JPH03263451A - Resin composition having excellent blow moldability - Google Patents

Abstract

PURPOSE:To obtain a resin composition having excellent coating-ability, heat- resistance, etc., and suitable for the blow-molding of a large-sized article by compounding a specific graft copolymer derived from vinyl cyanide, etc., to a specific copolymer. CONSTITUTION:The objective composition is produced by compounding (A) a graft copolymer produced by the copolymerization of a vinyl cyanide compound (e.g. acrylonitrile) and an aromatic vinyl compound (e.g. styrene and/or alpha-methylstyrene) to a rubbery polymer and (B) a copolymer produced by copolymerizing a vinyl cyanide compound and an aromatic vinyl compound to an organic silane compound monomer or copolymerizing a vinyl cyanide compound, an aromatic vinyl compound and a copolymerizable vinyl compound to an organic silane compound monomer. The content of the rubbery polymer in the composition is 10-30wt.% and the ratios of the vinyl cyanide compound and the organic silane compound unit to the resin components excluding the rubbery polymer are 35-50wt.% and 0.005-0.12wt.%, respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a thermoplastic resin composition with excellent paintability, heat resistance, etc., suitable for blow molding large parts.

[Conventional technology]

Blow molding has been used mainly for polyolefin resins as a technique for molding hollow containers, but it has also been used to mold large structural parts4 because it allows large molded products to be obtained using relatively simple equipment. As a technique, note [I'm copying. [2, Kashi 2, Compared to molded products made by injection molding, blow molded products have lower surface QL smoothness, so in applications where a good appearance is required, the surface of the molded product should be sandpapered or barred. 1. Processing, L-Gel Landing Processing and Batho. ) process was necessary. Particularly when used for the exterior parts of an automobile, the coating quality is required to be equivalent to that of metal materials, so careful finishing is required, and the burden placed on this cannot be ignored. Polyolefin has excellent blow moldability,
Although it is known that a relatively smooth surface of the molded product can be obtained, the paintability is not always good, the adhesion strength of the coating film is often low, and the heat resistance is also not 1 minute. In addition, although resin materials containing polyphenylene ogicide as one component have good blow moldability, paint film adhesion, and heat resistance, they have poor chemical resistance, which causes stress cracks caused by thinner etc. during painting, and the paint is sucked into the surface. It may cause a "wash-in" phenomenon where the gloss is lost.

By the way, ABS resin, which is an acrylo-tolyl-butane, 1, styrene copolymer, is a resin material with excellent paintability, but the characteristics of this resin are strength, L2 ease of injection molding, and appearance of injection molded products. Goodness (because it has J, it was not inspected as a blow molding abrasive material.Also, it is an injection molding method) Even if ABS resin, which was designed for processing in its original form, is applied to blow molding, it will not work as a parison. Since the strength is low and it is easy to draw down, it is difficult to obtain large molded products.Furthermore, the heat resistance is not necessarily 100%, and there are problems such as deformation during baking of the coating.

In order to add heat resistance to ABS resin, it is well known that α-methylstyrene is used as an aromatic vinyl compound. However, it was difficult to use it industrially because it thermally decomposed during extrusion.In other words, a material with excellent blow moldability and paintability, as well as excellent blow moldability, paintability, and heat resistance, had not yet been established. It was.

[Problems to be Solved by the Invention (2)] In view of the current situation, the present invention has been developed to provide a large molded product that is difficult to obtain by injection molding, and to provide a good painted appearance and coating film without the need for sanding or the like. An object of the present invention is to provide a resin material for blow molding that provides adhesive strength.

[Means to solve the problem]

The thermoplastic composition of the present invention having excellent blow moldability and paintability is a rubbery polymer (B) containing a vinyl cyanide compound (A).
), a graft copolymer (I) formed by copolymerizing an aromatic vinyl compound (S), a cyanide vinyl compound (A), and an aromatic vinyl compound (S) are copolymerized with an organosilane compound monomer. , or vinyl cyanide compound (A) and aromatic vinyl compound (S) and copolymerizable vinyl compound (
E) is a resin composition comprising a copolymer (II) copolymerized with an organic silane compound monomer, wherein (1) (B) in the composition is 10 to 30% by weight; , <jl) In the composition, (A) accounts for 35 to 50% by weight of the resin components excluding (B), and (Iij) The median content of the organosilane compound in the composition is 0.005 to 0. ], 2'u amount %.

Furthermore, when it is desired to improve heat resistance, a composition in which the component (S) is styrene and/or α-methylstyrene, and (
A composition obtained by copolymerizing component E) with L2 n-substituted maleimide is suitable.

The present invention will be explained in detail below.

Generally, a resin with excellent blow moldability, that is, a resin that does not easily draw down even when molded into a large parison, is said to have a high melt viscosity.

As a means to increase the melt viscosity of ABS resin, (a) increasing the rubbery polymer content, (b) increasing the molecular weight of the acrylonitrile-styrene copolymer component, and (c) glass of the copolymer. Examples include a method of copolymerizing components whose transition temperature increases by I-.

However, although ABS resins whose melt viscosity is simply increased by these methods are difficult to draw down, it is difficult to obtain a smooth molded product surface, which poses a practical problem. However, when the present inventors used a copolymer of a vinyl cyanide compound and an aromatic vinyl compound copolymerized with an organic silane compound as a component of an ABS resin, the molecular weight of the vinyl cyanide-aromatic vinyl copolymer decreased. It has been discovered that excellent drawdown resistance can be obtained without increasing the diameter, and the surface of the molded product is sufficiently smooth. This fact cannot be explained simply by the fact that cross-links occur between the copolymer molecular chains and the apparent molecular weight increases; the copolymer also acquires elastic properties, making the elongation uniform during blow molding. This is an unexpected effect, and is presumed to be due to a negative effect. In particular, this method
It is effective when applied to resin compositions copolymerized with components that increase the glass transition temperature, such as α-methylstyrene and n-substituted maleimide, which have a high melt viscosity and are therefore difficult to increase in molecular weight.

The resin composition of the present invention comprises a graft copolymer (I) having a vinyl cyanide compound and an aromatic vinyl compound copolymer chemically bonded to a rubbery polymer, and a vinyl cyanide compound and an aromatic vinyl compound copolymer. and, if necessary, a copolymer (II) of a monomer copolymerizable with these. The copolymer (II) is one produced without graft bonding during the graft copolymerization reaction (hereinafter referred to as n-1), or one produced by a reaction separate from the graft copolymerization reaction and mixed into the composition. This is what I did. The separately produced polymers include a component copolymerized with an organic silane compound (hereinafter referred to as U-2) and a component not containing an organic silane compound (hereinafter referred to as m-3), which are each independently prepared and used as a mixture. Also good. Copolymer (II) can be separated as an acetone-soluble component of the resin composition.

Examples of the organic silane compound include γmethacryloxypropyltrimethoxysilane, γmethacryloxypropylmethyldimethoxysilane, and γmethacryloxypropyltriethoxysilane. There is no particular limit to the amount of the silane compound contained in the copolymer (II), but the amount is 0.00 based on the resin composition combined with the copolymer (I).
5 to 0.12% by weight is preferred. If it is less than 0.005% by weight, the effect of improving blow moldability is not significant;
If it exceeds % by weight, processability will decrease. copolymer (I),
The vinyl cyanide compound (A) constituting (If) is acrylonitrile or methacrylonitrile, and the aromatic vinyl compound (S) is styrene or α-methylstyrene.
Examples of E) include (meth)acrylic acid ester compounds such as methyl methacrylate and butyl acrylate, n-phenylmaleimide, n-cyclohexylmaleimide, maleic anhydride, and the like. Among these, a preferred combination is acrylonitrile-styrene and/or α-methylstyrene and acrylonitrile-styrene-n-phenylmaleimide.

In the resin composition of the present invention, the content of vinyl cyanide compound units in the resin is also important.

Molded products obtained by blow molding have an inferior appearance compared to molded products made by injection molding, so they are usually painted. However, the paintability of blow molded products is relatively less likely to leave molding distortion, so the resin used The composition of the material is primarily involved.

In the resin composition of the present invention, the content of vinyl cyanide compound units in the resin components excluding the rubbery polymer is important, and 35 to 50% by weight is suitable, and 36 to 44% by weight.
is even more suitable. If the content is less than 35% by weight, stress cracks will occur on the surface of the molded product due to the paint or thinner, causing the paint to seep in, and if it exceeds 50% by weight, the resin will become colored when reworking the paring part, which is undesirable. .

Examples of the rubbery polymer in this resin composition include polybutadiene, butadiene-styrene copolymer, butadiene-styrene copolymer, and butadiene-styrene copolymer.
Diene-based rubbery polymers such as acrylonitrile copolymers, butyl acrylate-methyl methacrylate-(
Acrylic rubber such as meth)acrylic acid ester copolymer,
Examples include saturated rubbery polymers such as ethylene-propylene copolymer rubber. The content of the rubbery polymer (B) does not significantly affect paintability and blow moldability, so it can be set depending on the impact resistance required for the product, and is 10% by weight to 3% by weight.
0% by weight is preferred.

There are no particular limitations on the method for producing copolymers (I) and (II), and known methods such as emulsion polymerization, suspension polymerization,
Solution polymerization is applicable, but copolymer (I) with a high rubbery polymer content is prepared by emulsion graft polymerization, and copolymer (II) containing an organic silane compound is prepared by solution polymerization. A preferred method is to prepare the two by extrusion blending.

Copolymer (II) can be obtained by separately preparing a copolymer containing an organosilane compound (IT-2) and a copolymer containing no organosilane compound (II-3), and then producing a graft copolymer (
The most preferred method is to extrude and knead the three components including I) to form a resin composition.

For this resin composition, known heat stabilizers, ultraviolet absorbers,
It is optional to add a mold release agent, a lubricant, an antistatic agent, a flame retardant, and a coloring agent.

〔Example〕

The present invention will be explained below based on Examples.

Note that the numbers used below are parts by weight.

<Graft copolymerization reaction> G-1 = 60 parts of polybutadiene rubber latex (solid content equivalent) and 100 parts of deionized water were placed in a polymerization tank equipped with a reflux condenser, and heated to 70°C while replacing the gas phase with nitrogen. The temperature rose.

Next, to this was added a mixture of 1224 parts of Meg, 16 parts of acrylonitrile, 0.3 parts of t-dodecyl mercaptan, 0.2 parts of cumene hydroperoxide, 50 parts of deionized water, and 032 parts of sodium formaldehyde sulfoxylate. , 0.004 parts of ferrous sulfate, ethylenediaminetetotriacetate, and parts of salt were added continuously over a period of 5 hours to react.

During this time, the polymerization temperature was adjusted to 70°C, and after the completion of the additional addition, this state was maintained for an additional 30 minutes to complete the polymerization.

The polymerization rate of the monomer is 93.3%, and the content of acrylonitrile units in the resin components excluding the rubbery polymer is 36.1%.
Met.

1 2 G-2: Put 40 parts of polybutadiene rubber latex rubber solids, 100 parts of deionized water, 0.3 parts of potassium rosinate, and 0.2 parts of t-dodecyl mercaptan into a polymerization tank equipped with a reflux condenser, While replacing the gas phase with nitrogen, the temperature was raised to 70°C.

A mixture of 24 parts of acrylonitrile, 36 parts of styrene, 0.15 parts of cumene hydroperoxide, 0.4 parts of t-dodecyl mercaptan, and 0.3 parts of sodium formaldehyde sulfoxylate and ferrous sulfate in 50 parts of deionized water. An aqueous solution containing 0.004 part of ethylenediaminetetraacetic acid sodium salt was continuously added over 7 hours to cause reaction. During this time, the temperature of the polymerization system was controlled at 70°C, and after the completion of the additional addition, 0.02 part of cumene/hydrobar oxide was further added, and this state was maintained for 1 hour to complete the reaction.

The monomer polymerization rate is 97.5%, and the content of acrylonitrile units in the resin component excluding polymers and polymers is 39.3%.
Met.

<Organosilane compound copolymerization reaction> 5000 g of ethylbenzene in a flask with a reflux condenser
, styrene 1750g, acrylonitrile 3250g1
Add 10°0 g of γmethacryloxypropyltrimethoxysilane and 5°0 g of benzoyl peroxide J.
The reaction was carried out at 0°C for 3 hours. The copolymer was precipitated and recovered using methanol, and the acrylonitrile content was calculated from elemental analysis, and the γ methacryloxypropyltrimethoxysilane content was calculated from the silicon content determined by atomic absorption spectroscopy, and found to be 88.5%. , 0.35%.

Vinyl uccinide compound-aromatic vinyl compound copolymerization reaction> M-]: 170 parts of deionized water, potassium argenyl succinate [manufactured by Kao Soap ■, Latemul ASK] 1.0 part, disproportionated rosin acid Potassium 1.0 part, sodium formaldehyde sulfoxylate 0.4 part, ferrous sulfate 0.004 part
parts, ethylenediaminetetraacetic acid disodium salt 0.0
08 parts were placed in a polymerization tank equipped with a reflux condenser, and the temperature was raised to 65° C. while replacing the gas phase with nitrogen. Then,
To this, 40 parts of acrylonitrile, 6 parts of α-methylstyrene
0 part, 0.1 part of t-dodecyl mercaptan, 0.5 part of cumene hydroperoxide and 80 parts of deionized water, 0.1 part of sodium formaldehyde sulfoxylate, 0.001 part of ferrous sulfate, An aqueous solution consisting of 0.002 part of ethylenediaminetetraacetic acid disodium salt was continuously added over a period of 8 hours to cause a reaction. During this time, the polymerization temperature was adjusted to 65°C, and after the completion of the additional addition, this state was maintained for an additional hour to complete the polymerization.

M-2: The same reaction as M-1 was carried out using 27 parts of acrylonitrile and 73 parts of α-methylstyrene to obtain M-2.

M-3: The same reaction as M-1 was carried out without t-dodecyl mercaptan to give M-3.

M-4 to M-6 = Using a complete mixing type continuous reactor, 5 monomer solutions consisting of acrylonitrile, styrene, and ethylbenzene are continuously added while discharging the product at a constant rate to control the reaction rate in the polymerization system. By keeping the temperature constant, an acrylonitrile-styrene copolymer was obtained. At this time, M-4 to M-6 were obtained by changing the composition of the monomer that was continuously added.

The analytical values of M-1 to M-6 are collectively shown in Table 1.

Example 1 Graft copolymer G-1 and copolymer M-1 not containing organosilane compound units were latex blended at a solid content ratio of 35:85, and the solid content was 1.3 parts per 100 parts of total solid content.
of magnesium sulfate was added to obtain an aggregate. 10 parts by weight of a copolymer containing an organic silane compound was added to 90 parts by weight of the resin powder obtained by washing the aggregate with water, dehydration, and drying, and 0.2 parts by weight of a phenolic heat stabilizer [manufactured by Sumitomo Chemical ■, BHT] was added. ,
After adding 0.5 parts by weight of ethylene bisstearylamide, the mixture was pelletized using an extruder. Pellets are molded using a blow molding machine with a cylinder temperature of 220℃ and a die diameter of 50m.
The molten resin was extruded through a die with a slit interval of 3.2 mm, and the swell ratio and drawdown ratio were determined from the molded parison according to the following equations, and they were 1.85° and 0.9, respectively.
It was 5.

The cooled parison was coated with a 23°C paint solution (Refrac 55).
(Original Kasei): Non-brushing: 169 Thinner 50
: 15 : 35) for 20 seconds, and then heated at 80℃ for 30 seconds.
After drying for a few minutes and observing the surface condition, no cracks were observed. In addition, the pellets were made into test pieces by injection molding, and the Izod impact value and heating deformation temperature were measured based on the standards, and they were 13 kgcm/cm.
The temperature was 100°C.

In Examples 2 to 4 and Comparative Examples 1 to 4, similar tests were conducted by changing the ratio of each copolymer.

The results are summarized in Table 2. In Comparative Example 2, parison molding itself was impossible. The blow moldability was judged to be good if the swell ratio was 1.5 or more and the drawdown ratio was 0.8 or more.

Example 5 Graft copolymer latex G-2 was made into powder by the same method as used in Example 1, and copolymer M-4 not containing an organic silane compound and organic silane compound copolymer which were separately polymerized were added. A heat stabilizer and a lubricant were added, and the mixture was pelletized using an extruder.

The same evaluation as in Example 1 was performed and the results are shown in Table 2.

Examples 6 and 7, Comparative Examples 5 and 6 The same operation as in Example 5 was carried out by changing the ratio of each component, and the results are summarized in Table 2.

From Table 2, good blow moldability and impact strength can be obtained when the rubbery polymer is 10 to 30% by weight and the organosilane compound unit content is 0.005 to 0.12, and resins excluding the rubbery polymer can be obtained. Acrylonitrile unit content in the ingredients is 0.3
It is clear that good coating properties can be obtained with an amount of 5% by weight or more. In this case, α-methylstyrene copolymer (Examples 1 to 4), n-phenylmaleimide copolymer (Example 6)
．． It is clear that it is also effective when using 7).

(Items with margins)]] September 1990 7”11 Special Ir'J Secretary I1j Matsutoshi-dono 1゜ Incident Display 2000 Special Revised Application No. 59850 2 , Title of the Invention 7I] - Resin Composition with Excellent Moldability CJ 3° Amendment - Relationship with the Case of R. Patent Applicant: 1-J Medojimahama, Osaka Yamakita 1, Osaka Prefecture f-12 June (
003) Asahi Ihi Sei T Gyo Co., Ltd. Representative Rei Yukaku - 4, Agent Zip Code 04 Tokyo Chuo 1st Shintomi 11th 3-0 J7 My Building 3rd Floor [Detailed Description of the Invention] Column 6° Correction details

Claims (5)

[Claims] (1) A vinyl cyanide compound (A) is added to the rubbery polymer (B).
), a graft copolymer (I) obtained by copolymerizing an aromatic vinyl compound (S), a cyanide vinyl compound (A), and an aromatic vinyl compound (S) copolymerizing with an organosilane compound monomer. , or a resin composition consisting of a copolymer (II) formed by copolymerizing a vinyl cyanide compound (A), an aromatic vinyl compound (S), and a copolymerizable vinyl compound (E) with an organic silane compound monomer. (i) (B) in the composition is 10 to 30% by weight,
(ii) In the composition, (A) accounts for 35 to 50% by weight of the resin components excluding (B), and (iii) the organosilane compound unit in the composition is 0.0%.
05 to 0.12% by weight of a thermoplastic resin composition having excellent blow moldability. (2) The thermoplastic resin composition with improved heat resistance and excellent blow moldability according to claim 1, wherein (A) constituting the composition is acrylonitrile and (S) is styrene and/or α-methylstyrene. thing. (3) The heat with improved heat resistance and excellent blow moldability according to claim 1, wherein (A) constituting the composition is acrylonitrile, (S) is styrene, and (E) is n-substituted maleimide. Plastic resin composition. (4) A blow-molded product using the resin composition according to claim 1, 2, or 3. (5) A product obtained by coating the molded product according to claim 4.