WO2017142033A1

WO2017142033A1 - Volatile organic compound adsorbent and resin composition in which volatile organic compound adsorbent is blended

Info

Publication number: WO2017142033A1
Application number: PCT/JP2017/005755
Authority: WO
Inventors: 裕史小野; 皆川　円
Original assignee: 水澤化学工業株式会社
Priority date: 2016-02-18
Filing date: 2017-02-16
Publication date: 2017-08-24
Also published as: MY186075A; PH12018501732A1; JP6861200B2; CN108698017A; SG11201806560RA; JPWO2017142033A1; CN108698017B

Abstract

A volatile organic compound adsorbent which is composed of an MFI type zeolite having an SiO₂/Al₂O₃ (molar ratio) of 50 or more, and which is characterized in that the zeolite has an interplanar spacing (d) of the (053) plane of 2.99 Å or less in the X-ray diffraction spectrum and a nitrogen adsorption of 100 (cm³/g) or more at the nitrogen partial pressure P_N2 (P/P₀) of 0.005.

Description

Volatile organic compound adsorbent and resin composition containing volatile organic compound adsorbent

The present invention relates to a volatile organic compound adsorbent comprising MFI-type zeolite.

Zeolite is a crystalline aluminosilicate having SiO ₂ , Al ₂ O _3, etc. in the skeleton and having regular channels (pores). In particular, MFI-type zeolite is rich in silica, and is widely known as containing 10-membered ring-shaped pores (5.1 × 5.5 Å and / or 5.3 × 5.6 Å).

It is known that Al ₂ O ₃ in the crystal skeleton of zeolite has an influence on hydrophilicity, and the higher the amount of Al, the higher the hydrophilicity and the lower the amount. Silica-rich MFI zeolite is low in hydrophilicity due to its low Al content, and therefore exhibits high adsorptivity to hydrophobic organic components, and has a pore size close to that of low molecular weight hydrocarbons. Therefore, use as an adsorbent for organic compounds has been proposed (see Patent Documents 1 to 3).

Further, MFI-type zeolite also has an action of reducing a characteristic odor (hereinafter referred to as a resin odor) generated with deterioration of the resin (see Patent Document 4).

By the way, volatile organic compounds such as toluene, xylene, and ethyl acetate (hereinafter sometimes abbreviated as VOC) have a large influence on the environment, and are known to cause, for example, photochemical smog. The concentration of VOCs discharged and scattered from fixed sources such as factories by the prevention method is strictly limited. For this reason, an adsorbent for efficiently removing such a volatile organic compound from the exhaust gas is required.

The aforementioned MFI-type zeolite is frequently used as a VOC adsorbent because it exhibits high adsorptivity to various organic compounds. However, since the adsorption capacity is small, it is used in large quantities to obtain the desired effect. There was a need. For this reason, the improvement of the adsorption | suction performance and capacity | capacitance of MFI type zeolite with respect to VOC is calculated | required. In particular, there is a demand for an adsorbent capable of exhibiting sufficient adsorptivity even when VOC such as toluene is present at a low concentration in the atmosphere.

JP H01-171554 JP H09-253484 A Japanese Patent Laid-Open No. 2003-126589 JP 2002-069315 A

Therefore, an object of the present invention is to provide a volatile organic compound adsorbent exhibiting excellent adsorptivity even when the volatile organic compound is present at a low concentration. Another object of the present invention is to provide an adsorbent exhibiting excellent adsorptivity, particularly for toluene.

Another object of the present invention is to provide a resin composition containing a volatile organic compound adsorbent.

The present inventors conducted many experiments on the volatile organic compound adsorption performance of zeolite. As a result, the inventors have found that MFI-type zeolite obtained by synthesis at a low temperature exhibits excellent adsorptivity to VOC (toluene) in a low concentration atmosphere, and have completed the present invention.

According to the present invention, in the volatile organic compound adsorbent composed of MFI-type zeolite having a SiO ₂ / Al ₂ O ₃ (molar ratio) of 50 or more, the zeolite has an (053) plane spacing in the X-ray diffraction spectrum. Volatility characterized in that (d value) is 2.99% or less and nitrogen adsorption amount at nitrogen partial pressure P _N2 (P / P ₀ ) 0.005 is 100 (cm ³ / g) or more. An organic compound adsorbent is provided.

The volatile organic compound adsorbent of the present invention is
(1) SiO ₂ / Al ₂ O ₃ (molar ratio) is 90 or more,
(2) The toluene adsorption amount at toluene partial pressure P _T (P / P ₀ ) 0.01 is 8.2% by mass or more,
(3) The alkali metal content in terms of oxide is suppressed to 0.1% by mass or less,
Is preferred.

Further, according to the present invention, there is provided a resin composition in which the volatile organic compound adsorbent is blended with a resin.

The resin composition in which the adsorbent of the present invention is blended with a resin,
(1) 0.005 to 100 parts by mass of the adsorbent per 100 parts by mass of the resin;
(2) the resin is a thermoplastic resin;
Is preferred.

The volatile organic compound adsorbent of the present invention has an extremely low toluene content, that is, an atmosphere having a toluene partial pressure P _T (P / P ₀ ) of 0.01, as shown in the examples described later. The toluene adsorption amount in the atmosphere is 8.2% by mass or more, and the highest is 9.0% by mass or more. For example, none of the conventionally known MFI type zeolite adsorbents exhibit a toluene adsorptivity of 8.2% by mass or more in such a low toluene concentration atmosphere. Therefore, the volatile organic compound adsorbent of the present invention is suitably applied by being carried on an environmental purification facility used in a chemical factory or the like, for example, an exhaust rotor having a honeycomb structure.

2 is an X-ray diffraction image of a volatile organic compound adsorbent composed of MFI-type zeolite obtained in Example 2. FIG. The X-ray-diffraction image of (053) plane of Example 3, the comparative example 2, and the comparative example 3. FIG. The nitrogen adsorption isotherm measurement result of Example 2, Comparative Example 1, Comparative Example 2, and Comparative Example 3. The toluene adsorption isotherm measurement result of Example 2, Comparative Example 2 and Comparative Example 3. 2 is a scanning electron micrograph of a volatile organic compound adsorbent composed of MFI type zeolite obtained in Example 1. FIG. FIG. 6 is a scanning electron micrograph of a volatile organic compound adsorbent composed of MFI-type zeolite obtained in Example 6. FIG.

The adsorbent comprising the MFI type zeolite of the present invention is used for adsorbing and removing volatile organic compounds. A volatile organic compound means an organic compound having a boiling point in the range of 50 to 260 ° C. under atmospheric pressure, such as toluene, xylene, ethyl acetate, ethanol, benzene, methyl ethyl ketone, dichloroethane, trichloroethane, and the like. Is toluene.

<MFI type zeolite>
The MFI type zeolite used as the adsorbent has X-ray diffraction peaks as shown in FIG. 1 because the pores have a 10-membered ring shape unique to the zeolite. For example, a sharp diffraction peak of (011) plane near 2θ = 7.9 °, (200) plane near 2θ = 8.9 °, and (051) plane near 2θ = 23.1 ° is shown.
Such zeolite is silica-rich with a SiO ₂ / Al ₂ O ₃ (molar ratio) of 50 or more, preferably 90 or more, more preferably 100 or more, most preferably 5000 or more, and therefore has low hydrophilicity and hydrophobicity. Excellent adsorbability for high organic compounds. On the other hand, zeolite with a high aluminum content (the above molar ratio is less than 50) has high hydrophilicity and cannot obtain an excellent adsorptivity to VOC.

The MFI-type zeolite used in the present invention is produced by a reaction at a low temperature (80 to 130 ° C.). As a result, the interplanar spacing (d value) of the (053) plane in the X-ray diffraction spectrum is as follows. 2.99 mm or less, and nitrogen adsorption amount at nitrogen partial pressure P _N2 (P / P ₀ ) 0.005 is 100 (cm ³ / g) or more, preferably 103 (cm ³ / g) or more. . It will be described later that the d value and the nitrogen adsorption amount can be obtained by the reaction at a low temperature.

Said d value represents the space | interval of the specific surfaces which the pore in a zeolite has. When the d value is small, the zeolite has no distortion, the pores are uniformly distributed, and the pore volume is large.
That is, this MFI-type zeolite has fine and uniform distribution of micro-sized pores as described above in relation to having a small d value as described above. As a result, As described above, even if the nitrogen partial pressure P _N2 (P / P ₀ ) is as low as 0.005, a large nitrogen adsorption amount is exhibited. In other words, showing the above nitrogen adsorption amount means that micro-sized pores are densely distributed, and as a result, it is extremely excellent for volatile organic compounds, particularly toluene. Adsorbability can be demonstrated.

Further, the above MFI type zeolite has an alkali metal (hereinafter referred to as alkali) amount in terms of oxides suppressed to 1.70% by mass or less, preferably 1.25% by mass or less, and particularly 0.1% by mass or less. It is desirable. That is, such an alkali component (for example, Na or K) is mixed in the zeolite as an unavoidable impure component in the manufacturing method, but if this amount is large, the hydrophilicity of the zeolite increases, and organic Although the adsorptivity with respect to a component will fall significantly, in this invention, since such an alkali amount is suppressed to a small quantity, the fall of the adsorptivity with respect to the organic compound by an alkali is avoided effectively, As a result, , High adsorptivity to VOC can be ensured. For example, as shown in the examples described later, the MFI-type zeolite used in the present invention has a toluene adsorption amount of 8. in an atmosphere where the toluene partial pressure P _T (P / P ₀ ) is 0.01. When the alkali amount in terms of oxide is suppressed to 0.1% by mass or less although it is 2% by mass or more, it is 9% by mass or more, and particularly shows a toluene adsorption amount close to 10% by mass.

<Manufacture of MFI type zeolite>
The MFI-type zeolite described above is heated in a mixed gel containing a silica source and an alumina source in the presence of a template and a seed crystal, preferably in the presence of an alkali metal hydroxide for preparing a raw material to be described later. The silica source and the alumina source are reacted (crystallization).

The silica source is preferably one having a high SiO ₂ purity excluding impurities such as Na ₂ O and Al ₂ O ₃ to some extent. For example, tetraethyl orthosilicate, colloidal silica, silica gel dry powder, silica hydrogel, etc. are used. . These silica sources are dissolved once in an aqueous solution at the time of reaction and reconstructed into MFI type zeolite. However, if there are few impurities or non-reactive components unnecessary for the reaction, the type of silica source is MFI type zeolite. Does not significantly affect crystallization.
However, silica gel dry powder or silica hydrogel that can be produced by a relatively simple method is preferable from the viewpoint of cost, and it is particularly desirable to use silica hydrogel. Silica hydrogel is prepared by gradually dropping an alkali silicate such as sodium silicate into a mineral acid such as sulfuric acid with stirring to a final pH of about 3.0 to 9.0, followed by filtration and washing with water to be discharged. It can be easily obtained by washing until the pH of the solution reaches about 5.0 to 7.0. The production of silica hydrogel may be performed during raw material mixing or before and after washing with water, or may be performed at room temperature.
As the alumina source, for example, aluminum sulfate, basic aluminum sulfate, sodium aluminate or the like can be used, and sodium aluminate is particularly preferable.
The above mixed gel is, for example, MFI type having a molar ratio of 112 so that the SiO ₂ / Al ₂ O ₃ (molar ratio) of the target MFI type zeolite is higher than that of SiO ₂ / Al ₂ O ₃ (molar ratio). When obtaining zeolite, it contains Si component and Al component such that the molar ratio of the mixed gel is 120. Generally, silica source and alumina source are mixed in an aqueous medium at room temperature. Can be obtained.

The silica source and the alumina source are mixed so that SiO ₂ / Al ₂ O ₃ (molar ratio) has a predetermined quantitative ratio, but MFI-type zeolite containing a particularly large amount of Si component (for example, a molar ratio of 1000 In the case of manufacturing the above, the use of an alumina source can be omitted. That is, a raw material used for industrial use may contain a small amount of Al component as an inevitable impurity.

The mixed gel containing the silica source and the alumina source is further mixed with a template and a seed crystal, preferably an alkali metal hydroxide, and is mixed as a seeded mixed gel in the presence of the template and the seed crystal at a low temperature. MFI-type zeolite is obtained by crystallization by reaction.
There are no particular restrictions on the method of adding the template, the seed crystal, and the alkali metal hydroxide, and part or all of the mixed gel and / or part or all of the raw material of the mixed gel is preliminarily prior to crystallization. Can be used as a mixture.

The template is a structure-directing agent for forming pores in a 10-membered ring form unique to MFI-type zeolite, and an amine compound containing an n-alkyl group having 2 to 4 carbon atoms and a nitrogen cation in the molecule, for example, Further, a salt of a tetraalkyl (ethyl, n-propyl or n-butyl) ammonium cation and an anion (for example, Br ⁻ ), a hydroxide of the ammonium, or the like is used.

That is, in the reaction of the silica-alumina hydrosol (SiO chain by condensation), an intermediate including a charge is generated and a Si—O—Si chain is formed as shown in the following general formula.
^{OH-Si-O - + SiOH} → [OH-Si-O ... SiOH] -
→ OH-Si-O-Si ^-- OH
→ OH—Si—O—Si (—OH) —O ⁻ + H ² O
In the Si—O—Si chain as described above, the template cation protects the intermediate, and at the same time, the Si—O—Si chain is formed so as to surround the template cation. As a result, a 10-membered ring structure unique to MFI-type zeolite can be formed.

If such a template is, for example, tetrapropylammonium bromide (TPA-Br), it is used in an amount of TPA / SiO ₂ = 0.03 to 0.20 (molar ratio) with respect to the Si component of the mixed gel. However, this amount varies greatly depending on the type of template, particularly the carbon number of the alkyl group.
Although not necessary when the quaternary ammonium hydroxide is used as a template, a silica source is dissolved when a salt of quaternary ammonium and an anion such as Br or Cl is used as a template. Therefore, an alkali metal hydroxide (for example, caustic soda) of A ₂ O / SiO ₂ = 0.01 to 0.20 (molar ratio, A is an alkali metal element) is added to the Si component of the mixed gel. . In this case, the effect of shortening the time required for crystallization is obtained as the addition amount of the alkali metal hydroxide is increased. However, when A ₂ O / SiO ₂ exceeds 0.20, in the obtained MFI-type zeolite, A large amount of the alkali metal that acts hydrophilically remains, and the adsorptivity of the present invention may not be sufficiently exhibited. For this reason, A ₂ O / SiO ₂ is preferably 0.15 or less, particularly preferably 0.10 or less.

In order to produce the above-mentioned MFI type zeolite, it is necessary to carry out the above reaction at a low temperature, specifically 80 to 130 ° C., preferably 95 to 120 ° C., particularly preferably 95 to 98 ° C. . For this reason, the above reaction must be performed in the presence of seed crystals. As a result, crystallization is promoted, and the crystallization can be completed in a short time, for example, 48 hours or less, particularly 20 hours or less, while performing the reaction at a low temperature.
As such a seed crystal, it is necessary to use the previously prepared MFI-type zeolite. Of the production methods as described later, an MFI-type zeolite containing a template may be used. MFI-type zeolite from which the template is removed may be used. This seed crystal is appropriately pulverized and then used in an amount of 0.02 to 20 parts by mass, preferably 0.05 to 5.0 parts by mass per 100 parts by mass of SiO _{2 with} respect to the Si component of the mixed gel. The
If the amount of seed crystals added is 0.05 parts by mass or less, the effect of shortening the time required for crystallization is weak. When the addition amount is excessive, the composition of the seed crystal affects the composition of the obtained MFI-type zeolite and, for example, an unnecessary interface is formed by core-shell formation. This is undesirable because the formation of distributed pores is hindered. In particular, when the amount is 5.0 parts by mass or more, there is no significant change in the crystallization time, and the amount of seed crystals used increases, leading to an increase in cost.

Furthermore, as described above, the reaction of the mixed gel in the presence of the template and the seed crystal (mixed gel containing the seed crystal) is performed at 80 to 130 ° C., and thereby, the d value and the nitrogen adsorption amount described above are performed. It is possible to obtain a silica-rich MFI zeolite exhibiting the following.
For example, when MFI-type zeolite is produced by a conventionally known method, the reaction temperature is set to a high temperature of about 180 ° C. or at least about 150 ° C., which completes the crystallization in a short time. According to their research, when the reaction is carried out at a temperature higher than 130 ° C., the d value of the obtained MFI-type zeolite (surface distance of (053) plane) exceeds 2.99 mm, and the nitrogen content When the pressure P _N2 (P / P ₀ ) is 0.005, the nitrogen adsorption amount becomes lower than 100 (cm ³ / g). The reason for this is not exactly understood, but if the reaction is carried out at a high temperature, the template undergoes thermal decomposition during crystallization of the MFI-type zeolite, or even if the template does not thermally decompose, This is not because vibrations are promoted, and as a result, the effect of the template for protecting the intermediate is weakened, and the crystal structure of the resulting MFI-type zeolite is distorted or the formed pores are distorted. The present inventors have estimated.
That is, in the present invention, since the reaction is performed at a low temperature as described above, decomposition and vibration of the template due to thermal energy are avoided, and as a result, distortion of the zeolite and distortion of the pores are prevented, and the size is uniform. Therefore, it is considered that the obtained MFI-type zeolite has a small interplanar spacing d value of a specific plane ((053) plane) and exhibits a large nitrogen adsorption amount. It is. In particular, the d value of the (053) plane is as small as 2.99 mm or less as in the present invention indicates that the MFI-type zeolite has a very dense crystal structure, that is, micro-sized pores are present. It can be said that the MFI type zeolite is densely and uniformly distributed. Usually, the analysis of the d value of zeolite is not confused with other peaks in the XRD measurement range, and it is preferable to use a peak on a relatively high angle side (for example, around 30 °). In the case of MFI type zeolite, the (053) plane meets this condition, and it is analyzed that the volatile organic compound adsorbent comprising the MFI type zeolite of the present invention has a dense crystal structure.
Although the MFI type zeolite can be crystallized even at a reaction temperature of 80 ° C. or lower, the progress of the reaction becomes extremely slow and the practicality is lost.

The present invention prevents the distortion and pore distortion of the zeolite obtained as described above, and as a result of being able to finely distribute pores of uniform size, a high BET ratio as in the examples described later. Has a surface area. That is, the volatile organic compound adsorbent of the present invention has a BET specific surface area of 430 m ² / g or more, preferably 440 m ² / g or more, particularly preferably 450 m ² / g or more.

Further, as long as the reaction temperature is in the low temperature range, this reaction may be performed under atmospheric pressure or under pressure using an autoclave or the like. In view of cost and the like, it is preferable to carry out the reaction under atmospheric pressure because crystallization is sufficiently promoted even if it is carried out under atmospheric pressure by using seed crystals.

After the above reaction, according to a conventional method, filtered water washing and drying are carried out, followed by calcination at a temperature of about 500 to 800 ° C. for about 0.5 to 10 hours, whereby the template in the zeolite is removed. MFI type zeolite in which pores suitable for adsorption of the target VOC, particularly toluene, are densely distributed can be obtained.

In addition, when a large amount of alkali such as Na or K is used in the synthesis of the above zeolite, the alkali content increases, and these alkalis act hydrophilicly. The adsorptivity to the compound is greatly impaired. In this case, the MFI-type zeolite that has undergone the calcination process is dispersed again in an aqueous solution, and dealkalization with an acid such as hydrochloric acid or sulfuric acid, or ion exchange between alkali and ammonium using various ammonium salts, and subsequent calcination of ammonium removal It is desirable to remove the alkali content by a series of dealkalization methods.
In particular, a series of dealkalization methods using various ammonium salts are suitable. In this case, for example, it is preferable to use about 10 to 200 parts by mass of ammonium chloride with respect to the calcined MFI-type zeolite, and subsequent ammonium removal. The firing is preferably performed at 300 to 600 ° C. for about 0.5 to 10 hours.

The MFI-type zeolite thus obtained usually has a median diameter of 0.1 to 20 μm, preferably 0.5 to 10 μm. However, it is preferable that the MFI-type zeolite is appropriately pulverized into a powder for use. In consideration of ease of use, etc., the particle size is adjusted to a size of 1.0 to 4.0 μm for use. However, for example, when kneaded into a resin composition or mixed with a liquid containing a hydrophobic solvent such as a paint or a coating agent, it is submicron order (medium) to improve the dispersibility or increase the specific surface area. It can also be used after being finely pulverized to a diameter of 0.1 to 1.0 μm. Moreover, when filling in equipment, such as an adsorption column and an adsorption tower, after mixing appropriately with the binder generally used, it can shape | mold and use as a granular material, for example.

The volatile organic compound adsorbent of the present invention comprising the above-mentioned silica-rich MFI type zeolite exhibits high adsorptivity to volatile organic compounds typified by toluene, xylene and ethyl acetate, and these compounds have a low concentration. These compounds can be effectively adsorbed and removed even in the atmosphere existing in step (b). For this reason, such an adsorbent is suitably applied by being carried on an environmental purification facility used in a chemical factory or the like that discharges a gas containing a volatile organic compound, for example, an exhaust rotor having a honeycomb structure.

Further, the volatile organic compound adsorbent of the present invention having such characteristics is blended in a resin and used for the preparation of a resin composition. From the obtained resin composition, preferably a master batch is prepared, and a film or various Various articles such as members are formed. At this time, the volatile organic compound adsorbent of the present invention can be added to the resin alone or in combination with other adsorbents and additives. The blending amount of the volatile organic compound adsorbent of the present invention is not limited at all. For example, the adsorbent is in the range of 0.001 to 1000 parts by mass, preferably 0.005 to 100 parts by mass per 100 parts by mass of the resin. Can be blended. In particular, when the adsorbent of the present invention is applied to a resin for the purpose of reducing the unreacted monomer during resin processing and the characteristic resin odor caused by deterioration, the adsorbent is 0.005 to 100 parts by mass of the resin. It is preferably 10 parts by mass.
In addition, by adding the volatile organic compound adsorbent of the present invention to resins used in automobile parts and housing building materials, substances that cause odors, particularly sick house syndrome (toluene and aldehydes), which are peculiar to new cars and new buildings. The effect of improving the living environment can be expected, for example, by adsorbing the above)), and it can be made into a highly functional fiber having a deodorizing function by being incorporated into the fiber in the fiber processing step. In such a case, the adsorbent is preferably 1 to 100 parts by mass per 100 parts by mass of the resin.

As the base resin, any of a thermoplastic resin and a thermosetting resin can be used. From the viewpoint of moldability, a thermoplastic resin is preferable. The following can be mentioned as an example of such a thermoplastic resin.
Low-density polyethylene, high-density polyethylene, polypropylene, poly-1-butene, poly-4-methyl-1-pentene, or random or block co-polymerization of α-olefins such as ethylene, propylene, 1-butene, 4-methyl-1-pentene Olefin resins such as polymers and cyclic olefin copolymers;
Ethylene / vinyl acetate copolymers, ethylene / vinyl alcohol copolymers, ethylene / vinyl copolymers such as ethylene / vinyl chloride copolymers;
Styrene resins such as polystyrene, acrylonitrile / styrene copolymer, ABS, α-methylstyrene / styrene copolymer;
Vinyl resins such as polyvinyl chloride, polyvinylidene chloride, vinyl chloride / vinylidene chloride copolymer, polymethyl acrylate, polymethyl methacrylate;
Polyamide resins such as nylon 6, nylon 6-6, nylon 6-10, nylon 11 and nylon 12;
Polyester resins such as polyethylene terephthalate (PET), polybutylene terephthalate, polyethylene naphthalate, and copolymerized polyesters thereof;
Polycarbonate resin;
Polyphenylene oxide resin;
Biodegradable resins such as polylactic acid;
The thermoplastic resins exemplified above can be used alone, but can also be used as a blend of two or more.
In the present invention, olefinic resins and polyester resins are particularly suitable, and olefinic resins are most suitable as the base resin.

In addition, since the volatile organic compound adsorbent of the present invention has micro-sized pores densely and uniformly distributed, the active sites (for example, solid acid points) possessed by the MFI zeolite are also densely and uniformly distributed. It is expected that That is, the volatile organic compound adsorbent of the present invention is a catalyst to which MFI type zeolite is generally applied, for example, an acid catalyst, a disproportionation catalyst, an isomerization catalyst, a hydrocarbon synthesis catalyst, an FCC catalyst, and an olefin polymerization catalyst. The use as a catalyst, a denitration catalyst, etc. or as a catalyst carrier is not limited at all.

The invention is illustrated by the following experimental example.
Various measurements in the experiment were performed by the following methods.

(1) X-ray diffraction (measurement and analysis conditions for d-value analysis of surface spacing)
A dried sample was placed in a desiccator that had been conditioned at a relative humidity of 75%, and allowed to stand at room temperature for 48 hours or more to adsorb a saturated amount of water. The extracted sample was subjected to X-ray diffraction measurement at 2Θ = 29.6 to 30.2 °. The X-ray diffraction measurement was performed using Cu-Kα under the following conditions using ultima 4 manufactured by Rigaku Corporation.
Target: Cu
Filter: Curved crystal graphite monochromator Detector: SC
Voltage: 40 kV
Current: 50 mA
Step size: 0.005 °
Counting time: 10 sec / step
Slit: DS2 / 3 ° RS0.3mm SS2 / 3 °
Of the X-ray diffraction in the target range, the d value (Å) was determined based on the following formula for the angle having the maximum peak.
(Bragg condition)
d = nλ / 2sinΘ
d: spacing between planes n: integer λ: wavelength sin Θ: angle formed between crystal plane and X-ray (confirmation of crystal type)
The confirmation of the crystal was performed by changing the following among the conditions used for measuring the d value.
Measurement range: 3 to 40 °
Current: 40 mA
Step size: 0.02 °
Counting time: 0.6 sec / step

(2) Measurement of nitrogen adsorption isotherm Nitrogen adsorption is measured using a Tristar manufactured by micromeritics, and an adsorption isotherm in the range where the nitrogen partial pressure P _N2 (P / P ₀ ) is in the range of 0.005 to 0.95. Asked. The pretreatment was performed under vacuum conditions at 200 ° C. for 2 hours. For each adsorbent described later, the measured value at a nitrogen partial pressure P _N2 (P / P ₀ ) of 0.005 was taken as the nitrogen adsorption amount (cm ³ / g).

(3) Measurement of toluene adsorption isotherm For the measurement of toluene adsorption, Belsorb made by Nippon Bell Co., Ltd.
Using Max, an adsorption isotherm was obtained when the toluene partial pressure P _T (P / P ₀ ) was in the range of 0.0001 to 0.10. The pretreatment was performed under vacuum conditions at 150 ° C. for 2 hours. The equilibrium judgment time was 300 seconds. Toluene used was a grade for chromatograph manufactured by Wako Pure Chemical Industries, Ltd. For each adsorbent described later, the measured value at a toluene partial pressure P _T (P / P ₀ ) of 0.01 was converted to an adsorbed amount per adsorbent unit mass to obtain an adsorbed amount of toluene (% by mass).

(4) Composition analysis About elemental analysis required for calculation of alkali metal content in terms of oxide and SiO ₂ / Al ₂ O ₃ (molar ratio), Rigaku ZSX primus II manufactured by Rigaku Corporation was used, and the target was Rh and the analytical line were Kα, and the others were measured under the following conditions.
The sample was based on a product dried at 110 ° C. for 2 hours.

(5) Measurement of median diameter (D50%) The median diameter (μm) on a volume basis was measured using a laser diffraction type particle size distribution measuring device Mastersizer 3000 manufactured by Malvern and using water as a solvent. .

(6) BET specific surface area The specific surface area by BET method was computed from the adsorption isotherm calculated | required by (2).

(Comparative Example 1)
Silton MT-100 (SiO ₂ / Al ₂ O ₃ = 105) which is MFI type zeolite manufactured by Mizusawa Chemical Co., Ltd. was used. Shilton is a registered trademark of Mizusawa Chemical Industry Co., Ltd.

(Comparative Example 2)
MFI type zeolite made by Tosoh Corporation, HSZ890HOA was used.

(Comparative Example 3)
MFI type zeolite made by Union Showa Co., Ltd., ABSCENTS-3000 was used.

(Comparative Example 4)
(Preparation of silica hydrogel)
Silica hydrogel by a conventionally known method using 40% by mass sulfuric acid and No. 3 sodium silicate (SiO ₂ = 22.8% by mass, Na ₂ O = 7.6% by mass, H ₂ O = 69.6% by mass) Was prepared. When the composition analysis was conducted, SiO ₂ = 38.5 mass%, Na ₂ O = 0.02 mass%, and H ₂ O = 61.4 mass%.
(Synthesis of MFI type zeolite)
In a 2 L stainless steel mug, silica hydrogel, TPA-Br, 49 mass% NaOH and water, SiO ₂ mass is 200 g, and each component is in a molar ratio of SiO ₂ : Na ₂ O: TPA-Br: H ₂ O = The mixture gel was prepared by mixing at room temperature with stirring so that the ratio was 1: 0.025: 0.045: 16.
Next, the mixed gel was transferred to a 1.5 L autoclave with a built-in stirring blade, heated to 170 ° C. over 2.5 hours under stirring conditions, and then subjected to a crystallization reaction for 12 hours while maintaining 170 ° C. after the temperature rising. It was. After completion of the reaction, the liquid was filtered and subsequently washed with water having a volume three times that of the mixed gel to obtain an MFI type zeolite containing a template. The median diameter of MFI-type zeolite after washing with filtered water was 10.0 μm.
After drying for 10 hours in a constant temperature drying shelf at 110 ° C., the template was removed using a muffle furnace at 600 ° C. for 2 hours to obtain an MFI-type zeolite containing no template.
(Milling of MFI type zeolite)
The MFI type zeolite was pulverized using a swirling jet mill. The median diameter of the powder after pulverization was 7.7 μm.

Example 1
Comparison was made except that the composition of each component was changed to SiO ₂ : Na ₂ O: TPA-Br: H ₂ O = 1: 0.03: 0.05: 16 with a SiO ₂ mass of 200 g. A mixed gel was prepared in the same manner as in Example 4, and finally 1.0% by mass of seed crystals (MFI type zeolite having a median diameter of 7.7 μm obtained in Comparative Example 4) with respect to SiO ₂ was further added. Stirring was performed for 5 minutes to prepare a mixed gel containing seed crystals.
Next, under stirring conditions, the temperature of the mixed gel containing seed crystals was raised to 95 ° C. over 1 hour in a temperature-controllable hot water layer, and a crystallization reaction was performed for 20 hours while maintaining 95 ° C. After completion of the reaction, the reaction solution was filtered and subsequently washed with 3 times the volume of water of the mixed gel to obtain an MFI-type zeolite containing a template. The median diameter of MFI-type zeolite after washing with filtered water was 1.0 μm.
After drying for 10 hours in a constant temperature drying shelf at 110 ° C., the template was removed using a muffle furnace under the condition of holding at 600 ° C. for 2 hours to obtain an MFI type zeolite containing no template.
Thereafter, the MFI-type zeolite was pulverized using a swirling jet mill in the same manner as in Comparative Example 4 to obtain a volatile organic compound adsorbent composed of the MFI-type zeolite. The median diameter was 1.0 μm.

(Example 2)
90 g of water was added to 10 g of the volatile organic compound adsorbent composed of the MFI-type zeolite of Example 1 and redispersed by stirring. Then, 10 g of ammonium chloride was added, and exchange treatment was performed for 3 hours. After washing with filtered water, the obtained ammonium-MFI type zeolite was dried for 10 hours in a constant temperature drying shelf at 110 ° C., and then the ammonium was removed using a muffle furnace under the condition of holding at 500 ° C. for 3 hours to remove alkali. -An MFI type zeolite was obtained. The zeolite was pulverized again using a swirling jet mill to obtain a volatile organic compound adsorbent composed of MFI-type zeolite. The median diameter was 1.0 μm.

(Example 3)
A volatile organic compound adsorbent composed of MFI-type zeolite was obtained in the same manner as in Example 1 except that the reaction vessel was a 1.5 L autoclave with a built-in stirrer, the reaction temperature was 105 ° C., and the reaction time was 16 hours. It was. The median diameter was 2.0 μm.

(Example 4)
The composition of the mixed gel was SiO ₂ : Na ₂ O: TPA-Br: H ₂ O = 1: 0.025: 0.045: 16 in a molar ratio, and the reaction vessel was a 1.5 L autoclave with a built-in stirrer, reaction A volatile organic compound adsorbent composed of MFI-type zeolite was obtained in the same manner as in Example 1, except that the temperature was 110 ° C. and the reaction time was 18 hours. The median diameter was 4.0 μm.

(Example 5)
In addition to the raw materials shown in Example 1, sodium aluminate (Al ₂ O ₃ = 23.0% by mass, Na ₂ O = 19.2% by mass, H ₂ O = 57.8% by mass) was used as a mixed gel. At a room temperature under stirring so that the composition of SiO ₂ : Al ₂ O ₃ : Na ₂ O: TPA-Br: H ₂ O = 1: 0.008: 0.05: 0.04: 16 Finally, 1.0% by mass of seed crystals (MFI-type zeolite having a median diameter of 7.7 μm obtained in Comparative Example 4) with respect to SiO ₂ was added to prepare a mixed gel containing seed crystals. Thereafter, a volatile organic compound adsorbent composed of MFI-type zeolite was obtained in the same manner as in Example 1 except that the reaction vessel was a 1.5 L autoclave with a built-in stirrer and the reaction temperature was 120 ° C. The median diameter was 1.8 μm.

(Example 6)
The SiO ₂ mass is 380 g, the MFI type zeolite having a median diameter of 1.0 μm obtained in Example 1 is used as a seed crystal, the seed crystal addition amount is 3.0 mass%, and the composition of each component is in molar ratio. SiO ₂ : Na ₂ O: TPA-Br: H ₂ O = 1: 0.03: 0.045: 20 The raw materials including seed crystals were mixed under stirring conditions to obtain a mixed gel containing seed crystals. Was prepared. Subsequent operations were performed in the same manner as in Example 1 to obtain a volatile organic compound adsorbent composed of MFI-type zeolite. The median diameter was 0.7 μm.

(Example 7)
Using the same raw materials as in Example 5, the SiO ₂ mass is 240 g, the MFI zeolite having a median diameter of 0.7 μm obtained in Example 6 is used as a seed crystal, and the addition amount of the seed crystal is 2.0 mass%. The composition of each component is SiO ₂ : Al ₂ O ₃ : Na ₂ O: TPA-Br: H ₂ O = 1: 0.0077: 0.12: 0.04: 20.3 in molar ratio. Raw materials including seed crystals were mixed under stirring conditions to prepare a mixed gel containing seed crystals. Thereafter, a volatile organic compound adsorbent composed of MFI-type zeolite was obtained in the same manner as in Example 1 except that the crystallization reaction was performed for 48 hours. The median diameter was 0.5 μm.

Tables 2 and 3 show the test results on the physical properties, nitrogen adsorption amount and toluene adsorption amount of the MFI type zeolites of Comparative Examples 1 to 4 and the volatile organic compound adsorbents prepared in Examples 1 to 7.

Application example: Preparation of resin composition containing adsorbent Adsorbent of Example 6 was mixed with polyethylene pellets (product name: LF440B) manufactured by Nippon Polypro Co., Ltd., and 170 using a lab plast mill manufactured by Toyo Seiki Seisakusho. By melt-kneading at 0 ° C. and cutting into chips, a resin composition having an adsorbent content of 0.5 parts per 100 parts by mass of the resin was obtained. In addition, components other than the adsorbent are not added.

Evaluation of resin odor adsorption capacity;
The resin odor reduction performance was evaluated using the resin composition in which the adsorbent was blended and the polyethylene pellet not containing the adsorbent, which were obtained in the preparation of the resin composition.
Weigh each 5g of resin composition containing adsorbent in a 500mL screw mouth storage bottle or polyethylene pellets without adsorbent, wrap Teflon tape around the bottle's screw part in triplicate, and then close the lid. And sealed. This was prepared for each subject (for 5 people). A storage bottle containing polyethylene pellets was placed in a constant-temperature shelf dryer preheated at 50 ° C. and left as it was at 50 ° C. for 90 hours. Two types of storage bottles were taken out from the thermostatic shelf dryer, opened and immediately smelled, and the degree of odor (0: no odor, 1: slightly odor, 2: odor) was evaluated by each subject. In addition, it tested in the state which does not know which pellet is contained with respect to the test subject. The test results are shown in Table 4.

Claims

In the volatile organic compound adsorbent composed of MFI-type zeolite having a SiO 2 / Al 2 O 3 (molar ratio) of 50 or more,
The zeolite has an (053) plane spacing (d value) of 2.99 mm or less in the X-ray diffraction spectrum,
A volatile organic compound adsorbent having a nitrogen adsorption amount of 100 (cm 3 / g) or more at a nitrogen partial pressure P N2 (P / P 0 ) of 0.005.
The adsorbent according to claim 1, wherein SiO 2 / Al 2 O 3 (molar ratio) is 90 or more.
Toluene adsorption amount of toluene partial pressure P T (P / P 0) 0.01 is 8.2% by mass or more, according to claim 1 or 2 sorbent according.
The adsorbent according to any one of claims 1 to 3, wherein the alkali metal content in terms of oxide is suppressed to 0.1 mass% or less.
A resin composition in which the adsorbent according to any one of claims 1 to 4 is blended with a resin.
6. The resin composition according to claim 5, wherein 0.005 to 100 parts by mass of the adsorbent is blended per 100 parts by mass of the resin.
The resin composition according to claim 5, wherein the resin is a thermoplastic resin.