JPH0155669B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an aromatic polymer composition containing a styrene compound-grafted polyolefin wax and having improved lubricity and mold release properties. Thermoplastic aromatic polymers such as polyolefins and polycarbonates 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 parts such as precision machines and electrical appliances, 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, aromatic polymers with higher fatty acids,
Methods have been proposed that include blending higher fatty acid amides, higher fatty acid metal salts, higher fatty acid esters, liquid paraffin, wax, etc., and applying a mold release agent such as silicone oil to the mold. However, in the method of blending the lubricant into an aromatic polymer, a large amount of the lubricant must be blended in order to improve mold releasability, resulting in a decrease in the mechanical strength of the aromatic polymer composition. There was a problem. In addition, the method of applying a mold release agent has disadvantages such as making the molding operation complicated and often impairing the appearance and weld strength of the molded product. The present inventors have investigated techniques for improving the aforementioned lubricity and mold release effects during molding of aromatic polymers such as polyphenylene oxide and polycarbonate, and have identified The inventors have discovered that the above object can be achieved without impairing the mechanical strength and melt fluidity of the aromatic polymer by creating a composition containing a styrene-based compound grafted polyolefin wax, and have thus arrived at the present invention. To summarize the present invention, the present invention comprises: (a) an aromatic polymer other than a styrenic polymer selected from aromatic polycarbonate, polyphenylene oxide, and aromatic polyester;
and (b) 0.05 per 100 parts by weight of the aromatic polymer (a).
1 to 900 parts by weight of a styrenic compound per 100 parts by weight of polyolefin wax with an intrinsic viscosity of 0.04 to 0.5 dl/g, ranging from 1 to 30 parts by weight.
The gist of the present invention is an aromatic polymer composition containing a styrenic compound-grafted polyolefin wax in which parts by weight are grafted. Aromatic polymer (a) constituting the composition of the present invention
is an aromatic polymer other than a styrenic polymer containing a styrenic hydrocarbon component unit, such as bisphenol A polycarbonate, bisphenol F polycarbonate, bisphenol AD
Aromatic polycarbonates such as polycarbonate, polyphenylene oxides such as polyphenylene oxide, modified polyphenylene oxide, grafted polyphenylene oxide, and polyethylene terephthalate, polybutylene terephthalate, polyethylene terephthalate isophthalate, polyethylene 2 , 6-naphthalene dicarboxylate, polyphenylene terephthalate,
It is selected from aromatic polyesters such as bisphenol A/terephthalic acid copolycondensate and bisphenol A/terephthalic acid/isophthalic acid copolycondensate. These aromatic resins may be foams. Among these aromatic resins, polyethylene terephthalate, polycarbonate, polyphenylene oxide, etc. are preferably used in the composition of the present invention. The styrene compound grafted polyolefin wax (b) constituting the composition of the present invention is a styrene compound grafted polyolefin wax obtained by graft copolymerizing a specific amount of a styrene compound onto a specific polyolefin wax. The polyolefin wax subjected to graft copolymerization has its intrinsic viscosity [measured at 135°C in decalin solvent]
is required to be in the range of 0.04 to 0.5 dl/g, more preferably in the range of 0.05 to 0.4 dl/g, and particularly preferably in the range of 0.05 to 0.3 dl/g. When the intrinsic viscosity of the polyolefin wax becomes smaller than 0.04, when the styrene compound-grafted polyolefin wax obtained from the polyolefin wax is blended with an aromatic polymer, the lubricating effect and mold release effect of the composition decrease. Although it is excellent, the appearance shrinkage rate of the molded product becomes inferior. In addition, when the intrinsic viscosity of the polyolefin wax is greater than 0.5, when a styrene compound-grafted polyolefin wax prepared from the polyolefin wax is similarly blended with an aromatic polymer, the lubricating effect of the composition and the release No improvement in moldability effect was observed, and no improvement in moldability was 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 copolymer of two or more α-olefins. It is a combination and has an intrinsic viscosity within the above-mentioned 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. Examples include polyethylene wax or ethylene/α-olefin copolymer wax obtained by medium/low pressure polymerization. Among these polyolefin waxes, polyolefin waxes containing ethylene as a main component are preferred. Specifically, the styrene compounds grafted to the styrene compound grafted polyolefin wax of the present invention include styrene, α-methylstyrene, o-methylstyrene, m-methylstyrene,
Examples include p-methylstyrene. The grafting ratio of the styrene compound in the styrene compound grafted polyolefin wax (b) constituting the composition of the present invention must be in the range of 1 to 900 parts by weight based on 100 parts by weight of the polyolefin wax. The amount is preferably in the range of 10 to 500 parts by weight. When the grafting ratio of the styrene compound is less than 1 part by weight,
Compatibility with aromatic polymers decreases, and although the composition can provide some degree of lubricity and mold release effects, it is undesirable because the mechanical strength of the molded product decreases. Furthermore, if the grafting ratio of the styrene compound 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 is blended. Intrinsic viscosity [η] of the styrenic compound-grafted polyolefin wax constituting the composition of the present invention
[Measured in decalin solvent at 135℃] is usually
It ranges from 0.05 to 1.0 dl/g, preferably from 0.07 to 0.6. The styrenic compound-grafted polyolefin wax of the present invention can be produced by a conventionally known method. For example, a method is adopted in which the polyolefin wax and the styrene compound are reacted under heating in a solution state or a molten state, and the reaction is carried out in the presence of a radical initiator if necessary. be able to. As a radical initiator, organic peroxide,
Organic peresters such as benzoyl peroxide, dichlorobenzoyl peroxide, dicumyl peroxide, di-tert-butyl peroxide, 2,5-dimethyl-2,5-di(peroxybenzoate) hexyne-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-butyl perphenyl 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, dimethylazoisobutyrate. Among these, dicumyl peroxide, di-tert-butyl peroxide, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexyne-3,2,5-dimethyl-2,5-di(tert- Dialkyl peroxides such as 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 styrenic compound-grafted polyolefin wax in the aromatic polymer composition of the present invention
The blending ratio of (b) needs to be in the range of 0.05 to 30 parts by weight, and more preferably in the range of 0.1 to 20 parts by weight, based on 100 parts by weight of the aromatic polymer (a). is preferred. When the blending ratio of the styrene compound-grafted polyolefin wax (b) to 100 parts by weight of the aromatic polymer (a) is less than 0.05 parts by weight, improvements in the lubricity effect and mold release effect of the composition are observed. If the amount exceeds 30 parts by weight, the molded product will experience 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 agents, heat stabilizers, weather stabilizers, calcium carbonate, SBR, NBR, styrene/maleic acid copolymer, etc. can be added. As a method for preparing the aromatic polymer composition of the present invention, a mixture consisting of the aromatic polymer (a), the styrene compound grafted polyolefin wax (b), and other additives as necessary is prepared. , by directly using a Henschel mixer, V-blender, or ribbon blender after mixing, or by kneading and granulating with an extruder, etc., or by melt-kneading and granulating with a Banbury mixer, single-screw or multi-screw extruder, kneader, etc. A method of molding or 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, rotary 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 using Examples. Example 1 High-density polyethylene wax with an intrinsic viscosity of 0.08 dl/g (trade name: Mitsui Hi-wax)
350g of 100P (manufactured by Mitsui Petrochemical Industries, Ltd.) was placed in a glass reactor (No. 1) and melted at 140°C. Next, 13 g of styrene monomer and 2.8 g of di-tert-butyl peroxide (hereinafter abbreviated as DTBPO) were added, and after heating and reacting for 6 hours, the mixture remained in a molten state.
Volatiles were removed by degassing in mmHg vacuum for 1 hour, followed by cooling. The amount of styrene grafted in the obtained styrene-grafted polyethylene wax (hereinafter referred to as SG-I) was 3.2 g per 100 g of styrene-grafted polyethylene wax. Next, the obtained SG-1 and grafted polyphenylene ether (manufactured by Asahi Dow, Zylon 300V,
(hereinafter referred to as G-PPE) in the proportions shown in Table 1, and then a 20mmφ extruder (set temperature
The pellets were granulated at 280°C and 50 rpm, and the extrusion amount was determined. In addition, the granulated sample was 200 x 200 x 1 mm in a compression molding machine.
A square plate was formed. Performance was evaluated using the method described below. Tensile properties: Measured by ASTM D638 method. Mold releasability: Depending on the condition when taking out the formed 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 divide the middle into three stages,
This was done using a 5-level evaluation. Appearance of molded plate: visual inspection Examples 2 to 4 High-density polyethylene wax (trade name: Mitsui Hi-wax 200P: Mitsui Petrochemical Industries, Ltd.) with an intrinsic viscosity of 0.13 dl/g was prepared in the same manner as in Example 1.
Styrene and vinyltoluene-grafted waxes were synthesized using a styrene- and vinyl-toluene-grafted wax. Styrene grafting amount 9.1wt%...called SG- 50wt%...calling SG- Vinyl toluene grafting amount 8.9wt%...calling SG- G-PPE using SG-, SG-, and SG-
A blending experiment similar to that in Example 1 was conducted. The results are shown in Table 1. Comparative Examples 1-2 Blend experiments similar to those in Example 1 were conducted for GPPE using high-density polyethylene wax (trade name: Mitsui Hi-wax 100P or 200P, manufactured by Mitsui Petrochemical Industries, Ltd.). The results are shown in Table 1.

【table】

[Table] Examples 5 to 8 Graft wax SG synthesized in Examples 1 to 4
, SG, SG, SG to make polycarbonate resin (product name Panlite L-1250, Teijin Kasei Co., Ltd.
A blending experiment was carried out on the PC (manufactured by Co., Ltd., hereinafter referred to as PC). The results are shown in Table 2. Comparative Examples 3-4 A blending experiment similar to that in Example 1 was conducted for PC using polyethylene wax (Mitsui Hi-wax 100P, 200P). The results are shown in Table 2.

【table】

[Table] Examples 9 to 12 Using the styrene grafted polyethylene waxes (SG- to SG-) obtained in Examples 1 to 4,
Performance evaluation was performed on commercially available glass fiber reinforced polybutylene terephthalate (trade name FR-PMT G-230A, manufactured by Mitsui Petrochemical Industries, Ltd., hereinafter referred to as FR-PBT). The results are shown in Table 3. However, the extruder used was 20mmφ, and the temperature was set at 270℃.
Granulation was performed at 50 rpm. Furthermore, the cylinder temperature during injection molding was set at 260°C, and the mold temperature was set at 70°C. Comparative Examples 5 and 6 For comparison, the results for FR-PBT resin alone are shown in Table 3.
Shown below.

【table】

【table】

【table】

Claims (1)

[Scope of Claims] 1 (a) an aromatic polymer other than a styrene polymer selected from aromatic polycarbonate, polyphenylene oxide, and aromatic polyester, and (b) the aromatic polymer ( a) 0.05 per 100 parts by weight
1 to 900 parts by weight of a styrenic compound per 100 parts by weight of polyolefin wax with an intrinsic viscosity of 0.04 to 0.5 dl/g, ranging from 1 to 30 parts by weight.
An aromatic polymer composition comprising: a styrenic compound-grafted polyolefin wax obtained by grafting part by weight of the styrenic compound.