JPH0229696B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an aromatic polymer composition containing a specific graft-modified polyolefin wax and having improved lubricity and mold release properties. Thermoplastic aromatic polymers such as ABS, polycarbonate, polyphenylene oxide, and modified products thereof are molded by injection molding, blow molding, extrusion molding, and various other molding methods. As the molecular weight of these aromatic polymers increases, the melt viscosity generally increases, resulting in a decrease in fluidity during melt molding and poor lubricity. In addition, when removing a molded product from a mold during molding of aromatic polymers, a draft angle is usually provided in the mold or a mold release agent is applied to the mold to make it easier to release the mold. ing. However, when molded products are applied to precision machinery, electrical appliance parts, etc., it is often not allowed to provide a draft angle. As a result, if the shape of the molded product is complex, the position and thickness of the ejector pins will be restricted, making it difficult to remove the molded product and causing damage to the molded product more frequently. There is. Various attempts have been made to improve the lubricity or mold release properties of these aromatic polymers during molding. For example, methods include blending higher fatty acids, higher fatty acid amides, metal salts of higher fatty acids, higher fatty acid esters, liquid paraffin, wax, etc. with aromatic polymers, or applying a mold release agent such as silicone oil to the mold. Proposed. However, in the method of blending the lubricant with an aromatic polymer, a large amount of the lubricant must be blended in order to improve mold release properties.
As a result, there were problems such as a decrease in the mechanical strength of the aromatic polymer composition. In addition, the method of applying a mold release agent makes the molding operation complicated,
There are disadvantages such as often impairing the appearance and weld strength of the molded product. The present inventors investigated techniques for improving the above-mentioned lubricity effect and mold release effect during molding of aromatic polymers such as polyphenylene oxide, polycarbonate, polystyrene, and ABS. By creating a composition containing a specific graft-modified polyolefin wax,
The inventors have discovered that the above object can be achieved without impairing the mechanical strength of aromatic polymers, and have arrived at the present invention. To summarize the present invention, the present invention provides an aromatic polymer (A) selected from ABS, polycarbonate, polyphenylene oxide, and modified products thereof.
Intrinsic viscosity 0.04 to 0.6 dl/g per 100 parts by weight
Styrenic compound (a) and acrylonitrile (b) are added to 100 parts by weight of polyolefin wax (a).
Graft-modified polyolefin wax (B) obtained by grafting the sum of (b) in a proportion of 1 to 900 parts by weight
The gist of the invention is an aromatic polymer composition characterized in that the aromatic polymer composition contains 0.05 to 30 parts by weight. The present invention will be explained in detail below. As the aromatic polymer (A) constituting the composition of the present invention, one or more selected from ABS, polycarbonate, polyphenylene oxide, and modified products thereof can be used. Specifically, ABS; bisphenol A polycarbonate;
Aromatic polycarbonates such as bisphenol F polycarbonate and bisphenol AD polycarbonate; polyphenylene oxides or modified products thereof such as polyphenylene oxide, modified polyphenylene oxide, and grafted polyphenylene oxide. Can be done. These may be used alone or in combination of two or more to form the composition of the present invention. These aromatic resins may be foams. The graft-modified polyolefin wax (B) constituting the composition of the present invention is a specific polyolefin wax containing a styrene compound (a) and acrylonitrile.
This is a styrene compound/acrylonitrile graft-modified polyolefin wax obtained by graft copolymerizing a specific amount of (b). The polyolefin wax to be subjected to graft copolymerization has an intrinsic viscosity (measured in decalin solvent at 135°C) of 0.04 to
It is necessary to be in the range of 0.6 dl/g, and more preferably in the range of 0.05 to 0.5 dl/g. The intrinsic viscosity of polyolefin wax is 0.04
When the size is smaller, even if the styrene compound/acrylonitrile graft-modified polyolefin wax obtained from the polyolefin wax is blended with an aromatic polymer, the lubricity and mold release effects of the composition are excellent; The appearance shrinkage rate of the molded product becomes poor. In addition, when the intrinsic viscosity of the polyolefin wax becomes larger than 0.6, the styrenic compound prepared from the polyolefin wax
Even if an acrylonitrile graft-modified polyolefin wax is similarly blended with an aromatic polymer, no improvement in the lubricating effect and mold release effect of the composition is observed, and no improvement in moldability is observed. Here, the polyolefin wax is a homopolymer of α-olefin such as ethylene, propylene, 1-butene, 1-hexene, 4-methyl-1-pentene, 1-decene, or a mixture of two or more α-olefins. It is a copolymer and has an intrinsic viscosity within the above range. For example, polyethylene wax obtained by thermal decomposition of high-pressure polyethylene, high-pressure polymerized polyethylene wax obtained by radical polymerization of ethylene at high pressure, ethylene or ethylene and the above α-olefin in the presence of a transition metal compound catalyst. Polyethylene wax or ethylene/α-olefin copolymer wax, polypropylene wax, poly-1-butene wax, poly4-methyl-1-pentene wax, polypropylene-4-
Examples include methyl-1-pentene copolymer wax. Note that the polyolefin wax referred to herein also includes oxides of polyolefin wax. The oxygen content in this case is usually within 10% by weight. Specifically, the styrene compound (a) to be grafted to the graft-modified polyolefin wax (B) constituting the composition of the present invention includes styrene, α-methylstyrene, o-methylstyrene,
Examples include m-methylstyrene and p-methylstyrene. Furthermore, the grafting ratio of the styrene compound (a) and acrylonitrile (b) in the graft-modified polyolefin wax (B) is as follows:
The total amount of (b) must be in the range of 1 to 900 parts by weight, and more preferably in the range of 5 to 500 parts by weight. When the total grafting ratio of (a) and (b) is less than 1 part by weight, the compatibility with aromatic polymers decreases, and the composition can still achieve some degree of lubricity and mold release effect. However, this is not preferable because the mechanical strength of the molded product decreases. Furthermore, if the total grafting ratio of (a) and (b) exceeds 900 parts by weight, the lubricating effect and mold release effect of the composition will not be improved as in the case where low molecular weight polystyrene or the like is blended. Furthermore, the ratio of amounts of (a) and (b) grafted onto the polyolefin wax depends on the compatibility between the graft-modified polyolefin wax (B) and the aromatic compound (A) constituting the composition of the present invention. The weight ratio (b)/
(a) is 0.1 to 5, more preferably 0.1 to 1, particularly preferably 0.2 to 1. The graft-modified polyethylene wax (B) contains about 10% of vinyl monomers other than (a) and (b), such as (meth)acrylic acid ester, vinyl chloride, maleic anhydride, etc. It does not matter if it is grafted within The intrinsic viscosity [η] of the graft-modified polyolefin wax (B) constituting the composition of the present invention [measured in a decalin solvent at 135°C] is usually in the range of 0.05 to 0.9 dl/g, preferably 0.07 to 0.7. It is. The graft-modified polyolefin wax (B) constituting the composition of the present invention can be produced by a conventionally known method. For example, a method is adopted in which the polyolefin wax is reacted with the styrene compound (a) and acrylonitrile (b) under heating in a solution or molten state. The method can be shown to be carried out in the presence of In this case, the styrene compound (a) is first grafted onto the polyolefin wax, and then the acrylonitrile (b) is grafted onto the polyolefin wax. There are several methods, including a method in which (a) and (b) are simultaneously grafted onto a polyolefin wax. Among these, the graft-modified polyolefin (B) produced
Has little coloring property when heated, and is an aromatic polymer.
It is preferable that it has good compatibility with (A). The radical initiators used in the above reaction include organic peroxides and organic peresters, such as benzoyl peroxide, dichlorobenzoyl peroxide, dicumyl peroxide, di-tert-butyl peroxide, 2,5-dimethyl-2,5-di(peroxybenzoate), ) hexin-3, 1,
4-bis(tert-butylperoxyisopropyl)benzene, lauroyl peroxide, tert-
Butyl peracetate, 2,5-dimethyl-2,
5-di(tert-butylperoxy)hexyne-
3,2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, tert-butylbenzoate, tert-butylperphenyl acetate,
tert-butyl perisobutyrate, tert-butyl per-sec-octoate, tert-butyl perpivalate, cumyl perpivalate and tert-butyl perdiethyl acetate, other azo compounds such as azobis-isobutylnitrile, dimethyl azoiso There is butyrate. Among these, dicumyl peroxide, di-tert-butyl peroxide, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexyne-3,2,
Dialkyl peroxides such as 5-dimethyl-2,5-di(tert-butylperoxy)hexane and 1,4-bis(tert-butylperoxyisopropyl)benzene are preferred. The temperature during the reaction is usually in the range of 130 to 300°C, preferably 135 to 250°C. The blending ratio of the graft-modified polyolefin wax (B) in the aromatic polymer composition of the present invention is based on 100 parts by weight of the aromatic polymer (A).
It is necessary to range from 0.05 to 30 parts by weight, and more preferably from 0.1 to 20 parts by weight. If the blending ratio of the graft-modified polyolefin wax (B) to 100 parts by weight of the aromatic polymer (A) is less than 0.05 parts by weight, no improvement in the lubricity effect and mold release effect of the composition will be observed. If the amount exceeds 30 parts by weight, the molded product will exhibit significant delamination and the balance between mechanical strength and impact strength will be lost. The aromatic polymer composition of the present invention may consist only of the above-mentioned two essential components, but other additives such as dyes, pigments, glass fibers, Carbon black, antistatic agent, heat stabilizer, weather stabilizer, calcium carbonate, SBR,
NBR, styrene/maleic acid copolymer, etc. can be blended. As a method for preparing the aromatic polymer composition of the present invention, a mixture consisting of an aromatic polymer (A), a graft-modified polyolefin wax (B), and other additives as necessary is mixed with Henschel A method of directly using a mixer, V-blender, or ribbon blender after mixing, or further kneading and granulating with an extruder, etc., or granulating after melt-kneading with a Banbury mixer, single-screw or multi-screw extruder, kneader, etc. A method of molding can be adopted. The aromatic polymer composition of the present invention can be used not only for injection molding, but also for blow molding, injection blow molding, compression molding,
Reduces adhesion to molds, dies, rolls, etc. in extrusion molding, rotational molding, etc., improving work efficiency.
Furthermore, since fluidity is improved, molded products with excellent appearance and dimensional accuracy can be obtained, and are useful for industrial parts and electrical appliance parts. Next, the composition of the present invention will be specifically explained with reference to Examples. Example 1 420 g of high-density polyethylene wax (trade name: Mitsui Hiwax 110p, manufactured by Mitsui Petrochemical Industries, Ltd.) having an intrinsic viscosity of 0.08 dl/g was charged into a 1.5 glass reactor and melted at 140°C. Next, 190 g of styrene monomer, 90 g of acrylonitrile, and 11.7 g of di-tert-butyl peroxide (hereinafter abbreviated as DTBPO) were added, and the mixture was heated and reacted for 4 hours, and then degassed in a 5 mmHg vacuum for 1 hour to volatilize the molten state. was removed and then cooled. The amount of styrene and acrylonitrile grafted in the obtained styrene/acrylonitrile grafted polyethylene wax (hereinafter referred to as ASW-) is
34g in 100g of styrene/acrylonitrile grafted polyethylene wax (grafting rate 85%)
It was hot. Next, the obtained ASW-1 was converted into a commercially available
After dry blending 1, 3, and 5 parts by weight to 100 parts by weight of ABS (Styrac 101 manufactured by Asahi Kasei), use a 20 mmφ extruder (set temperature 280°C, 50 rpm).
It was granulated and the extrusion amount was determined. Further, the granulated sample was molded into a test piece for a tensile strength test using an IS-50 injection molding machine manufactured by Toshiba Machine Co., Ltd. At the same time, a spiral flow test was conducted (resin temperature 260°C, mold temperature 50°C, extrusion pressure 1000Kg/cm ² ). Tensile properties: Measured by ASTM D638 method. Spiral length: e.g. Mod.Plastics, 34 ,
The length of the spiral obtained under the above setting conditions was measured using the spiral flow test method as described in [12], page 111. The larger this value is, the better the fluidity during melting is. Mold releasability: Depending on the condition when taking out the molded square plate from the metal frame, 5 indicates a state in which the square plate can be removed from the metal frame without resistance, and a state in which it cannot be removed without forcibly peeling between the square plate and the metal frame with a razor etc. 1, and the middle was divided into 3 stages, and the evaluation was performed on a 5-stage scale. Comparative Example 1 The ABS used in Example 1 was tested alone in the same manner as in Example 1. The results are shown in Table 1. Examples 2-3 The following styrene-acrylonitrile graft waxes were synthesized in the same manner as in Example 1.

[Table] ABS was evaluated in the same manner as in Example 1 using ASW- and ASW-. The results are shown in Table 1. Example 4 In the same manner as Example 1, the intrinsic viscosity was 0.23 dl/g.
Using oxidized high-density polyethylene wax [trade name: Mitsui Hiwax 405MP, manufactured by Mitsui Petrochemical Industries, Ltd. (oxygen content 1.0wt%)], the weight ratio of acrylonitrile/styrene was 1/2, and the acrylonitrile/styrene weight ratio was 1/2.
An acrylonitrile-styrene graft wax (ASW-) with a styrene graft amount of 31 wt% was synthesized and evaluated in the same manner as in Example 1. The results are shown in Table 1. Comparative Example 2 A styrene-grafted wax was synthesized in the same manner as in Examples 1-4, except that only styrene was grafted instead of acrylonitrile and styrene (SW-1: Styrene-grafted wax) amount 22wt%). Using this SW-, evaluations similar to those in Examples 1 to 4 were performed. The results are shown in Table 1. It can be seen that the lubricity effect is significantly smaller than that of the examples. Comparative Example 3 Evaluation was carried out in the same manner as in Examples 1 to 4, except that Mitsui Hiwax 110P was used instead of the acrylonitrile/styrene graft wax synthesized in Examples 1 to 4. The results are shown in Table 1. It can be seen that the lubricity effect is significantly smaller than in the examples, and the tensile strength is significantly lowered.

【table】

[Table] *The molded square plate was destroyed inside the mold Examples 5 to 7, Comparative Example 4 Various graft waxes were synthesized in the same manner as in Example 1 using the raw material high waxes and graft monomers shown in Table 2.

[Table] Next, using each graft wax, polycarbonate resin (trade name Panlite L-
1250, manufactured by Teijin Kasei Ltd. (hereinafter referred to as PC), the performance was evaluated. The results are shown in Table 3. However, the extruder used was a 20mmφ one, and the temperature was set at 280℃.
Granulation was performed at 50 rpm. Furthermore, the cylinder temperature during injection molding was set at 295°C. For comparison, the results for polycarbonate resin alone are shown in Table 3 (Comparative Example 4). Comparative Example 5 A blending experiment was conducted on PC in the same manner as in Examples 5 to 7 except that Mitsui Hiwax 200P was used instead of the acrylonitrile/styrene monomer graft wax in Examples 5 to 7.
In any case, surging occurred in the extruder and granulation could not be completed. Comparative Example 6 Styrene graft wax used in Comparative Example 2
Using SW-, performance evaluations were performed on polycarbonate resins in the same manner as in Examples 5 to 7. The results are shown in Table 3. It can be seen that the effect of increasing the spiral flow is small and the tensile strength is significantly reduced.

【table】

【table】

Claims (1)

[Claims] 1 Intrinsic viscosity based on 100 parts by weight of aromatic polymer (A) selected from ABS, polycarbonate, polyphenylene oxide, and modified products thereof.
0.04 to 0.6 dl/g polyolefin wax
A graft-modified polyolefin wax (B) obtained by grafting a styrene compound (a) and acrylonitrile (b) in a ratio of 1 to 900 parts by weight in total to 100 parts by weight (0.05 to 30 parts by weight) An aromatic polymer composition characterized in that it contains parts by weight.