JPS6329700B2 - - 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 having excellent mechanical properties and moldability by mixing a filler coated with a specific modified liquid rubber with a polyolefin resin. 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, in the method of manufacturing a polyolefin resin composition by simply mixing an inorganic filler with a polyolefin resin, the stiffness of the composition increases, but the tensile strength and impact strength decrease, and the fluidity of the molten resin decreases. This has disadvantages such as deterioration of molding processability. In addition, in a method in which an inorganic filler is pretreated with an organic acid or the like and then the treated filler is mixed with a polyolefin resin, the impact strength of the resulting composition can be improved 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 of improving the mechanical strength, thermal properties, etc. of a polyolefin resin composition by heating and mixing a polyolefin resin, an inorganic filler coated with polydiene liquid rubber, an unsaturated carboxylic acid or its derivative, and a radical generator. (Tokuko Showa 53
-20537) 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, thinned liquid polybutadiene, and sulfur are mixed together and vulcanized to improve hardness, tensile modulus, tensile strength, abrasion resistance, etc. A reinforcing method (Japanese Patent Application Laid-open No. 147743/1983) has been proposed, and although this method is effective for rubber, even if this method is applied to the production of filler-containing polyolefin resin compositions, It was not possible to achieve a sufficiently good 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 covers the surface of filler A with modified liquid rubber B, which has at least one side chain in the molecule and has at least one acidic group, unsaturated group, and imide group in the side chain. The present invention also relates to a method for producing a polyolefin resin composition, which comprises heating and mixing the coated filler with a polyolefin resin D in the presence of a radical generator C. 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 copolymers thereof, or mixtures of these polymers. Next, the liquid rubber that is the starting material for the modified liquid rubber that plays an important role as a filler coating in the present invention preferably has a number average molecular weight of 300 to 300.
10,000, a polymer or copolymer of a conjugated diene such as butadiene or isoprene, that is, a liquid polydiene-based rubber, produced by conventionally known methods. 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 50 mol % based on the conjugated diolefin, especially butadiene or isoprene.
A typical manufacturing method is anionic polymerization of the following amounts of aromatic vinyl monomers, such as styrene, α-methylstyrene, vinyltoluene, or divinylbenzene, at a temperature of 0°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 ―
No. 17485, No. 43-27432), or toluene,
A polymerization method in which the molecular weight is controlled by using an aromatic hydrocarbon such as xylene as a solvent, a dispersion of a metal such as sodium as a catalyst, and adding an ether such as dioxane (Japanese Patent Publication No. 7446/1989, 33 ―1245
No. 34-10188) is a suitable manufacturing method. It is also produced by coordination anionic polymerization using an acetyl acetate compound of a Group 8 metal, such as cobalt or nickel, and an alkyl aluminum halide (Japanese Patent Publication No. 45-507,
46-30300) low polymer, aluminum chloride,
In addition to low polymers produced by cationic polymerization using a Friedel-Crafts catalyst, such as boron trifluoride or complexes thereof, pyrolyzed 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 above liquid rubber, and a liquid rubber obtained by further modifying this is used. . 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.
Conventionally known methods for adding maleic acid, maleic anhydride, citraconic acid, citraconic anhydride, etc. at a temperature of .degree. C. can be used. (Tokuko Showa 46-11195
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, a liquid rubber modified with the above-mentioned unsaturated dicarboxylic acid anhydride or its derivative, such as a liquid diene rubber, has at least one side chain represented by the following general formula per molecule. An introduced modified liquid rubber, for example 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 above imidization is a primary amine, such as hydroxyalkylamines such as β-hydroxyethylamine, β-hydroxypropylamine, β-hydroxyethylamine, β-hydroxyethylamine, etc. Diamines such as aminopropylamine 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, use a hydrocarbon solvent such as benzene, toluene, cyclohexane, or xylene, an alcohol solvent such as butyl cellosolve, or an ether solvent such as diethylene glycol dimethyl methyl ether (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 solvent used in the imidization (excluding alcoholic solvents) 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, in the present invention, when the modified liquid rubber coats the filler, the acidic groups in the modified liquid rubber interact with the polar groups on the surface of the filler,
Wetting or chemical bonding occurs, and when this coated filler is heated and mixed into a polyolefin resin in the presence of a radical generator, the main chain in the liquid rubber becomes entangled with the polyolefin layer, and the radicals generated from the radical generator cause It is presumed that the unsaturated groups in the liquid rubber main chain and/or the highly reactive unsaturated groups present in or near the side chains polymerize to further strengthen the entanglement with the polyolefin layer. In addition, at this time, if a vinyl group with high radical polymerizability exists in the main chain of the liquid rubber, the modified liquid rubber can bond to the polyolefin resin or to each other liquid rubber via this vinyl group, resulting in so-called coupling. Improves effectiveness. Therefore,
When it is desired to enhance the radical polymerizability of the 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. In addition, 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 preferably blended in an amount of 0.5 to 20 parts by weight per 100 parts by weight of the filler. 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 20 parts by weight, the mechanical strength will decrease, which is not preferable. In addition, 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, carbon fiber,
Wood fiber, wood flour, or a mixture thereof can be used. The shape and size of these fillers are not particularly limited, but in the case of granular fillers, those with an average particle diameter of 10 μm or less are preferable, and those that have been surface-treated can also be used. The filler is used in an amount of 5 to 400 parts by weight per 100 parts by weight of the polyolefin resin.
In the present invention, it is preferable to mix the filler within the above range in view of the balance between mechanical strength and moldability of the composition. Further, the radical generator used in the method of the present invention may be any radical generator as long as it promotes the crosslinking reaction of the polyolefin resin and modified liquid rubber. For example, dicumyl peroxide, t-butyl peroxybenzoate, 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, g-
T-butyl peroxide, 2,2'-azobisisobutyronitrile, or a mixture thereof is used. These radical generators are required in an amount of 0.001 parts by weight or more per 100 parts by weight of the polyolefin resin. This amount is preferably 0.005 to 1.0 parts by weight, and if it is less than 0.001 parts by weight, the effect of addition is small;
Even if 1.0 parts by weight or more is added, no greater effect can be expected. In the present invention, in addition to the filler and radical generator coated with polyolefin resin with modified liquid rubber as described above, if necessary,
Colorants, stabilizers, plasticizers, lubricants, etc. can be added. In the present invention, the method of coating the surface of the filler with the modified liquid rubber can be roughly divided into a dry method and a wet method. The dry method is a method in which modified liquid rubber is directly mixed and coated on the surface of the filler without using a solvent.If the viscosity is high, the viscosity of the liquid rubber is reduced by heating using a mixer with strong kneading power such as a kneader. Mixing is generally carried out by reducing the temperature. In the wet method, the modified liquid rubber is first dissolved or dispersed in some kind of solvent to lower its viscosity.
Next, this is coated on the surface of the filler using a mixer such as a Henschel mixer or a ribbon blender.
Next, the solvent is removed by heating the mixer or transferring it to another heating machine. Another wet method involves dissolving or dispersing the modified liquid rubber in a large amount of solvent, adding the filler to this, mixing with a stirrer to form a slurry, and then centrifuging this slurry. There is also a method of coating the filler by removing excess solvent or dispersant by washing or filtering, and drying. Solvents used in the wet method include toluene,
Aromatic hydrocarbons such as xylene, aliphatic hydrocarbons such as hexane and heptane, alicyclic hydrocarbons such as cyclohexane and decalin, and their derivatives, and halogenated carbons such as methylene chloride, chloroform, carbon tetrachloride, and trichloroethylene. Examples include hydrogen, ethers such as diethyl ether, ketones such as acetone and methyl ethyl ketone, organic solvents such as esters such as ethyl acetate, water, and mixtures thereof. but,
Since organic solvents are expensive and have problems in use in terms of heat susceptibility, toxicity, etc., the preferred solvent is water. Furthermore, when the filler is so-called precipitated calcium carbonate produced from milk of lime, a water-dispersible filler is available, and the modified liquid rubber is dissolved or dispersed in this water dispersion or milk of lime. This is preferable because uniform coating can be achieved. It is also advantageous because the dehydration step when producing precipitated calcium carbonate as a product can be omitted. In addition, in order to improve the solubility of the modified liquid rubber in water or to stabilize the liquid rubber solution or dispersion, it is preferable to use the liquid rubber after neutralizing it in the form of a salt. In order to dissolve the modified liquid polybutadiene represented by the general formula in water, it is generally carried out to dissolve the polybutadiene while neutralizing it with an alkali, for example, caustic potash, in an amount approximately equivalent to the acid value of the polybutadiene. In the method of the present invention, the above-mentioned coated filler,
By mixing the polyolefin resin and the radical generator under heating, the desired polyolefin resin composition can be obtained. 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 can be 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, and has high tensile strength, impact strength, and excellent rigidity, and is particularly excellent in tensile strength and rigidity. Furthermore, the modified liquid rubber acts as a plasticizer during heating and mixing to improve dispersion. Also,
The above compositions generally have a high melt index, so they have excellent fluidity, can be easily injection molded, have a good appearance, and have good mechanical strength, rigidity, heat resistance, chemical resistance, etc. Excellent molded products 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%)
1000g, maleic anhydride 163g, xylene 10g,
Antigen 3C (trademark, manufactured by Sumitomo Chemical Co., Ltd.) 2g
Pour into a separable flask and place under nitrogen stream.
The reaction was carried out at 195°C for 5.0 hours. Next, unreacted maleic anhydride and xylene were distilled off under reduced pressure to synthesize maleated liquid polybutadiene A having an acid value of 80. Next, 1000 g 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'1000g,
140g maleic anhydride and 0.5g hydroquinone
into 2 separable flasks and incubate at 100℃.
By heating for a period of time, a modified liquid polybutadiene having a side chain represented by the above general formula was synthesized. Example 1 The modified liquid polybutadiene produced in Production Example 1 was first dissolved in acetone to obtain a solution with a concentration of 20% by weight. Next, 67 parts by weight of calcium carbonate and the solution
17.5 parts by weight (as modified liquid polybutadiene)
3.5 parts by weight) was placed in an eggplant-shaped flask of a rotary evaporator, and acetone was removed by heating while rotating the mixture to obtain calcium carbonate coated with modified liquid polybutadiene. Next, polypropylene (trademark: Mitsui Noblen)
JHH-G) 100 parts by weight, the above-mentioned coated calcium carbonate
Mix 70.5 parts by weight and 0.04 parts by weight of peroximon and heat at 190°C using a Brabender plastograph.
The mixture was kneaded for 5 minutes. At this time, almost no odor was detected and workability was good. Then press molding (220
℃ for 6 minutes) to prepare a sheet, and its 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. Table 1 shows the results.
Shown below. Comparative Example 2 Mixing was carried out in the same manner as in Example 1, except that the maleated liquid polybutadiene A obtained in Production Example 1 was used instead of the modified liquid polybutadiene in Example 1, and a sheet was obtained and its physical properties were measured. did. The results are shown in Table 1. Comparative Example 3 Maleated liquid polybutadiene A obtained in Production Example 1 was used instead of the modified liquid polybutadiene in Example 1, and 1.85 weight of maleic anhydride was added when mixing polypropylene, coated calcium carbonate, and radical generator. A sheet was obtained by mixing in the same manner as in Example 1, except that 100% was added.
Table 1 shows its physical property values. In addition, in this method, maleic anhydride volatilizes violently during kneading using the Prabender Plastograph.
Work was significantly hindered. Example 2 Water was gradually added dropwise to the modified liquid polybutadiene produced in Production Example to obtain a modified polybutadiene aqueous solution (concentration 10% by weight). Next, 67 parts by weight of calcium carbonate and 35 parts by weight of the solution (3.5 parts by weight as modified liquid polybutadiene) were sufficiently stirred and dried in an oven to produce coated calcium carbonate. Example 1 using this
A sheet was obtained and its physical properties were measured. The results are shown in Table 2. Examples 3 to 8 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 are obtained. Comparative Examples 4 and 5 As comparative examples, tests were conducted in the same manner as above using only a combination of polyolefin and filler, and the results shown in Table 2 were obtained. Here, in addition to the modified liquid polybutadiene used in the above Examples and Comparative Examples, the formulations and test methods are as follows. [Blend] Mitsui Noblen JHH-G: Polypropylene homopolymer manufactured by Mitsui Toatsu Chemical Co., Ltd., MI=
8g/10min Mitsui Noblen BJH-G: Polypropylene block copolymer manufactured by the same company, MI=4
g/10min Nisseki Stafrene E-750(C): Manufactured by Nippon Petrochemical Co., Ltd.
High density polyethylene, density = 0.963
g/cc, MI=5.5g/10min Calcium carbonate: Whiten P-30 Shiraishi Kogyo Co., Ltd.
Mica: Imported product (made in the Republic of China) Peroximone: Peroxide manufactured by Nippon Oil & Fats Co., Ltd.
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: Conforms to ASTM D 256 Tensile strength: Conforms to ASTM D 638 Melt index: Conforms to ASTM D 1238

【table】

【table】

[Table] From the results in Tables 1 and 2, it can be seen that the molded products made by the method of the present invention are superior in mechanical strength, moldability, etc. compared to the products made by the conventional method shown in the comparative example. Recognize.

Claims (1)

[Scope of Claims] 1. The surface of filler A has at least 1 part in the molecule.
A polyolefin resin characterized in that it is coated with a modified liquid diene rubber B having side chains represented by the following general formula, and the coated filler is heated and mixed with a polyolefin resin D in the presence of a radical generator C. Method of manufacturing the composition. 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 B 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.