JPH08134292A - Modified propylene resin composition - Google Patents

Abstract

(57) [Summary] [Object] To provide a modified propylene resin composition having an improved balance between melt fluidity and melt tension, excellent moldability, and good transparency. [Structure] 100 parts by weight of a propylene resin and 1 to 15% by weight of an aromatic monounsaturated monomer and 0.001 to 3% by weight of a polyunsaturated monomer, which are modified with both monomers. Consisting of 100 parts by weight,
Melt tension (MT) and melt flow rate (MF
R) and logMT + 0.7logMFR ≧ 0.9
A modified propylene resin composition having the following relationship.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a modified propylene resin composition having an improved balance between melt fluidity and melt tension, excellent moldability, and good transparency.

[0002]

2. Description of the Related Art Polypropylene is relatively inexpensive and has good moldability, heat resistance, solvent resistance, mechanical properties, and appearance, so it is processed into various molded products and used in various fields. Has been done. However, polypropylene has a low melt tension, so vacuum molding, calender molding,
There have been various problems in moldability in various molding methods such as blow molding, sheet molding and blown film molding, such as sagging of the sheet, bubble instability, and poor product appearance.

As one of the methods for increasing the melt tension of polypropylene, there is a method of blending polypropylene with low density polyethylene produced by a high pressure method. However, this method is not preferable because it has a drawback that mechanical properties such as rigidity are deteriorated. On the other hand, for example,
24376, Japanese Patent Publication No. 5-17936, Japanese Patent Publication No. 5-591
In each of the 43 publications and the like, a method is proposed in which polypropylene is blended with an organic peroxide and a crosslinking aid to partially crosslink. However, this method has a drawback in that the melt fluidity is lowered and a good balance between the melt fluidity and the melt tension cannot be obtained.

Therefore, in order to improve the balance between the melt fluidity and the melt tension, in JP-A-6-207055, polypropylene is derived from a large amount of an aromatic vinyl monomer and other copolymerizable monomers. Compositions have been proposed in which a segmented polymer with a polymer is blended with polypropylene. However, even in this method, the balance between melt fluidity and melt tension is still insufficient, and since a large amount of aromatic vinyl monomer and other copolymerizable monomer are contained, the transparency when molded is high. However, there is a disadvantage that it is economically disadvantageous.

[0005]

The object of the present invention is to solve the above-mentioned drawbacks of the prior art, to improve the balance between melt fluidity and melt tension, and to provide excellent moldability and transparency when molded. It is to provide a propylene resin composition.

[0006]

[Means for Solving the Problems]

[Summary of the Invention] The inventors of the present invention have conducted extensive studies to solve the above problems, and from a propylene resin modified with a specific amount of an aromatic monounsaturated monomer and a polyunsaturated monomer, and an unmodified propylene resin. Becomes, melt tension (M
The present invention has been completed by finding that a composition having a specific relationship between T) and melt flow rate (MFR) solves the above problems.

That is, the present invention is modified with 100 parts by weight of a propylene resin and both monomers having an aromatic monounsaturated monomer content of 0.1 to 15% by weight and a polyunsaturated monomer content of 0.001 to 3% by weight. Propylene resin 1-100
By weight, melt tension (MT: unit is g) and melt flow rate (MFR: unit is g / 10).
Min) and logMT + 0.7logMFR ≧ 0.9
The modified propylene resin composition is characterized in that

[Detailed Description of the Invention] Propylene Resin The propylene resin used in the present invention is a homopolymer resin of propylene or a block, random or graft of propylene containing propylene as a main component and other unsaturated monomer. And other copolymer resins. Here, the other unsaturated monomer does not include an aromatic monounsaturated monomer and a polyunsaturated monomer constituting the modified propylene resin described later, and, for example,
Ethylene, butene-1, pentene-1, hexene-1,
Α-olefins such as 3-methylbutene-1, 4-methylpentene-1, heptene-1, octene-1, decene-1; acrylic acid, methacrylic acid, maleic anhydride, methyl acrylate, ethyl acrylate, methacrylic acid Unsaturated carboxylic acids such as methyl or its derivatives; vinyl esters such as vinyl acetate and vinyl butyrate; vinyl silanes such as vinyl trimethoxysilane and γ-acryloyloxypropyltrimethoxysilane are preferable. Two or more kinds of these other unsaturated monomers may be contained in combination, but the preferable content thereof is 0.1 to 20 mol% in the case of α-olefin or vinyl ester, and 0.01 in the case of saturated carboxylic acid or its derivative or vinylsilane
~ 8 mol%. Among the propylene resins, a preferable resin is a homopolymer resin of propylene or a block or random copolymer of propylene containing propylene as a main component and another α-olefin. Two or more kinds of these propylene resins may be used in combination.

Modified propylene resin The modified propylene resin used in the present invention is a propylene resin obtained by modifying the propylene resin with both aromatic monounsaturated monomer and polyunsaturated monomer. Here, the aromatic monounsaturated monomer is a compound having one carbon-carbon unsaturated bond represented by a vinyl group, for example, styrene, methylstyrene, dimethylstyrene, ethylstyrene, isopropylstyrene, dichlorostyrene, Examples include α-methylstyrene and bromostyrene. Of these, styrene is preferably used.

The polyunsaturated monomer is a vinyl group,
A compound having two or more carbon-carbon unsaturated bonds such as an allyl group, an acryl group, and a methacryl group in the molecule, for example,
Divinylbenzene, diallylbenzene, divinylnaphthalene, diallyl isophthalate, diallyl terephthalate, triallyl cyanurate, triallyl isocyanurate, 1,6-hexanediol diacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, ethylene glycol dimethacrylate. , Trimethylolpropane trimethacrylate, and the like. Among them, divinylbenzene is preferably used.

The modified propylene resin is (a) 0.1 to 15 parts by weight, preferably 0.5 to 15 parts by weight, and (b) a large amount based on 100 parts by weight of the propylene resin. 0.001 to 3 parts by weight of unsaturated monomer,
Preferably, 0.01 to 2 parts by weight and (c) 0.01 to 5 parts by weight of organic peroxide are used, and the compounding ratio (b) / (a) is 0.0.
It can be produced by a method of blending within the range of 01 to 0.2, preferably 0.005 to 0.1, and reacting while melting and kneading. If the blending ratio is too low, a satisfactory improvement in melt tension cannot be expected, while if the blending ratio is too high, the crosslinking reaction increases and the melt fluidity deteriorates.

If the amount of (a) the aromatic monounsaturated monomer or (b) the polyunsaturated monomer is too small, the effect of sufficiently improving the melt tension is not exhibited, while if it is excessive, the melt fluidity and melt tension are good. It is not preferable because the balance cannot be obtained and the appearance of the product is not improved.

As the organic peroxide used here, a compound having a decomposition temperature in the range of 140 to 270 ° C., which has a half-life of 1 minute, is preferably used. For example, 1,1-bis (t
-Butylperoxy) cyclohexane, t-butylperoxyisopropyl carbonate, 2,2-bis (t-
Butylperoxy) octane, t-butylperoxyacetate, 2,5-dimethyl-2,5-di (benzoylperoxy) hexane, t-butylperoxylaurate, di-t-butylperoxyisophthalate, t-butylperoxybenzene, Dicumyl peroxide, α,
α'-bis (t-butylperoxy-m-isopropyl) benzene, t-butylcumyl peroxide, 2,5
-Dimethyl-2,5-di (t-butylperoxy) hexane, di-t-butylperoxide, 2,5-dimethyl-2,5-di (t-butylperoxy) hexyne-3,
Examples thereof include di-isopropylbenzene hydroperoxide, cumene hydroperoxide, t-butyl hydroperoxide and the like. Two or more of these organic peroxides can be used in combination.

As a device used for the reaction while melt-kneading, an ordinary melt-kneading machine such as a single-screw or twin-screw extruder, a Banbury mixer, a kneader blender, a mixing roll, and a Brabender plastograph are used. The kneading temperature at that time is preferably 180 to
It is in the range of 280 ° C. If the kneading temperature is too low, the organic peroxide tends to be difficult to decompose sufficiently, while if the kneading temperature is too high, the thermal decomposition of the propylene resin tends to take precedence, and any expected improvement in melt tension Does not tend to be enough.

The modified propylene resin thus obtained has an aromatic monounsaturated monomer content of 0.1 to 15% by weight, preferably 1 to 13% by weight and a polyunsaturated monomer content of 0.001 to 3% by weight. %, Preferably 0.01 to 2% by weight modified resin. If the aromatic monounsaturated monomer content or the polyunsaturated monomer content is too small, the effect of sufficiently improving the melt tension is not exhibited, while if it is excessive, a good balance between the melt fluidity and the melt tension cannot be obtained. The appearance of the product is not improved, which is not preferable.

Modified propylene resin composition In the modified propylene resin composition of the present invention, the modified propylene resin thus obtained is 1 to 100 parts by weight, preferably 3 to 50 parts by weight, and particularly preferably 100 parts by weight of the propylene resin. Is obtained by blending 5 to 30 parts by weight and melt-kneading. Melt kneading may be carried out by directly applying each component blend to various molding machines and molding, but usually, the composition is usually melt kneaded by the above-mentioned usual melt kneader before being applied to the molding machine. Therefore, a method of granulating and then applying to a molding machine is preferably adopted. Here, if the amount of the modified propylene resin is too small, the effect of improving the melt tension is not exhibited, while if it is excessive, a good balance between the melt fluidity and the melt tension cannot be obtained, which is not preferable.

In the melt-kneading, in addition to the above-mentioned essential components, other optional components can be appropriately blended, if necessary, as long as the effects of the present invention are not significantly impaired. Examples of optional components include antioxidants, light stabilizers, antistatic agents, flame retardants, lubricants, processing aids, neutralizing agents, heavy metal deactivators, nucleating agents, plasticizers, colorants, and fillers. , A molecular weight modifier (radical generator), a foaming agent and the like.
In particular, it is preferable to add an antioxidant in order to suppress thermal oxidative deterioration during melt-kneading and impart durability to the product.

As the antioxidant, those generally used as antioxidants for plastics can be used, and a typical example thereof is 2,6-di-t-butyl-4.
-Methylphenol, 2,2'-methylene-bis- (4
-Methyl-6-t-butylphenol), 4,4'-butylidene-bis- (3-methyl-6-t-butylphenol), 4,4'-thiobis- (3-methyl-6-t-)
Butylphenol), octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate, tetrakis- [methylene-3- (3 ', 5'-di-
t-butyl-4′-hydroxyphenyl) propionate] methane, 6- (3,5-di-t-butyl-4-hydroxyanilino) -2,4-bis-octylthio-1,
3,5-triazine, tris- (3,5-di-t-butyl-4-hydroxybenzyl) isocyanurate, tris- (4-t-butyl-2,6-dimethyl-3-hydroxybenzyl) isocyanurate, etc. Radical scavenger,
Alternatively, di-lauryl-thio-di-propionate, di-
Examples thereof include peroxide decomposers such as stearyl-thio-di-propionate and tris-nonylphenyl-phosphite. Two or more of these antioxidants can be used in combination.

Of the resulting modified propylene resin composition,
Log between the melt tension (MT: unit is g) and the melt flow rate (MFR: unit is g / 10 minutes)
Only resin compositions having a relationship of MT + 0.7 log MFR ≧ 0.9 can be used in the present invention. If this relationship is not satisfied, the balance between melt fluidity and melt tension is not good, which is not preferable. Here, the values of MT and MFR are obtained by the measuring method described in Examples below.

[0020]

The present invention will be further described below with reference to specific examples. Evaluation method (1) Melt tension (MT: unit is g) Using a melt tension tester manufactured by Toyo Seiki Seisakusho,
Record the tension when the extruded product of 190 ° C molten resin extruded from an orifice with an inner diameter of 1.48 mm and a length of 10.0 mm at a speed of 10 mm / 10 min is wound up by a rotary pulley at a take-up speed of 3.9 m / min. Calculated from the chart. The chart may have runout width (hunting), in which case the center value of hunting is used.

(2) Melt flow rate (MFR: unit is g / 10 minutes) The melt flow rate is measured according to ASTM-D1238 under the conditions of a temperature of 230 ° C. and a load of 2.16 kg.

(3) Balance coefficient of MT and MFR logMT + 0.7logMFR In order to confirm whether or not there is a relationship of 0.9, the value of logMT + 0.7logMFR is calculated from the values of MT and MFR obtained by the above method,
This is evaluated as a balance coefficient.

(4) Haze A resin sample is formed into a sheet having a thickness of 0.05 mm by a press molding machine, and the haze is measured according to JIS-K7105 to evaluate transparency.

Production of Modified Propylene Resin Polypropylene having an MFR of 1.0 g / 10 min was heated at a temperature of 15
The mixture was fed at a speed of 5.0 kg / hour to a twin-screw extruder rotating in the same direction set at 0 ° C. and a screw rotation speed of 100 rpm, and at the same time, (a) styrene, (b) divinylbenzene and (c) organic peroxide. A mixed solution of 1,1-bis (t-butylperoxy) cyclohexane, which is an oxide, was added to 5 parts by weight of (a) styrene, 0.05 part by weight of (b) divinylbenzene, and ( C) While adjusting the pressure pump so that the amount of the organic peroxide was 0.1 part by weight, the mixture was supplied to the mixing section of the extruder through the supply port and melt-kneaded with the polypropylene. At this time, while the unreacted material was degassed and removed from the vent portion under reduced pressure, the molten resin was extruded in the form of a strand from the discharge port of the extruder, and this was cut to form pellets of the modified propylene resin (modified PP-1). Obtained. Also,
In the same manner, pellets of modified propylene resin (modified PP-2 to modified PP-13) were produced with the formulations shown in Table 1. The styrene content and the polyunsaturated monomer content in the obtained modified propylene resin were determined by the calibration curve method of IR measurement. The measurement results are shown in Table 1.

Experimental Example 1 A polypropylene 4 having an MFR of 1.0 g / 10 min was placed in a Labo Plastomill manufactured by Toyo Seiki Co., Ltd., which had an internal volume of 60 ml.
0 g, 6 g of modified PP-1 as a modified propylene resin, and tetrakis- [methylene-3- as an antioxidant.
0.03 g of (3 ', 5'-di-t-butyl-4'-hydroxyphenyl) propionate] methane and tris- (4-t-butyl-2,6-dimethyl-3-hydroxybenzyl) isocyanurate. 04 g of each component was blended and melt-kneaded for 3 minutes at a temperature of 200 ° C. and a rotor rotation speed of 160 rpm to prepare a modified propylene resin composition. The evaluation results of this resin composition are shown in Table 2.

Examples 2 to 10 and Comparative Examples 1 to 9 With the formulations shown in Tables 2 and 3, modified propylene resin compositions were prepared in the same manner as in Example 1. The evaluation results of these resin compositions are shown in Tables 2 and 3.

[0027]

[Table 1]

[0028]

[Table 2]

[0029]

[Table 3]

[0030]

According to the present invention, a modified propylene resin composition having an improved balance between melt fluidity and melt tension and excellent moldability can be obtained. As a result, this modified propylene resin composition has a product appearance that does not have fish eyes in film molding, a beautiful bubble state and high expansion ratio in vacuum molding, in addition to productivity improvement during molding of propylene resin. The sheet can be prevented from sagging, and the blow molding can be expected to stabilize bubbles and reduce the wall thickness, and is useful as various molding materials such as vacuum molding, calender molding, blow molding, sheet molding, and inflation molding.

Claims (1)

[Claims] 1. A propylene resin modified with 100 parts by weight of propylene resin and both monomers having an aromatic monounsaturated monomer content of 0.1 to 15% by weight and a polyunsaturated monomer content of 0.001 to 3% by weight. 1 to 100 parts by weight, log between melt tension (MT: unit is g) and melt flow rate (MFR: unit is g / 10 minutes).
A modified propylene resin composition having a relationship of MT + 0.7 log MFR ≧ 0.9.