JP2000026616A - Polyolefin resin composition for profile extrusion and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a composition which can give a molding suffering little from surface roughening and wrinkling and having excellent surface appearance by mixing a polyolefin resin with a modifier containing polytetrafluoroethylene particles and an organic polymer. SOLUTION: A particle dispersion obtained by mixing an aqueous dispersion containing 0.1-90 wt.% polytetrafluoroethylene particles having a mean particle diameter of 0.05-1.0 μm with an aqueous dispersion containing organic polymer particles having a mean particle diameter of 0.05-1.0 μm is coagulated or spray- dried to obtain a powdery modifier having a mean particle diameter of 1-100 μm, desirably, 5-10 μm. Part of a polyolefin resin having a melt flow rate of 0.1-7.0 g/10 min is mixed with the modifier in an amount corresponding to 0.01-20 wt.% polytetrafluoroethylene, and the resulting mixture is agitated at 150-270 deg.C, desirably, 170-250 deg.C to obtain a masterbatch. This masterbatch is mixed with the remainder of the polyolefin resin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a polyolefin resin composition suitable for profile extrusion, and in particular, to obtain a profile extruded product having an excellent surface shape without surface roughness or wrinkles, and It relates to the one that is less likely to warp.

[0002]

2. Description of the Related Art A profile extrusion molding method is known as a technique for molding a resin material into a complicated shape. The profile extrusion method is performed, for example, as follows. In other words, the resin material is put into the cylinder of the extruder, kneaded by the rotation of the screw while heating inside, and plasticized,
It is extruded through a profile extrusion die provided at the extrusion outlet, and is continuously sent to a cooling zone such as a sizing plate, a sizing die, or a water tank to be cooled to obtain a desired profile extrusion molded product. At this time, by changing the shape of the die, it is possible to obtain deformed extruded products of various shapes (hereinafter sometimes abbreviated as molded products).

[0003]

However, when molding a polyolefin resin by a profile extrusion molding method, there are the following problems. A crystalline resin such as a polyolefin resin has a large molding shrinkage and a low melt tension (melt strength) as compared with an amorphous resin such as a vinyl chloride or styrene resin. For this reason, at the time of extrusion, for example, drawdown is increased, and the surface of the molded body is likely to be rough and wrinkled, and a smooth surface shape may not be obtained. Also,
Polyolefin resins generally have high specific heat and tend to take a long time to cool. For this reason, there has been a problem that, particularly when a molded article having a complicated shape is extruded, the molded article is likely to be warped in the longitudinal direction.

[0004] In order to improve these problems, Japanese Patent Laid-Open Publication No.
Japanese Patent Application Laid-Open No. 262928/1995 proposes a method of reducing molding shrinkage by using a resin composition obtained by adding an inorganic filler to a polyolefin resin.
According to this method, a certain effect can be obtained, but the effect is insufficient for a molded article having a complicated shape. The effect of suppressing the occurrence was insufficient.

[0005] The present invention has been made in view of the above circumstances, and has as its object to solve the following problems. That is, the present invention provides a polyolefin-based resin composition for profile extrusion, in which the surface of the molded product is less likely to be roughened and wrinkled when a polyolefin-based resin is subjected to profile extrusion molding, and a molded product having an excellent surface shape is obtained. Further, the present invention provides a polyolefin-based resin composition for profile extrusion in which a molded article is less likely to warp. Further, the present invention provides a polyolefin resin composition for profile extrusion, which can obtain the above-mentioned effect of improving the surface shape and suppressing the warpage of a molded article having a complicated shape, particularly a large and complicated molded article.

[0006]

Means for Solving the Problems In order to solve the above problems, a first invention of the present invention provides a polyolefin resin,
A polyolefin-based resin composition for profile extrusion, characterized by comprising a modifier containing polytetrafluoroethylene particles and an organic polymer. In the polyolefin resin composition for profile extrusion, the amount of the polytetrafluoroethylene component is 0.01 to 20 parts by weight with respect to 100 parts by weight of the polyolefin resin.
It is preferable that the above-mentioned modifier is blended. Further, the melt flow rate of the polyolefin resin is 0.1 to
It is preferably 7.0 g / 10 minutes. Further, the polyolefin resin composition for profile extrusion contains an inorganic filler in an amount of 0.1 to 5 parts by weight based on 100 parts by weight of the polyolefin resin.
It is preferable that it is blended so as to be 0 parts by weight. Further, the polyolefin resin composition for profile extrusion is obtained by mixing a part of the raw material polyolefin resin and a polyolefin resin modifier containing polytetrafluoroethylene particles and an organic polymer to form a master batch. It is preferable that the master batch is mixed with the remaining raw material polyolefin resin for production.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, a polyolefin resin (hereinafter abbreviated as a resin component) is a base resin of the polyolefin resin composition for profile extrusion (hereinafter abbreviated as a resin composition) of the present invention. . Examples of the resin component include polypropylene (PP); high density polyethylene (HDPE); low density polyethylene (LDPE); linear low density polyethylene (LLDPE); poly-1-butene; polyisobutylene; propylene and ethylene and / or Random copolymer or block copolymer in any ratio with 1-butene; ethylene-propylene-
Diene terpolymer (the ratio of ethylene to propylene is not limited, but the diene component is preferably 50% by weight or less); polymethylpentene; cyclic polyolefin such as a copolymer of cyclopentadiene with ethylene and / or propylene A random copolymer, a block copolymer or a graft polymer of ethylene or propylene and a vinyl compound (but the vinyl compound component is 50% by weight)
It is as follows. As the vinyl compound, for example, vinyl acetate, alkyl methacrylate, acrylic ester, aromatic alkyl ester, aromatic vinyl and the like are used. ). These can be used alone or 2
A mixture of more than one species can be used. The resin component is appropriately selected depending on the characteristics and shape of the molded article, molding conditions, and the like. Among these examples, PP, HDPE, LDP
E, LLDPE, ethylene-propylene random or block copolymers are preferable because they have high versatility, are inexpensive, and are suitable.

The resin component has a melt flow rate (hereinafter referred to as MFR) of 0.1 to 7.0 g / 10 minutes, more preferably 0.3 to 3.0 g / 10 minutes. 0.1g /
If the time is less than 10 minutes, the fluidity is insufficient, and it may be difficult to mold the resin composition. On the other hand, when the amount exceeds 7.0 g / 10 minutes, the melt tension of the resin composition decreases, and drawdown tends to occur. For this reason, rough surface and wrinkles on the surface of the molded body are likely to be generated, and a preferable appearance may not be obtained. The MFR is a value measured according to ASTM D1238. For example, the measurement conditions of PE are as follows: load 2.16
kg, 190 ° C .; PP measurement conditions were a load of 2.16 kg,
230 ° C.

The modifier used in the present invention has a particle size of 1
0 μm or less polytetrafluoroethylene (hereinafter PTF)
E) and an organic polymer. Polytetrafluoroethylene (hereinafter PTF) in the modifier
E) is preferably from 0.1 to 90% by weight. When the amount is less than 0.1% by weight, the effect of adding the modifier is not obtained when blended into the resin composition, and when the amount exceeds 90% by weight, the PTFE particles in the modifier agglomerate to the polyolefin resin. Becomes difficult to disperse.

The organic polymer constituting the modifier is not particularly limited. However, if a polymer having high compatibility with the polyolefin resin component is used, the dispersibility of the modifier in the resin component can be improved. And PTF in the resin component
This is preferable because FE can be efficiently and uniformly dispersed.

Specific examples of the monomer constituting the organic polymer include styrene, p-methylstyrene, o-methylstyrene, p-chlorostyrene, o-chlorostyrene,
Styrene monomers such as p-methoxystyrene, o-methoxystyrene, α-methylstyrene; methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, butyl acrylate, butyl methacrylate, acrylic acid-2 -(Meth) acrylates such as ethylhexyl, 2-ethylhexyl methacrylate, dodecyl acrylate, dodecyl methacrylate, tridecyl acrylate, tridecyl methacrylate, octadecyl acrylate, octadecyl methacrylate, cyclohexyl acrylate, cyclohexyl methacrylate Monomers; vinyl cyanide monomers such as acrylonitrile and methacrylonitrile; vinyl ether monomers such as vinyl methyl ether and vinyl ethyl ether; vinyl compounds such as vinyl acetate and vinyl butyrate Nsan vinyl monomer, ethylene,
Olefinic monomers such as propylene and isobutylene;
Examples include diene monomers such as butadiene and isoprene. These monomers can be used alone or in combination of two or more.

Of these, styrene-based monomers, (meth) acrylate-based monomers, and olefin-based monomers are preferred because they have good compatibility with the polyolefin-based resin component. Particularly preferred are those selected from the group consisting of long-chain alkyl (meth) acrylate monomers having 12 or more carbon atoms; styrene and olefin monomers.
Monomers containing at least 20% by weight of at least one kind of monomer can be mentioned.

The modifier is preferably obtained by any of the following three production methods. (1) A particle dispersion obtained by mixing an aqueous dispersion of PTFE particles having an average particle diameter of 0.05 to 1.0 μm and an aqueous dispersion of organic polymer particles is modified by powdering by coagulation or spray drying. Get the agent. (2) In the presence of an aqueous dispersion of PTFE particles having an average particle diameter of 0.05 to 1.0 μm, a monomer constituting an organic polymer is polymerized to obtain a particle dispersion. Is solidified or powdered by spray drying to obtain a modifier. (3) In a dispersion obtained by mixing an aqueous dispersion of PTFE particles having an average particle diameter of 0.05 to 1.0 μm and an aqueous dispersion of organic polymer particles, a monomer having an ethylenically unsaturated bond is mixed. After emulsion polymerization to obtain a particle dispersion, the particle dispersion is pulverized by coagulation or spray drying to obtain a modifier.

In the above method (1) to (3),
When solidifying and powdering, specifically, for example, the particle dispersion is poured into hot water at about 60 to 95 ° C. in which a metal salt such as calcium chloride or magnesium sulfate is dissolved,
The solids are separated by salting out, filtered and dried to obtain the modifier. In the production method (1), it is preferable that the particle dispersion is heated to 70 to 90 ° C., held for 1 hour, and then solidified. When pulverizing by spray drying, the particle dispersion can be directly pulverized according to a conventional method.

Examples of the monomer having an ethylenically unsaturated bond used in the production method (3) include styrene monomers, (meth) acrylate monomers, vinyl cyanide monomers, and vinyl ethers. A series monomer, a diene monomer, a vinyl carboxylate monomer, an olefin monomer and the like are used. The monomer having an ethylenically unsaturated bond is preferably blended in a range of 1 to 40% by weight based on the monomer component of the organic polymer in the modifier. If it is less than 1% by weight, solidification is difficult, and if it exceeds 40% by weight, dispersibility of the modifier may be poor.

In the above-mentioned production methods (1) to (3), the average particle diameter of the raw PTFE particles is 0.05 to 1.
0 μm. Those having a thickness of less than 0.05 μm are difficult to manufacture. On the other hand, if the thickness exceeds 1.0 μm, the P
It may be difficult to control the particle diameter of the TFE particles to 10 μm or less. Commercially available raw materials for the aqueous dispersion of PTFE particles include Fluon AD-1, AD-936 manufactured by Asahi ICI Fluoropolymer Co., Ltd., and Polyflon D-1, D-2 manufactured by Daikin Industries, and Mitsui DuPont Fluorochemical Co., Ltd. Teflon 30J manufactured by the company.

In the production methods (1) to (3), the average particle diameter of the organic polymer particles is preferably 0.0
It is 5 to 1.0 μm. If it is less than 0.05 μm, it is difficult to manufacture, and if it exceeds 1.0 μm, the dispersibility of the modifier may be poor. Further, in the production method of (1) to (3), the concentration of the aqueous dispersion of the PTFE particles, the concentration of the aqueous dispersion of the organic polymer particles, the polymerization conditions of the monomer, the monomer having an ethylenically unsaturated bond The conditions for emulsion polymerization of the body are appropriately adjusted depending on the raw materials, the composition, and the like.

In the production methods (1) to (3), the modifying agent may be a powder in which PTFE particles having a particle diameter of 10 μm or less are dispersed in particles made of an organic polymer, or a PTFE having a particle diameter of 10 μm or less. Part or all of the surface of the particles is obtained as a powder coated with an organic polymer. In the production method (3), a modifier containing a polymer of a monomer having an ethylenically unsaturated bond and an organic polymer in the same form as the organic polymer is obtained.

The average molecular weight of the organic polymer in the modifier varies depending on the type of monomer and the production method, but is usually 100,000 or more, preferably 300,000 to 2,000,000. The average particle size of the modifier is usually 1 to 100 μm, preferably 5 to 100 μm.
To 10 m. If it is less than 1 μm, it is difficult to handle, and if it exceeds 100 μm, the dispersibility of the modifier may be reduced when it is mixed with the resin component.

Meanwhile, ordinary PTFE fine powder having an extremely small average particle diameter is obtained by recovering from an aqueous dispersion of PTFE particles as a raw material. In this recovery step, the PTFE fine powder often aggregates to form a lump (aggregate) having a particle diameter of 100 μm or more. Even if PTFE fine powder, which tends to be agglomerated, is directly mixed with the resin component, the PTFE is not dispersed in the resin component, and it is difficult to produce a resin composition having a uniform composition. For this reason, for example, even if PTFE fine powder is blended with the resin component so that the same amount of PTFE as the resin composition of the present invention is blended, the same effect as in the present invention is not necessarily obtained. On the other hand, in the above-mentioned production methods (1) to (3), the average particle size of the PTFE particles in the aqueous dispersion of the raw material is set to 0.05 to 1.0 μm.
m, and by collecting and powdering together with the organic polymer, the PTFE particles in the modifier are less likely to aggregate,
The particle diameter can be controlled so as not to exceed 10 μm. In addition, the resulting modifier itself is not easily aggregated and has good dispersibility. The manufacturing methods of the above (1) and (2)
There is an advantage that the operation is easy and the manufacturing time is short. Furthermore, in the production method (2), the affinity between the PTFE particles and the organic polymer is good, and the properties of the modifier tend to be stable. Further, the manufacturing method of the above (3) is characterized in that:
The properties of the modifier tend to be stable and the PTFE particles in the modifier tend to be less likely to agglomerate, as in the production method of (1).

By using such a modifier,
The modifier is evenly dispersed in the resin component, and as a result, the PTFE contained in the modifier is evenly dispersed in the resin component, and a resin composition having a uniform composition that is efficiently fiberized is obtained. That is, in the present invention, it is possible to improve the melt tension of the polyolefin-based resin composition by using a modifier capable of maximizing the effect of reinforcing the melt tension of PTFE with respect to the resin component. Then, when the resin composition is formed by profile extrusion, a molded article having a small drawdown during extrusion and having an excellent surface shape can be obtained. In addition, the improvement in the melt tension makes it difficult for the molded body to be warped, and can prevent the molded body from being deformed. In the present invention, since the above-described effect of improving the melt tension is large,
Even when molding large and complex shaped extruded products,
The above-described effects of improving the surface shape and suppressing the warpage are obtained.

In the resin composition of the present invention, the resin component and the modifier are contained in an amount of 0.01 to PTFE in the resin composition.
Preferably, they are mixed so as to be 20% by weight.
If it is less than 0.01% by weight, the effect of reinforcing the melt tension with respect to the resin component cannot be sufficiently obtained, and if it exceeds 20% by weight, the fluidity and moldability of the resin composition are reduced, and the surface shape of the molded article is improved. The effect may not be obtained.

Further, additives such as a stabilizer, a lubricant and an inorganic filler can be added to the resin composition of the present invention, if necessary. In particular, by adding an inorganic filler, molding shrinkage can be reduced, and therefore, it is possible to further suppress the occurrence of warpage of the molded body, which is preferable.

Examples of the inorganic filler include, for example, calcium carbonate, talc, glass fiber, magnesium carbonate, mica, kaolin, calcium sulfate, aluminum hydroxide, magnesium hydroxide, silica, clay, zeolite and the like. These can be used alone or in combination of two or more. The amount of the inorganic filler is preferably 0.1 to 50 parts by weight, more preferably 1 to 50 parts by weight, based on 100 parts by weight of the resin component. If the amount is less than 0.1 part by weight, the effect of addition cannot be obtained, and if it exceeds 50 parts by weight, the effect is saturated.

As the stabilizer, pentaerythrityl-tetrakis {3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate}, triethylene glycol-bis {3- (3-tert-butyl) 5-Methyl-4-
Phenol-based stabilizers such as hydroxyphenyl) propionate; phosphorus-based stabilizers such as tris (monononylphenyl) phosphite and tris (2,4-di-tert-butylphenyl) phosphite; dilauroyl dipropionate; Examples thereof include a sulfur-based stabilizer. These can be used alone or in combination of two or more. The amount of the stabilizer is 0.01 to 0.5 part by weight, more preferably 0.05 part by weight, based on 100 parts by weight of the resin component. If the amount is less than 0.01 part by weight, the effect of addition cannot be obtained, and if it exceeds 0.5 part by weight, the effect is saturated.

Examples of the lubricant include metal salts of saturated or unsaturated fatty acids. Specific examples include sodium, calcium, and magnesium salts such as lauric acid, palmitic acid, oleic acid, and stearic acid. These can be used alone or in combination of two or more. The amount of the lubricant is 100 resin components.
Usually, it is preferably 0.1 to 2 parts by weight based on parts by weight. If the amount is less than 0.1 part by weight, the effect of addition cannot be obtained, and if it exceeds 2 parts by weight, the effect is saturated.

The method of mixing the resin component and the modifier is not particularly limited. For example, when the mixing (production of the resin composition) and the profile extrusion of the resin composition are simultaneously performed, the efficiency is improved. More specifically, for example, a resin component and a modifier are added to an extruder together with additives such as an inorganic filler as necessary, and kneaded while heating internally, and extruded from a die for profile extrusion. Then, the uncooled molded body is continuously guided to a cooling zone and cooled to obtain a profile-extruded molded body composed of a resin composition containing the resin component and the modifier. At this time, it is preferable that the resin component, the modifying agent, and the additive are previously mixed in a solid state (powder mixing), and the mixture is put into an extruder, whereby the mixing efficiency is improved, which is preferable.

Alternatively, it is preferable to prepare a master batch containing a part of the resin component of the raw material and the modifying agent in advance so that the resin component and the modifying agent can be efficiently and uniformly mixed in a short time. . Specifically, for example, a part of the raw material resin component and the modifying agent are put into an extruder, kneaded while heating inside, and extruded from a mesh-shaped die provided with a plurality of holes, and the reforming is performed. A pellet of a master batch containing a high concentration of the agent is obtained. This masterbatch is put into an extruder together with the remaining raw material resin components and, if necessary, additives such as inorganic fillers, kneaded while heating internally, and extruded from a die for profile extrusion. Then, the uncooled molded body is continuously guided to a cooling zone and cooled to obtain a profile-extruded molded body composed of a resin composition containing the resin component and the modifier. Also in this case, it is preferable to mix the materials before being put into the extruder in a solid state before putting them into the extruder, because the mixing efficiency is improved, which is preferable. The additives can also be added during the production of the master batch.

The masterbatch is adjusted so that the concentration of the modifier in the masterbatch is 1 to 50% by weight. Outside this range, the effect of improving the mixing efficiency may not be sufficiently obtained. In addition, by making the masterbatch into fine pellets or granules to some extent as described above, the operability when mixing with the remaining resin components is improved. The method of mixing and molding the resin component and the modifier at the time of production of the masterbatch is not limited, but the extrusion molding method is efficient and preferable because the mixing and molding can be performed simultaneously.

The extrusion temperature at the time of the profile extrusion molding or the production of the masterbatch is, for example, 150 to 270 ° C., more preferably 170 to 250 ° C. If the temperature is below 150 ° C,
If the resin component does not melt sufficiently and exceeds 270 ° C., operability may decrease. Although the cooling method in the cooling zone is not particularly limited, for example, a method of bringing an uncooled molded body into contact with air; a method of forcibly blowing cold water or air on the uncooled molded body; For example, a method of passing through the inside of a sizing die provided with a jacket through which the refrigerant circulates.

[0031]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to embodiments. First, in Experimental Examples 1 and 2 below, modifiers B-1 and B-2 corresponding to the modifier of the present invention were produced, and Experimental Example 3
, A masterbatch containing the modifier B-2 was produced. Then, using the products manufactured in these Experimental Examples 1 to 3, in Examples and Comparative Examples, modified extrusion molded articles were produced by a modified extrusion molding method, and their physical properties and properties were evaluated. Unless otherwise specified below, “parts” indicating the blending amounts represent “parts by weight”.

Experimental Example 1 (Production of Modifier B-1) 190 parts of distilled water and 1.5 parts of sodium dodecylbenzenesulfonate were placed in a separable flask equipped with a stirrer, a condenser, a thermocouple, and a nitrogen inlet. , 100 parts of styrene and 0.5 part of cumene hydroperoxide.
The temperature was raised to 0 ° C. Next, a mixed solution of 0.001 part of iron sulfate, 0.003 part of disodium ethylenediaminetetraacetate, 0.24 part of Rongalite salt, and 10 parts of distilled water was added to perform radical polymerization. After the end of the exotherm, raise the temperature in the system to 40
C. for 1 hour to complete the polymerization, thereby obtaining a styrene polymer particle dispersion (hereinafter referred to as P-1). The solid concentration of P-1 was 33.3% by weight, the particle size distribution showed a single peak, and the weight average particle size was 96 nm.

On the other hand, Fluon AD936 manufactured by Asahi ICI Fluoropolymer Co., Ltd. was prepared as a raw material of the PTFE particle dispersion. The solid concentration of AD936 is 63.0% by weight,
It contained 5 parts of polyoxyethylene alkylphenyl ether per 100 parts of PTFE. Also, A
The particle size distribution of D936 showed a single peak, and the weight average particle size was 290 nm. To AD936, 833 parts, 1167 parts of distilled water was added, and the solid concentration was 26.2% by weight.
PTFE particle dispersion F-1 was obtained. F-1 contained 25% by weight of PTFE particles and 1.2% by weight of polyoxyethylene nonylphenyl ether.

Then, 160 parts of F-1 (PTFE 40
Parts) and 181.0 parts of P-1 (60 parts of polystyrene) were charged into a separable flask equipped with a stirrer, a condenser, a thermocouple, and a nitrogen inlet, and charged at room temperature under a nitrogen stream.
Stirred for hours. Thereafter, the inside of the system was heated to 80 ° C. and kept for 1 hour. No solid matter was separated through a series of operations, and a uniform particle dispersion was obtained. The solid content concentration of this particle dispersion was 29.3% by weight, the particle size distribution was relatively broad, and the weight average particle size was 168 nm.

341.8 parts of this particle dispersion is charged into 700 parts of 85 ° C. hot water containing 5 parts of calcium chloride, and the solid content is separated by salting out, followed by filtration and drying. 1,
98 parts were obtained. This B-1 was formed into a strip shape at 250 ° C. by a press molding machine, and the ultrathin section was observed with a microtome without transmission using a transmission electron microscope. P
Although TFE was observed as a dark part, no aggregate of PTFE particles having a particle diameter exceeding 10 μm was observed.

Experimental Example 2 (Production of Modifier B-2) 75 parts of dodecyl methacrylate and 25 parts of methyl methacrylate
0.1 part of azobisdimethylvaleronitrile was dissolved in 1 part of the mixture. A mixed solution of 2.0 parts of sodium dosylbenzenesulfonate and 300 parts of distilled water was added thereto, and the mixture was stirred at 10,000 rpm for 4 minutes with a homomixer, and then passed twice through a homogenizer at a pressure of 300 kg / cm ² .
A stable dodecyl methacrylate / methyl methacrylate pre-dispersion was obtained. This was charged into a separable flask equipped with a stirrer, condenser, thermocouple, and nitrogen inlet,
Radical polymerization was performed by stirring the internal temperature at 80 ° C. for 3 hours under a nitrogen stream to obtain a dodecyl methacrylate / methyl methacrylate copolymer particle dispersion (hereinafter referred to as P-2). The solid content concentration of P-2 was 25.1% by weight, the particle size distribution showed a single peak, and the weight average particle size was 198%.
nm.

Next, F-1 used in Experimental Example 1 was reduced to 160
Part (PTFE 40 parts) and 159.4 parts of P-2 (dodecyl methacrylate / methyl methacrylate copolymer 40).
) Into a separable flask equipped with a stirrer, condenser, thermocouple, nitrogen inlet, dropping funnel,
The mixture was stirred at room temperature for 1 hour under a nitrogen stream.

Then, the temperature of the system was raised to 80 ° C., and 0.001 part of iron sulfate, 0.003 part of disodium ethylenediaminetetraacetate, 0.24 part of Rongalite salt, 10 parts of distilled water
Of a mixture of 20 parts of methyl methacrylate and 0.1 part of tertiary butyl peroxide.
It was added dropwise over 0 minutes. After completion of the dropwise addition, the internal temperature was maintained at 80 ° C. for 1 hour to complete the radical polymerization. No solid content was separated through a series of operations, and a uniform particle dispersion was obtained. The solid content concentration of the particle dispersion is 28.5% by weight, the particle size distribution is relatively broad, and the weight average particle size is 248 nm.
Met.

349.7 parts of this particle dispersion liquid was poured into 600 parts of hot water at 75 ° C. containing 5 parts of calcium chloride, the solid content was separated, and the solid was separated by filtration and dried. Got a part. After drying this B-2, it was shaped into a strip at 220 ° C. by a press molding machine. Then, this was cut into an ultrathin section using a microtome and observed with a transmission electron microscope without staining. As in Experimental Example 1, the particle diameter was 10 μm.
Aggregates of PTFE particles exceeding the above were not observed.

Experimental Example 3 (Production of Masterbatch M-1) B-2 obtained in Experimental Example 2 was mixed with 75 parts of linear homopolypropylene pellets prepared as a resin component.
After blending 5 parts and performing hand blending (powder mixing), the mixture is charged into a twin screw extruder (ZSK30 manufactured by Werner & Pfleiderer), melt-kneaded at a barrel temperature of 200 ° C. and a screw rotation speed of 200 rpm, and shaped into pellets. Then, a master batch of a modifier (hereinafter referred to as M-1) was obtained. The linear homopolypropylene pellets used were Novatec PP EA7 manufactured by Nippon Polychem Co., Ltd.
Was 1.2 g / 10 min.

Examples 1 to 5 and Comparative Examples 1 to 4
In Examples 5 to 5, linear homopolypropylene pellets as resin components and B-1 and B-2 obtained in Experimental Examples 1 and 2 or M-1 obtained in Experimental Example 3 were used at the ratios shown in Table 1.
Was hand blended to produce a polyolefin-based resin composition. At this time, in Examples 3 to 5, talc (inorganic filler) was further added. In Comparative Examples 1-4, commercially available powdered PTFE containing no organic polymer was replaced with linear homopolypropylene pellets at the ratios shown in Table 1 in place of B-1 and B-1 and M-1. Hand blended.

The linear homopolypropylene pellets used were the following two types of Novatec PP manufactured by Nippon Polychem Co., Ltd.
The respective MFRs were as follows. EA9: MFR 0.5 g / 10 min FY6: MFR 2.5 g / 10 min The following PTFE and talc were used. CD123: powdered PTFE (“Fluon CD123” manufactured by Asahi ICI Fluoropolymers Co., Ltd .: molecular weight: 12 million) Talc: LMS-100 manufactured by Fuji Talc Co., Ltd. The MFR of each resin composition was determined by ASTM.
It measured at 230 degreeC and the load of 2.16 kg according to D1238.

Next, the polyolefin-based resin composition thus adjusted was charged into an extruder, and was subjected to profile extrusion and cooling under the following conditions. Outer diameter φ for extruder
A die for heteromorphic molding having a length of 50 mm and L (length) / D (outer diameter) = 28 was attached. The set temperature of the cylinder at the time of extrusion molding was 200 ° C., and the set temperature of the die was 210 ° C.

A vacuum sizing die was used for the cooling zone. This sizing die is provided with a hole for evacuation on the inner wall thereof, and the suction force causes the uncooled molded body fed into the sizing die to adhere to the inner wall. While circulating a refrigerant through a jacket provided in the above, the inside molded body is cooled. This time, cooling was performed while circulating water at 20 ° C. In addition, the length of the sizing die is 300 mm,
The distance between the extruder, the die and the sizing was kept at 50 mm. The uncooled molded body extruded from the die was continuously sent to sizing, cooled, and then cut into a predetermined size.

FIG. 1 shows the cross-sectional shape of the thus obtained extruded molded product. 1 are dimensions (unit: m)
m). The deformed extruded product 1 has a thin portion 2 and a thick portion 3, a projection 5 projecting inward and a projection 6 projecting outward on one bottom surface 4, and a bottom surface 7 on the other bottom surface 7. Was a substantially hollow rectangular parallelepiped having a complicated shape on which a projection 8 projecting to the outside was formed.

The surface properties of the molded product were visually observed, and the following three grades were evaluated. : The surface of the molded body has a good surface shape without rough surface and wrinkles. Δ: Some surface roughness and wrinkles are observed on the surface of the molded body. ×: Skin roughness, wrinkles, etc. are observed on the surface of the molded body.

After cooling by sizing, 50
A molded body cut to a length of 0 mm was separately prepared, and the difference in height between the central part and the end part when this molded body was allowed to stand horizontally was measured as the amount of warpage. went. : The amount of warpage is less than 5 mm Δ: The amount of warpage is 5 mm or more and less than 10 mm ×: The amount of warpage is 10 mm or more

Further, pellets of the resin composition constituting the molded product are separately prepared, and extruded at a constant extrusion rate (down speed of 10 mm / min) using a descending flow tester (Capillograph, manufactured by Toyo Seiki Co., Ltd.). At a constant speed (1 m / min) and the melt tension was measured. The die is L (length) / D (outer diameter) is 10.0mm / 2.0mmφ
The measurement temperature was 210 ° C. These evaluation results are shown in Table 1.

[0049]

[Table 1]

[Examples 6 to 13 and Comparative Examples 5 to 7] Molded articles were prepared in the same manner as in Examples 1 to 5 and Comparative Examples 1 to 4 by using polyethylene pellets as the resin component and by the blending shown in Table 2. After production, physical properties were measured and evaluated. The following polyethylene pellets manufactured by Grand Polymer Co., Ltd. were used. 3000B (HIZEX 3000B) (HDPE):
MFR 0.6 g / 10 min. Mirason 50 (LDPE): MFR 1.9 g / 10 min. Ultzex 1520L (LLDPE): MFR
2.3 g / 10 minutes The physical properties and evaluation results of the obtained molded article are shown in Table 2. However, the MFR of the resin composition is ASTM D12
This is a value measured at a load of 2.16 kg and 190 ° C. according to No. 38.

[0051]

[Table 2]

[Examples 14 to 20] As a resin component, a mixture of the polypropylene pellets and polyethylene pellets used in Examples 1 to 15 was used. In the same manner as in Examples 4 to 4, a molded body was manufactured, and physical properties were measured and evaluated. The physical properties and evaluation results of the obtained molded body are shown in Table 3. However, the MFR of the resin composition has a load of 2.1 according to ASTM D1238.
6 kg, measured at 230 ° C.

[0053]

[Table 3]

From the results shown in Tables 1 to 3, in Examples according to the present invention, molded articles having better surface shapes were obtained as compared with Comparative Examples, and warpage of the molded articles could be prevented.
Therefore, it was confirmed that the modifier and the resin composition of the present invention were very effective for profile extrusion of a complicated shape.

[0055]

As described above, when the resin composition of the present invention is shaped by extrusion, a molded article having a small drawdown during extrusion and an excellent surface shape can be obtained. Also,
The improvement in the melt tension makes it difficult for the molded article to be warped during cooling, and can prevent deformation of the molded article. In the resin composition of the present invention, since the effect of improving the melt tension is large, the effect of improving the surface shape and the effect of suppressing warpage can be obtained even when a large-sized and complex-shaped extruded product is molded. Further, by adding an inorganic filler to the resin composition, molding shrinkage can be reduced, and furthermore, occurrence of warpage can be prevented. Further, in the resin composition of the present invention, a part of the raw material polyolefin resin and a modifier are mixed to form a masterbatch, and when the masterbatch is mixed with the remaining raw material polyolefin resin, efficiently and in a short time The modifier can be uniformly mixed in the polyolefin resin.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a profile extruded product obtained in an example and a comparative example.

[Explanation of symbols]

 1: Extruded molded article.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08L 27:18 101: 00) B29K 23:00 (72) Inventor Kazuo Ueda 3816 Noto, Tama-ku, Kawasaki-shi, Kanagawa Prefecture Address Resin Development Center, Mitsubishi Rayon Co., Ltd. (72) Inventor Atsunori Koshirai 20-1, Miyukicho, Otake City, Hiroshima Prefecture F-term in Central Research Laboratory, Mitsubishi Rayon Co., Ltd. 4F070 AA12 AA71 AB11 AB24 AC79 AE01 FA03 FA17 FB03 FB06 FB09 FC05 4F207 AA03 AA16 AB07 AC04 AC08 AE01 AG09 AP16 KA01 KB21 KL51 4J002 AC033 AC063 BB031 BB033 BB051 BB121 BB123 BB151 BB171 BB183 BC033 BC083 BC093 BC113 BC123 BD183 BE3103BG01 BD152 BE043 BG013

Claims (4)

[Claims] 2. A polyolefin resin composition for profile extrusion, comprising a polyolefin resin and a modifier containing polytetrafluoroethylene particles and an organic polymer. 2. The amount of the polytetrafluoroethylene component is 0.1 to 100 parts by weight of the polyolefin resin.
2. The polyolefin resin composition for profile extrusion according to claim 1, wherein the modifier is blended in an amount of from 0.01 to 20 parts by weight. 3. 3. The polyolefin resin composition for profile extrusion according to claim 1, wherein the melt flow rate of the polyolefin resin is 0.1 to 7.0 g / 10 minutes. 4. A part of a raw material polyolefin resin,
A masterbatch is prepared by mixing a polyolefin-based resin modifier containing polytetrafluoroethylene particles and an organic polymer, and the masterbatch is mixed with the remaining raw material polyolefin-based resin. ~ 3
A method for producing the polyolefin resin composition for profile extrusion according to any one of the preceding claims.