JP2511022B2 - Hydrophilic heat-fusible fibrous material - Google Patents

Description

TECHNICAL FIELD The present invention relates to a hydrophilic heat-fusible fibrous material, and more specifically, to other fibrous materials such as natural pulp, natural fiber and glass fiber. It is possible to partially bond other fibrous materials by mixing and shaping the mixture into a shape such as a sheet, and then subjecting it to high temperature heat treatment to melt at least a portion thereof, and it is excellent even after heat fusion. The present invention relates to a hydrophilic heat-bonding fibrous material made of a thermoplastic resin having wettability and hydrophilicity.

(Prior Art and Problems Thereof) A pulp-like material produced from a thermoplastic resin as a raw material, a so-called synthetic pulp, is known. For example, Japanese Patent Publication Sho 52-470
In Japanese Patent Publication No. 49, a high-temperature, high-pressure dispersion liquid consisting of a hydrocarbon solvent of polyolefin and water is discharged into a decompression region to carry out flash spinning to obtain a fibrous substance of polyolefin dispersed in water, which is beaten. Alternatively, a method for producing a polyolefin pulp-like substance by refining is described.

Since such synthetic pulp is hydrophobic and does not have water absorbability, surface treatment is performed by adding polyvinyl alcohol or a nonionic surfactant to the synthetic pulp in order to impart wettability and water absorbability to the synthetic pulp. Is known to do.

However, for example, a surface-treated polyolefin synthetic pulp with polyvinyl alcohol exhibits dispersibility when immersed in water, but exhibits water repellency in a dry state, does not wet, and does not absorb water.

Further, the synthetic pulp surface-treated with a nonionic surfactant shows a wettability when a surfactant having a large HLB is used, but has a large foaming upon wetting, and a surfactant having a small HLB is used. It has the drawback of lacking wettability.

Further, the synthetic pulp surface-treated with such a surfactant is mixed with other fibrous substances such as natural pulp, natural fiber, and glass fiber, and the synthetic pulp is partially melted to melt the other fibrous substances. When it is subjected to a heat treatment at a high temperature such that it adheres, there is a drawback that the surfactant adhering to the synthetic pulp is oxidized and decomposed, and the hydrophilicity of the synthetic pulp applied by the surface treatment with the surfactant is lost. . In order to solve this drawback, even if an unsurface-treated synthetic pulp is mixed with other fibrous materials and the mixture obtained by fusing this mixture with synthetic pulp is subjected to surface treatment with a surfactant, It is difficult to treat only pulp effectively.

Such a problem exists not only in the synthetic pulp as described above but also in all the various fibrous materials of the thermoplastic resin.

(Object of the Invention) An object of the present invention is to provide a thermoplastic resin fibrous material having excellent hydrophilicity and wettability even in a dry state.

The present invention is further mixed with other fibrous substances such as natural pulp, natural fibers, glass fibers, etc., and the mixture is subjected to heat treatment at a high temperature to melt at least a part thereof to form other fibrous substances. It is an object of the present invention to provide a hydrophilic heat-fusible fibrous material which is excellent in hydrophilicity and wettability after being adhered, and which is hardly deteriorated.

(Structure of the Invention) The present invention provides one or more heat-resistant stabilizers selected from the group consisting of phenolic antioxidants and phosphorous acid antioxidants on the surface of a fibrous material of a thermoplastic resin. And a polypropylene glycol having a molecular weight of 200 to 10,000 adhered thereto, which is a hydrophilic heat-fusible fibrous material.

(Preferred embodiment of the invention) The fibrous material of the thermoplastic resin in the present invention is a fiber obtained by melt spinning a thermoplastic resin, a fibrous material obtained by flash spinning a solution or emulsion of a thermoplastic resin, or a pulp. A fibrous material, a fibrous material obtained by weaving a stretched film of a thermoplastic resin, a fiber obtained by composite melt spinning of two or more thermoplastic resins having different melting points, or the like.

As the thermoplastic resin, polyolefin, polyester, polyacrylonitrile and other hydrophobic thermoplastic resins can be exemplified, but in particular, polyethylene, polypropylene, ethylene-propylene copolymer,
A polyolefin obtained from one or more kinds of ethylene and α-olefin such as ethylene-1-butene copolymer and ethylene-4-methyl-1-pentene copolymer has a remarkable hydrophilic property. It is preferable because it can be improved.

Methods for producing fibrous materials from thermoplastic resins are known per se, and fibrous materials of thermoplastic resins produced by various methods can be used in the present invention, but in particular, a solution or emulsion of polyolefin. Fibers or pulp-like substances of polyolefins obtained by flash-spinning are preferred. This fiber or pulp-like substance preferably has a specific surface area of 0.1 m ² / g or more.

Further, a substance obtained by adding polyvinyl alcohol to the above-mentioned polyolefin fiber or pulp-like substance by treatment with polyvinyl alcohol is more preferable as the above-mentioned fibrous substance. The content of polyvinyl alcohol is preferably 0.01 to 10% by weight with respect to the above fiber or pulp-like substance.

In the present invention, on the surface of the fibrous material of the thermoplastic resin,
One or more heat resistant stabilizers selected from the group consisting of phenolic antioxidants and phosphorous acid antioxidants are attached.

The phenolic antioxidant is represented by the following formula (I) In the formula, R is a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, and n is an integer of 1 to 3, and is preferably a styrenated phenol.
Particularly preferred phenolic antioxidants are distyrylphenol and distyrylcresol.

Further, as the phosphorous acid-based antioxidant, the following formula (I
I) P (OR ') ₃ (II) wherein R'is an alkyl group having 10 to 20 carbon atoms or a compound of formula (III) (Wherein Z is a hydrogen atom or an alkyl group having 1 to 20 carbon atoms), which is an aryl group represented by: and is preferably a trialkyl- or triaryl phosphite. Particularly preferred phosphite antioxidants are tridecyl phosphite, trioctadecyl phosphite, tristearyl phosphite, triphenyl phosphite and tris (nonylphenyl) phosphite.

The above heat stabilizers may be used alone or in combination of two or more. In particular, by using the above-mentioned phenol-based antioxidant and phosphorous acid-based antioxidant in combination, the hydrophilicity of the fibrous material of the present invention even after heat fusion, the effect that the wettability is hardly reduced. It can be further improved.

The amount of the heat stabilizer attached to the fibrous material is 0.001 to 10% by weight, particularly 0.01 to 5.0% by weight, based on the fibrous material.
It is preferred that When the adhesion amount of the heat resistance stabilizer is less than the above range, the effect of preventing thermal deterioration of the polypropylene glycol and the fibrous material of the thermoplastic resin is insufficient,
When the fibrous material of the present invention is heat-sealed, its hydrophilicity decreases, and when the amount of adhesion is more than the above range, the effect of imparting hydrophilicity of polypropylene glycol is hindered.

In the present invention, the polypropylene glycol attached to the fibrous material of the thermoplastic resin is obtained by polymerizing propylene oxide by a conventional method and has a molecular weight of 200 to 10,000, preferably 400 to 6,000.

Here, the molecular weight of polypropylene glycol (PPG) is a value determined by gel permeation chromatography (GPC), and is calculated from the comparison of the molecular weights of standard PPG of known molecular weight and sample PPG. If the molecular weight of polypropylene glycol is out of the above range and is too small, the adhesion to the fibrous material is reduced, and if it is too large, the effect of imparting hydrophilicity is reduced.

The amount of the polypropylene glycol attached to the fibrous material is 0.01 to 10% by weight based on the fibrous material, and particularly 0.05 to 5
It is preferably in the weight%. If it is less than the above range, the effect of improving the hydrophilicity of the fibrous material is hardly exhibited, and if it is more than the above range, the performance of the fibrous material as the heat-sealing property is deteriorated.

As a method of adhering polypropylene glycol to a fibrous material together with a heat resistance stabilizer, a mixture of polypropylene glycol and a heat resistance stabilizer, or a method of spraying an aqueous solution or an aqueous dispersion thereof onto the fibrous material, polypropylene glycol and a heat resistance stabilizer. A method of immersing the fibrous material in a mixture or an aqueous solution or an aqueous dispersion thereof, a method of adding a mixture of polypropylene glycol and a heat stabilizer or an aqueous solution or an aqueous dispersion thereof to an aqueous slurry of the fibrous material, and the like. Can also be adopted. The above methods and are preferable because the mixture of polypropylene and the heat-resistant stabilizer is well adsorbed and adhered to the surface of the fibrous material during stirring and mixing in an aqueous solution or an aqueous dispersion, and the above methods are particularly preferable. It is preferable to carry out uniform adsorption and adhesion treatment with independent desired amounts. The temperature for adsorbing and adhering the mixture of polypropylene glycol and the heat-resistant stabilizer to the fibrous substance is generally 0 to 90 ° C., and it is convenient to carry out at room temperature.

As described above, adsorption of the mixture of polypropylene glycol and the heat-resistant stabilizer to the fibrous material, after the adhesion treatment, the fibrous material is dehydrated by a usual method and optionally dried to obtain the hydrophilic property of the present invention. Heat-fusible fibrous material.

(Effects and Uses of the Invention) The hydrophilic heat-fusible fibrous material of the present invention has excellent hydrophilicity and wettability even in a dry state.

Further, the fibrous material of the present invention includes organic fibers such as natural pulp, natural fibers, semi-synthetic fibers, synthetic fibers having a melting point higher than that of the fibrous material of the present invention, and other inorganic fibers such as glass fibers. Mixing with the fibrous material, forming an aggregate of any shape such as a sheet-like material from the mixture, and then melting the aggregate at a high temperature such that at least a part of the fibrous material of the present invention is melted. It is used for making a hydrophilic article by adhering or bonding the other fibrous material by melting at least a part of the fibrous material of the present invention by applying. The other mixing ratio of the fibrous material of the present invention to another fibrous material is preferably such that the fibrous material of the present invention is contained in an amount of 5 to 80% by weight in the mixture of both.

The fibrous material of the present invention has an excellent feature that its hydrophilicity and wettability are hardly deteriorated even after being subjected to heat treatment at a high temperature such that it is heat-melted as described above.

It is known that polypropylene glycol having a molecular weight of 200 to 10,000 is used as a surfactant, but a synthetic pulp to which polyethylene glycol, which is a similar compound similarly known as a surfactant, is attached,
In the present invention, polypropylene glycol is attached to the fibrous material of the thermoplastic resin to impart hydrophilicity because it exhibits almost no parent-child aqueous chemistry. It is apparent that it is not due to the special combination effect of the fibrous material of the thermoplastic resin and the polypropylene glycol having the specific molecular weight.

Further, a fibrous material of a thermoplastic resin to which only polypropylene glycol is adhered has its hydrophilicity lowered when subjected to a heat treatment at a high temperature such that it melts. Since the specific heat-resistant stabilizer and polypropylene glycol are attached to the surface of the product, it is subjected to heat treatment at a high temperature (about 180 to 300 ° C) that heat-bonds the fibrous material at least partially. Even after that, it is possible to exert a remarkably excellent effect that the effect of imparting hydrophilicity to the fibrous material by polypropylene glycol is hardly reduced.

The one obtained by partially adhering the other fibrous material by mixing the fibrous material of the present invention with the other fibrous material and subjecting it to a heat treatment at a high temperature to melt at least a part is It can be used for applications where hydrophilic fibrous materials have been conventionally used, for example, non-woven fabric materials, water-based liquid absorbent materials, oil absorbent materials, insulating materials and other applications such as water permeable filters and water absorbent mats.

Example 1 Pulp-like material produced from polyethylene (polyvinyl alcohol content 1.1% by weight, Mitsui Petrochemical Industry Co., Ltd.)
(Registered trademark SWP.E400, 100 g) is added to 10 l of water, and polypropylene glycol (Wako Pure Chemical Industries, Ltd., PPG-2000) 1.0 g having a molecular weight of 2000 and mono (or di or tri) styryl phenol (large Uchi Shinko Chemical Industry Co., Ltd.
The composition to which 0.2 g of trade name Nocrac SP) was added was vigorously stirred in a mixer at room temperature for 30 seconds to adhere polypropylene glycol and Nocrac SP to the pulp.

The composition after stirring was dehydrated by a 25 × 25 cm square sheet machine and further dehydrated by a hand press to prepare a sheet having a moisture content of 50% by weight and an absolute dry basis weight of 1500 g / m ² . . 90% or more of the polypropylene glycol and Nocrac SP used were adhered to this sheet.

Regarding the fibrous material (A) obtained as described above,
The hydrophilicity was evaluated by the following evaluation method-1 and evaluation method-2.

Evaluation method-1 (Preparation of test material) Micro glass fiber (Johns-Manville, Code10)
6) A mixture of 78 parts by weight and 22 parts by weight of the fibrous material (A) was added to water to adjust the slurry concentration of the mixture to 5 g / l, which was then added to a JIS type pulper (volume 2 l). And stirred for 30 seconds to prepare a water slurry.

The obtained water slurry was dehydrated by a 25 × 25 cm square sheet machine and dried at room temperature to prepare a test sheet having a basis weight of 100 g / m ² .

The hydrophilicity of the test sheet was measured in a hot air circulation dryer at a temperature shown in Table 1 for 5 minutes. The results are shown in Table 1. In addition, in Table 1,
The hydrophilicity of the sheet heat-treated at 140 ° C, which is an insufficient temperature for heat fusion, is also shown.

(Hydrophilicity test method) 1 cm ³ of water at 20 ± 2 ° C. is dropped on the test sheet, and the time required until the water is completely absorbed by the sheet is measured.

Evaluation method-2 (Preparation of test material) Wood pulp (NBSP, Sanyo Kokusaku Pulp Co., Ltd.) was used in place of the micro glass fiber, and the slurry concentration of the mixture was adjusted.
A test sheet having a basis weight of 300 g / m ² was prepared in the same manner as in Evaluation method-1 except that the amount was changed to 10 g / l.

This test sheet was heat treated in the same manner as in Evaluation Method-1, and the hydrophilicity of the obtained sheet was measured. The results are shown in Table 2. In Table 2, the hydrophilicity of the sheet heat-treated at 140 ° C. is also shown.

(Hydrophilicity test method) Same as Evaluation method-1.

Example 2 Styrylphenol was replaced with tristearyl phosphite (C
_A test sheet was prepared in the same manner as in Example 1 except that ₁₈ H ₃₇ O) ₃ P was used. The results of Evaluation Method-1 and Evaluation Method-2 for this test sheet are shown in Table 1 and Table 2, respectively.

Comparative Examples 1 to 4 As the hydrophilicity-imparting treatment agent, fibrous substances were prepared in the same manner as in Example 1 except that the substances shown in Table 3 were used instead of the mixture of polypropylene glycol and monostyrylphenol. .

Evaluation method in Example 1 for these fibrous materials −
The hydrophilicity was evaluated according to 1 and Evaluation Method-2. Evaluation method-
Table 1 shows the results of No. 1 and No. 2 of the evaluation method-2.
Shown in the table.

Example 3 The amount of Nocrac SP (heat-resistant stabilizer) added was 0.01 g (Sample 1), 0.02 g (Sample 2), 0.05 g (Sample 3) and 0.1 g.
A fibrous material to which polypropylene glycol and a heat-resistant stabilizer were adhered was produced in the same manner as in Example 1 except that each was changed to (Sample 4).

Evaluation method in Example 1 for each of these fibrous materials
The hydrophilicity was measured according to 1. Table 4 shows the results.

Claims (8)

(57) [Claims] 1. A thermoplastic resin fibrous material having one or more heat-resistant stabilizers selected from the group consisting of phenolic antioxidants and phosphorous acid antioxidants and a molecular weight of 200 on the surface thereof. A hydrophilic heat-fusible fibrous material characterized by having 10,000 to 10,000 polypropylene glycol attached thereto. 2. The phenolic antioxidant is represented by the following formula (I): In the formula, R is a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, and n is an integer of 1 to 3, wherein the styrenated phenol has the formula: The described fibrous material. 3. The phosphorous acid-based antioxidant is represented by the following formula (II) P (OR ′) ₃ (II), wherein R ′ is an alkyl group having 10 to 20 carbon atoms or a compound represented by the formula (III ) (Wherein Z is a hydrogen atom or an alkyl group having 1 to 20 carbon atoms), which is an aryl group, and is a trialkyl- or triaryl phosphite. The fibrous material according to item 1. 4. The fibrous material according to claim 1, wherein the amount of the heat stabilizer attached is 0.001 to 10% by weight based on the fibrous material. 5. The amount of the polypropylene glycol attached is
The fibrous material according to claim 1, which is 0.01 to 10% by weight based on the fibrous material. 6. The fiber according to claim 1, wherein the fibrous material of the thermoplastic resin is a polyolefin fiber or a pulp-like substance obtained by spinning a solution or emulsion of a polyolefin. Thing. 7. The fibrous material according to claim 6, wherein the fiber or pulp-like substance of the polyolefin is a substance containing polyvinyl alcohol therein. 8. The content of polyvinyl alcohol in the fiber or pulp-like substance of the polyolefin is 0.01 to 10% by weight based on the fiber or pulp-like substance of the polyolefin.
The fibrous material according to claim 7, characterized in that