JPH0364575A - Nonwoven polyolefin sheet - Google Patents

Abstract

PURPOSE:To obtain a nonwoven sheet having excellent waterproofing and antistatic properties by applying a treating agent containing a specific phosphate compound to a nonwoven polyolefin sheet. CONSTITUTION:A three-dimensional network fiber structure produced e.g. by flush spinning of a polyolefin polymer is pressed to obtain a nonwoven sheet composed of fine fibers having complicate crosssection. The nonwoven sheet is imparted with antistaticity without lowering the waterproofing property by applying >=0.01wt.% of a treating liquid containing the compounds of formula I and formula II (M is lithium, sodium, potassium, H or ammonium: R is 6-7C alkyl) at a molar ratio (I/ II) of >=2. An excellent effect can be attained with a small amount of additive without emitting odor by the use of the above treating agent.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a sheet that is waterproof and has excellent antistatic properties. More details: Packaging materials, protective clothing, windbreakers - 1 Excellent waterproofing and anti-static properties that can be used favorably as sheets for raincoats, bedding, etc. [Conventional technology] Polyolefin nonwoven sheets conventionally used for the above-mentioned purposes Various types of sheets are known. For example, a non-woven sheet obtained by spinning fibers based on a conventional synthetic fiber spinning method and pulling them at high speed using a high-speed air stream, a non-woven sheet obtained by a melt-blowing method, and a polyolefin made into fibrillar three-dimensional network fibers by a so-called flash spinning method. A non-woven sheet made of carbon fibers is known. Nonwoven sheets produced by flash spinning are characterized by the fact that the constituent fibers are extremely fine and have a complicated cross-sectional shape, and these characteristics are used for various purposes.

When used in the above-mentioned applications, the nonwoven sheet is required to have waterproof properties and antistatic properties. In order to meet this demand, Japanese Patent Publication No. 55-51068 states:
(1) (2) A fiber treatment agent which is a compound of the chemical formula Ml-R3-11PO4 (n is 1 or 2) and is a mixture of a compound in which R is 1 and a compound in which R is 2 in approximately equimolar amounts. It is disclosed that if used, antistatic properties can be imparted without impairing waterproof properties.

[Problem to be solved by the invention]

A fiber treatment agent made of a compound having the structure disclosed in Japanese Patent Publication No. 55-51068 can impart waterproofness and antistatic properties to a nonwoven sheet, but this fiber treatment agent has a It is necessary to use at least 0.1%. However, when applying these fiber treatment agents to a nonwoven sheet, it is desired that the amount applied be as small as possible from the viewpoint of odor and printing characteristics, and the above-mentioned fiber treatment requires an application amount of at least 0.1%. The problem with these agents is that their range of practical use is limited.

The present invention solves the problems of the previously known fiber treatment agents that can impart both waterproofness and antistatic properties, and achieves practically sufficient waterproofness even when applied in an extremely small amount. We have discovered a fiber treatment agent that can impart antistatic properties to nonwoven sheets, and by applying this fiber treatment agent, we can achieve both waterproofing and antistatic properties, as well as improve product characteristics such as odor and use characteristics such as printing characteristics. The purpose is to provide an excellent polyolefin nonwoven sheet.

[Means to solve the problem]

The object of the present invention is to consist of a compound represented by the following chemical formula [I] and a compound represented by the following chemical formula (II), in which the molar ratio of the compound [I] is at least twice the molar ratio of the compound [■]. This is achieved by a polyolefin nonwoven sheet characterized by containing a fiber treatment agent in an amount of 0.01% or more based on the weight of the fibers.

RM2PO4... [I] R2MPO4... [■] M is lithium, sodium, potassium, hydrogen or ammonium, R is an alkyl group having 6 or 7 carbon atoms.

The nonwoven polyolefin sheet of the present invention can be manufactured by a known method. For example, JP-A-61160-469 discloses an example of a method for producing polypropylene continuous filament nonwoven fabric, and JP-A-63-6107 (3) (4) discloses an example of a method for producing polypropylene ultrafine fibers. Japanese Patent No. 64-40618 discloses an example of a nonwoven sheet having a sheath-core structure, in which the core is made of polyethylene terephthalate or a copolymer thereof and the sheath is made of polyolefin such as polyethylene or polypropylene.

In addition, as an example of the flash spinning method, for example,
An example of high-density polyethylene is disclosed in Japanese Patent Publication No. 172073, and an example of polypropylene is disclosed in Japanese Patent Publication No. 62-192598.

For example, a polyolefin polymer is dissolved under high temperature and pressure with halogenated carbon such as trichlorofluoromethane or trichlorotrifluoroethane, halogenated hydrocarbon such as methylene chloride, hydrocarbon such as cyclohexane, or a mixture thereof. After that, by applying a sudden pressure drop, the solution is given a structure that looks like it has undergone extremely fine phase separation.

This liquid is discharged from a spinning nozzle to give orientation to the polymer and to discipline the three-dimensional network fibers (so-called flash spinning). After shaking this off onto a conveyor belt and making it into a web, it is heated to room temperature or an appropriate temperature ( The polyolefin polymer is partially or completely pressed using a roll (smooth roll, embossed roll, etc.) kept at a temperature below the melting point (melting point or lower) or a felt calendar to form a sheet.

This nonwoven sheet is made of fibers with extremely fine and complex cross sections.

The basis weight of the nonwoven sheet of the present invention is 30 to 200 g/m'
, preferably 40 to 100 g/rn'. 30g/
If it is smaller than m', sufficient waterproofness cannot be obtained. Moreover, if it is too thick, the flexibility will be impaired and it will wrinkle or break during manufacturing, which is unfavorable from a quality standpoint.

The obtained nonwoven sheet was given the chemical formula [I]; RM2PO4
, chemical formula Cn); A fiber treatment agent consisting of a mixture of a compound represented by R2MPO4 and containing at least twice the molar ratio of the compound (II) is applied to the nonwoven sheet.

The fiber treatment agent of the present invention has an alkyl group consisting of hexyl or heptyl (that is, various alkyl groups such as n-hexyl, isohexyl, n-butylisoheptyl, etc.).
The monoalkyl phosphate (5) (6) monoalkyl phosphatide salt (5) (6) is composed of phate salts and dialkyl phosphate salts, and therefore provides a sufficiently large antistatic effect even if the amount applied to the nonwoven sheet is small. Potassium octyl phosphate, potassium decyl phosphate, potassium lauryl phosphate, etc. rapidly increase water permeability to improve oiliness, which impairs the waterproofness of nonwoven polyolefin sheets made of polyethylene and polypropylene.

Furthermore, as the molar ratio of the dialkyl phosphate salt increases, its lipophilicity increases, and when it is attached to a nonwoven polyolefin sheet, the water permeability of the nonwoven sheet increases and its waterproof properties are lost.

A conventional method can be applied to apply the fiber treatment agent. Specific examples include a clip-nip method, a coating method, a gravure roll method, a kiss roll method, and a spray method.

The applied fiber treatment agent is dried and finished by hot air heating using a tenter or contact heating.

Further, by performing a corona discharge treatment in advance before applying the fiber treatment agent, the wettability of the surface of the nonwoven sheet is improved and the application of the fiber treatment agent can be facilitated. Additionally, water repellents such as palmitic acid triglyceride, stearic acid triglyceride, and dimethylpolysiloxane, oil repellents such as perfluoroalkyl phosphate and perfluoropolyethylene, and surfactants may be used in combination. .

The fiber treatment agent used in the present invention may also contain phosphates and other inorganic salts as long as the effects are not affected. In order to avoid problems even when such other compounds are mixed and used, the monoalkyl phosphate salt of the compound of chemical formula CI) and the dialkyl phosphate salt of the compound of chemical formula [■] are added to the second light intensity point beyond the first equivalence point. It is preferable to adjust the pH to between 6 and 8 before use.

The fiber treatment agent of the present invention exhibits an antistatic effect when applied to the nonwoven sheet in an amount of 0.01% by weight or more. Generally, fiber treatment agents are 2
．． Although it has been practiced to apply 0% by weight, such a large amount is not economical, and depending on the type of fiber treatment agent, there may be an odor problem, and it is also unfavorable in terms of printing characteristics. In this respect, the present invention's non-(7) (8) woven sheet has a much smaller amount of 001 weight compared to the amount of fiber added, which is conventionally considered to be common knowledge, in order to obtain the required waterproof and antistatic properties. By adding a small amount of % or more,
You can achieve your goals. However, depending on the application, it may be 0.2~
It may be added in an amount of 0.3% by weight to provide even better antistatic properties.Also, for products that have undergone softening treatment or embossing on the surface for use in clothing, etc., the treatment liquid becomes film-like. As the molar ratio of potassium phosphate potassium hydrogen increases, the antistatic properties of the nonwoven polyolefin sheet greatly improve, water permeability decreases, and waterproof properties are maintained.

〔Example〕

The present invention will be explained in detail with reference to Examples below. Prior to describing Examples, methods for measuring various physical properties of the nonwoven sheet of the present invention will be described.

・Antistatic property (half-life measurement method) After charging a test piece in a corona discharge field, this charging voltage is %
The antistatic property was evaluated using a method of measuring the time (half-life) until decay occurs (JIS-L-1094).

This measurement method is suitable for evaluating the static electricity decay characteristics of woven or knitted materials. A half-life of 60 seconds or less is acceptable, and a half-life of 10 seconds or less is more preferable.

・Water resistance test Measured using the hydrostatic pressure method of method A and method B of the waterproof test method for textile products (JIS-L-1092). In the water resistance test, it is sufficient that the water pressure resistance (mmH20) of the treated nonwoven sheet is 70% or more of the water pressure resistance (mmF120) of the untreated nonwoven sheet.

- Ice charcoal test (spray test) Measured using the waterproof test method for textile products (JIS-L-1092). In the ice charcoal test (spray test), even if the surface was moist, there was no moisture on the back surface, and the wood bark was 70 or higher, which was considered to be a pass.

・Moisture permeability test Method for testing moisture permeability of textile products (JIS-L-1099)
A (9) (10) Method 1 (calcium chloride method): This test method involves creating an air layer within a moisture-permeable cup, and drying the inside of the moisture-permeable cup with calcium chloride with the test piece as the boundary. With the outside in a humid state, water vapor is forcibly absorbed by the vapor pressure difference that occurs during this period, and the amount of permeation is measured to evaluate moisture permeability. Therefore, this test method is suitable for measuring moisture permeability under wearing conditions where the inside of clothing is humid, and can be applied to all textile materials including moisture-permeable waterproof materials. The water vapor permeability is such that the water vapor permeability (g/m''·day) of the treated nonwoven sheet is 70% or more of the water vapor permeability (g/m'·day) of the untreated nonwoven sheet.

Application of the fiber treatment agent and preparation of measurement samples in each of the Examples described below were performed in the following manner.

The nonwoven sheet was immersed in a fiber treatment agent solution and nipped between rubber rolls having a hardness of 75±5 to remove excess solution from the surface of the nonwoven sheet. The wet nonwoven sheet was air dried, followed by drying at 105° C. for 3 minutes. Next, the temperature was adjusted in a prespecified constant temperature room at 20±2° C. and 40±2% RH.

Examples 1 to 3, Comparative Examples 1 to 3 A polyolefin nonwoven sheet made of three-dimensional network fibers is used. That is, polyethylene polymer and a solvent are discharged from a high temperature and high pressure condition to a low temperature and low pressure area through a nozzle, the solvent is flashed to form a fibrillated reticular fiber, which is then deposited on a wire gauze, heat-pressed and bonded using a calendar roll at 130°C, and the date A non-woven polyethylene sheet of 63 g/m''' - 0.2 mm thick was obtained. This non-woven sheet was subjected to corona discharge treatment and treated with 0.2% by weight of various fiber treatment agents as shown in Table 1. The treatment was carried out in an aqueous solution.These fiber treatment agents were all mixtures of monoalkyl phosphate potassium hydrogen and dialkyl phosphate potassium having alkyl groups shown in Table 1 (approximately 3:1 molar ratio). there were.

Each of these fiber treatment agents was applied in an amount of 0.2% by weight to the nonwoven sheet. Since the surface of the nonwoven sheet had been previously subjected to a corona discharge treatment, it was possible to easily attach it to the nonwoven sheet.

(11> (12) All of the treated nonwoven sheets showed excellent antistatic properties;
It can be seen that the good water resistance of the nonwoven sheet is lost when increasing above C7 (heptyl).

Examples 4 to 6, Comparative Examples 4 and 5 The molar ratio of compound [I] and compound [■] as a fiber treatment agent to the polyethylene nonwoven sheet obtained in Example 1, that is,
The effects on antistatic properties and water pressure resistance were investigated when the molar ratios of monohexylphosphate potassium hydrogen and dihexylphosphate potassium hydrogen were changed. The hydrogen ion concentration (P)I) of the fiber treatment agent solution was adjusted to between 6 and 8 (M at the first and second equivalent points), and 0.2% by weight was applied to each of the nonwoven sheets.

Table 3 shows an example in which 0.05% by weight of (14) potassium tylphate (mixture with a molar ratio of 1:1) was added.

Table-3 A fiber treatment agent consisting of a mixture of molyhexylphosphate potassium hydrogen and dihexylphosphate potassium hydrogen in a ratio of 3:1 was applied to a nonwoven sheet (16) Table-2 The ratio of monohexylphosphate potassium hydrogen was It was found that more than twice the amount of carbon di-xylphosphate was required.

Examples 7 to 12, Comparative Examples 6 and 7 A mixture of potassium monohexylphosphate hydrogen and potassium dihexylphosphate in a molar ratio of 3:1 was used as a fiber treatment agent for the polyethylene nonwoven sheet obtained in Example 1. The fiber treatment agent was applied to the nonwoven sheet in varying amounts. In addition, as Comparative Example 7, sufficient antistatic properties can be imparted by adding 0.01% by weight or more of potassium sesquibutyl phosphate (potassium monobutyl phosphate and dibu (15). A sufficient antistatic effect cannot be obtained with addition of 0.05% by weight of phate potash.

Examples 13 to 15, Comparative Example 8 A polypropylene deposit nonwoven sheet consisting of three-dimensional network fibers was obtained in the same manner as in Example 1.

This sheet was partially crimped with an embossing roll at 155°C to give a fabric weight of 69 g/m' and a thickness of 0.22 +n+n.
A nonwoven sheet was obtained. The nonwoven sheet was previously subjected to a corona discharge treatment, and a fiber treatment agent consisting of a mixture of monohexylphosphate potassium hydrogen and dihexylphosphate potassium hydrogen at a molar ratio of 3:1 was applied.
A product with the adhesion amount shown in 4 was obtained.

These materials have an antistatic effect, water repellency, and sufficient moisture permeability.

(17) Examples 16 and 17 Polyolefin nonwoven sheets made of polypropylene were obtained by ordinary melt spinning and melt blowing methods. Each of these nonwoven sheets had a weight of 40 g/m'.

The sheet was previously subjected to a corona discharge treatment, and then a fiber treatment agent consisting of a mixture of potassium monohexylphosphate hydrogen and potassium dihexylphosphate in a ratio of 3 to 1 mole was applied.

The amount of fiber treatment agent attached to these nonwoven sheets was 0.
1% by weight and 0.08% by weight. The honest meter half-life of the nonwoven sheet is 1.7 seconds and 1.4 seconds, respectively.
The deicing charcoal (spray method) is 80 and 90, respectively, and has sufficient antistatic effect and water repellency.

Example 18 A nonwoven sheet consisting of fibers with a sheath-core structure consisting of polyethylene in the sheath and polyethylene terephthalate in the core was obtained by a two-component melt spinning method. The basis weight of this non-woven sheet is 40
g/m''.The sheet was coated with 0.5 of a fiber treatment agent consisting of a mixture of potassium monohexyl phosphate hydrogen and potassium dihexyl phosphate in a ratio of 3 to 1 mole.
% by weight and an aqueous solution containing 10.0% by weight of isopropyl alcohol, and was finished by drying. The amount of fiber treatment agent adhered to this nonwoven sheet was 0.1% by weight. In addition, the half-life on the Honestometer was 2.2 seconds, and the value on ice charcoal (spray method) was 80.

Examples 19 to 22, Comparative Example 9 Antistatic properties and water repellency when the compound [Work] and the metal (M) of the compound [■] were changed as fiber treatment agents to the polyethylene nonwoven sheet obtained in Example 1. We investigated the effects.

The fiber treatment agent used consisted of monohexyl phosphate salt and dihexyl phosphate salt, and the molar ratio was 3:1. Hydrogen ion concentration (P
)I) was adjusted to between 6 and 8 (between the first and second equivalent points), and the nonwoven sheet was treated so that the amount of the fiber treatment agent attached was 0.2% by weight.

(19) (20> Table 5 It was found that the antistatic effect and waterproof property did not substantially change even by changing the metal (M).

Examples 23 to 25, Comparative Examples 10 to 12 The polyethylene nonwoven sheet obtained in Example 1 was subjected to antistatic treatment with a fiber treatment agent consisting of 3 moles of potassium monohexylphosphate hydrogen and 1 mole of potassium cyhexylphosphate. A treated sheet (21) was created by applying anti-static treatment using a fiber treatment agent consisting of 1 mol of potassium monobutyl phosphate and 1 mol of potassium dibutyl phosphate, and varying the amount of adhesion so that the half-life of the honest meter was 60 seconds or less. did. The odor of the treated sheets and the drying properties of the printing ink were compared.

(22) Comparison of odor is made in Examples 23, 24, 25 and Comparative Example 1
100 g of samples of 0°11, 12, and 13 were each cut into pieces approximately 50 m x 5 cm in size, placed in a 500 Erlenmeyer flask, and the narrow neck was sealed with a silicone rubber stopper. After leaving this condition in a constant temperature room at 24℃ for 24 hours,
The silicone rubber stopper was removed, the odor was smelled from the opening, and the odor was evaluated using the commonly used 6-level odor intensity display method, and an odor intensity of 2 or less was considered to be a pass.

Table - 76-level odor intensity display method Regarding the drying time of ink, see the table below for oil-based offset ink (
Impermeable ink: Compared to the ingredients of ordinary oil-based offset inks, the pigments, resins, drying oils, auxiliary agents, metal soaps, etc. remain unchanged, while the petroleum-based high boiling point solvent is kept to about 1%. ) printed on the entire surface in a size of 15cm x 20cm, and
Leave it in a room at ℃. Press the Sellotape against the printed surface every hour and check the time until the ink no longer transfers to the Sellotape, which is considered the drying time. Pass if dry within 1-4 hours (○), semi-pass if dry within 5-8 hours (
△), 8 hours or more was regarded as a failure (x).

It can be seen that the hexyl phosphate salt of the present invention is useful in terms of odor and ink drying properties when applied in small amounts.

〔Effect of the invention〕

The present invention provides a polyolefin nonwoven sheet of the present invention comprising a compound represented by the following chemical formula CI) and a compound represented by the following chemical formula [■], wherein the molar ratio of the compound CI) is twice the molar ratio of the compound [■]. By containing the above fiber treatment agent at 0.01% or more based on the weight of the fiber, the polyolefin nonwoven sheet can have excellent antistatic properties without impairing its waterproof properties. It is possible to In addition, it has been confirmed through actual experiments that applying a small amount of this fiber treatment agent is not only advantageous in terms of cost, but also produces less odor and does not cause problems in printability.

RM2PO,... CI) R2MPO4... [II) M is lithium, sodium, potassium, hydrogen or ammonium, R is an alkyl group having 6 or 7 carbon atoms.

Claims (1)

[Claims] A compound represented by the following chemical formula [I] and the following chemical formula [II]
A polyolefin consisting of a compound represented by the following and containing a fiber treatment agent in which the molar ratio of the compound [I] is at least twice the molar ratio of the compound [II] based on the weight of the fiber: 0.01 or more Non-woven sheet RM_2PO_4...[I
] R_2MPO_4... [II] M is lithium, sodium, potassium, hydrogen or ammonium, R is an alkyl group having 6 or 7 carbon atoms.