JPH04163370A - Thermal storage fiber - Google Patents

Abstract

PURPOSE:To extremely readily obtain thermal storage fiber with a great quantity of thermal storage by forming a resin layer capable of preventing a latent thermal storage material on the surface of fiber prepared by spinning a molten mixture of the latent thermal storage material with a polyolefin from bleeding. CONSTITUTION:Thermal storage fiber is readily obtained by coating the surface of fiber prepared by spinning a molten mixture of a latent thermal storage material (referred to as P.C.M.), e.g. a crystalline long-chain hydrocarbon or crystalline fatty acid with a polyolefin (e.g. polyethylene or polypropylene) with a resin (e.g. a polycarbonate resin or polyurethane resin) and preventing the P.C.M. from bleeding. The aforementioned fiber has a great quantity of thermal storage.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a fibrous M heating body, that is, a heat storage fiber, which utilizes latent heat generated due to phase change.

[Conventional technology]

Latent heat storage material (hereinafter referred to as IP, c, Ml. p, c.

N (abbreviation for phase change material) is characterized by a constant heat radiation or heat absorption temperature and a high heat storage density. This P, C, M.

Generally, it is used by enclosing it in a container, but in recent years there has been active research into encapsulating it or dispersing it in a matrix and fixing it.

As an example of P, C, M dispersed and immobilized in a matrix, cross-linked polyethylene resin Pereso I~ is P,
A fiber that is swollen and fixed with C or M has been proposed (see JP-A-62-187782).On the other hand, as an example of a fiber with a heat storage function, "Solar α" developed by Unitika Co., Ltd. ” is there.

This fiber is a double-structured fiber that is divided into a core and a sheath, and the core of the hollow fiber that serves as the sheath is filled with zirconium carbide. Zirconium carbide has the property of absorbing visible light and reflecting infrared light. For this reason, it absorbs energy with short wavelengths of 2 μm or less, which accounts for 95% of sunlight, converts it into heat, and stores energy in the material.

[Problem to be solved by the invention]

Although fibers with two heat storage functions have the excellent properties of zirconium carbide, they have the disadvantage that their own heat storage capacity is very small. In addition, the manufacturing method (manufacturing process) is manufactured by forming a hollow fiber and filling the center with zirconium carbide powder.
It also has the disadvantage that it is complicated.

The inventors focused on the large amount of latent heat stored in P, C, and M, and searched for a method to make them into fibers.

We have found that by spinning a mixture of C, M, and polyolefin in a molten state, fibers with a large amount of heat storage can be produced in a simple process. However, the fibers obtained in this way have a large amount of latent heat storage, and maintain their strength and original shape even during the solidification-melting cycle of the contained P, C, and M. , P during this solidification ← melting cycle.

It has the problem of causing C, M, and ooze to occur. The bleeding of P, C, and M from the fibers tends to decrease as the proportion of polyolefin contained increases, but the proportion of P, C, and M decreases accordingly, and the unit volume decreases. The amount of latent heat stored per unit decreases. In addition, when heat storage fibers are used in clothing such as ski wear, P
, C, and M cause staining, so it is necessary to prevent seepage as much as possible.

Therefore, the present invention provides a heat storage fiber which has a large heat storage capacity and can be manufactured by a simple manufacturing method, and which is made of P, C, M
An object of the present invention is to provide a heat storage fiber that can prevent seepage of .

[Means to solve the problem]

In order to solve the above problems, this invention provides p, c.

The present invention provides a heat storage fiber in which a bleed-out prevention resin layer of P, C', and M is formed on the surface of the fiber obtained by spinning a molten mixture of polyolefin and polyolefin.

P, C, and M used in this invention are not particularly limited, but include, for example, crystalline long-chain hydrocarbons, crystalline fatty acids,
Examples include crystalline organic compounds such as crystalline fatty acid esters and crystalline aliphatic alcohols. The melting point and freezing point (heat storage temperature) of the heat storage material may be selected as appropriate depending on the application.

Further, examples of the polyolefin include, but are not limited to, polyethylene, polypropylene, ethylene-vinyl acetate copolymer, and the like. In the present invention, for example, these polyolefins are used without crosslinking.

The proportion of polyolefin and P, C, M is not particularly limited, but for example, 10 to 70 parts by weight of polyolefin, P
, C, M, 90 to 30 parts by weight (however, the total amount of both is 100 parts by weight). If the amount of polyolefin increases beyond this range, the amount of latent heat per unit weight may become extremely small.

Mixing of polyolefin and P, C, and M, which may not form fibers or threads if the amount is too large, is carried out, for example, by heating the two to a temperature equal to or higher than the melting point of the polyolefin and stirring. For more uniform mixing, it is desirable to use a mixing means such as a kneader or roller.

Spinning from the mixture is performed, for example, by pulling the mixture while extruding it from a nozzle in a molten state, but the method is not limited to this method. Fibers are obtained in this manner, and the thickness of the fibers is not particularly limited, as long as it is appropriately set depending on the intended use so that the fibers function as fibers. Furthermore, the cross-sectional shape is not limited to a circular shape.

The fibers obtained in this way have P, C, and M dispersed in the polyolefin matrix, and do not deform even when the temperature reaches such a temperature that P, C, and M dissolve. However, it still retains its latent heat at the melting point of the mixed l), C, and fertilizer.

In order to prevent P, C, and M from seeping out from the fibers, a dyeing-preventing resin layer is formed on the surface of the fibers by coating or the like. The coating method is not particularly limited, but a method of applying a water-soluble emulsion by dipping or the like is effective in terms of safety and workability.

Such bleed-out prevention resins are (able to form a pin-pole-free continuous coating film on the surface of the Al-spun fibers (having film-forming properties), (b) P, C, M,
When using the above as p, c.

(2) It is a polar resin with excellent wax halia properties that prevents the contained P, C, and M from seeping out, since it is a nonpolar long-chain alkyl group as the entire or main component. C) Resist the expansion and contraction of the fibers due to solidification and melting of P, C, and M due to temperature changes, as well as the impact and abrasion caused by contact between heat storage fibers or between heat storage fibers and surrounding objects when handling heat storage fibers. It is necessary to have mechanical strength.

As a method for forming such a resin film independently on each fiber, dipping as described above is useful. The spun fibers are immersed in a coating liquid of anti-bleeding resin, such as a water-soluble emulsion, so that the coating liquid adheres to the fiber surface, and the solvent is removed by evaporation to form a resin film on the fiber surface. .

These operations may be performed continuously or in a hatched manner. Incidentally, when the solvent is volatilized, it is preferably carried out at a temperature lower than the boiling point of the solvent. This makes it easier to prevent the seepage prevention resin layer from becoming pores.

The thickness of the seepage prevention resin layer is not particularly limited, but is, for example, about 0.01 to 0.21.

If it is thicker than this, there is a risk that cost 1- will be too high, and if it is thin, it may not be possible to prevent seepage.When using a liquid made by dissolving a seepage-preventing resin in an organic solvent as a coating liquid, the resin ``As mentioned above, it has excellent wax barrier properties and mechanical properties, and it also dissolves in volatile organic solvents and has excellent film forming properties.''
Must be. When using the above as P, C, M, 1].

Since C and M contain nonpolar long-chain alkyl groups as the entire or main component, polar resins are preferred from the standpoint of wax barrier properties. Examples of resins that satisfy such performance include polycarbonate resins, polyurethane resins (including urethane elastomer I-mer), methacrylic resins,
Useful materials include polyphenylene oxide, modified polyphenylene oxide F (modified PPE), polysulfone, and nitrile rubber, or a blend of two or more thereof.

The organic solvent is preferably a solvent that is a good solvent for the bleed-out prevention resin and has a boiling point of 150° C. or lower from the viewpoint of volatility. For example, tetrahydrofuran (THF)
, dichloromethane, etc., but are not limited to these.

On the other hand, when using an emulsion as the coating liquid, for example, emulsions having the following resin skeletons are preferable, but the emulsion is not limited thereto. That is, the main components of the resin skeleton are epoxy resin, urethane resin, acrylic resin, polyester resin, NBR and tolyl rubber),
It is an emulsion of vinylidene chloride resin or a modified product of each of these resins. These emulsions can be used alone, modified, or mixed. Note that the term "emulsion" as used herein includes not only emulsions in the original meaning, but also those called suspensions, disversions, terrasoxes, and the like.

The epoxy resin emulsion is an emulsion containing an epoxy resin as a main component, and examples of its synthesis are described in, for example, JP-A-53-47454 and JP-A-54-3024.9. Commercially available products include, for example, “Pateracol Exp, 38” from Dainippon Ink & Chemicals ■.
There is a modified epoxy resin aqueous dispersion available under the name 5j.

Urethane resin emulsions include, for example, prepolymers obtained from polyethers, polyesters, and diisocyanates, which are optionally emulsified using a surfactant and then chain-extended with a bifunctional compound such as 1,2-cyamine. Resin, blocked isocyanate, and sardine ana-1
There are emulsions whose main component is a thermosetting resin, which is a mixture of resins having functional groups (e.g., hydroxyl groups) that are reactive with ~ groups.
No. 14727, Japanese Patent Application Laid-open No. 159858/1983,
It is described in Japanese Patent Application Laid-open No. 132051/1983. Commercially available products include, for example, water-dispersed urethane produced by Dainippon Ink and Chemicals under the name "Bondei Soxilise" and ionomer type water-based urethane produced under the name "Hytran Series".

As the polyester resin emulsion, for example, an aromatic polyester ionomer aqueous dispersion available from Dainippon Ink & Chemicals under the name "Finetex ES series" is used.

As the acrylic emulsion, for example, various copolymer resin emulsions commercially available from Dainippon Ink and Chemicals under the trade name "Boncoat" can be used.

The NBR emulsion has acrylonitrile-butadiene as its main component, and for example, carboxylated NBR commercially available from Dainippon Ink & Chemicals (2) under the trade name "Luckstar" is used.

As the vinylidene chloride resin emulsion, for example, a vinylidene chloride resin emulsion commercially available from Kureha Chemical Industry Co., Ltd. under the trade name ``1 Crehalon Latex'' is used.

These emulsions have excellent wax barrier properties because the main component resin is polar. Among the various emulsions mentioned above, it is preferable to select one that is formed into a film at a drying temperature of 50 to 80°C and has excellent mechanical properties. Even when an emulsion is used as the coating liquid, the coating process is performed at a temperature lower than the boiling point of the emulsion solvent (for example, the boiling point of water is l
Preferably, the temperature is lower than OO°C. Furthermore, the emulsion used here is in the form of particles (not limited to solid particles) in which the anti-bleeding resin is independently liberated in the solvent. For this reason, while the solvent is evaporating (drying),
The loose particles fuse together to form a film, forming a seepage prevention resin layer. At this time, if the drying speed is fast, the film may dry without being fully fused and a film with holes may be formed. Therefore, when an emulsion is used as the coating liquid, it is more preferable to perform the coating treatment at a temperature lower than the boiling point of the solvent of the emulsion and at an air drying temperature. In this way, a seepage-preventing resin film with fewer pores can be produced. The natural drying temperature is, for example, the temperature at which drying is performed without heating, and is 15
The temperature is around ~25°C.

In addition, commercially available emulsions generally have poor film-forming properties (film-forming properties).
Even if the resin is of the same type, the dried film may be sticky depending on the product number. When such an emulsion is used in the present invention, when the heat storage fibers are wound up, the fibers may stick together, causing the resin layer to peel off from the fibers, or the wound heat storage fibers may not be able to be pulled out. In order to prevent this from happening, it is preferable to select a commercially available emulsion product with a product number that does not give a dry film tackiness. Alternatively, it is preferred to mix a non-tacky part number emulsion with an emulsion that provides a tacky dry film to reduce tackiness. Needless to say, when mixing, it is preferable to select a combination that provides a stable mixed emulsion.

The bleed-out prevention resin is preferably one that does not impair the flexibility of the fiber.

[For production]

Heat storage fibers produced by mixing P, C, and M, which have a large amount of latent heat storage, with polyolefin and spinning them do not deform even when the temperature reaches the melting point of the mixed P, C, and M. Moreover, it maintains the latent heat at its melting point.

In addition, since a resin layer to prevent P, C, and M from seeping out is formed on the surface, P, C, and M can be prevented from seeping out during the solidification ← melting cycle of P, C, and M. Prevented.

The manufacturing process is also simple, consisting of mixing P, C, M and polyolefin, spinning, and forming a resin layer.

Therefore, the heat storage fiber of the present invention has a large amount of heat storage, and the manufacturing process thereof is also simple.

〔Example〕

FIG. 1 schematically represents one example of the fiber used for the heat storage fiber of the present invention. This fiber 1 is obtained by spinning a molten mixture of P, C, M, and polyolefin. Second
The figure schematically represents one embodiment of the heat storage fiber of the present invention.

This heat storage fiber 10 has a core of fiber 1 shown in FIG.
], C, M, the resin layer 2 is used as a sheath to prevent seepage. The resin layer 2 is formed by coating the surface of the fiber 1 with the coating liquid and removing the solvent to form a film. In Fig. 2, for convenience of expression, the resin layer 2 is
The fiber 1 is drawn to be exposed except for a portion of the fiber 1.

In Figure 1.2, for convenience of expression, the width of the t seedlings is exaggerated.

Note that this invention is not limited to what is shown in FIGS. 1 and 2.

Specific examples and comparative examples of the present invention are shown below, but the present invention is not limited to the following examples. In addition, 1%
"and 1 part" refer to "1% by weight" and "part by weight", respectively.

Example 1 - Paraffin (melting point 5
2°C), and high-density polyethylene "Shorex 86006M" manufactured by Showa Denko @ (melting point 128°C) was used as the polyolefin.

70 parts of the paraffin and 30 parts of the polyethylene were placed in a beaker and mixed while heating to 150°C in an oil bath. Next, this mixture was kneaded for about 30 minutes using a Ni-Goo to disperse it uniformly, and then put into a glass syringe in a molten state, and while extruding the mixture,
It was spun by pulling from the end and cooled.

The diameter of the produced fibers was approximately 0.5 mm.

FIG. 1 is a simple perspective view of a fiber 1 produced by the above method.

A resin layer 2 was formed on the surface of this fiber 1 by coating to obtain an M thermal fiber 10. FIG. 2 is a simple perspective view of the heat storage fiber 10 produced by the above method.

The coating was performed by dipping the fiber 1 in a blend solution of water-soluble epoxy resin emulsion EXP-385 and water-soluble urethane resin emulsion EXP-382 manufactured by Dainippon Ink & Chemicals @. A resin layer 2 was formed by drying and removing the solvent of the blend solution. The diameter of the entire heat storage fiber including the thickness of resin layer 2 is 0.
．． 6 I was drunk. The length was set at 2 m, but it could be made as long as desired.

Fiber 1 and heat storage fiber IO produced in Example 1 above were mixed at 30%
A comparison was made by subjecting the sample to cold and heating cycles of 200 times at ←→70°C, measuring the weight before and after that, and calculating the rate of seepage. The results are shown in Table 1. However, the bleeding rate was calculated using the following formula.

Table 1 As shown in Table 1, the heat storage fiber of the present invention contains P, C,
There was no seepage of M.

〔Effect of the invention〕

According to this invention, it is possible to provide a heat storage fiber that has a large amount of heat storage, has little oozing of P, C, and M, and can be manufactured by a simple process.

[Brief explanation of drawings]

FIG. 1 is a perspective view schematically showing an example of a fiber used in the heat storage fiber of the present invention, and FIG. 2 is a perspective view schematically showing an example of the fiber used in the heat storage fiber of the present invention.
FIG. 2 is a perspective view schematically showing an example. 1...Fiber 2...Resin layer 1o...Heat storage fiber agent Patent attorney Takehiko Matsumoto

Claims (1)

[Claims] 1. A heat storage fiber obtained by spinning a molten mixture of a latent heat storage material and a polyolefin, in which a resin layer to prevent seepage of the latent heat storage material is formed on the surface of the fiber.