JP3207256B2 - Thermal odor generating microcapsules - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat-sensitive odor-generating microcapsule for temperature control, which informs the ambient temperature condition by odor.

[0002]

2. Description of the Related Art Conventionally, as a temperature control method which is easy and practical, there is a case where a temperature indicating material whose hue changes with temperature is used. If it is attached to an electrical component such as a transistor, an integrated circuit, or a capacitor where overheating is likely to occur, the state of heat generation can be visually detected. In the case of this method, the discoloration of the temperature indicating label or the paint is actually confirmed by eyes. It is suitable for conducting tests and experiments that can be watched by the human eye at any time, or for controlling the temperature of familiar parts. However, it cannot be applied to a system that controls the entire temperature in a large space such as a factory.

[0003] Materials which emit an odor when heat is applied have been known. For example, JP-A-53-133697, JP-A-64-75284, JP-A-1-97067, JP-A-2-14
No. 7,858, JP-A-2-14698, JP-A-2-5958, and the like. In these, the shell of the microcapsule is destroyed by high heat such as a cigarette fire or a heated thermal head, and the fragrance filled therein volatilizes to emit an odor.

[0004] If a certain odor is emitted at a certain temperature, it can be applied to a device or the like that warns of an overheated state.
In the case of an overheat alarm, it is usually necessary to continue to emit a warning signal at least to some extent until an observer notices the warning signal. In the case of conventional heat-sensitive microcapsules, the odor has little persistence because the odorous substance volatilizes as soon as the shell is broken. Therefore, there has been a problem that the conventional heat-sensitive microcapsules can hardly withstand actual use as an overheat alarm for temperature control.

[0005] Moreover, the shell is broken at a considerably high temperature. Few microcapsules can freely select the heat-sensitive temperature in a wide range. Considering safety, it is very difficult to form microcapsules for temperature management that can notify temperature abnormalities relatively early in the range where the temperature does not rise sufficiently, for example, from room temperature to about 200 ° C. There was a point.

JP-A-63-97168 describes a microcapsule consisting of a bilayer membrane for controlling the temperature. Its intended use environment is limited to water, and its application range is narrow.

[0007]

DISCLOSURE OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and the temperature can be freely selected. It is an object of the present invention to provide a heat-sensitive odor-generating microcapsule which can be easily and surely notified to a person.

[0008]

A heat-sensitive odor generating microcapsule of the present invention, which has been made to achieve the above object, will be described with reference to FIG. 1 corresponding to an embodiment.

As shown in the figure, the heat-sensitive odor generating microcapsule of the present invention comprises an odorous substance 1 and a temperature to be heated.
The kneaded product with the hot-melt composition 2 having a melting temperature
It is included in. 1a shows a state in which the odorous substance 1 is sealed inside at a temperature lower than the melting point of the hot-melt composition 2, and FIG. 1b shows that the hot-melt composition 2 is melted by receiving heat, The state when the substance 1 evaporates from the shell 3 is shown.

The hot-melt composition 2 is hydrophobic, and its melting point is preferably in the range from room temperature to about 200 ° C. In particular, the melting point of the heat-meltable composition 2 can be adjusted quite freely by appropriately combining substances having different components. The temperature may be appropriately selected based on the normal temperature of the environment to be sensed, the expected temperature at the time of abnormality, and the like.

Examples of the heat-fusible composition 2 include a fatty acid compound and other compounds. Examples of the fatty acid-based compound include a fatty acid and a fatty acid derivative.

The fatty acid is preferably a hydrophobic fatty acid, and may be any of linear, branched and cyclic fatty acids. These fatty acids may be saturated or unsaturated. Unsaturated fatty acids are
It may be a triple bond such as acetylenic acid or a double bond. The number of unsaturated groups in the molecule may be one, for example, a monoene, or more than one, for example, a di-, tri-, or tetra-ene.

The fatty acid derivatives include fatty acid chlorides, fatty acid anhydrides, fatty acid esters and the like. Examples of the fatty acid anhydride include a single acid anhydride and a mixed acid anhydride. Specific examples include acetic anhydride.

The fatty acid ester may be an ester of a hydroxyl compound and a fatty acid or an ester of a thiol and a fatty acid. In that case, the number of hydroxyl groups of the hydroxyl compound may be one, or two or more. In the case of an ester of a compound having one hydroxyl group and a fatty acid, examples thereof include an ester with a linear monohydric alcohol and an ester with a cyclic monovalent hydroxyl compound. In the case of an ester with a chain alcohol, for example, an ester of a fatty acid with methanol, ethanol and the like can be mentioned. Monohydric alcohols are not limited to saturated alcohols.
For example, allyl ester, propenyl ester and the like can be mentioned. Examples of the ester with a cyclic hydroxyl compound include esters with cyclohexanol, phenol, α-furfuryl alcohol, and the like. The cyclic hydroxyl compound may be an assembled ring hydroxyl compound. For example, cholesteric esters and the like can be mentioned. Examples of the ester with a compound having two or more hydroxyl groups include a fatty acid ester with a polyol such as α, ω-diol, mono-, di-, or
Tri-glycerides and the like can also be mentioned.

Examples of the fatty acid which forms an ester with a hydroxyl compound include lower vinyl acid. Specific examples include acrylic acid and methacrylic acid. In this case, the fatty acid may be a monobasic acid or a dibasic acid. The dibasic acid may be a saturated dibasic acid or an unsaturated dibasic acid. In the case of a dibasic acid ester, it may be either a monoester ester-bound to only one of the two carboxyl groups or a diester ester-bound to both. Specific examples of the fatty acid ester include such a monoethyl ester and a dibasic acid diethyl ester. For example, there is dialkylmalonic acid diethyl ester.

The fatty acid constituting the ester with the hydroxyl compound may be a derivative fatty acid having a substituent other than a hydrocarbon group bonded to its carbon chain. Examples of such fatty acids include oxyfatty acids, halogenated fatty acids, cyano fatty acids, keto acids, fatty acids having a carboxyl group bonded in the middle of the main chain, fatty acids having a silicon-based substituent, and sulfur crosslinked. Fatty acids.

The main chain of the oxy fatty acid may be saturated or unsaturated. Examples include natural polyoxysaturated acids, 2-oxysaturated fatty acids, 3, ω-dioxysaturated acids, 2,3-dioxysaturated acids, ricinoleic acid, and other oxyalkenoic acids. Such an oxy fatty acid may be substituted by an alkyl group side chain group. An example is 3,3-dialkyl-3-oxypropionic acid. The configuration of the hydroxyl group does not matter. D or L-2-methyl-2-oxysaturated acid. Other methyl-substituted oxyacids are also included.

Examples of the halogenated fatty acid include 2-fluoro acid, ω-chloro saturated acid, and 2, ω-dibromo saturated acid. These may be further substituted by an alkyl side chain group or the like. Examples of the cyano fatty acid include 2-cyano-3,3-dialkyl acid and 2-cyano-α, β-unsaturated-3-alkyl acid. As keto acid,
Examples include 2-keto-saturated acids, 3-keto-saturated acids, 2,4-diketo-saturated acids, 4-keto-2-alkenoic acids, and other long-chain keto acids. Such keto acids may be dicarboxylic acids. For example, monoketodicarboxylic acid can be mentioned. Fatty acids having a carboxyl group bonded in the middle of the main chain include, for example, α-alkyl-substituted carboxylic acids. Examples of the fatty acid substituted with a silicon-based substituent include 12-silyl ricinoleic acid. Examples of the sulfur-crosslinked fatty acid include epithio saturated fatty acids. If the basis is stearic acid, various substitutions are mentioned. For example, oxystearic acid and ketostearic acid can be mentioned. Stearic acid also includes polysubstitutes such as mixed substitutes. For example, nitrile
And threo-9,10-dioxystearic acid, nitrilo- and threo-dioxystearic acid.

Examples of the ester comprising the above-mentioned derivative fatty acid and a hydroxyl compound include, for example, 12-
Examples thereof include alkynyl silyl ricinoleate, sodium salt of α-sulfon stearic acid ester, ω-alkylthio and ω-alkyl sulfonyl carboxylate.

Examples of the heat-fusible composition include alcohols, carbonyl compounds, nitrogen compounds, other hydrocarbon compounds, and sulfur-containing compounds, in addition to the above fatty acid compounds.

The alcohol may be a saturated alcohol or an unsaturated alcohol. The unsaturated alcohols include β, γ-unsaturated primary alcohols, terminally unsaturated alcohols, and other unsaturated long-chain alcohols. The alcohols may be polyhydric alcohols. For example, glycols, glycerin and the like can be mentioned. Examples of the glycols include α, ω-glycol, alkanol-1,2 and other 1,2-diols. Glycerin may be substituted glycerin therein. The alcohol may be a chain alcohol or a cyclic alcohol. Examples of the cyclic alcohol include a cyclic glycol. These alcohols, of course,
An ester or ether may be formed. For example, di-n-alkynyl ether having a triple bond, 2
There are long chain vinyl ethers with heavy bonds.

As the carbonyl compound, specifically,
There are aldehydes, ketones, and acyloins. Ketene such as aldehyde trimer is also included.

The number of aldehyde groups of the aldehyde is not limited to one. For example, dialdehyde may be used. The main chain may be saturated or unsaturated. It may be bonded to another compound via an aldehyde group. For example, α, β
-Unsaturated aldehydes, α, β-unsaturated aldehyde derivatives, saturated aldehyde derivatives, α, β-aldehyde derivatives and the like. Examples of ketones include dialkyl ketones having two chain groups, such as methyl alkyl ketone. A phenylalkyl ketone having a chain group and an aromatic group is also included. A macrocyclic ketone in which an oxy group is bonded to a part of a cyclic body is also included. Ketones are not limited to saturated ketones. Also included are unsaturated ketones. For example, α, β-unsaturated ketones and cyclic unsaturated ketones are also included. For example, an α-diketone having a plurality of carbonyl groups is also included. The acyloin also includes long-chain acyloin, cyclic acyloin, and the like. Ketenes include koketen.

Examples of the nitrogen-containing compound include amines, amides, nitriles and the like. Amines include primary amines, secondary amines, and tertiary amines. These may be aliphatic amines or aromatic amines. Examples of the amide include an aliphatic amide such as an N-methyl aliphatic amide, and a carbamic acid ester. Nitriles include, for example, aliphatic nitriles.

Other hydrocarbon compounds include, for example, n-alkane, n-alkene-1, n-alkylbenzene, n-alkylnaphthalene and the like. These hydrocarbon compounds may be substituted with halogens. For example, 1-fluoroalkane, 1-chloroalkane, 1-
Bromoalkane, 1-iodoalkane and the like can be mentioned.

Examples of the sulfur-containing compound include thiol and sulfide. For example, n-alkanethiol-1 and the like can be mentioned.

These heat-fusible compositions may be used alone or in combination as long as the object of the present application is not impaired.

In the heat-sensitive odor generating microcapsules, an odorous substance is used in addition to these heat-fusible compositions.
The odorous substance may be any compound that emits an odor by volatilization, and the type thereof is not particularly limited as long as it is insoluble in water. Among them, a substance that does not interfere with various devices and does not affect the human body is preferable. In such a case, a so-called fragrance that gives a pleasant feeling to a person can be used. In the case of a fragrance, for example, it may be a natural fragrance or a synthetic fragrance.

As the natural flavor, both animal flavor and vegetable flavor can be used. Examples of the synthetic fragrance include a hydroxyl compound and a derivative thereof, a carbonyl compound, an ether, a lactone, an ester, a heterocyclic compound, a synthetic musk, and the like. Among them, examples of the hydroxyl compound include alcohols and phenols. As carbonyl compounds, aldehydes,
Ketones are exemplified. Specific examples include aliphatic aldehyde, aromatic aldehyde, aliphatic ketone, aromatic ketone, alicyclic ketone, and macrocyclic ketone. Examples of the ethers include acetal, cyclic ether, alicyclic ether and the like. Lactones include alicyclic lactones and macrocyclic lactones. Esters include aliphatic acid esters and aromatic acid esters. As the synthetic fragrance, a terpene-based compound may also be used. As terpene compounds, terpene hydrocarbons,
Terpene-based alcohols, terpene-based aldehydes, terpene-based ketones and the like can be mentioned. Perfumes are usually mostly oily, hydrophobic mixed solutions. These fragrances may be used alone or in combination.

The odorous substance is not limited to a fragrance, but a combination of a specific type of odor and a specific melting point is preferably determined in advance. When the heat-fusible composition and the odorous substance are selected in accordance with the combination, it is possible to obtain a heat-sensitive odor-generating microcapsule capable of accurately confirming the temperature state based on the difference in odor.

The method for coating the kneaded product of the odorous substance 1 and the hot-melt composition 2 with the shell 3 is not particularly limited. A conventionally known microcapsule manufacturing method can be appropriately selected and used.

For example, an interfacial polymerization method can be used. The polymerizable compound undergoes interfacial polymerization on the surface of the core material, and the surface of the core material is coated with the polymer. in situ
A polymerization method may be used. One monomer is polymerized directly on the particle surface. An in-liquid curing coating method may be used. The core material is emulsified in a solution of the matrix, and the resulting emulsion is further emulsified with another liquid to cure the droplets and form a shell.
A phase separation method may be used. The core substance is suspended in a solution in which the solute forming the shell is dissolved, and a substance that is poorly soluble in the solute is added.
Powder bed method may be used. The core material is rolled in a pot-like container containing the powder, and the powder adheres to the surface. An air suspension coating method may be used. The particles are suspended and coated in an updraft. A vacuum deposition coating method may be used. The core material is exposed to a stream of metal vapor coming out of the furnace, and the metal vapor is cooled on the surface of the core material. The spray drying method may be used. The core material is suspended in a solution of the solute forming the shell and then spray dried.

In addition, a melting dispersion cooling method may be used. An in-liquid drying method may be used. The inclusion exchange method may be used. An inorganic wall capsule may be used. An electrostatic merging method may be used.

However, an interfacial polymerization method in which a porous shell 3 is obtained is more preferable. If the shell 3 is porous, the fragrance will be
The fragrance is easily released while being wrapped in the scent.

When the heat-sensitive odor-generating microcapsules receive heat of a predetermined temperature or more, the heat-fusible composition melts and changes in the direction of the arrow in FIG. Volatilizes from the gap 4 of the shell 3 formed by the above.

[0036]

When the temperature exceeds the melting temperature, the hot-melt composition 2 starts to melt. If the odorous substance 1 is kneaded in advance in such a hot-melt composition 2, the hot-melt composition 2 starts melting when the environment exceeds the specific temperature, and the shell 3
, The odorous substance 1 evaporates continuously. If the composition of the heat-fusible composition 2 is changed, it is easy to change the melting temperature.

The shell 3 effectively suppresses volatilization of the odorous substance 1 until the hot-melt composition 2 is melted, and the odorous substance 1
To store for a long time. Even if the hot-melt composition 2 is melted, the odorous substance 1 is prevented from volatilizing in a short time.

[0038]

According to the microcapsules of the present invention, the heat-sensitive temperature can be selected quite freely. Moreover, even if the sheet is applied to a sheet or the like, and the sheet is attached, or the powder is sprayed as it is, the temperature condition of a narrow local portion can be easily detected relatively early.

The emission time of the odor signal is relatively long. Even if the observer is made to patrol without being stationed, or simply installing an odor sensor, it is possible to detect an abnormality in a device that may overheat, such as a generator, a motor, an air conditioner, or a heater.

[0040]

Embodiments of the present invention will be described below.

Example 1 The filling composition shown in Table 1 was dispersed and emulsified in a dispersion medium having the composition shown in Table 2 for 20 minutes, and then an emulsifying hardener having the composition shown in Table 3 was added thereto for 1 hour. Heated. When a microcapsule wall was formed on the surface of the filling composition dispersed in the dispersion medium to generate a slurry, the slurry was filtered, and then the slurry was dried. As shown in the cross-sectional view of FIG. 1, the microcapsules in which the surface of the filling composition was covered with a porous shell 3 having gaps 4 were collected in a powder form.

Based on the recovered microcapsule powder, an aqueous ink having the composition shown in Table 4 was formed, and silk screen printing was performed on the sheet material to form a temperature detection odor label.

The obtained odor label was affixed to a heating test table and subjected to a temperature rise test. When the temperature reached 40 ° C., a strong green odor was continuously emitted.

Table 1 Perfume Compound (Green) 3 parts by weight (Synthetic Perfume 6E-88916 manufactured by Ogawa Perfume Co., Ltd.) Hexadecane-1-ol 30 parts by weight Epicoat 828 15 parts by weight (Epoxy resin manufactured by Yuka Shell Epoxy Co., Ltd.) Table 2 1.5% sodium alginate 500 parts by weight Euramine P-1500 5 parts by weight (urea resin manufactured by Mitsui Toatsu Chemicals, Inc.) Table 3 Epicure U 15 parts by weight Pure water 60 parts by weight Table 4 Microcapsules 5 parts by weight Gold / Silver Binder 10 parts by weight (aqueous binder manufactured by Mino Group Co., Ltd.) Pure water Appropriate Example 2 Instead of not using green as a perfume compound, floral (trade name: Ogawa Perfume Co., Ltd., 6E-8891)
Using 4), microcapsule powder was recovered in the same manner as in Example 1 except that behenic acid was used instead of using hexadecane-1-ol.

An aqueous ink having the composition shown in Table 5 was formed based on the recovered microcapsule powder, and silk screen printing was performed on the sheet material to form an odor label for temperature detection.

When the obtained odor label for temperature detection was affixed to a heating test table and subjected to a temperature rise test, the temperature became 80 ° C.
A strong floral odor was emitted continuously.

Table 5 Microcapsules 5 parts by weight Binder for gold and silver 10 parts by weight (aqueous binder manufactured by Mino Group Co., Ltd.) Pure water Appropriate Example 3 Citrus (trade name: Ogawa Perfume Co., Ltd.) instead of using green as a perfume compound Made 6E-8891
Microcapsule powder was recovered in the same manner as in Example 1 except that 5) was used and 1,10-diandiol was used instead of using hexadecane-1-ol.

Based on the recovered microcapsule powder, an aqueous ink having the composition shown in Table 6 was formed, and the sheet material was subjected to silk screen printing to form a temperature detection odor label.

The resulting odor label was affixed to a heating test table and subjected to a temperature rise test. When the temperature reached 70 ° C., a strong citrus odor was continuously emitted.

Table 6 Microcapsules 5 parts by weight Binder for gold and silver 10 parts by weight (aqueous binder manufactured by Mino Group Co., Ltd.) Pure water Appropriate From the above results, a perfume is kneaded with the thermoplastic resin, and the thermosensitive odor generating microfilled in the capsule The capsule was found to emit a persistent thermal odor at the intended temperature.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a heat-sensitive odor generating microcapsule to which the present invention is applied.

[Explanation of symbols]

1 is an odorous substance, 2 is a hot-melt composition, 3 is a shell, and 4 is a gap.

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hiromichi Mizusawa 2003-3, Kawagoe-shi, Saitama Prefecture (72) Inventor Koichi Ota 2-126-10 Miyahara-cho, Omiya-shi, Saitama (56) References JP-A-4 -222324 (JP, A) JP-A-3-296753 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G01K 11/00

Claims (2)

(57) [Claims] 1. Melting to an odorous substance and temperature to be heated
A heat-sensitive odor-generating microcapsule characterized in that a kneaded product with a hot-melt composition having a temperature is included in a shell. 2. The heat-sensitive odor-generating microcapsule according to claim 1, wherein the shell is porous.