JPH0386732A - Injection molded thermoplastic resin article and its production - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] [Industrial application field] The present invention provides wax remover resistance, scratch resistance,
Related to thermoplastic resin molded products with excellent impact resistance and gloss.

More specifically, the present invention relates to a thermoplastic resin molded article to which a polyamide graft ionomer thin film is welded, and a method for producing the same.

[Prior Art] Thermoplastic resins are widely used for automobile exterior parts due to their features such as light weight, ease of processing, low price, and flexibility.

Among thermoplastic resins, ethylene-based copolymers, such as ethylene-vinyl acetate copolymers, are widely used in products such as mudguards due to their advantages such as flexibility, cold impact resistance, injection moldability, and price. Injection molded products are widely used for automotive exterior parts.

However, in the case of such automobile exterior parts, ethylene-based copolymers have poor scratch resistance, so it has been pointed out that they suffer from scratches due to, for example, splashing of pebbles. In addition, among thermoplastic resins, olefin homopolymers such as polypropylene and polyethylene are widely used in automobile exterior parts such as bumpers due to their advantages such as heat deformation resistance and injection moldability. There is. However, when such olefin homopolymers are used for automobile exterior parts, there are problems with cold impact resistance and scratch resistance. Furthermore, olefin copolymers with improved cold impact resistance have the disadvantage that the appearance of the molded product is less glossy and only a matte molded product can be obtained. In addition, as thermoplastic resins, general-purpose engineering plastics such as polyamide resin, ABS resin, and polycarbonate resin are widely used in automobile exterior parts such as bumpers and rear panels due to their advantages such as heat deformation resistance and rigidity.

However, even when such engineering plastics are used, their weather resistance and cold impact resistance are insufficient.

On the other hand, when such thermoplastic resins are used as automobile exterior parts, a technique has been established in which one surface is painted to enhance the sense of unity with the car body and to give a sense of luxury. However, in order to paint molded products, a high degree of heat resistance and solvent resistance was required, and in order to ensure the adhesion of the paint film, it was necessary to use an expensive brand suitable for painting. In the case of ethylene-vinyl acetate copolymer resin, which is a molding material, there is a problem that when cleaning the surface with a solvent such as trichlorethylene in the painting process, the surface of the molded product will swell due to the processing temperature, so it is difficult to paint. In addition, in the case of olefin-based homopolymers, there is no suitable brimer and stable adhesion strength of the coating film cannot be obtained. It was necessary to use a brand with improved film adhesion. Additionally, there was a problem in that the painting process itself was time-consuming.

[Problems to be solved by the invention] In order to solve these problems, the main body of thermoplastic resin,
It is conceivable to cover the surface with a surface coating layer that has a gloss very close to the painted appearance, cold impact resistance, and scratch resistance. Metal ion crosslinked product of ethylenically unsaturated carboxylic acid copolymer (
Since ethylene ionomer (hereinafter referred to as ethylene ionomer) has the above-mentioned physical properties, various thermoplastic resin molded products have been proposed in which it is used as a skin layer.

Ethylene-based ionomer, which is used as the surface coating layer of such thermoplastic resin molded products, has excellent scratch resistance, cold impact resistance, and gloss, but in the case of automobile exterior parts, it is used in new cars for the purpose of rust prevention. A so-called wax remover process, which removes the applied wax using a mixture of high-temperature water and kerosene, is carried out at automobile dealerships throughout the country.

At this time, the ethylene-based ionomer surface coating layer had the disadvantage that the surface was attacked and whitened. Therefore, there has been a need for a method for improving the wax remover resistance without impairing the above-mentioned features of the ethylene ionomer.

As a result of extensive studies on this point, the present inventors have developed a graft copolymer (hereinafter referred to as PAO ionomer) in which 5 to 30% by weight of a polyamide oligomer is grafted onto an ethylene ionomer instead of an ethylene ionomer. If a thin film of this PAO ionomer is welded as a surface coating layer of a thermoplastic resin molded product, no whitening phenomenon will occur even when treated with a wax remover at high temperatures, resulting in improved transparency, gloss, and It was discovered that a molded product with excellent scratch resistance and cold impact resistance could be obtained.Furthermore, such injection molded products can be produced by vacuum forming a surface coating layer made of PAO ionomer to specific properties in advance, The coating layer is brought into close contact with the injection mold, and
The present inventors have discovered that by injection molding any thermoplastic resin, it is possible to easily obtain a highly accurate molded product in which the thermoplastic resin body and the PAO ionomer surface coating layer are tightly laminated, and the present invention has been completed. .

[Means for Solving the Problems] The present invention provides an unsaturated carboxylic acid having an unsaturated carboxylic acid content of 5 to 30% by weight,
A thermoplastic resin injection molded product, which is obtained by welding a thin film of 10 to 1000μ thick of a graft copolymer obtained by graft copolymerizing 3 to 30% by weight of a polyamide oligomer to an ethylene ionomer having a degree of neutralization of 10 to 90%, and This is the manufacturing method.

The above ethylene-based ionomer is a copolymer of ethylene and an unsaturated carboxylic acid, or in some cases, a multi-component copolymer of these and other polar vinyl monomers, which is partially metal-chlorinated (neutralized). As the unsaturated carboxylic acid, one having 3 to 8 carbon atoms, particularly acrylic acid or methacrylic acid, is suitable. Further, as other polar vinyl monomers which are optional components in the copolymer, vinyl acetate, esters of acrylic acid or methacrylic acid, etc. can be used. Examples of metal salts include salts of lithium, sodium, potassium, calcium, magnesium, zinc, etc., but zinc is preferred from the viewpoint of reactivity with the polyamide oligomer described below.

Further, the unsaturated carboxylic acid content in the ethylene ionomer is 5 to 30% by weight, preferably 7 to 25% by weight, and the degree of neutralization is 10 to 90%, preferably 20 to 80%.

If the unsaturated carboxylic acid content is less than 5% by weight, the graft polymerization reaction with the polyamide oligomer described below will not occur substantially, and if it exceeds 30% by weight, the resulting PA
The heat deformation resistance of the O ionomer deteriorates. The degree of neutralization is 1
If it is less than 0%, a glossy appearance cannot be obtained, and if it is more than 90%, fluidity is extremely reduced and moldability is inhibited.

In the present invention, this ethylene ionomer is used as a backbone polymer, and a graft copolymer (PAO ionomer) obtained by graft copolymerizing 3 to 30% by weight, preferably 5 to 25% by weight, of polyamide oligomer is used as a surface coating material. used.

The polyamide oligomer to be graft copolymerized with the ethylene ionomer has a primary amino group at its terminal,
The other end is terminated with an alkylamide. This is to prevent further polymerization of the oligomer due to the temperature during the graft reaction.

Such polyamide oligomers are lactam or ω
- Obtained by polymerizing an aminocarboxylic acid monomer in the presence of a primary amine as an end capping agent (polymerization degree regulator).

Examples of lactam or ω-aminocarboxylic acid monomers include those having 6 to 12 carbon atoms, such as caprolactam, laurolactam, 6-aminocapro, phosphoric acid, 9-aminononanoic acid, 11-aminoundecanoic acid, 12-aminododecanoic acid, etc. Among them, ε-caprolactam is particularly preferred.

As the terminal blocking agent, alkylamines having about 1 to 20 carbon atoms, cycloalkylamines, aromatic amines, etc. can be used, but specifically, n-butylamine, n-
Amylamine, n-hexylamine, cyclohexylamine, aniline, etc. are preferred. The average degree of polymerization varies depending on the number of carbon atoms in the lactam or ω-aminocarboxylic acid monomer, but is suitably 5 to 35. The most preferred polyamide oligomer is As the degree of polymerization, about 1O~35
caprolactam oligomer. Average degree of polymerization is 10
If it is less than 35, no substantial effect of improving wax remover resistance can be obtained, and if it is greater than 35, the grafting reaction rate will be slow, transparency will be impaired and it will become cloudy, making it impractical.

The graft copolymerization reaction between the ionomer and the polyamide oligomer is carried out at a temperature higher than the melting point of the ionomer, preferably 1
The ionomer and polyamide oligomer are kneaded at a temperature of 50 to 250° C. As the zero reaction device, any device capable of melting and mixing the polymers may be used, but a screw extruder is suitable.

In the graft copolymerization reaction between an ionomer and a polyamide oligomer, the primary amino group at the end of the polyamide oligomer coordinates with the carboxyl salt of the ionomer to form an ammine complex salt, or reacts with the carboxyl group to form an ammonium salt. and combine.

The reactivity of graft copolymerization varies depending on the type of cation in the ionomer, especially the one at the end of the polyamide oligomer.
In view of the reactivity of graft copolymerization by coordination of the grade amino group to the carboxyl salt of the ionomer, an ionomer neutralized with zinc ions is preferred.

The amount of the polyamide oligomer to be graft copolymerized in the present invention is 3 to 30% by weight, more preferably 5 to 25% by weight, based on the ethylene ionomer. If it is less than 3% by weight, no substantial effect of improving wax remover resistance can be obtained, and if it is more than 30%, the graft reactivity will be significantly reduced.

The thickness of the PAO ionomer thin film is 10 to 1000μ,
Preferably it needs to be in the range of 50 to 700u. If the thickness is thinner than the above range, the wax remover resistance and scratch resistance will not be sufficient, and if the thickness is thicker than the above range,
This is not preferable because vacuum formability becomes difficult.

Of course, additives such as weathering stabilizers, antistatic agents, pigments, and lubricants may be added to the PAO ionomer.

The thermoplastic resin used as the molded product body of the present invention is
Thermoplastic resins other than PAO ionomers, such as olefin homopolymers such as polyethylene and polypropylene, ethylene-vinyl acetate copolymers, ethylene-(meth)
Acrylic acid copolymers and their ionomers, ethylene copolymers such as ethylene-propylene copolymers, ethylene-4-methyl-pentene-1 copolymers, polycarbonates, polyamides, ABS, polyacetals, polyesters, PBT, etc. engineering plastic resins, polystyrene, polymethyl methacrylate, thermoplastic elastomers, etc., but if injection molding is possible,
There are no particular restrictions.

To manufacture the injection molded article of the present invention, first, a PAO ionomer coating layer matching the external shape of the injection molded article is formed by vacuum forming. Usually 50 to 1
Next, this vacuum-formed PAO ionomer coating layer is inserted into an injection mold to perform injection molding of thermoplastic resin. In this case, if you use a mold that shares the vacuum molding mold and the injection molding mold, you can omit the steps of removing the mold from the vacuum molding mold and inserting it into the injection molding mold, making molding easier. You can get the goods.

That is, a PAO ionomer thin film is vacuum formed using a mold for both injection molding and vacuum forming, and a PAO ionomer thin film with a thickness of 10 to 1000 μm is molded along the inner surface of the mold,
Next, the injection molded article of the present invention can be manufactured by injection molding the thermoplastic resin in the above mold.

[Effects of the Invention] According to the present invention, a thin layer of PAO ionomer is formed on the surface of an injection molded product made of thermoplastic resin, so that whitening phenomenon and thermal deformation caused by wax remover treatment in car wash lines are avoided. PAO that is not observed, has excellent scratch resistance and cold impact resistance, and has a transparent surface.
Because it is a thin layer of ionomer, the molded product has excellent gloss.
The lens effect makes the underlying molding stand out and give it depth, giving it the appearance of a painted molding. Furthermore, if the PAO ionomer is colored with a pigment, any paint-like appearance can be obtained regardless of the hue of the underlying molded product. Such thermoplastic resin molded products can be used for automotive exterior parts such as mudguards, bumper parts, and side protectors.

Further, the molded article of the present invention can be widely used in various industrial applications other than automobile exterior parts by taking advantage of the above-mentioned characteristics.

[Example" Next, the present invention will be explained by examples.

The PAO ionomer and thermoplastic resin used are as follows.

PAO onomer Physical properties of door ionomer, physical properties of polyamide oligomer (same below), graft reaction amount of polyamide oligomer 5wt%, M.

F.

00 05g/10min (190°C, 2160g, same below) PAO ionomer 2 - Physical properties of ionomer - Grafting reaction amount of polyamide oligomer f 5wt
%・M.

F.

01 01g/10min PAO ionomer 3 ・Physical properties of ionomer ・Graft reaction amount of polyamide oligomer 5wt% ・M.

F.

01 4g/10 minutes PAO A Onoma-4 ・Physical properties of ionomer ・Graft reaction amount of polyamide oligomer 10wt% ・M.

F.

0° 01g/10min low density polyethylene Product name Miraran M68 Manufactured by Mitsui Petrochemical Industries density 01 916g/cc M.

F.

23g/10 minutes Bo1 Ethylene 2 High-density polyethylene Product name Hi-ZEX 1300J Mitsui Petrochemicals Density 0.965g/cc M, F, R13g/10 minutes Industrial density 0.91g/cc M, F, R 1,8g/10 min (230℃, 2.16kg) and ±2 Ethylene-vinyl (hereinafter abbreviated as EVA) Product name Evaflex EV450 Mitsui・Manufactured by DuPont Polychemicals Vinyl acetate content 19wt% M, F, R 15g/10 minutes Ethylene-methacrylate A (hereinafter abbreviated as HMA)
) Product name Nucrel N714 Made by DuPont Mitsui Polychemicals Methacrylic acid content 12wt% M, F, R 14g/10 minutesProduct name Amilan CM1017C Made by Toshi ■Botandan plate Product name Toyolac #500 Made by Toshi ■ Density 1. 04g/cc M, F, R3g/10 minutes (200℃ load 5kg/crrr) Product name Panlite L-1250 Manufactured by Teijin Kasei WJ Density 1.20g/cc B Neistomer Product name Milastomer 8030B M, F, R manufactured by Mitsui Petrochemical Industries ■ 0.5 g/10 min (230°C 2.16 kg) Density 0.89 g/cc Hardness (JISA) 86 1 Pellets of PAO ionomer (1) in 65 mm pieces Screw extrusion 1jl (screw metaling type, L/D=24
)+700mm width T-Gui (manifold type) and a roll take-up machine were used to form a sheet with a thickness of 400μ and a width of 400mm.

Next, this sheet was heated to 80°C using an infrared heater.
It was preheated at 10°C for 10 seconds. Next, take out this sheet and make it into a size of 40mm (depth) x 120mm x 80mm.
The mold was inserted into a mold for both injection molding and vacuum molding having a cavity of 0.0, and vacuum molded at a vacuum pressure of 0.6 g/crrf.Next, polyethylene (1) was injection molded under the following conditions.

Injection molding machine Toshiba Machine's 1S-100 model (in-line screw type) Nozzle temperature 180°C, injection pressure 80kg/cnf, mold temperature 40°C, resin thickness 3mm Ionomer (1)/polyethylene (1) obtained by these operations ) The following evaluations were performed on the two-layer molded product.

(1) Wax remover resistance Ionomer (
1) on the surface, distance 30cm, pressure 10kg/crtr
The product was sprayed from the nozzle for 15 seconds, and the appearance after spraying was observed. If there was no change, it was rated as ○, if the surface appeared to be corroded and whitened, it was rated as ×, and if it was in between, it was rated as Δ.

(2) Cold impact resistance - The two-layer molded product was left in a thermostatic chamber at an ambient temperature of 30°C, and a 535g steel ball was dropped from a height of 50cm onto the surface of the ionomer (1). Items that could not be broken were marked as ○, and items that could be broken were marked as ×.

(3) Scratch Resistance The epidermis of the PAO ionomer layer was rubbed with the side of a 100 yen coin, and those that were scratched were marked as x, and those that were not marked as ○.

(4> Transparency Observe with the naked eye, ○ if transparent, × if opaque
, and the middle was set as △.

The above results are shown in Table-1.

Evaluation was carried out in exactly the same manner as in Example 1 of the long blood dish except that PAO ionomer (2) was used instead of PAO ionomer (1). The results are shown in Table-1.

Evaluation was carried out in exactly the same manner as in Example 1, except that PAO ionomer (3) was used instead of PAO ionomer (1). The results are shown in Table-1.

Long Blood Dish 2 1 Evaluation was carried out in exactly the same manner as in Example 1 except that PAO ionomer (4) was used instead of PAO ionomer (1). The results are shown in Table 1.

In Example L, PAO ionomer (1) was used instead of PAO ionomer (1).
Ethylene ionomer without graft copolymerization of polyamide oligomer (containing methacrylic acid 115 w
t, %, ion type zinc, neutralization degree 60%, M, F, R
The evaluation was carried out in exactly the same manner except that 1.0 g/10 minutes) was used. The results are shown in Table-1.

In Example 1, polyethylene (2) was used instead of polyethylene (1), and the nozzle temperature of the injection molding machine was set to 2.
Evaluation was performed in exactly the same manner as in Example-1 except that the temperature was changed to 20°C. The results are shown in Table-1.

In Example-1, instead of polyethylene (1),
Using polypropylene, the nozzle temperature of the injection molding machine was set to 24
Evaluation was performed in exactly the same manner as in Example-1 except that the temperature was changed to 0°C. The results are shown in Table-1.

In the back blood plate Example-1, instead of polyethylene (1),
Evaluation was performed in exactly the same manner as in Example-1 except that EVA was used. The results are shown in Table-1.

and plate 21 In Example-1, instead of polyethylene (1),
Evaluation was performed in exactly the same manner as in Example-1 except that EMAA was used. The results are shown in Table-1.

In Toho Mei Nu Example-1, instead of polyethylene (1),
6-Use nylon and set the nozzle temperature of the injection molding machine to 250
Evaluation was carried out in exactly the same manner as in Example-1, except that the temperature was changed to □°C. The results are shown in Table-1.

In Kooukai 2 Satun Example-l, instead of polyethylene (1),
Using ABS resin, the nozzle temperature of the injection molding machine is 250℃
The evaluation was carried out in exactly the same manner except that . The results are shown in Table-1.

In the X blood plate two top example-1, instead of polyethylene (1),
Evaluation was carried out in exactly the same manner as in Example 1, except that polycarbonate resin was used and the nozzle temperature of the injection molding machine was changed to 280°C. The results are shown in Table-1.

From the results of these Examples and Comparative Examples, the thermoplastic resin injection molded product of the present invention using an ethylene ionomer graft-copolymerized with a polyamide oligomer as a surface coating material has particularly improved wax remover resistance. That is clear.

Margin below Table-1

Claims (2)

[Claims] (1) 10 to 1000μ of a graft copolymer obtained by graft copolymerizing 3 to 3% by weight of a polyamide oligomer to an ethylene ionomer with an unsaturated carboxylic acid content of 5 to 30% and a degree of neutralization of 10 to 90%. A thermoplastic resin injection molded product made by welding a thin film. (2) Using a common mold for injection molding and vacuum forming, the unsaturated carboxylic acid content is 5 to 30% by weight, and the degree of neutralization is 10 to 90%.
polyamide oligomer 3 to the ethylene ionomer
A thin film of a graft copolymer obtained by graft copolymerizing ~3% by weight is vacuum formed, and 10 to 10% of the graft copolymer is
2. The method of manufacturing a thermoplastic resin injection molded product according to claim 1, wherein a thin film having a thickness of 0.00 μm is molded along the inner surface of a mold, and then the thermoplastic resin is injection molded in the mold.