or a semi-cured product obtained by semi-curing a resol type phenolic resin by heating or an acid. is there.

The novolac type phenol resin used in the present invention is a reaction of phenols (P) and aldehydes (F) in a compounding molar ratio (F / P) of 0.5 to 1.0. A modified resin is charged in a kettle, and one or more kinds selected from hydrochloric acid, sulfuric acid, phosphoric acid, paratoluenesulfonic acid, benzenesulfonic acid, oxalic acid, maleic acid, formic acid, acetic acid, etc. are added as a resinizing catalyst. When it is obtained, it is heated after adding a denaturing agent, and refluxed for an appropriate period of time, and then vacuum dehydration or atmospheric dehydration is performed to remove the condensed water produced by the reaction, and the remaining water and unreacted phenol are removed. It can be obtained by the method of removing the kind.

The resol type phenol resin used in the present invention reacts phenols (P) and aldehydes (F) at a compounding ratio such that the compounding molar ratio (F / P) is 1.0 to 2.0. Charged in a kettle, and as a catalyst for resinification, hydroxides or oxides of alkali metals and alkaline earth metals such as sodium hydroxide, potassium hydroxide, barium hydroxide and calcium hydroxide, amines such as ammonia and triethylamine. One or more selected from the above are added, and when a modified resin is to be obtained, a modifier is added, followed by heating, reflux reaction for an appropriate time, and removal of condensed water generated by the reaction. Therefore, it can be obtained by vacuum dehydration or atmospheric dehydration.

The phenols used as raw materials for the phenol resin used in the present invention include phenol, orthocresol, metacresol, paracresol, bisphenol A, bisphenol F, catechol, resorcin, hydroquinone, propylphenol, butylphenol, octylphenol, nonylphenol. It is 1 type (s) or 2 or more types selected from 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 semi-cured product used in the present invention, a method of semi-curing with heat and an acid is typically mentioned, and a semi-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, and the mixture is semi-cured.

In the present invention, the degree of curing of the powdery phenolic resin semi-cured product is shown 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, the uncured phenolic resin dissolves in acetone, but it disappears as the curing proceeds. 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 1
It becomes 00%, and 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 semi-cured product having a cured structure with an acetone extraction rate of 10 to 90% is produced, the heating temperature is preferably 100 to 140 ° C.

The powdery phenolic resin semi-cured product is pulverized by a hammer mill, a free mill, a pulverizer,
A turbo mill, a jet mill, etc. can be used. 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. On this occasion,
The feed rate of the raw material to the crusher, the rotation speed of the crusher, and the mesh size of the screen of the crusher vary the particle size obtained.

[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 Phenolic 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. After that, 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% formaldehyde aqueous 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 70 at 120 ° C. Heated for minutes. The semi-cured novolak resin obtained was roughly pulverized with a hammer mill and then finely pulverized with a palpelizer.
The obtained powdery novolak resin semi-cured product (D1) had an average particle size of 30 μm and an acetone extraction rate of 35%.

[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 120 ° C.
Heated for 2 hours. The semi-cured novolak resin obtained was roughly pulverized with a hammer mill and then finely pulverized with a palpelizer. The obtained powdery novolak resin semi-cured product (D2) had an average particle size of 60 μm and an acetone extraction rate of 13%.

[Production Example 3] The resol-type phenol resin (B2) synthesized in Synthesis Example 2 was heated at 100 ° C for 1 hour. The obtained semi-cured resol resin was roughly crushed with a hammer mill and then finely crushed with a palpelizer. The average particle size of the obtained powdery resol resin semi-cured product (D3) was 30 μm, and the acetone extraction rate was 50%.

[Production Example 4] The resol-type phenol resin (B2) synthesized in Synthesis Example 2 was heated at 110 ° C for 1 hour. The obtained semi-cured resol resin was roughly crushed with a hammer mill and then finely crushed with a jet mill. The average particle size of the obtained powdery resol resin semi-cured product (D4) is 7
μm, and the acetone extraction rate was 35%.

[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 110 ° C.
Heated for 1 hour. The semi-cured novolak resin obtained was roughly crushed with a hammer mill and then finely crushed with a pulverizer and a jet mill. The powdery novolak resin semi-cured product (D5) thus obtained had an average particle size of 0.6 μm and an acetone extraction rate of 65%.

[Production Example 6] The resol-type phenol resin (B2) synthesized in Synthesis Example 2 was heated at 120 ° C for 1.5 hours. The obtained semi-cured resol resin was roughly crushed with a hammer mill and then finely crushed with a palpelizer. The obtained powdery resol resin semi-cured product (D6) had an average particle size of 150 μm and an acetone extraction rate of 25%.

[Examples 1 to 4] Polyamide and Preparation Example 1
Powdery novolac resin semi-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,
The powdery novolak resin semi-cured products (D1, D3, D5, D6) obtained in Nos. 3, 5, and 6 were melt-kneaded in a twin-screw extruder at 280 ° C. for 1 minute to obtain a compound. A phenol resin composition is molded by injection molding,
Each test piece was produced.

[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
MD648, burning test by Underwriters Laboratories
Safety standard UL94 (○: burning time within 10 seconds,
Δ: burning for 10 seconds or longer, ×: burnt down). 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 semi-cured powdery phenolic resin were more Izod impact strength than those obtained in Comparative Examples 1 to 6. It was confirmed that mechanical and physical properties such as heat distortion temperature, bending strength, and flame retardancy were improved.

[0033]

EFFECTS OF THE INVENTION According to the present invention, the characteristics of a phenolic resin such as flame resistance, heat resistance and impact resistance can be obtained without impairing the excellent characteristics such as abrasion resistance that polyamide has conventionally. Can be given. Therefore, the present invention can be applied not only in the field where polyamide has been conventionally used but also in the field where flame retardancy, heat resistance and impact 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 powdery phenol resin semi-cured product. 2. The powdery phenolic resin semi-cured product is obtained by mixing a novolac type phenolic resin and a curing agent and semi-curing the mixture by heating to heat the powdery phenolic resin semi-cured product and / or the resol type phenolic resin. The phenolic resin composition according to claim 1, which is a powdery phenolic resin semi-cured product obtained by semi-curing with an acid. 3. The phenol resin composition according to claim 1, wherein the powdery phenol resin semi-cured product has an acetone extraction rate of 10 to 90%. 4. The phenol resin composition according to claim 1, 2 or 3, wherein the powdery powdered phenol resin semi-cured product has a particle size of 1 to 100 μm.