JPS598755A - Preparation of molding material of resin having wear resistance - Google Patents

Abstract

PURPOSE:To enable uniform dispersion, and to obtain a molding material having improved heat resistance, wear resistance and self-lubiricating properties, by adding a polar solvent having affinity for polyamide-imide resin to the resin when it is blended with an imparter for wear resistance and an imparter for good fluidity. CONSTITUTION:In preparing a molding material obtained by blending densely (A) 30-90wt% polyamide-imide resin with (B) 10-70wt% graphite and/or molybdenum disulfide as an imparter for wear resistance and (C) 0-30wt% resin selected from polyphenylene sulfide resin, polyamide resin, and aromatic polyester resin, having more improved fluidity than component A, as an imparter for good fluidity, 1-50pts.wt. polar solvent (e.g., N-methyl-2-pyrrolidone, DMF, or DMSO) having affinity for the three components based on 100pts.wt. total amounts of the three components. The solvent is removed from the mixture and it is blended under molten state, or the mixture is blended under molten state and the solvent is removed.

Description

[Detailed description of the invention] 4. The invention is heat resistant) 71. The present invention relates to a method for productively and effectively producing a molding material based on polyamylimide resin, which can provide molded articles with excellent wear resistance and self-lubricating properties.

Polyamide-imide resin has (1 (po 11, (
Because it contains both polyamide bonds and polyamide bonds, it has excellent heat resistance, mechanical strength, chemical resistance, electrical properties, etc., and can be formed into a melted OV form, making it suitable for high-performance industrial applications. Material parts can be supplied using a highly productive injection molding method, and are particularly useful for applications such as electrical/electronic parts used at high temperatures, space/air equipment parts, and office equipment parts. 1-Resin has excellent thermal properties and mechanical strength, but on the other hand, it lacks thermal properties and self-lubricating properties, so when it is used as a sliding material, it is usually It is necessary to carry out modification by adding and blending wear-resistant agents such as graphite and molybdenum disulfide. However, since the melt viscosity of polyamide-imide resins is generally quite high, it is extremely difficult to blend an abrasion resistance imparting agent with good slip properties in a heating bath using an extruder. For example, when using a -shaft extruder to melt and knead polyamide-imide resin with abrasion-resistant powder, the wear-resistance imparting powder may slip in the feed section 7 of the extruder. This results in poor biting, making it difficult to perform stable melting and cross-wire operations continuously. Furthermore, even if cross-crossing were forcibly achieved, it would be quite difficult to ensure uniform dispersion of the wear-resistant additive in the resulting mixture, and the mechanical strength of the mixture would be poor. Cheap.

The present inventors therefore sought to efficiently produce a molding material made of polyamide-imide resin and a wear-resistance imparting agent represented by graphite and molybdenum disulfide, with high productivity. As a result of intensive studies aimed at this purpose, it was discovered that the above object can be effectively achieved by simultaneously mixing a good solvent for polyamide-imide resin prior to so-called melt mixing, and the present invention has been achieved.

That is, the present invention provides (a) polyamideimide resin 30 to
9 Oli amount %, 6 kagraphite and/or molybdenum disulfide 10'-70% by weight, and (1) polyamide resin having better fluidity than polyamideimide resin, polyamide resin, and aromatic polyester resin. Choose at least 1f! IiO~60
When obtaining a molding material whose weight percentages are closely blended, the above (a), ←J) and ? ) to the total weight part of )
Polar M medium 1 to 6 having affinity for polyamideimide resin
To provide a method for producing a wear-resistant resin molding material, which comprises mixing 0 parts by weight, and then removing the solvent from the mixture and then melt-mixing it, or melt-mixing it and then removing the solvent. It is.

(6) Polyamideimide resin (hereinafter referred to as PA) used in the present invention
(abbreviated as engineering resin) has a repeating unit represented by the general formula % formula % as the main structural unit and 30 to 1
00 mol%, preferably 70 to 100 mol%),
Other aromatic polymers which may contain polyamide and/or polyimide units having the following general formula (II) t or tllD in an amount of less than 70 moles, preferably less than 1t50 moles.

111 0 0 0 0 111 0 0 This structure (some of the imide bonds in D and Φ,
The amic acid bond \c, -OH1 as its ring-closing precursor. In the above general formula (D to Gl (1), Ar is a hexavalent aromatic group containing at least one 6-membered carbon ring, of which two carbonyl groups are adjacent to each other in the benzene ring of the Ar group. It is possible to specifically list structures characterized by being bonded to a carbon atom, such as, for example.

Examples of Ar' include divalent and aromatic groups containing at least one 6-membered carbon ring. Ar# is a tetravalent carbonyl group containing at least one (7) six-membered carbon ring, two of which are bonded to adjacent carbon atoms in the benzene ring of the Ar'' group. R is 2
It is an aromatic and/or aliphatic group residue, and specific examples include the following. Also, Bi is hydrogen, methyl group
It is a phenyl group.

The p A I resin of the above general formula (1) used in the present invention is dinotylformamide, Nmethylar 1!1-amide, N
-Notylpyrrole-one, cresol, etc.%
R4]1. "r fc structural unit (1) as a main component as necessary" 2 general formulas θ0 and σ) polyamide 1 unit and #1Ct
To copolymerize the d polyimide unit, the structural unit (P of D
This is achieved by substituting and reacting with Q O I11 111 0 01 0 during the production of AI resin.

Among them, a typical PA resin is sold by Amoco, USA and has the molecular structure. The manufacturing method for these is described in British Patent No. 1.856.5 filed by Nutan Good Oil Company.
No. 64, American Patent No. 3,661,832, and the like. There are no particular restrictions on the method for producing the PA resin, and any known method can be used.

Molybdenum disulfide, which is used as a wear-resistance modifier in the present invention, is a fine powder that is commonly used as a wear-resistance modifier for plastics. JllJ 'A<・Bi average particle diameter θ1~5
071, high density 0.1-0.6, specific surface area 5-600
It has characteristics of 7 nol/Q and a friction coefficient of 0.05 to 0.60. Like this Grapheye I (graphite)
Suitable examples include Nippon Graphite Co., Ltd.'s C9 commercially available cssp"C22,'CP,B","CB-100",
"CB-450",'ASSP",n A p I,"
A CP-1000' 11 Toka 6 Ke') Neru.

Suitable examples of molybdenum disulfide include "Moly Powder A I" and "Moly Powder B" commercially available from Nippon Graphite Co., Ltd.
``, ``Moly Powder C'', etc.

The molding material of the present invention comprises (a) FAI resin and (in) a wear-resistant additive, and optionally) polyphenylene sulfide resin, polyamide resin, and aromatic polyamide resin, which have better fluidity than polyamide-imide resin. At least one selected from resins may be further included as a good fluidity imparting agent. Polyphenylene sulfide resin (hereinafter referred to as PP) used here
(abbreviated as S resin) and Vj, general formula (-ph-s-1°, where -ph- is etc., and Q is F, C1, Br or mouth (3, m
represents an integer from 1 to 4.

It is commercially available under the trademark "Rydon" from Phillips Petroleum Company in the United States. Its manufacturing method is disclosed in U.S. Pat. No. 3,354,129 and the corresponding Japanese Patent Publication No. 45-3368.

Polyamide resins and aromatic polyester resins used as fluidity imparting agents are selected from those with superior fluidity and heat resistance than FAI resins, especially those with a melt viscosity of 1 x 105 points.・Bottom, cleverness is 5
A material having a thermal decomposition temperature of 650° C. or higher is used. If the melt viscosity is 1 x 10 or more, the effect of improving the fluidity of the molding material is small, and the melting heat w1 temperature is 5
p p below 50°C.

■It is not suitable because it thermally decomposes when mixed with resin, making stable mixing operation difficult. The melt viscosity referred to here is
Using an elevated flow tester made by Shimadzu, 350℃
The values are measured by extruding under the conditions of a load of 10 to 200 kg, a nozzle diameter of 1 mm, and a nozzle length of 2 mm. This is the 1 weight loss temperature when the temperature is increased for 37 minutes.

Specific examples of polyamide resins that meet the above conditions include those represented by the following formula.

(m/n=30/70) Examples of aromatic polyester resins that meet the above conditions include those represented by the following formula.

4 to 250150 molar ratio (Unichikane soil II [2100”) rrvh =
97/3 molar ratio - The proportion of the above (a) FAI resin, ((2) abrasion resistance imparting agent and l/→ good fluidity imparting agent in the molding material is 60 to 90% by weight) %, stem) is 10-70
It should be set so that weight % and weight → are 0-30 weight φ. Here, if (B) is less than 10% by weight, the extruder can be melted and breaded relatively uniformly, but the abrasion resistance is not sufficient and the stem is shattered).The upper limit of the content is the theoretical closest packing value. 70 weight φ or less, especially 50% or less -f
Talented. In addition, if the content h;- in (c) is too large, it will impede the mechanical properties and heat resistance of the Flyl shape, so a value of 30 weight scale or less, especially 20 weight scale downwind, is appropriate.
When attempting to tribread (I-I) and (c) in the usual manner and melt-mix them using an extruder ('t-;, t
As the melt viscosity increases, problems such as poor biting and powder flying occur, which not only worsens the workability of the extruder, but also
Since uniform dispersibility decreases, it becomes extremely difficult to achieve a stable, juvenile, and intimate blend.

However, in advance (a), (b) and (c) above)
By mixing a polar aggressive medium, the extrusion operation 1'1 during melt mixing and uniform dispersibility are greatly improved.

Polar solvents that have an affinity for FAI resin (used in the present invention) are polar organic solvents that have the property of dissolving or swelling FAI resin, and particularly useful ones include Methyl-2-pyrrolidone (NMP),
1.1.14-dimethylace1amide (DtJAC),
N. 14 - J. J. Holm
amide (DEM), j・l, N-methylformamide (DMF), Ij1cou/notylmethogine acetamide l'', N-methylcuff0rolacta J1, dinotylnulphoyasito (DMS○), Tetranotyl urea, dinotylnurfone, hexamethylphosphoramide, tetranotyl phosphoramide, tetranotyl urea, dinotyl urea, butyl
Lactam, N-acetyl.

1), rQ-cresol, and p-cresol.
゛kiru.

(→ Addition of polar solvent (q), ((b) and and) in a combined amount of 100 parts by weight, 1 to 60 parts by weight, especially 5 to 50 parts by weight, is suitable, and 1 part by weight 't FjB less than 1
If the amount exceeds 60 parts by weight, the mixture becomes liquid and it becomes difficult to melt and mix in the extruder, and it becomes difficult to remove the solvent. The process becomes complicated;! S doesn't look good. -1- The mixing operation described in (a), step) and e3) is carried out in the preferred manner.
Kuba (a), 1-J) Add the polar solvent of 1-J) in fine powder form to the polar solvent of 1-J) in a mortar, a ball mill, a ribbon blender, and a pupil stirrer. It is fed to various mixing machines (vessels) such as machine-attached paper, yoshi, can, etc., and is heated to 0 to 300 °C to obtain a uniform mixture under a temperature condition of 10 to 100 °C. During this mixing operation, some of the FAI resin is dissolved or swollen in the polar solvent, causing the surrounding wear-resistance imparting agent to coagulate. / plays the role of adhesion.Additionally, when mixing, use glue as necessary.
, +JI, carbon fiber, asbenu 1-fiber, and other fiber reinforcing agents may be additionally blended.

As a method for obtaining the molding material of the present invention, -1- (a)
~ (a method of (1) feeding a mixture of ingots into a melt-extrusion mill to pelletize it, and then drying a de-Ming agent; and (2)
After heating to remove solvent and drying, feed to melt extruder 17
Although the above method also improves the ability to feed into the extruder, extrusion stability, and uniform dispersibility, it is possible to efficiently obtain a compact blend. In addition, the method (1) described above may be carried out using an extruder equipped with Ben 1, and the solvent may be partially removed during melt mixing, or the method described above (
2) It is of course possible to add any desired operations, such as a method in which the pellets obtained by the method are pulverized and then subjected to deflation. For bath melt mixing, devices used for melt blending plastics, such as hot rolls, nokunbarimigizer, silabender, extruder, etc., can be used. The mixing operation is performed until the homogeneous mixture is 1
1) Continuing with Ranno') Ruu. The mixing temperature is set at a crystallinity higher than the crystallinity at which the compounding system has M melting ability and lower than the thermal decomposition temperature of the FAI resin.
400°C, preferably from 50 to 370°C. Thus, the molding material of the present invention is mainly applied to the production of friction-resistant, 11/: wear f, 'r shaped products by injection molding. Molded products obtained by melt-molding the molding material of the present invention have an extremely excellent balance of heat resistance, mechanical properties, and sliding properties, and include piston rings,
It is useful for various sliding parts such as bearings, comb V-tube survanes, Nulast washer, thermal insulation sleeves for rotary E bodies, and parts of printers.

Hereinafter, the present invention will be further explained in detail by giving examples.

It should be noted that the values of ratio, ratio, and part shown in this example mean a weight ratio, a weight ratio, and a heavy material part, respectively, unless otherwise specified.

However, the melting temperature and decomposition temperature of the added resin in this example were measured by the same method as defined in the description of the polyamide resin.

FAI resin powder shown in Examples 1 to 5 (Amoco'1--Ron 40
00 T F 〃) 55 parts, fine graphite powder with an average particle size of 7 μ and a bulk density of 0.2
4〃) After pre-tri-blending using a 5 parts Hennel mixer, 1.1.1q- with the composition shown in Table 1.
Methylacetamide (hereinafter abbreviated as DMAC) was gradually added and mixing was continued to uniformly blend the mixture.

Next, the compression ratio 2 is
, to a 40 mmφ single screw extruder equipped with a 671 screw, and perform a melt mixing operation under the extrusion conditions shown in Table 1 to produce PAI resin 7 graphite/PPS resin/
D M /lC four-component homogeneously blended pellets were obtained. During this extrusion operation, the feeding state of the raw materials in the extruder feed section was extremely stable. The load current applied to the extruder screw shaft was stable at a low level of 15 to 10 amperes.

Next, the 4-way blended PET obtained above was placed in a normal vacuum dryer, and the blended PET was heated to 100 to
Gradually raise the temperature to 200' over 2 hours, and then increase the temperature to 200'.
Dl,iAC was removed by treatment at 0°C for 20 hours. The amount of residual l) MAC in the obtained dried blended pellets was analyzed by gas chromatography and was found to be 0.5% or less.

Next, the desolventized blended pellets obtained above were molded using a normal injection molding machine (barre/V temperature 300-[60°C], mold temperature 230-[60°C]).
240° C. and an injection pressure of 1700 kg/cA) to create a molded test specimen. The obtained molded test piece was 165
24 hours at ℃, 24 hours at 245℃, 48 hours at 260'C
After performing five stages of heat treatment in chronological order, the physical properties were measured, and results with an excellent balance of physical properties as shown in Table 1 were obtained. .

Table 1 Comparison reference example 1 Fine graphite powder (“CP” manufactured by Nippon Graphite Co., Ltd.) 4
0 parts, FAI resin powder (Amoco "1-ron 4000T"
After preliminary tri-blending of 55 parts of F〃) and 5 parts of PPS resin powder (Philips Co., Ltd. "Lylon P-4") using a heno-el mixer, 5 parts of DM A CO was added. 70 parts were gradually added and mixing was continued to achieve uniform blending.

Next, this homogeneous mixture was fed to the same extruder as in Example 1.
The raw material slipped in the extruder feed section, making it extremely difficult to feed the raw material. In the case of a product containing 70 parts of D M AC, there are always two raw materials and it is close to a solution state,
The composition extruded from the die is too fluid and
− It was impossible.

As mentioned above, blended compositions containing DMAC of 1 part or less and 60 parts or more were stable and failed as IY engineered compositions intended for melt-kneading/extrusion operations.

Examples 4-5 N-methylpyrrolidone (hereinafter N M
The logarithmic viscosity is 0.45 (polymer concentration = 0.5%,
Solvent: NMP, Measuring temperature: 30'C) 1
7J p A I resin, graphite fine powder (Nippon Graphite Co., Ltd. C, P”), synthesized by melt polymerization / ζ phase 71 viscosity 2.
05 (polymer concentration, Part 1, solvent 98% concentrated sulfuric acid, measurement temperature: 25°C), polyhexamethylene isophthalamide resin powder having the following properties: M melt viscosity 1200 voids and decomposition temperature 1°C 396'C. NMP with the composition shown in Table 2 was charged into a co-rotating mixer and mixed at 60t-2 for 6 hours7.Then, this mixed mixture was fed to a 15mIIIφ single-screw lavender Buchnugoo graphite fine powder. A homogeneous melt-blended pellet was obtained by melt mixing at a processing temperature of 150 rpm and a screw rotation speed of 25 rpm. During this extrusion operation, the material was incorporated smoothly and stably in the Braventer feed section. 1 screw 11 VC
Calculate/l/ was stable at a low level of 300-400 (g-m,).

Next, the NMP-containing uniform mixture pallet obtained above was heated to 200°C.
After vacuum drying to remove NMP, the temperature was 32°C.
Molded specimens were prepared by compression molding at 0°C and a pressure of 100 kg/c4, followed by 24 hours at 165°C and 24 hours at 260°C.
Heat treatment was performed in six stages for 48 hours at 240 t; The physical properties of the resulting heat-treated test piece were measured, and as shown in Table 2, it was found to have an excellent balance of sliding properties, heat resistance, and mechanical properties.

Table 2 Examples 6 to 7 Molybdenum disulfide fine powder (Nippon Graphite Co., Ltd. "Moly Powder B") having characteristics of average particle size 5/7 and high density 1/I 0.3, PAi resin powder (Amoco Co., Ltd. "L- -Ron 400
0TF″) and the melt viscosity given by the formula m/n=50150 mono 4 ratio 2700 voids and decomposition humidity 41
Aromatic Boriende) V resin powder having the properties shown in Table 6 was charged into a stainless steel 201V autoclave, pre-triblended, and then mixed with trimethylformamide (hereinafter abbreviated as DMF) in the proportion shown in Table 39. )
was gradually added and mixing continued. During this mixing operation, F
At least a portion of the AI resin is dissolved or swollen in the DMF solvent such that 2+=1. Molybdenum chloride and polyester resin powder L') cause agglomeration/adhesion, resulting in a four-component aggregation mixture! I got 1 shiku.

Temperatures from -pioo to 120'C and from 20 to 60
DMF was removed under reduced pressure of mmHg to obtain a desolventized aggregate mixture. The resulting desolventized agglomerated mixture had a particle size of 5 to 60 mm by weight and a bulk density of 6.5 mm. Bee, σ) residual DMF in the desolvated flocculation mixture
When the amount was analyzed by gas chromatography, it was 1.0 cm.

Next, the solvent-free agglomerated mixture obtained above was applied to the same extruder as in Example 1 to obtain FAI resin 1Z molybdenum sulfide 7 aromatic borienute/l/3-component homogeneously blended pellets 1-. During this extrusion operation, the raw material supply at the extruder supply section was stable with smooth feeding.

Subsequently, the resulting pellets were prepared and heat-treated to form test pieces in the same manner as in Example 1, and the physical properties were measured as shown in Table 6. It has an excellent balance of mechanical properties, heat resistance and sliding properties.

Table 3

Claims (1)

[Claims] (a) Polyamide diimide resin 30-90% by weight, P)
Tallaphite and/or moly disulfide 11f 10~
A molding material is obtained in which at least one type selected from polyphenylene sulfide resins, polyamide resins, and aromatic polyester resins, which have better fluidity than polyamide-imide resins, and in which at least one type of resin having a weight ratio of 0 to 30 is closely blended. In this case, for 1100 parts by weight of the above-mentioned maxims (a), (b) and 2), 1-60 parts by weight of a polar solvent having an affinity for the polyamide-imide resin ki: t'j:
A method for producing a wear-resistant resin molding material, which involves mixing 7, then removing the solvent from this mixture and then melt-mixing it, or thoroughly melt-mixing it and then removing the solvent.