JP5257944B2 - Manufacturing method of inorganic / polymer composite molded body - Google Patents

Description

  The present invention relates to a method for producing an inorganic / polymer composite molded body using an extruder.

In general, inorganic powders such as calcium carbonate, silica, mica and clay are blended to improve the physical properties of resins and rubbers (for example, wear resistance, heat resistance, impact resistance, toughness, tensile strength, tear strength, etc.) There are things to do.
In recent years, nanoscale chemistry has attracted attention, and attempts have been made to blend inorganic powder having a nano-order particle size into resin or rubber.
However, when nano-order inorganic powder is blended with the resin, the inorganic powder aggregates to cause poor dispersion and further increase the viscosity. In addition, when used, the inorganic powder may fly up as dust, which may impair the working environment.

In order to solve the above problems, in Patent Document 1, a metal compound such as tetraethoxysilane and water are blended with polypropylene and mixed with an extruder, and then the metal compound is hydrolyzed to sub-micron order silica. It has been proposed to produce particles in polypropylene to produce a microporous film.
In Patent Document 2, a step of forming a homogeneous phase composed of a supercritical fluid, a metal compound and a polymer, a step of foaming the polymer by reducing the pressure of the homogeneous phase, and a phase reduction of the supercritical fluid and the metal compound in the foamed cell. There has been proposed a method for producing an inorganic / polymer composite molded body having a step of separating and a step of decomposing a metal compound to obtain a solid metal oxide.

JP-A-10-287758 JP 2007-332242 A

However, in the method described in Patent Document 1, the amount of the metal compound that can be uniformly mixed is limited from the viewpoint of the affinity with the polymer. Therefore, in order to obtain a desired inorganic powder amount, it was necessary to repeat the mixing of the metal compound in the extruder a plurality of times.
In addition, if the amount of water added to hydrolyze the metal compound is too small, the amount of silica particles generated is insufficient, and the residual amount of unreacted metal compound contained in the film after molding increases. was there. On the other hand, when the amount of water is too large, a drying process over a long period of time is required to remove moisture, resulting in low productivity.

  In the production method described in Patent Document 2, since the decomposition of the metal compound is insufficient, the undecomposed metal compound is decomposed after molding using heat, boiling water, active energy radiation, or the like to form a solid metal oxide It was necessary to. Therefore, productivity tends to be low.

  Therefore, an object of the present invention is to provide a method for producing an inorganic / polymer composite molded body that can produce an inorganic / polymer composite molded body containing a sufficient amount of inorganic powder with high productivity.

  As a result of examining the method for solving the above problems, the present inventors have found that the method described in Patent Document 1 hardly decomposes a metal compound such as tetraethoxysilane, and the metal compound is not effectively used. I found it. Moreover, it discovered that decomposition | disassembly of a metal compound could be accelerated | stimulated by making a catalyst exist in molten polymer. And based on the knowledge, it further examined and invented the manufacturing method of the following inorganic substance and a polymer composite molded object.

[1] A molten polymer and a flowable metal compound capable of forming a homogeneous phase with the molten polymer are mixed to prepare a compatible melt, and the solid metal compound is prepared from the flowable metal compound. A composite material preparation step of preparing a composite material containing a polymer and a solid metal compound by reacting a fluid metal compound contained in the melt into a solid metal compound in the presence of a reaction catalyst for generating ,
A method for producing an inorganic / polymer composite molded body having a molding step of extruding the composite material ,
A method for producing an inorganic / polymer composite molded body, comprising a foaming agent addition step of adding a foaming agent to the melt or the composite material before the molding step, and extruding and foaming the composite material in the molding step. .
[ 2 ] The method for producing an inorganic / polymer composite molded article according to [ 1 ], wherein the foaming agent is carbon dioxide and / or nitrogen.
[ 3 ] The fluid metal compound is at least one selected from the group consisting of a metal alkoxide, a metal β-diketonate complex, and a metal acetate, and the metal contained in the fluid metal compound is silicon or titanium. The method for producing an inorganic / polymer composite molded article according to any one of [1] and [2] , which is at least one selected from the group consisting of calcium, zinc, tin and indium.
[ 4 ] In the composite material preparation step, a catalyst releasing compound that releases an acid catalyst or a base catalyst is added to a polymer, and the fluid metal contained in the melt in the presence of the catalyst released from the catalyst releasing compound. The method for producing an inorganic / polymer composite molded article according to any one of [1] to [ 3 ], wherein the compound is reacted.
[ 5 ] The method for producing an inorganic / polymer composite molded article according to [ 4 ], wherein the catalyst releasing compound is a disilazane and / or a chlorosilane.
[ 6 ] The method for producing an inorganic / polymer composite molded body according to any one of [1] to [ 5 ], wherein water is added to the melt in the composite material preparation step.

  According to the method for producing an inorganic / polymer composite molded body of the present invention, an inorganic / polymer composite molded body containing a sufficient amount of an inorganic powder composed of a solid metal compound can be produced with high productivity.

An embodiment of the method for producing an inorganic / polymer composite molded body of the present invention will be described.
The inorganic / polymer composite molded body produced by the production method of the present embodiment is a foamed molded article containing a foamed polymer and a solid metal compound present in the foamed cell of the foamed polymer.

<Inorganic / polymer composite moldings>
As the polymer constituting the inorganic / polymer composite molded body, a thermoplastic resin is used, and among them, an olefin resin, a polyester resin, and a polyamide resin are preferable.

Olefin resin: α-olefin such as ethylene or propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, or cyclopentene, cyclohexene, cyclooctene, cyclopentadiene, 1,3-cyclohexadiene , Bicyclo [2.2.1] hept-2-ene, tricyclo [4.3.0.1 ^2,5 ] deca-3,7-diene, tetracyclo [4.4.0.1 ^2,5 . ^1,7,10 ] cycloolefin homopolymers such as dodec-3-ene, copolymers of the above α-olefins, and other monomers copolymerizable with α-olefins, vinyl acetate, maleic acid, And copolymers with maleic anhydride, vinyl alcohol, methacrylic acid, methyl methacrylate, ethyl methacrylate and the like.

  Polyester resins: terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, adipic acid, sebacic acid and other dicarboxylic acid monomers and ethylene glycol, propylene glycol, 1,4-butylene Diols such as glycol, 1,4-cyclohexanedimethanol, diethylene glycol, triethylene glycol, polypropylene glycol, polyoxytetramethylene glycol, alkylene oxide adducts of bisphenol compounds or derivatives thereof, diols such as trimethylolpropane, glycerin, pentaerythritol, or polyvalent Examples include copolymers with alcohol monomers, (co) polymers such as hydroxycarboxylic acids such as lactic acid, p-hydroxybenzoic acid, and 2,6-hydroxynaphthoic acid.

  Polyamide resin: a polymer having an acid amide bond in a chain obtained by polycondensation of a lactam having a three or more member ring, a polymerizable ω-amino acid, a dibasic acid and a diamine. Specifically, polymers such as ε-caprolactam, aminocaproic acid, enanthractam, 7-aminoheptanoic acid, 11-aminoundecanoic acid, 9-aminononanoic acid, α-pyrrolidone, α-piperidone, hexamethylenediamine, nonamethylene A polycondensation obtained by polycondensation with a diamine such as diamine, undecamethylenediamine, dodecamethylenediamine, or metaxylenediamine, and a dicarboxylic acid such as terephthalic acid, isophthalic acid, adipic acid, sebacic acid, dodecane dibasic acid, or glutaric acid. Or a copolymer thereof. For example, nylon-4, nylon-6, nylon-7, nylon-8, nylon-11, nylon-12, nylon-6, 6, nylon-6, 10, nylon-6, 11, nylon-6, 12, Nylon-6T, nylon-6 / nylon-6, 6 copolymer, nylon-6 / nylon-12 copolymer, nylon-6 / nylon-6T copolymer, nylon-6I / nylon-6T copolymer, etc. Is mentioned.

  When the resin is a copolymer, the structure may be random, block, or the like. When the resin has stereoregularity, any of isotactic, atactic, and syndiotactic may be used. Good.

In addition to the above resins, polycarbonate resin, acrylic resin, urethane resin, polyvinyl alcohol, vinyl chloride resin, styrene resin, polyacrylonitrile, cellophane, polyvinylidene chloride, fluororesin, polyacetal, polysulfone, ABS resin Resins such as polyetheretherketone can also be used.
Natural rubber, isoprene rubber, butadiene rubber, 1,2-polybutadiene rubber, styrene-butadiene rubber, chloroprene rubber, nitrile rubber, butyl rubber, ethylene-propylene rubber, chlorosulfonated polyethylene, acrylic rubber, epichlorohydrin rubber, polysulfide rubber In addition, rubber such as silicone rubber, fluorine rubber, and urethane rubber, elastomer, and the like can be used.

Examples of the solid metal compound include various metal oxides or hydroxides, and oxides or hydroxides having at least one metal selected from the group consisting of silicon, titanium, calcium, zinc, tin, and indium. Things are preferred. In the present invention, the metal includes a semimetal.
The solid metal compound plays a role of improving the mechanical properties and thermal properties of the inorganic / polymer composite foam molded article.

  In addition, inorganic / polymer composite moldings include, for example, plasticizers, stabilizers, impact resistance improvers, flame retardants, crystal nucleating agents, lubricants, antistatic agents, surfactants, pigments, dyes, fillers, and antioxidants. Additives such as agents, processing aids, ultraviolet absorbers, antifogging agents, antibacterial agents, and antifungal agents may be contained. An additive may be used individually by 1 type and may use 2 or more types together.

In the inorganic / polymer composite molded body, the expansion ratio is preferably 2 to 50 times, and more preferably 3 to 30 times. If the expansion ratio is 2 times or more, the characteristics as a foam can be sufficiently exhibited, and if it is 50 times or less, the mechanical strength of the inorganic / polymer composite molded body can be made sufficient.
The average foam diameter of the foam cell is preferably 1.0 to 500 μm, and more preferably 1.0 to 200 μm. If the foamed cell has an average foam diameter of 1.0 μm or more, the foamed cell can be easily formed, and if it is 500 μm or less, the mechanical strength of the inorganic / polymer composite molded article can be made sufficient.

<Method for producing inorganic / polymer composite molded body>
The manufacturing method of the present embodiment includes a composite material preparation step, a foaming agent addition step, and a molding step.

(Composite preparation process)
In the composite material preparation step in the present embodiment, first, a pellet-like polymer is supplied from an hopper to an extruder and melted. The extruder used at that time may be either a single screw extruder or a twin screw extruder. A tandem type extruder in which screws are arranged in series can also be used.

Next, the fluid metal compound and the catalyst releasing compound are added to the polymer melted in the extruder.
As a method for adding the fluid metal compound and the catalyst releasing compound, for example, a method of adding the fluid metal compound to the molten polymer in the extruder using a pump or the like in a liquid state or a gas state; For example, a method of dissolving and adding together with a foaming agent can be used.
The fluid metal compound and the catalyst releasing compound may be added simultaneously, or the catalyst releasing compound may be added after the addition of the fluid metal compound.

A flowable metal compound is a metal compound that can form a homogeneous phase with a polymer in a molten state. A metal compound capable of forming a homogeneous phase with a polymer in a molten state is a liquid metal compound, a gaseous metal compound, or a solid before mixing with a polymer in a molten state. It is a metal compound that melts when mixed. In addition, the fluid metal compound is decomposed into a solid metal compound.
Among such fluid metal compounds, at least one selected from the group consisting of metal alkoxides, metal β-diketonate complexes, and metal acetates is preferable because a solid metal compound can be easily obtained.
The metal is preferably at least one selected from the group consisting of silicon, titanium, calcium, zinc, tin and indium because a solid metal compound can be easily obtained.
Particularly, among the fluid metal compounds, tetramethoxysilane is more preferable because a solid metal compound can be obtained more easily.

The catalyst releasing compound is one that releases an acid catalyst or a base catalyst. Further, the catalyst releasing compound is preferably a polymer, a fluid metal compound, or a compound having high affinity with the foaming agent. Furthermore, it is preferable that the decomposition product does not affect the inorganic / polymer composite molded body.
Specifically, the catalyst releasing compound is preferably a silane coupling agent that generates an acid or a base, silazanes, and chlorosilanes. These compounds generate bases such as ammonia and acids such as hydrochloric acid by hydrolysis and promote hydrolysis of the fluid metal compound.
Among the catalyst releasing compounds, disilazanes and / or chlorosilanes are more preferable because of their high affinity for carbon dioxide, which is a typical blowing agent. Further, since disilazanes and chlorosilanes form silica by decomposition, when the fluid metal compound is a silicon compound, it is the same as the hydrolyzate silica and has the advantage that no impurities are generated.
Furthermore, since the catalyst releasing compound is completely compatible with carbon dioxide, trimethylchlorosilane and hexamethyldisilazane are particularly preferable.

In the composite material preparation step, the flowable metal compound and the catalyst releasing compound are added, and then the molten polymer, the flowable metal compound and the catalyst releasing compound are mixed to prepare a compatible melt.
In addition, the catalyst releasing compound is decomposed to release the catalyst, and the decomposition of the fluid metal compound is promoted in the presence of the catalyst to obtain a solid metal compound. Thereby, the composite material containing a polymer and a solid metal compound is prepared.
In the decomposition of the fluid metal compound, water, heat, etc. contained in the polymer are used. In order to promote hydrolysis, it is preferable to add water to the melt.

(Foaming agent addition process)
In the foaming agent addition step in the present embodiment, the foaming agent is added to the melt in the extruder.
Examples of the method of adding the foaming agent include a method of supplying a foaming agent in a liquid state with a plunger pump, a method of supplying a foaming agent in a gas state directly or under pressure, and a direct or pressurization in a supercritical state. The method of supplying in the state which carried out is mentioned.

As the foaming agent, those capable of forming a homogeneous phase with the polymer and the fluid metal compound are used, and for example, nitrogen, carbon dioxide, and various chlorofluorocarbon gases are used. A foaming agent may be used individually by 1 type, and may use 2 or more types together.
Among the foaming agents, carbon dioxide and / or nitrogen are preferable, and carbon dioxide is more preferable from the viewpoint of affinity for the polymer and compatibility with the fluid metal compound. Carbon dioxide is preferably in a highly soluble high-pressure liquid state, subcritical state, or supercritical state, and more preferably in the supercritical state.

  The foam nucleating agent can be added either before, during or after adding the foaming agent. Examples of the foam nucleating agent include inorganic particles such as talc, calcium carbonate, clay, magnesium oxide, glass powder, titanium oxide, and anhydrous silica. A foam nucleating agent may be used individually by 1 type, and may use 2 or more types together.

(Molding process)
In the molding step, the composite material obtained in the composite material preparation step is discharged from a die and extruded.
When the composite material is discharged from the die and released to atmospheric pressure, the pressure of the composite material rapidly decreases. In the present embodiment example in which a foaming agent is added, foaming occurs due to a decrease in pressure, so that the obtained molded body becomes a foamed body.
In this molding process, the solubility of the foaming agent and the flowable metal compound rapidly decreases without sufficient time for the foaming agent and the unreacted flowable metal compound to diffuse out of the polymer. A metal compound precipitates on the surface.

  The composite material preparation step, the foaming agent addition step, and the molding step are performed continuously and in parallel, and the inorganic / polymer composite molded body is continuously manufactured.

In the method for producing an inorganic / polymer composite molded body described above, decomposition of the fluid metal compound can be promoted by the catalyst released from the catalyst releasing compound added together with the fluid metal compound. Therefore, since the conversion rate of the decomposition reaction in which the fluid metal compound is converted into a solid metal compound can be improved, a sufficient amount of the solid metal compound can be obtained in the extruder even if the amount of the fluid metal compound is reduced. Can be obtained. Therefore, it is not necessary to repeatedly mix the fluid metal compound with the polymer in order to add a large amount of the fluid metal compound.
In addition, since the fluid metal compound is converted into a solid metal compound by the catalyst, there is no need to separately perform a step of converting the fluid metal compound into a solid metal compound after molding.
Therefore, according to the said manufacturing method, the inorganic substance and polymer composite molded object which contains a sufficient quantity of inorganic powder using an extruder can be manufactured with high productivity.

Note that the present invention is not limited to the above embodiment. For example, in the composite preparation step, the catalyst releasing compound may not be added, and instead, an acid catalyst or a base catalyst that converts the fluid metal compound into a solid metal compound may be added.
In the foaming agent addition step, a foaming agent may be added to the composite material.
Alternatively, the foaming agent addition step may be omitted to obtain a non-foamed inorganic / polymer composite molded body.

EXAMPLES Hereinafter, although an Example demonstrates this invention further more concretely, this invention is not limited to these.
[Example 1]
Acrylic resin (Mitsubishi Rayon Co., Ltd., Acrypet IR K304) pellets are supplied from a hopper to an extruder (Toyo Seiki Seisakusho Co., Ltd., twin screw segment extruder 2D30W2) and heated at a cylinder temperature of 240 ° C. Melted.
Further, carbon dioxide supplied from a liquefied carbon dioxide gas cylinder is pressurized to 12 MPa by a pressure pump, and this is used as a foaming agent to 2.0 ml / min with respect to an acrylic resin (7 g / min) completely melted in an extruder. Supplied in proportion.
At the same time, a mixture of tetramethoxysilane and hexamethyldisilazane was supplied to the acrylic resin completely melted in the extruder so as to have a ratio of 100% by mass with respect to 100% by mass of carbon dioxide. At that time, the mixture had a ratio of 1 ml of hexamethyldisilazane to 4 ml of tetramethoxysilane.
While maintaining at 240 ° C., acrylic resin, carbon dioxide, tetramethoxysilane and hexamethyldisilazane were mixed in an extruder to prepare a melt, and tetramethoxysilane was decomposed to obtain silica. Thereby, the composite material containing an acrylic resin and silica was obtained.
Further, the temperature of the die was set to 140 ° C., the temperature was lowered with the die, the composite material was discharged from the die and the pressure was reduced, and foam molding was performed to obtain a foamed silica / acrylic resin composite molded body.
About the obtained silica-acrylic resin composite molded article, the total content of silicon compounds other than silica and silica, and the content of silica were measured by the following methods. The results are shown in Table 1.

-Total content of silicon compound and silica Mass using a thermal analyzer (TG / DTA6200, manufactured by SII Nanotechnology Co., Ltd.) in a nitrogen atmosphere while heating a sample of a silica / acrylic resin composite molded body to 500 ° C Was measured, and the total content of the silicon compound and silica was determined by the formula (1).

-Silica content Using a thermal analyzer, the mass was measured while heating in the same manner as the measurement of the total content of the silicon compound and silica, and the silica content was determined by the following formula.
[Silica content (mass%)] = {[mass of residual component at 500 ° C.] / [Mass of inorganic substance / polymer composite at 25 ° C.}} × 100

[Example 2]
Pellets of polylactic acid (manufactured by Nature Works, PLA Polymer 4060) were supplied from the hopper to the extruder, and heated and melted at a cylinder temperature of 190 ° C.
Further, the pressure of carbon dioxide supplied from the liquefied carbon dioxide gas cylinder is increased to 12 MPa, and the ratio is 2.0 ml / min with respect to polylactic acid (8 g / min) completely melted in the extruder as a foaming agent. Supplied with.
At the same time, a mixture of tetramethoxysilane and hexamethyldisilazane was supplied to polylactic acid completely melted in the extruder so as to have a ratio of 100% by mass with respect to 100% by mass of carbon dioxide. At that time, the mixture had a ratio of 1 ml of hexamethyldisilazane to 4 ml of tetramethoxysilane.
While maintaining the temperature at 190 ° C., polylactic acid, carbon dioxide, tetramethoxysilane and hexamethyldisilazane were mixed in an extruder to prepare a melt, and tetramethoxysilane was decomposed to obtain silica. Thereby, a composite material containing polylactic acid and silica was obtained.
Further, the set temperature of the die was set to 120 ° C., the temperature was lowered with the die, the composite material was discharged from the die and the pressure was reduced, and foam molding was performed to obtain a foamed silica / polylactic acid composite molded body.
Table 1 shows the results of measuring the total content of silicon compound and silica and the content of silica for this silica-polylactic acid composite molded article.

[Comparative Example 1]
A silica / acrylic resin composite molded body was obtained in the same manner as in Example 1 except that only the tetramethoxysilane was supplied without supplying the mixture of tetramethoxysilane and hexamethyldisilazane in Example 1. Table 1 shows the total content of the silicon compound and silica contained in the obtained silica / acrylic resin composite molded article, and the measurement results of the silica content.

[Comparative Example 2]
A silica / polylactic acid composite molded body was obtained in the same manner as in Example 2 except that only the tetramethoxysilane was supplied without supplying the mixture of tetramethoxysilane and hexamethyldisilazane in Example 2. Table 1 shows the total content of the silicon compound and silica contained in the obtained silica / acrylic resin composite molded article, and the measurement results of the silica content.

In Examples 1 and 2 in which hexamethyldisilazane was supplied together with tetramethoxysilane, a sufficient amount for the inorganic / polymer composite molded body was obtained even though there was no step of decomposing tetramethoxysilane into silica after molding. Of silica.
On the other hand, in Comparative Examples 1 and 2 in which hexamethyldisilazane was not supplied, the amount of silica contained in the inorganic / polymer composite molded body was small.

  The inorganic / polymer composite molded body obtained by the method for producing an inorganic / polymer composite molded body of the present invention can be used for packaging films such as shrink films, battery separators, and heat insulating materials.

Claims (6)

A molten polymer and a flowable metal compound capable of forming a homogeneous phase with the molten polymer are mixed to prepare a compatible melt, and a solid metal compound is generated from the flowable metal compound. A composite material preparation step of preparing a composite material containing a polymer and a solid metal compound by reacting a fluid metal compound contained in the melt into a solid metal compound in the presence of a reaction catalyst;
A method for producing an inorganic / polymer composite molded body having a molding step of extruding the composite material ,
A method for producing an inorganic / polymer composite molded body, comprising a foaming agent addition step of adding a foaming agent to the melt or the composite material before the molding step, and extruding and foaming the composite material in the molding step. . The method for producing an inorganic / polymer composite molded article according to claim 1 , wherein the foaming agent is carbon dioxide and / or nitrogen. The fluid metal compound is at least one selected from the group consisting of a metal alkoxide, a metal β-diketonate complex, and a metal acetate, and the metal contained in the fluid metal compound is silicon, titanium, calcium, The method for producing an inorganic / polymer composite molded article according to claim 1 or 2 , which is at least one selected from the group consisting of zinc, tin and indium. In the composite material preparation step, a catalyst releasing compound that releases an acid catalyst or a base catalyst is added to the polymer, and the fluid metal compound contained in the melt is reacted in the presence of the catalyst released from the catalyst releasing compound. The manufacturing method of the inorganic substance and polymer composite molded object in any one of Claims 1-3 . The method for producing an inorganic / polymer composite molded article according to claim 4 , wherein the catalyst releasing compound is a disilazane and / or a chlorosilane. Wherein at composite preparation step, adding water to the melt method for producing inorganic-polymer composite molded article according to any one of claims 1-5.