JPH09221566A - Heat-resistant lubricant for thermoplastic resin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a lubricant which has excellent heat resistance and is effective to improve the flowability of even a thermoplastic resin having a high molding temperature by synthesizing an ester of a carboxylic acid with an aromatic polyhydric alcohol. SOLUTION: At least one carboxylic acid selected from among 16C or higher higher aliphatic monocarboxylic and polycarboxylic acids is reacted with an aromatic polyhydric alcohol being a bisphenol A/alkylene oxide adduct (the number of moles of addition is 0-6) to obtain an ester acting as a heat-resistant lubricant. This lubricant is desirably used in an among of 0.1-5 pts.wt. per 100 pts.wt. thermoplastic resin.

Description

Detailed Description of the Invention

[0001]

[0001] The present invention relates to a heat-resistant lubricant for thermoplastic resins. More specifically, the present invention relates to a lubricant for a thermoplastic resin, which is excellent in heat resistance and can give a fluidity improving effect even to a thermoplastic resin having a high molding processing temperature.

[0002]

2. Description of the Related Art Conventionally, thermoplastic resins have been used for press molding,
In molding processes such as extrusion molding and injection molding, there is a drawback that the melt viscosity is high and the moldability is reduced. These are due to the lubricity of the resin, and lubricants have been blended for the purpose of preventing such disadvantages.

Examples of conventionally used lubricants for thermoplastic resins include low molecular weight polyethylene waxes, higher fatty acids such as stearic acid and metal salts thereof, higher fatty acid esters, and higher fatty acid amides. However, these conventional lubricants cause bloom or bleed-out, or have insufficient releasability or lubricity,
I'm still not satisfied.

Particularly in recent years, a thermoplastic resin having a high molding processing temperature has been developed, and its use as a material capable of substituting for a metal has been remarkably increased in many fields. However, the molding processing temperature of such a thermoplastic resin is relatively high. In general, the temperature is 180 ° C or higher, and even higher one may reach 350 ° C. When a conventional lubricant is used for a thermoplastic resin having a high processing temperature, any of the conventional lubricants is inferior in heat resistance.

[0005] Even amides such as stearic acid amide and ethylene bis stear amide, which have relatively excellent heat resistance, are still inferior in heat resistance to thermoplastic resins having a high molding temperature, so that they have fluidity as a lubricant. And the physical properties such as impact strength and heat deformation temperature of the thermoplastic resin are reduced. In particular, when used for ester-based thermoplastic resins such as polycarbonate and polyethylene phthalate, they have the disadvantage of decomposing the resin itself.

[0006] Ester-type castor-hardened oil is also relatively excellent in heat resistance and does not cause much deterioration in physical properties as in amide-type oils, but is still heat-resistant to thermoplastic resins having high molding and processing temperatures. Since it is inferior, the effect of improving fluidity as a lubricant is not sufficient.

[0007]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned drawbacks of the prior art, and has an object to improve the fluidity of a thermoplastic resin having a high molding temperature. It is an object of the present invention to provide a lubricant for a thermoplastic resin having an excellent heat resistance capable of giving an effect.

[0008]

Means for Solving the Problems As a result of intensive studies for achieving the above object, the present inventor has found that a heat resistant lubricant having a novel composition consisting of an ester of a carboxylic acid and an aromatic polyhydric alcohol is The present invention has been completed by solving the above drawbacks and finding that it is a lubricant that can withstand high temperatures during molding of thermoplastic resins.

That is, the present invention is a heat resistant lubricant comprising an ester of a carboxylic acid and an aromatic polyhydric alcohol.

The carboxylic acid used in the present invention includes higher aliphatic monocarboxylic acid and polyvalent carboxylic acid. The higher aliphatic monocarboxylic acid used in the present invention is preferably a saturated aliphatic monocarboxylic acid having 16 or more carbon atoms and a hydroxycarboxylic acid, and examples thereof include palmitic acid, stearic acid, behenic acid and montanic acid. Particularly preferred among these are stearic acid, behenic acid and 1,2-hydroxystearic acid. A carboxylic acid having less than 16 carbon atoms is not preferable because it has poor fluidity and heat resistance when kneaded into a thermoplastic resin.

Examples of the polyvalent carboxylic acid used in the present invention include carboxylic acids of dibasic acid or more, and examples thereof include aliphatic dicarboxylic acids such as malonic acid, succinic acid, adipic acid, pimelic acid, azelaic acid and sebacic acid. Examples thereof include aromatic dicarboxylic acids such as phthalic acid and terephthalic acid, and alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid and cyclohexylsuccinic acid. Of these, particularly preferred are adipic acid and sebacic acid.

The aromatic polyhydric alcohol used in the present invention is preferably an alkylene oxide adduct of bisphenol, such as bisphenol A ethylene oxide adduct and bisphenol A propylene oxide adduct. Of these, particularly preferred is an ethylene oxide adduct of bisphenol A. The number of alkylene oxide adducts is usually 0 to
6, preferably 0-4. If the number of additions exceeds 6, the heat resistance tends to deteriorate as the number of additions increases, which is not preferable.

Among the carboxylic acids used in the present invention, the amount of polyvalent carboxylic acid used is 0 to 1 mol based on 2 mol of the higher aliphatic monocarboxylic acid. An ester having more excellent heat resistance can be obtained as the amount of the polycarboxylic acid used increases. In the ester of the present invention, the amount of the aromatic polyhydric alcohol used is 1 to 2 mol based on 2 mol of the carboxylic acid, and this amount of the polyhydric carboxylic acid used in combination with the higher aliphatic monocarboxylic acid is It changes according to the quantity.

The lubricant of the present invention may contain other lubricant components such as paraffin wax, fatty acid metal salts, fatty acid amides and fatty acid esters, and various additives such as colorants, antistatic agents and weathering agents.

Suitable thermoplastic resins for use in the lubricant of the present invention include, for example, polyolefin resin, polyamide resin, polyester resin, polycarbonate resin, polyphenylene oxide resin, polyphenylene sulfide resin, styrene resin, polysulfone resin, polyacetal resin, Polyether ether ketone resin, polymethacrylic resin, polyimide resin, polyamide-imide resin,
Polyetherimide resin, polyether sulfone resin,
Examples thereof include polytetrafluoroethylene resin and thermoplastic elastomer. Further, it is also suitable for a polymer alloy composed of two or more kinds of the above resins.

Examples of the polyolefin resin include polypropylene and polyethylene. Examples of the polyamide resin include nylon 6, nylon 66, nylon 11, nylon 12, nylon 46, nylon 610, nylon 612, and the like, and also include aromatic polyamide. Examples of the polyester resin include polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate and polybutylene naphthalate.
Furthermore, aromatic polyesters such as polyarylate are also included. As the polyphenylene oxide resin, 2,6
It also includes a polymer of dimethyl and 2,6-diphenylphenol grafted with a styrene resin or another resin.

As the styrene resin, polystyrene,
AAS resin (acrylonitrile-acryl-styrene copolymer), AES resin (acrylonitrile-propylene rubber reinforced styrene-ethylene copolymer), AS resin (acrylonitrile-styrene copolymer), ABS resin (acrylonitrile-butadiene-styrene copolymer) Merged), M
Examples thereof include S resin (methyl methacrylate-styrene copolymer), and the ABS resin also includes heat resistant ABS resin such as α-methyl modified and N-phenylmaleimide modified.

As the thermoplastic elastomer, a styrene-isoprene copolymer as a styrene elastomer,
Examples thereof include styrene-butadiene copolymers, and further include polyolefin-based elastomers, polyvinyl chloride-based elastomers, polyurethane-based elastomers, polyester-based elastomers, and polyamide-based elastomers.

The amount of the lubricant of the present invention used is 0.1 to 5 parts by weight, preferably 0.3 to 2.
0 parts by weight. If the amount used is less than 0.1 part by weight, a sufficient lubricant effect cannot be obtained, and if it exceeds 5 parts by weight, the effect remains unchanged even if added, and in some cases mechanical properties deteriorate, which is not preferable.

The mixing of the lubricant of the present invention and the thermoplastic resin can be carried out by any means known to those skilled in the art. For example, a lubricant is blended with the thermoplastic resin granulated product during or after the polymerization of the thermoplastic resin. After that, they can be melt-kneaded and mixed with a twin-screw extruder or the like.

[0021]

The present invention will now be described with reference to the following examples, which should not be construed as limiting the invention thereto.
In the following, “part” means part by weight.

Synthesis of the Ester of the Present Invention Ester 1 In a reaction vessel equipped with a thermometer, a test tube with a condenser, a dropping funnel, a nitrogen introducing tube and a stirrer, 1 mol of stearic acid and 2 mol of bisphenol A ethylene oxide adduct are added. Molar and titanium octylene glycolate 0.000
16 mol was charged, and 6 at 190 ° C to 230 ° C in a nitrogen stream.
An hourly dehydration reaction was performed to obtain ester 1 having an acid value of 1.0.

Ester 2 Ester 2 having an acid value of 1.0 in the same manner as Ester 1 except that 1 mol of behenic acid is used instead of 1 mol of stearic acid.
I got

Ester 3 Ester 3 having an acid value of 1.5 was prepared in the same manner as Ester 1 except that 1 mol of stearic acid was replaced with 1 mol of a long-chain carboxylic acid having a molecular weight of 550 (manufactured by Toyo Petrolite: UNICID 550 acid). Obtained.

Ester 4 In a reaction vessel equipped with a thermometer, a test tube with a condenser, a dropping funnel, a nitrogen introducing tube and a stirrer, 1 mol of stearic acid, 0.5 mol of adipic acid, 2 mol of bisphenol A ethylene oxide adduct 1 Mol and titanium octylene glycolate 0.00016 mol and charged in a nitrogen stream 19
A dehydration reaction was performed at 0 ° C to 230 ° C for 6 hours to obtain an ester 4 having an acid value of 1.5.

Ester 5 An ester 5 having an acid value of 2.5 was obtained in the same manner as the ester 4 except that 0.5 mol of sebacic acid was used instead of 0.5 mol of adipic acid.

Ester 6 An ester 6 having an acid value of 1.0 was obtained in the same manner as the ester 4 except that 0.5 mol of terephthalic acid was used instead of 0.5 mol of adipic acid.

Ester 7 Acid value was the same as for ester 4 except that 0.07 mol of sebacic acid was used instead of 0.5 mol of adipic acid, and 1 mol of bisphenol A ethylene oxide 2 mol adduct was changed to 0.56 mol. 2.0 of ester 7 was obtained.

Ester 8 An ester 8 having an acid value of 1.5 was obtained in the same manner as the ester 1 except that 1 mol of 1,2-hydroxystearic acid was used instead of 1 mol of stearic acid.

Synthesis of Comparative Ester Ester 9 Bisphenol A Ethylene Oxide 2 Mole Adduct
Bisphenol A ethylene oxide 1 instead of 5 mol
Ester 9 having an acid value of 0.8 was obtained in the same manner as Ester 1, except that 0.5 mol of 0 mol adduct was used.

Ester 10 Bisphenol A Ethylene oxide 2 mol adduct 0.
An ester 10 having an acid value of 3.0 was obtained in the same manner as the ester 1 except that 0.25 mol of pentaerythritol was used instead of 5 mol.

Ester 11 Ester 1 having an acid value of 1.5 is the same as Ester 1 except that 1 mol of lauric acid is used instead of 1 mol of stearic acid.
1 was obtained.

Ester 12 Bisphenol A ethylene oxide 2 mol adduct 0.
An ester 12 having an acid value of 2.0 was obtained in the same manner as the ester 1 except that 0.33 mol of trimethylolpropane was used instead of 5 mol.

The following lubricants 1 and 2 were used as conventional lubricants. Lubricant 1: Castor hydrogenated oil (Kawaken Fine Chemicals) Lubricant 2: Ethylene bis stearoamide (EBS) (Kyoeisha Chemical)

Heat Resistance Test of Lubricants The lubricants of the present invention and comparative lubricants were heated using a differential thermal balance (TG-DTA manufactured by Rigaku Denki) at a heating rate of 10 ° C./m.
In, atmosphere: The thermal loss was measured under the condition of 50 cc / min of air, and the thermal loss rate (%) at 250 ° C., 300 ° C. and 350 ° C. was obtained. Table 1 shows the results.

[0036]

[Table 1]

[0037]

[Table 2]

Impact resistance and fluidity test Using the twin screw extruder, the thermoplastic resin of the present invention and the comparative lubricant were melt-kneaded at the compounding ratios shown in Table 2 to pelletize the pellets, followed by injection molding. Using a machine, test pieces (Invention Examples 1 to 13 and Comparative Examples 1 to 8) were prepared and Izod impact strength was measured. The melt flow rate (MFR) of the pellets kneaded as fluidity was measured. The results are shown in Table-2.

[0039]

[Table 3]

[0040]

[Table 4]

The injection molding conditions for the ABS resin and PC resin were set as follows. ABS resin: N-phenylmaleimide modified heat resistant ABS resin Mitsubishi Kasei Monsanto Superlex SPX-M-25 PC resin: Polycarbonate resin Mitsubishi Engineering Plastics Iupilon S-2000

Izod impact strength and melt flow rate were measured by the following methods: Izod impact strength: Izod impact strength was measured according to JIS K 7110, and a test piece was 4.0 mm × 12.6 mm (notched). Melt flow rate (MFR): JIS K7210
The measurement was carried out at a load of 5 kg and a measuring temperature of 250 ° C. in the case of ABS resin. In the case of PC resin, load 2.
The measurement was performed at 16 kg and a measurement temperature of 280 ° C.

As is clear from the results shown in Tables 1 and 2, the lubricant of the present invention has much higher heat resistance than conventional lubricants, is excellent in fluidity, and has physical properties of resin. It turns out that it is an excellent one that does not affect.

[0044]

As described in detail above, since the lubricant of the present invention has excellent heat resistance and excellent fluidity, it is extremely useful for improving the fluidity of a thermoplastic resin having a high processing temperature.

Claims (5)

[Claims] 1. A heat resistant lubricant comprising an ester of a carboxylic acid and an aromatic polyhydric alcohol. 2. The lubricant according to claim 1, wherein the carboxylic acid is a higher aliphatic monocarboxylic acid having 16 or more carbon atoms. 3. The lubricant according to claim 1, wherein the carboxylic acid is a higher aliphatic monocarboxylic acid having 16 or more carbon atoms and a polyvalent carboxylic acid. 4. The lubricant according to claim 1, wherein the aromatic polyhydric alcohol is an alkylene oxide adduct of bisphenol A. 5. The lubricant according to claim 4, wherein the addition number of the alkylene oxide adduct is 0 to 6.