JPS6331507B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing a polyolefin resin composition. More specifically, the present invention relates to a method for producing a polyolefin resin composition with excellent mechanical properties and moldability by mixing a specific modified liquid rubber with polyolefin. Traditionally, the mechanical properties of polyolefin resin,
In order to improve thermal properties and the like, methods have been used in which various compounds such as inorganic fillers and unsaturated organic acids are mixed into polyolefin resins. However, none of these methods achieved satisfactory results, and moreover, there were various problems in molding. For example, a method for producing a polyolefin resin composition by mixing an inorganic filler with a polyolefin resin is as follows:
Although the rigidity of the composition increases, it has drawbacks such as a decrease in tensile strength and impact strength, and a decrease in moldability due to a decrease in the fluidity of the molten resin. Furthermore, the method of pre-treating the inorganic filler with an organic acid or the like and then mixing the treated filler with a polyolefin resin can improve the impact strength of the resulting composition to some extent, but the treatment of the inorganic filler However, there are still practical problems such as the long time it takes to complete the process. Therefore, there is a method for improving the mechanical strength, thermal properties, etc. of a polyolefin resin composition by heating and mixing a polyolefin resin, an inorganic filler, a polydiene liquid rubber, an unsaturated carboxylic acid or its derivative, and a radical generator. -20056) is proposed. However, this method uses monomers such as unsaturated carboxylic acids or their derivatives, and is usually mixed using an extruder, etc., so the working environment is significantly contaminated due to volatilization of the monomers. The disadvantage was that the molding machine was easily corroded. On the other hand, for vulcanizable rubber such as SBR, a basic inorganic filler, maleated liquid polybutadiene, and sulfur are mixed and vulcanized all at once to enhance hardness, tensile modulus, tensile strength, wear resistance, etc. A method (Japanese Unexamined Patent Publication No. 147743/1983) has also been proposed, and although this method is effective for rubber, it is also sufficiently effective when applied to the production of filler-containing polyolefin resin compositions. However, it was not possible to achieve a significant improvement in mechanical strength. Therefore, the present inventors have developed a polyolefin resin composition that improves the mechanical properties, thermal properties, moldability, and other properties, does not pollute the environment during mixing, has good workability, and further improves the properties of polyolefin resin compositions such as mechanical properties, thermal properties, and moldability. As a result of research into a method for producing a polyolefin resin composition that does not cause corrosion of equipment such as machines, the inventors discovered that a specific modified liquid rubber could be used, and the present invention was completed. That is, the present invention comprises a polyolefin resin (A), a filler (B), a radical generator (C), and at least one side chain in the molecule, and at least one acidic group in the side chain. This is a method for producing a polyolefin resin composition, which is characterized by heating and mixing a modified liquid rubber (D) into which an unsaturated group and an imide group have been introduced. Any polyolefin resin may be used in the method of the present invention. For example, monoolefin polymers such as low density polyethylene, medium density polyethylene, high density polyethylene, polypropylene, polybutene-1, poly-4-methylpentene-1, ethylene-propylene copolymer, ethylene-butene copolymer, propylene-1, etc.
Copolymers such as butene copolymers or mixtures of these polymers are suitable. Particularly preferred are propylene homopolymers, propylene copolymers, high-density polyethylene and their copolymers, or mixtures of these polymers, and the addition of modified liquid rubber to these polymers reduces the thermal shear that the polymers undergo during processing. can be prevented, and the original excellent properties of the above polymer can be maintained. Next, the liquid rubber that is the starting material for the modified liquid rubber that plays an important role in the present invention is preferably a conjugated diene polymer or copolymer such as butadiene or isoprene with a number average molecular weight of 300 to 10,000, that is, a liquid rubber. It is a polydiene rubber and is produced by a conventionally known method. That is, using an alkali metal or an organic alkali metal compound as a catalyst,
A conjugated diolefin having 4 to 10 carbon atoms alone, or these diolefins together, or preferably an aromatic vinyl monomer such as styrene, α-methylstyrene, etc. in an amount of up to 50 mol % relative to the conjugated diolefin, especially butadiene or isoprene. 0 vinyltoluene or divinylbenzene
A typical manufacturing method is anionic polymerization at a temperature of 100°C to 100°C. In this case, in order to control the molecular weight and obtain a light-colored low polymer with a low gel content, an organic alkali metal compound such as sodium benzyl is used as a catalyst, and a compound having an alkylaryl group, such as toluene, is used as a chain transfer agent. chain transfer polymerization method (US Pat. No. 3,789,090), or a living polymerization method using a polycyclic aromatic compound such as naphthalene as an activator and an alkali metal such as sodium as a catalyst in a tetrahydrofuran solvent (Japanese Patent Publication No. 42 -17485, 43-27432), or by using an aromatic hydrocarbon such as toluene or xylene as a solvent, using a metal dispersion such as sodium as a catalyst, and adding an ether such as dioxane to reduce the molecular weight. Controlled polymerization method (Special Publication No. 32-7446
No. 33-1245, No. 34-10188) are suitable manufacturing methods. It is also produced by coordination anion polymerization using an acetylacetate compound of a Group 8 metal, such as cobalt or nickel, and an alkyl aluminum halide (Japanese Patent Publication Nos. 45-507 and 46-30300). In addition to low polymers produced by cationic polymerization using a Friedel-Crafts catalyst such as aluminum chloride, boron trifluoride, or complexes thereof, pyrolytic rubber, ozone decomposed rubber, etc. can also be used. In the present invention, an unsaturated dicarboxylic anhydride or its derivative-modified liquid rubber is produced by adding an unsaturated dicarboxylic anhydride or its derivative to the liquid rubber, and the liquid rubber is further modified. The method for producing the above-mentioned unsaturated dicarboxylic acid anhydride or derivative-modified liquid rubber includes adding 100 to 300% of the above liquid rubber or a mixture thereof.
A conventionally known method for adding maleic acid, maleic anhydride, citraconic acid, citraconic anhydride, etc. at a temperature of
issue). Furthermore, when performing these addition reactions, a method of preventing the gelation reaction by allowing phenylene diamines, pyrogallols, naphthols, etc. to be present in the system (West German Published Patent Application No. 2362534) can also be preferably employed. The amount of unsaturated dicarboxylic acid anhydride or its derivative to be added to the liquid rubber or mixture thereof is 0.01 to 1.0 mol, preferably 0.05 to 0.5 mol, per 100 g of liquid rubber. The amount of acid added is 0.01
If the amount is less than 1.0 mol, no effect can be expected when added to the polyolefin resin even if it is further modified, as described below, and if it is more than 1.0 mol,
This is not preferable because the compatibility with the polyolefin resin becomes poor. In the present invention, at least one side chain represented by the following general formula is introduced per molecule, which is further derived from a liquid rubber modified with the above-mentioned unsaturated dicarboxylic acid anhydride or its derivative, such as a liquid diene rubber. A modified liquid rubber, such as a modified liquid polybutadiene, is used. That is, the general formula is as follows. Here, in the above formula, R ₁ , R ₃ , and R ₄ are each a hydrogen atom, a halogen atom, or a hydrocarbon residue having 1 to 3 carbon atoms, and R ₂ is a carbon dioxide residue that may contain a nitrogen atom having 1 to 20 carbon atoms. The hydrogen residue, X, represents a hydrogen atom or a bond to the liquid rubber chain, and Y represents a bond to the liquid rubber chain. The modified liquid rubber having a side chain represented by the above general formula is prepared by adding the unsaturated dicarboxylic anhydride or its derivative modified liquid rubber obtained as described above at a reaction temperature of 50 to 300°C, preferably 100 to 200°C. is imidized with an amine compound containing a hydroxyl group, and then further treated with an unsaturated dicarboxylic anhydride or its derivative at a reaction temperature of 20 to 200°C, preferably
It is obtained by carrying out half-esterification at a temperature of 70-150° C. in the presence or absence of a catalyst such as a tertiary amine. The amine compound containing a hydroxyl group used in the imidization is a primary amine, and includes, for example, hydroxyalkylamines such as β-hydroxyethylamine and β-hydroxypropylamine, β-hydroxyethylaminoethylamine, and β-hydroxylamine. Diamines such as ethylaminopropylamine may also be used. The above imidization reaction can be carried out in the presence or absence of a solvent. It is preferable not to use a solvent, but if a solvent is used, benzene,
Hydrocarbon solvents such as toluene, cyclohexane, and xylene, alcohol solvents such as butyl cellosolve, and ether solvents such as dimethyl ether of diethylene glycol (diglyme) can be used. Subsequently, by performing half-esterification with an unsaturated dicarboxylic acid anhydride or its derivative, a modified liquid rubber having a side chain represented by the above general formula can be obtained.
It can be carried out in the presence or absence of a solvent. Although it is preferable not to use a solvent, if a solvent is used, the same solvent (excluding alcohol-based solvents) used during the imidization can be used. Further, the unsaturated dicarboxylic anhydride or its derivative used in this case may be the same as that used in producing the unsaturated dicarboxylic anhydride or its derivative-modified liquid rubber described above. Further, at this time, antioxidants such as hydroquinone and BHT are also preferably used. The modified liquid rubber of the present invention produced as described above has at least one side chain per molecule,
The modified liquid rubber has at least one acidic group, one unsaturated group, and one imide group in each side chain. Furthermore, since they are in the same side chain, it can be said that the distance between the acidic group and the unsaturated group is usually close. Therefore, when the modified liquid rubber of the present invention is mixed with a polyolefin resin and a filler, the polar moieties on the surface of the filler dispersed in the polyolefin resin interact with the acidic groups, and the modified liquid rubber It is thought that the particles aggregate on the surface of the filler. Then, due to the radicals generated from the radical generator,
It is presumed that the highly radically polymerizable unsaturated groups present in the vicinity of the acidic groups polymerize, and as a result, an organic layer consisting of liquid rubber is formed on the filler surface. Furthermore, from this organic layer, it is assumed that the liquid rubber main chain is intertwined with the polyolefin layer, and the modified liquid rubber used in the present invention acts as an ideal coupling agent for coupling the polyolefin resin and the filler. It is thought that there are. In addition, at this time, if a vinyl group with high radical polymerizability is present in the liquid rubber main chain, the modified liquid rubber can bond to the polyolefin resin or to each other liquid rubber via this vinyl group.
The coupling effect is further improved. Therefore, when it is desired to increase the radical polymerizability of a modified liquid rubber, it is preferable to use a modified liquid rubber in which the ratio of double bonds in the modified liquid rubber main chain is 50% or more of vinyl groups. Note that the modified liquid rubber is thought to work as a reactive plasticizer and to prevent the polyolefin resin from being cut due to thermal history. These modified liquid rubbers are polyolefin resins.
It is preferably blended in a proportion of 0.5 to 10 parts by weight per 100 parts by weight. If the amount of this modified liquid rubber is less than 0.5 parts by weight, mechanical strength cannot be expected, and if it exceeds 10 parts by weight, the mechanical strength decreases, which is not preferable. Fillers include calcium carbonate, talc, clay, mica, zinc white, calcium sulfate, calcium sulfite, calcium silicate, diatomaceous earth, silica, magnesium oxide, alumina, glass powder, glass fiber, asbestos, gypsum fiber, and carbon fiber. , wood fiber, wood flour, or a mixture thereof. In addition, the shape and size of the filler are not particularly limited, but in the case of granules, those with an average particle diameter of 10 μm or less are preferred;
Those that have been surface-treated can also be used. The filler is based on 100 parts by weight of polyolefin resin.
It is used in a proportion of 5 to 400 parts by weight. In the present invention, it is preferable to mix the filler in the above range in view of the balance between the mechanical strength and moldability of the composition. Furthermore, any radical generator may be used as long as it promotes the crosslinking reaction of the polyolefin resin and modified liquid rubber. For example, dicumyl peroxide,
t-Butylperoxybenzoate, 2,5-dimethyl-2,5-di(t-butylperoxy)hexane, 2,5-dimethyl-2,5-di(t-butylperoxy)hexene-3, α , α′-bis(t-butylperoxy)-p-diisopropylbenzene, t-butylcumyl peroxide,
1,1-bis(t-butylperoxy)-3,
3,5-trimethylcyclohexane, cumene hydroperoxide, di-t-butyl peroxide, 2,2'-azobisisobutyronitrile, etc., or mixtures thereof are used. These radical generators are mixtures of polyolefin resins, fillers, and modified polyolefins.
0.001 part by weight or more is required.
This amount is preferably 0.005 to 1.0 parts by weight,
If the amount is less than 0.001 part by weight, the effect will be small, and if it is added more than 1.0 part by weight, no greater effect can be expected. In the present invention, not only a filler, a modified liquid rubber, and a radical generator as described above, but also a colorant, a stabilizer, a plasticizer, a lubricant, etc. can be added to the polyolefin resin as necessary. In the method of the present invention, the desired polyolefin resin composition can be obtained by mixing the above raw material components under heating. The heating temperature in this case needs to be higher than the melting point of the resin used, and is generally about 150 to 300°C. Mixing is carried out using a suitable plastic kneader such as a Banbury mixer, kneader, mixing roll, continuous kneader or extruder. The polyolefin resin composition of the present invention obtained in this way has a tendency to cause environmental pollution due to the blending of monomers, difficult workability, It has no problems such as corrosion of equipment, has excellent tensile strength, impact strength, and rigidity, and has particularly excellent properties in terms of tensile strength and rigidity. Furthermore, the modified liquid rubber does not plasticize when heated and mixed. Acts as an agent and improves dispersion. In addition, after molding, the above composition has excellent fluidity because it acts as a coupling agent to the filler.
Injection molding can be easily performed, and molded products with beautiful appearance and excellent mechanical strength, rigidity, heat resistance, chemical resistance, etc. can be obtained. Due to its excellent properties, it can be used in a wide range of applications, including not only general plastic molded products but also industrial materials and construction materials. Next, the present invention will be explained in more detail with reference to Examples. Production example 1 Polybutadiene (trademark Nisseki Polybutadiene B-
2000, number average molecular weight 2000, 1,2 bond 65%)
1000 g of maleic anhydride, 163 g of xylene, and 2 g of Antigen 3C (manufactured by Sumitomo Chemical, trade name) were placed in two separable flasks and heated to 195°C under a nitrogen stream.
The reaction was carried out for 5.0 hours. Next, unreacted maleic anhydride and xylene were distilled off under reduced pressure to synthesize maleated liquid polybutadiene (A) with an acid value of 80. Next, 1000g of maleated liquid polybutadiene (A),
87.3 g of β-hydroxyethylamine and 200 g of butyl cellosolve were placed in two separable flasks, and while distilling off the water produced, the
After heating for a period of time, butyl cellosolve, unreacted amine, and produced water were distilled off under reduced pressure to synthesize imidized liquid polybutadiene (A'). Next, imidized liquid polybutadiene (A′)
1000 g, maleic anhydride 140 g and hydroquinone 0.5 g were placed in two separable flasks, and 100 g of
C. for 4 hours to synthesize a modified liquid polybutadiene () having a side chain represented by the above general formula. Example 1 3.5 parts by weight of modified liquid polybutadiene () produced in Production Example 1, 100 parts by weight of polypropylene (trademark Mitsui Noblen JHH-G), 67 parts by weight of calcium carbonate
parts by weight and 0.04 parts by weight of peroximone,
The mixture was kneaded for 5 minutes at 190°C using a Brabender Plastograph, and then press-molded (220°C, 5 minutes) to form a sheet. Test pieces were prepared and their impact strength, tensile strength, and melt index were measured. . The results are shown in Table 1. Comparative example 1 Polypropylene (trademark Mitsui Noblen JHH-
G) Mix 100 parts by weight and 67 parts by weight of calcium carbonate and use a Brabender plastograph.
The mixture was kneaded at 190°C for 5 minutes and then press-molded (220°C, 6 minutes) to form a sheet. Test pieces were prepared and their impact strength, tensile strength and melt index were measured. The result is the first
Shown in the table. Comparative Example 2 3.5 parts by weight of maleated liquid polybutadiene (A) produced in Production Example 1, 100 parts by weight of polypropylene (trademark Mitsui Noblen JHH-G), calcium carbonate
Mix 67 parts by weight and 0.04 parts by weight of peroximon and heat at 190°C using a Brabender plastograph.
Knead for 5 minutes, then press mold (220℃, 6
), a test piece was prepared, and its physical properties were measured. The results are shown in Table 1. Comparative Example 3 Maleated polybutadiene produced in Production Example 1
3.5 parts by weight of (A), 100 parts by weight of polypropylene (trademark Mitsui Noblen JHH-G), 67 parts by weight of calcium carbonate, 1.85 parts by weight of maleic anhydride and 0.04 parts by weight of peroximon were mixed and heated to 190°C using a Brabender plastograph. The mixture was kneaded for 5 minutes, and then press-molded (220°C, 6 minutes) to form a sheet. Test pieces were prepared, and their impact strength, tensile strength, and melt index were measured. The results are shown in Table 1. Examples 2 to 13 Test pieces were prepared in the same manner as in Example 1, except that the modified liquid polybutadiene () produced in Production Example 1 was used, and the types and amounts of the polyolefin, filler, and radical generator were changed. The results shown in Table 2 were obtained. Comparative Examples 4 to 6 For comparison with Examples 3, 7, and 8, experiments were conducted using only a combination of polyolefin and filler, and the results shown in Table 2 were obtained. Here, the formulations and test methods other than the modified liquid polybutadiene used in the above Examples and Comparative Examples are as follows. [Compound] Mitsui Noblen JHH-G: Polypropylene homopolymer manufactured by Mitsui Toatsu Co., Ltd.
MI=8g/10min Mitsui Noblen JS-G: Polypropylene homopolymer manufactured by Mitsui Toatsu Co., Ltd.
MI=1.5g/10min Mitsui Noblen GEB-G: Polypropylene random copolymer made by the company,
MI=0.5g/10min Mitsui Noblen BJH-G: Polypropylene block copolymer made by the same company, MI=4g/10min Nisseki Stafrene E-750-C: Made by Nippon Petrochemical Co., Ltd., high-density polyethylene density=0.963g/cc, MI= 5.5g/
10min Nisseki Stafrene E-809-M: Manufactured by the same company, high-density polyethylene, density = 0.950
g/cc, MI=0.9g/10min Calcium carbonate: Whiten P-30 manufactured by Shiraishi Kogyo Co., Ltd., heavy calcium carbonate Zinc white: manufactured by Sakai Chemical Industry Co., Ltd., Zinc White No. 3 Mica: Imported product (Republic of China) Talc: Nippon Talc Co., Ltd., Nippon Talc MS Peroximone: Nippon Yushi Co., Ltd. peroxide;
α,α′-bis(t-butylperoxy)-p-diisopropylbenzene Perhexine 25B: peroxide manufactured by the company,
2,5-dimethyl-2,5-
Di-t-butyl peroxyhexine-3 [Test method] Izot impact strength: Based on ASTM-D256 Tensile strength: Based on ASTM-D638 Melt index: Based on ASTM-D1238 Results in Tables 1 and 2 It can be seen from the above that the molded product produced by the method of the present invention is superior in mechanical strength, moldability, etc., compared to the molded product produced by the conventional method shown in the comparative example.

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Claims (1)

[Scope of Claims] 1. A polyolefin resin (A), a filler (B), a radical generator (C), and a modified liquid diene rubber having at least one side chain represented by the following general formula in the molecule ( A method for producing a polyolefin resin composition, which comprises heating and mixing D). General formula: In the above formula, R ₁ , R ₃ , and R ₄ are each a hydrogen atom, a halogen atom, or a hydrocarbon residue having 1 to 3 carbon atoms, and R ₂ is a hydrocarbon residue having 1 to 20 carbon atoms, which may contain a nitrogen atom. The group X represents a hydrogen atom or a bond to a liquid rubber chain, and Y represents a bond to a liquid rubber chain. 2. The method for producing a polyolefin resin composition according to claim 1, wherein the modified liquid diene rubber (D) is a modified liquid polybutadiene. 3. The method for producing a polyolefin resin composition according to claim 1 or 2, wherein the polyolefin resin (A) is polypropylene or high-density polyethylene.