JPS6345419B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention provides mechanical strength, rigidity, hardness, creep properties, dimensional stability, surface activity, heat resistance, moldability, etc. obtained by blending polyolefin with a high concentration of reactive filler and sulfate mineral filler. The present invention relates to a polyolefin composition that exhibits extremely excellent performance in various properties. For more details,
Polymerization of polyolefin and powder surface of carbonate, hydroxide, oxide, or silicate of group 1 metal of the periodic table to a thickness close to that of a monomolecular film with ethylenic double bonds. The present invention relates to a polyolefin composition obtained by melt-kneading a reactive filler formed by a coating reaction with an organic acid and a sulfate mineral filler, wherein the polyolefin in the polyolefin composition has a weight of 15 to 90%. %, reactive fillers from 9 to 84% by weight and sulfate mineral fillers from 1 to 84% by weight.
76% by weight polyolefin composition. By dispersing rigid particles such as inorganic fillers in a synthetic resin at a high concentration, that is, by bringing the rigid particles close to close packing, the viscoelastic properties, thermal expansion coefficient, melt fluidity, etc. of the synthetic resin can be greatly improved. It was previously expected that synthetic resin compositions with extremely unique properties could be obtained. However, in general, mixing inorganic fillers into synthetic resins, especially polyolefins, causes significant negative effects on both physical properties and moldability, and as the inorganic filler concentration increases, especially impact resistance, ductility, flowability, etc. This causes a significant decrease in properties such as elasticity and stretchability.
It has heretofore been difficult to obtain a composition that has performance sufficient to withstand practical use. The inventors of the present application aimed to improve these drawbacks and enhance the reinforcing effect of inorganic compounded polyolefin.
As a result of repeated research, we have used polymerizable organic acids as surface activators for inorganic fillers, which allows the polymer and inorganic fillers to bond together, greatly improving the above drawbacks and greatly enhancing the reinforcing effect of the inorganic fillers. succeeded in improving it. (Special Patent Application No. 69210 (1973)
47-17971), Japanese Patent Application No. 102601 (1972)
67339), Patent Application No. 102602 (1972)
67340), patent application No. 108500) (Japanese Patent Application No. 1973-
60544) In the course of further research, the present inventors found that when a sulfate mineral filler, in which the effect of the surface activator is small and a large reinforcing effect cannot be obtained, is used together with a reactive filler, It was discovered that it also has a great reinforcing effect.
The present invention has now been accomplished. That is, the present invention provides a powder surface of a carbonate, hydroxide, oxide, or silicate of a metal of group 1 or group of the periodic table to a thickness close to that of a monomolecular film.
9 to 84% by weight of a reactive filler formed by a coating reaction with a polymerizable organic acid having an ethylenic double bond;
Excellent mechanical properties, thermal properties, flame resistance, made by melt-kneading 1 to 76% by weight of a filler consisting of sulfate mineral powder and 15 to 90% by weight of polyolefin.
It is a polyolefin composition that has durability, acoustic properties, etc. The major features of the present invention will be described in more detail as follows. According to studies conducted by the inventors of the present application, sulfate minerals have a small effect as a surface activator, and even if the surface is coated with an organic acid, the composition does not have a large reinforcing effect. However, when a sulfate mineral and a reactive filler are heat-kneaded and blended into a polyolefin, the resulting composition has an excellent reinforcing effect comparable to a composition consisting of the reactive filler and the polyolefin. This reinforcing effect appears over a very wide range of concentrations of sulfate minerals. Considering the cause of this unique phenomenon, we find that in compositions consisting of a reactive filler and polyolefin, the polymer and filler are strongly bonded by the surface activator; This effect appears because the filler combined with the polymer has an affinity for sulfate minerals. That is, in the case of reactive fillers, they were bonded to the polymer by a surface activator, but
In the composition of the present invention, the sulfate mineral forms an ionic bond with the reactive filler due to filler-to-filler affinity;
It is presumed that an action such as binding to the polymer occurs through the two surface activators. More specifically, the effects of the composition of the present invention having such features are as follows. (1) The composition has outstanding mechanical properties such as strength, rigidity, hardness, and creep properties. (2) The composition has extremely excellent thermal properties such as heat resistance and dimensional stability. (3) The composition has outstanding properties such as surface activity, heat resistance, and weather resistance. (4) It is a composition that quickly damps vibrations and sounds, and has excellent anti-vibration and acoustic properties. (5) The composition has excellent moldability, fluidity, etc. (6) It is extremely simple, easily obtained, and economically inexpensive. (7) The composition has an extremely wide range of applications. For example, various compression molded products, extrusion molded products, blow molded products, injection molded products, thermoformed products, rotary molded products, calendar molded products, various foam molded products, secondary processed products such as stretched or forged products, etc. It is possible. The present invention will be specifically explained below. The composition ratio of the polyolefin composition of the present invention is 15 to 90% by weight of the polyolefin in the composition, 9 to 84% by weight of the reactive filler, and 1 to 1% of the sulfate mineral filler.
76% by weight, more preferably 20-70% by weight of polyolefin, reactive filler
ranging from 20 to 75% by weight and 5 to 60% by weight of sulfate mineral fillers. When the total filling amount (concentration) of fillers is lower than the range specified in the present invention, that is, 10% by weight or less, strength, rigidity, hardness, etc. are superior to polyolefin alone, but heat resistance, dimensional stability, The properties expected from the filling of the filler, such as sound absorption properties, are low. On the other hand, if the total amount (concentration) of the filler is higher than the range specified in the present invention, that is, 85% by weight or more, secondary agglomeration of filler particles will occur during the production of the polyolefin composition, resulting in unobtainable The properties of the resulting compositions are poor and this makes it very difficult to obtain integral molded articles from the resulting compositions. Furthermore, the most important feature of the present invention is when the filling amount (concentration) of the reactive filler is lower than the range specified in the present invention. The reinforcing effect exhibited by reactive fillers is hardly developed. The metal compound powder (hereinafter referred to as inorganic filler) that is a raw material for the reactive filler used in the present invention includes carbonates such as magnesium carbonate, calcium carbonate, and barium carbonate, magnesium hydroxide, calcium hydroxide, and water. Compounds with hydroxides or hydroxyl residues such as aluminum oxide or alumina hydrate, oxides such as magnesium oxide, aluminum oxide, beryllium oxide, calcium oxide, zinc oxide, calcium silicate, magnesium silicate, aluminosilicate, etc. Examples include silicates such as sodium acid and potassium aluminosilicate, which may be used alone or as a mixture of two or more,
Or basic magnesium carbonate, dolomite,
It can also be used as an inorganic filler contained as part of the composition, such as hydrates or double salts such as pilsonite, and minerals. In the present invention, the average particle diameter of the metal compound powder that fully exhibits the effect of the reactive filler is 0.01~
It is in the range of 50μ, particularly preferably in the range of 0.1 to 20μ. In carrying out the present invention, the surface of the metal compound powder must first be activated by the method described below. That is, the metal compound and the polymerizable organic acid are reacted to form a single molecule in which the metal on the powder surface of the metal compound and the polymerizable organic acid monomer are firmly bonded with the ethylenic double bond remaining. It is necessary to use a reactive filler with a thin film similar to a membrane formed on the surface of the filler. The polymerizable organic acid used in the present invention has a hydrocarbon moiety having one or more ethylenic double bonds, one or more carboxyl groups, and has 10 or less carbon atoms. unsaturated carboxylic acids, such as acrylic acid, methacrylic acid, crotonic acid, cinnamic acid, sorbic acid, α-chloroacrylic acid, and its α, β
Substituted substances, maleic acid, itaconic acid, vinyl acetic acid,
Allyl acetic acid, etc. In the present invention, the higher the acid strength, the more preferable it is, especially acrylic acid,
Methacrylic acid is effective in this invention. These acids may be used alone or as a mixture of two or more. Alternatively, an acid anhydride may be used as a precursor of a polymerizable organic acid to convert it into an organic acid. The amount of polymerizable organic acid required when reacting the above polymerizable organic acid with the metal compound is an amount that can uniformly coat the surface of the metal compound with a thickness close to that of a monomolecular film. be. More specifically, as estimated from the BET specific surface area measured for the metal compound powder, the amount is sufficient to uniformly coat the polymerizable organic acid to a thickness of 2 to 150 Å. This means that, for example, the amount of polymerizable organic acid to be reacted to a metal compound powder with an average particle size of 0.1 to 10μ is most commonly 0.01 to 10 parts by weight per 100 parts by weight of the metal compound powder.
Parts by weight range. Furthermore, in consideration of the appearance, heat deterioration resistance, etc. of the molded product of the composition, the more preferable amount of polymerizable organic acid to be used is estimated from the BET specific surface area, which is sufficient to coat the product with a thickness of 2 to 10 Å. It is quantity. One of the methods for producing the reactive filler of the present invention is a method in which the metal compound powder and the polymerizable organic acid are reacted in the above concentration range under dehydration conditions with high efficiency in various mixers. As the various mixers, various general powder mixers can be used, but high-efficiency mixers such as Henschel mixer, Mueller, and ribbon blender are particularly preferred. Furthermore, in order to increase the contact efficiency between the metal compound powder and the polymerizable organic acid, it is desirable to add the polymerizable organic acid to the reaction system in the form of a mist, but it is also possible to add it in the form of a gas. The atmosphere for this reaction can be normal pressure, reduced pressure, or increased pressure, but it must be carried out in the absence of liquid water, and the water generated during the reaction must be removed from the reaction system. It is desirable to carry out the process under conditions (dehydration conditions). If the reaction is carried out in the presence of excess liquid water, the reactive filler of the present invention cannot be produced. The reaction temperature range for this reaction is above room temperature and below the decomposition temperature of the polymerizable organic acid, and is usually preferably in the range of 50 to 200°C. Further, the reaction time range of this reaction is usually in the range of 1 minute to 2 hours, but is generally in the range of 5 to 30 minutes. In addition, in order to avoid polymerization of the polymerizable organic acid or polymerizable organic acid salt during this reaction, the reaction atmosphere should be appropriately selected (air or oxygen atmosphere is preferable in the case of acrylic acid), or It is preferable to add a polymerization inhibitor to the acid. As the polymerization inhibitor, general polymerization inhibitors such as hydroquinone, methoxyhydroquinone, p-benzoquinone, naphthoquinone, and t-butylcatechol can be used, and the amount used is 0 to 1% by weight based on the polymerizable organic acid. , especially 0.02
A range of ~0.5% by weight is recommended. Another method for producing the reactive filler of the present invention is to react the metal compound powder with an excessive concentration of the polymerizable organic acid by the method described above, and then react the metal compound powder with the polymerizable organic acid in an excessive concentration. This method purifies the salt by washing it with a nonaqueous solvent that easily dissolves it, filtering it, and drying it. Suitable solvents that can be used in this method include low boiling point solvents such as methanol, ethanol, propanol, diethyl ether, acetone, methyl ethyl ketone, and ethyl acetate. Another method for producing the reactive filler of the present invention is to stir and mix the sufficiently dried metal compound powder and polymerizable organic acid in the nonaqueous solvent, and then filter, wash, and dry. It's a method. This method includes:
In addition to the above-mentioned polar solvents, a non-polar solvent such as benzene, toluene, xylene, hexane, heptane, tetralin, decalin, chloroform, carbon tetrachloride, etc. may be used to carry out a heating reaction, followed by washing and purification with the above-mentioned polar solvent. It is possible. The sulfate mineral filler in the present invention refers to powders of sulfates and sulfites such as aluminum sulfate, barium sulfate, calcium sulfate, lead sulfate, magnesium sulfate, sulfite, and calcium sulfite. , it can also be used as a mixture of two or more types. Among these, those having a specific gravity of more than 3, such as barium sulfate, lead sulfate, and zinc sulfate, are particularly preferred because the composition has excellent mechanical strength, anti-vibration properties, and acoustic properties. The average particle size of such sulphate mineral fillers ranges from 0.01 to 50μ, particularly preferably 0.1
~20μ range. Although such a sulfate mineral filler may be used as it is, it is more preferable to coat the surface with a polymerizable organic acid like the above-mentioned reactive filler. In the present invention, polyolefins include ethylene,
Refers to polymers and copolymers of monoolefins such as propylene and butene as the main component. For example, high-density polyethylene, medium-low density polyethylene, crystalline polypropylene, crystalline ethylene-propylene block copolymer, polybutene, poly-
Examples include 3-methylbutene-1 and poly-4-methylpentene-1. The polyolefin composition of the present invention can be obtained by heating and kneading such a reactive filler, a sulfate mineral filler, and a polyolefin. Methods for producing such polyolefin compositions include a method of heating and kneading the above three components at the same time, and a method of heating and kneading the reactive filler and the polyolefin, adding a sulfate mineral filler to a composition obtained by heating and kneading the two. Alternatively, there is a method in which a reactive filler is added to a composition obtained by heating and kneading a sulfate mineral filler and a polyolefin, and the mixture is heated and kneaded. As the device used for heating and kneading, general kneading machines such as an extruder, co-kneader, intensive mixer, and mixing roll are used. The temperature for heating and kneading depends on various conditions such as the polyolefin used, the type of polymerizable organic acid, the presence or absence of a radical generator or stabilizer, the function of the kneading equipment, etc.
Although the temperature is appropriately selected depending on the purpose, generally a temperature range of 140 to 350°C, more preferably 170 to 280°C is desirable. During heating and kneading, it is preferable to use a radical generator in order to promote the reaction between the polymer radicals of the polyolefin and the polymerizable organic acid salt monomer on the surface of the reactive filler and to enhance the functionality of the composition. Examples of radical generators that can be used in the present invention include tetravalent tin compounds such as dibutyltin oxide, 2,5-dimethyl-2,5-di(t-butylperoxy)hexane, and 2,5-dimethyl-2・
5-di(t-butylperoxy)hexyne-3,
Organic peroxides such as dicumyl peroxide, t-butyl peroxymaleic acid, lauroyl peroxide, benzoyl peroxide, t-butyl perbenzoate, t-butyl hydroperoxide, isopropyl percarbonate, azobisisobutyronitrile These radical generators are commonly used radical generators, such as azo compounds such as, and inorganic peroxides such as ammonium persulfate, and one or a combination of two or more of these may be used. The amount of the radical generator to be used is usually in the range of 0.001 to 0.1 parts by weight per 100 parts by weight of the composition. In addition to the above composition, the resin composition of the present invention contains stabilizers, plasticizers, lubricants, crosslinking agents, pigments, flame retardants, antistatic agents, thickeners, foaming agents, fibrous reinforcing agents, and other additives. It's okay to stay. Hereinafter, in order to more specifically explain the characteristics of the present invention, the present invention will be explained in further detail using Examples and Reference Examples. However, the scope of the present invention will be limited by the following Examples and Reference Examples. Of course, this is not the case. Note that parts and percentages used in Examples and Reference Examples are parts by weight and percentages by weight, respectively. Example 1-1 10 kg of zinc oxide with an average particle diameter of 0.8 μ and a BET specific surface area of 8 m ² /g and 300 g of acrylic acid were mixed using a high-speed fluid mixer (Hensiel mixer) while blowing dry air at 90°C. The mixture was fluidized and mixed at 90° C. for 1 hour to react, thereby obtaining a reactive filler. Steam was generated during the reaction, but it was in gaseous form and was removed from the system. The obtained reactive filler was a smooth powder with no stickiness and no acrylic acid odor. The amount of acrylic acid used is the theoretical amount for the surface of zinc oxide.
The amount is sufficient to uniformly and uniformly coat a thickness of 38 Å. 30 parts of this reactive zinc oxide, 40 parts of barium sulfate powder (average particle size 3μ, BET specific surface area 1.8m ² /g),
30 parts of ethylene-propylene block copolymer and 2.5-2.5 dimethyl as a radical generator
Using an intensive mixer with an internal volume of 1.8, 1.8 kg of a mixture with 0.01 part of di(t-butylperoxy)hexane was mixed at a resin temperature of 230°C and a rotor rotation speed.
The resin composition was melt-kneaded for 3 minutes at 100r.pm and a floating weight of 4.0Kg/ ^cm2 , formed into a sheet using an 8" mixing roll, and then granulated. The resulting resin composition was injection molded and molded according to ASTM standards. The obtained results are shown in Table 1. Example 1-2 10 kg of barium sulfate powder used in Example 1-1 and 135 g of acrylic acid were mixed into Example 1-1. 1
Barium sulfate powder whose surface was coated with acrylic acid was obtained under the same conditions as those used to produce reactive zinc oxide. This powder had an acrylic acid odor and was somewhat sticky. Example 1 - This acrylic acid coated barium sulfate
A resin composition was prepared using the same composition, method, and conditions as in Example 1-1, except that barium sulfate was used in Example 1-1, and its physical properties were measured and evaluated. The results obtained are shown in Table 1. Reference example 1-1 70 parts of reactive zinc oxide used in Example 1-1,
A resin composition was obtained from 30 parts of ethylene-propylene block copolymer and 0.01 part of radical generator using the same kneading method and conditions as in Example 1-1, and its physical properties were measured and evaluated. The results are shown in Table 1. Reference Example 1-2 A resin composition was obtained from 70 parts of barium sulfate and 30 parts of the ethylene-propylene block copolymer used in Example 1-1 using the same kneading method and conditions as in Example 1-1. Physical properties were measured and evaluated. The results are shown in Table 1. Reference Example 1-3 From 70 parts of acrylic acid coated barium sulfate used in Example 1-2, 30 parts of ethylene-propylene block copolymer and 0.01 part of radical generator, the same kneading method as in Example 1-1 was carried out. A resin composition was obtained under the following conditions, and its physical properties were measured and evaluated. The results are shown in Table 1.

[Table] Examples 2-1 to 4 The procedure was the same as in Example 1-2, except that the amounts of reactive zinc oxide and acrylic acid-coated barium sulfate were changed as shown in Table 2. A resin composition was prepared, and its physical properties were measured and evaluated. The results obtained are shown in Table 2. Reference Example 2-1 Example 1- except that the amounts of reactive zinc oxide and acrylic acid coated barium sulfate were as shown in Table 2.
A resin composition was prepared in the same manner as in Example 2, and its physical properties were measured and evaluated. The results obtained are shown in Table 2. The results shown in Table 2 are shown in Figures 1 and 2.
As shown in Fig. 3.

[Table] Example 3-1 100 parts of heavy calcium carbonate with an average particle diameter of 1.0 μm and a BET specific surface area of 4 m ² /g were placed in a Henschel mixer, heated to 150°C, and while stirring, 500 ppm of hydroquinone was added. Gradually add 1 part of acrylic acid in the form of a mist using a spray addition device,
Reactive calcium carbonate was obtained by mixing for 30 minutes at normal pressure. During the reaction, water vapor and carbon dioxide gas were generated, but both were removed from the system in gaseous form. Reactive calcium carbonate thus obtained
20 parts, 30 parts of calcium sulfate powder with an average particle size of 5 μm and a BET specific surface area of 1.5 m ² /g, 50 parts of high-density polyethylene with an MI of 0.8 and a specific gravity of 0.953, and 2,5-dimethyl-2.5 as a radical generator. After premixing 0.01 part of -di(t-butylperoxy)hexane, the mixture was melt-kneaded using a Banbury mixer at a resin temperature of 220°C for 3 minutes, formed into a sheet using two rolls, and then pelletized. The obtained resin composition was compression molded, and its physical properties were measured and evaluated. The results obtained are shown in Table 3. Example 3-2 The calcium sulfate used in Example 3-1 was coated with acrylic acid using the same method and conditions as in Example 3-1 for producing reactive calcium carbonate to produce acrylic acid-coated calcium sulfate. Ivy. Example 3-
Example 3 except that calcium sulfate in Example 1 was replaced with this acrylic acid-coated calcium sulfate.
A resin composition was prepared in the same manner as in Example 1-1, and its physical properties were measured and evaluated. The results are shown in Table 3. Reference Example 3-1 After premixing 20 parts of reactive calcium carbonate, 80 parts of high-density polyethylene, and 0.01 part of the radical generator used in Examples 3-1 and 3-2, Example 3
A resin composition was prepared under the same kneading conditions as in Example 1-1, and its physical properties were measured and evaluated. The results obtained are shown in Table 3. Reference example 3-2 Calcium sulfate powder used in Example 3-1
After premixing 30 parts and 70 parts of high density polyethylene,
A resin composition was prepared under the same kneading conditions as in Example 3-1, and its physical properties were measured and evaluated. The results obtained are shown in Table 3. Reference Example 3-3 After premixing 30 parts of acrylic acid-coated calcium sulfate used in Example 3-2, 70 parts of high-density polyethylene, and 0.01 part of a radical generator, Example 3-1 was prepared.
A resin composition was prepared under the same kneading conditions, and its physical properties were measured and evaluated. The results obtained are shown in Table 3.

【table】 [Brief explanation of drawings]

1, 2 and 3 are examples 1-2,
2 is a graph showing the tensile strength, bending strength, and Izod impact strength of the resin compositions obtained in Examples 2-1 to 2-4 and Reference Examples 1-1, 1-3, and 2-1, respectively.

Claims (1)

[Claims] 1. A polymerizable organic acid having an ethylenic double bond is applied to the powder surface of a carbonate, hydroxide, oxide, or silicate of a metal of group 1 or group of the periodic table to a thickness close to that of a monomolecular film. 9 to 84% by weight of a reactive filler formed by a coating reaction, and 1 to 84% by weight of a sulfate mineral filler.
A polyolefin composition obtained by melt-kneading 76% by weight and 15 to 90% by weight of polyolefin.