JPH03146771A - Nonwoven fabric sheet of polyolefin - Google Patents

Abstract

PURPOSE:To provide excellent water proofing property and antistatic property to a nonwoven fabric sheet of polyolefin by treating the nonwoven fabric sheet with a treating agent containing both a fiber treating agent consisting of a specific phosphoric acid salt and an oil repellent consisting of fluorocarbon compound at specific amounts or above. CONSTITUTION:A nonwoven fabric sheet of polyolefin made, e.g. according to flash spinning method is treated with a treating liquid containing >=0.05wt.% fiber treating agent consisting of sodium mono- and dialkylphosphate expressed by formula I and formula II (M is lithium, sodium, potassium, H or ammonium; R is 6-7C alkyl) and having a molecular ratio of compound of formula I being >=2 times that of the compound of formula II and >=0.05wt.% oil repellent consisting of a fluorocarbon compound. When a nonwoven polyolefin prepared by a flushing method is treated with this treating agent, the sheet exhibits an excellent antistatic property as well as a water proofing property. The sheet is suitable for packaging material, protective cloth, rain coat, etc.

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 specifically, the present invention relates to a polyolefin nonwoven sheet having excellent waterproof and antistatic properties that can be preferably used as a sheet for packaging materials, protective clothing, windbreaker-1 raincoats, bedding, etc.

[Conventional technology]

Various types of polyolefin nonwoven sheets are conventionally known for use in the above-mentioned applications. 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:
If a fiber treatment agent that is a compound of the chemical formula MnR3-nPO4 (11 is 1 or 2) and is a mixture of a compound with R of 1 and a compound with R of 2 in approximately equimolar amounts will impair waterproofness. It is disclosed that antistatic properties can be imparted without any

[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 applicant, who is the same as the present invention, developed the invention in 1989 with the aim of solving the problems of the previously known fiber treatment agents mentioned above.
"Polyolefin Nonwoven Sheet" (Japanese Patent Application No. 1-200219) filed on March 3, consists of a compound represented by the following chemical formula [■] and a compound represented by the following chemical formula CID,
A fiber treatment agent in which the molar ratio of the compound [■] is more than twice the molar ratio of the compound [II] is 0.01% by weight of the fiber.
We have proposed a polyolefin nonwoven sheet characterized by containing the above.

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

This polyolefin nonwoven sheet can reduce the amount of fiber treatment agent used, so it has excellent odor and printing characteristics.
In addition, it had practically sufficient antistatic properties. However, waterproof properties tend to be lacking, and further improvements are expected depending on the application.

The present invention solves the problems of the conventional polyolefin nonwoven sheets that are coated with a fiber treatment agent that can provide both waterproofness and antistatic properties, and provides practically sufficient waterproofness and antistatic properties. The object of the present invention is to provide a polyolefin nonwoven sheet having the following properties.

[Means to solve the problem]

The object of the present invention is to treat fibers comprising a compound represented by the following chemical formula [■] 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 [II]. This is achieved by a polyolefin nonwoven sheet characterized by containing 0.05% by weight or more of the agent (A) and 0.05% by weight or more of the oil repellent (B) made from a fluorocarbon compound.

RM, P-port, ... [I] R, MPO, ... [II] 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, which has not yet been given a fiber treatment agent and an oil repellent, can be produced by a known method. For example, JP-A-61-160469 discloses an example of a method for producing a polypropylene continuous filament nonwoven fabric.
Japanese Unexamined Patent Publication No. 63-6107 discloses an example of a method for producing a nonwoven fabric of ultrafine polypropylene fibers by a melt blowing method. Further, as examples of the flash spinning method, for example, Japanese Patent Publication No. 172073/1983 discloses an example of high density polyethylene, and Japanese Patent Publication No. 192598/1987 discloses an example of polypropylene.

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 onto a conveyor belt and making it into a web, it is partially or completely crimped using a roll (smooth roll, embossed roll, etc.) kept at room temperature or an appropriate temperature (below the melting point of the polyolefin polymer) or a felt calender. , form into a sheet.

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

The amount of the aforementioned non-woven sheet is 30-200 g/m''
, preferably 40 to 100 g/m''. 30 g/m
If it is smaller than m'', sufficient waterproofness cannot be obtained.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 polyolefin nonwoven sheet of the present invention is made by adding a fiber treatment agent (A) and an oil repellent (B) to the aforementioned nonwoven sheet as described below.
) can be manufactured by adding

The monoalkyl phosphate salt and dialkyl phosphate salt having an alkyl group consisting of hexyl or heptyl used as the fiber treatment agent (A) in the present invention have a sufficiently large antistatic effect even if the amount applied to the nonwoven sheet is small. bring. For octyl phosphate salts, lauryl phosphate salts, etc., there is a rapid increase in water permeability due to the large improvement in oiliness, which greatly reduces the waterproofing effect of oil repellents made of fluorocarbon compounds, and non-woven polyolefins made of polyethylene and polypropylene. The waterproof properties of the sheet will be impaired. Furthermore, as the ratio of dialkyl phosphate salts consisting of hexyl and heptyne increases, the lipophilicity increases, similar to the above-mentioned phosphate salts consisting of octyl and lauryl, and when attached to a nonwoven polyolefin sheet, waterproof properties are maintained. Becomes exposed.

The oil repellent (B) made of a fluorocarbon compound used in the present invention includes fluoroalkylcarboxylic acid, perfluoroalkylcarboxylic acid, perfluoroalkylsulfonic acid and its salts (lithium, sodium, potassium, etc.), monoperfluoroalkylethyl Phosphate salts, fluorocarbons such as perfluoroalkylsulfonic acid jetanolamide, polytetrafluoroethylene polymers, polytetrafluoroethylene-hexafluoropropylene copolymers, polytrifluoromonochloroethylene polyvinyl fluoride polymers, polytetrafluoroethylene polymers Mention may be made of fluoropolymers such as perfluoroalkoxyethylene copolymers.

These fluorocarbon compounds are in the form of an aqueous solution, emulsion, or dispersion, and can be applied to a polyolefin nonwoven sheet together with the fiber treatment agent (A) by a conventional method.

Specific examples include dip-nip method, coating method, gravure roll method, kiss roll method, spray method, and the like. The applied fiber treatment agent (A) and oil repellent (B) are dried with a tenter or Teflon-coated hot roll, etc.
Finish. Further, by performing a corona discharge treatment 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 and the oil repellent becomes easier. Further, compounds such as palmitic acid triglyceride, stearic acid triglyceride microcrystalline wax, surfactants, etc. may be mixed with a solution consisting of a fiber treatment agent and an oil repellent.

Further, the fiber treatment agent (A) and oil repellent (B) of the present invention may contain phosphates and other inorganic salts as long as the effects are not affected.

Although the fiber treatment agent (A) and the oil repellent (B) can be applied to the nonwoven polyolefin sheet in separate two-step processes, it is preferable to carry out the treatment in a bath from the viewpoint of the process. When mixing the fiber treatment agent (A) and the oil repellent (B), there are problems with their compatibility, ionicity, pH, etc., and by making good use of them, a treatment solution with good solution stability can be created and used to produce nonwoven polyolefin sheets. Apply.

In this way, the monoalkyl phosphate salt of compound [I] and the dialkyl phosphate salt of compound (If) should be mixed and used in a manner that exceeds the first equivalence point and reaches the second equivalence point so that there is no problem even if other compounds are mixed and used. pH between 6 and
It is necessary to adjust it to 8 before use.

This fiber treatment agent (A
> When applying an oil repellent (B), the treatment liquid is less likely to form a film, and it is required to increase the amount of the fiber treatment agent (A) and oil repellent (B) to about 0.5% by weight each. There may be cases where Usually, a nonwoven sheet with sufficient antistatic effect can be obtained at 0.1 to 0.2% by weight of each.

In this way, by using the fiber treatment agent (A) made of an alkyl phosphate salt compound in a specific range and the oil repellent (B) made of a fluorocarbon compound, an antistatic effect can be achieved without impairing waterproofness. be able to.

〔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 A
The antistatic property was evaluated by a method of measuring the time until decay (half-life) (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 (mmHzo) of the treated nonwoven sheet is 70% or more of the water pressure resistance (mmHJ) of the untreated nonwoven sheet.

・Icing charcoal test (spray test) Measured using the waterproofing test method for textile products (JIS-L-1092). A sample with no wetting of water droplets and with a glacial charcoal of 70 or higher was considered to have passed.

・Otori humidity test 3 humidity test methods for textile products (JIS-L-1099)
Method A-1 (calcium chloride method): This test method involves creating an air layer within a moisture-permeable cup, using the test piece as a boundary, drying the inside of the moisture-permeable cup with calcium chloride, and keeping the outside of the moisture-permeable cup in a humid condition. During this time, water vapor is forcibly absorbed due to the vapor pressure difference, 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 moisture permeability of the treated nonwoven sheet (g/m'day) is 7 times higher than that of the untreated nonwoven sheet (g/m'day).
It is sufficient if the value is maintained at 0% or more.

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 solution consisting of a fiber treatment agent (A) and an oil repellent (B) 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 tenter dried at 105°C for 1 minute, followed by curing at 120°C for 1 minute. Next, the temperature was adjusted in a prespecified constant temperature room at 20±2° C. and 40±2% RH.

Examples 1 to 2 Comparative Examples 1 to 3 Polyethylene polymer and solvent were discharged from a nozzle into a low temperature and low pressure region from high temperature and high pressure conditions, and the solvent was flashed.
After forming fibrillated reticular fibers, deposited on wire mesh 13
Heat-pressed using a calendar roll at 0°C, date 63
A polyethylene nonwoven sheet with a thickness of 0.2 mm was obtained. This sheet was subjected to corona discharge treatment and treated with 0.2% by weight aqueous solutions of various fiber treatment agents as shown in Table 1. All of these fiber treatment agents were mixtures of monoalkyl potassium hydrogen phosphate and dialkyl potassium phosphate (approximately 3:1 molar ratio) having alkyl groups shown in the table. A perfluoroalkyl acrylate water repellent was applied to the nonwoven sheet at a concentration of 0.2% by weight, but since the surface of the nonwoven sheet had already been subjected to a corona discharge treatment, the treatment solution was applied to the nonwoven sheet sufficiently. (The adhesion amount of the treatment agent and oil repellent was 0.00 ml.)
It was 2% by weight. ) It can be seen that when the fiber treatment agent (A) and the oil repellent (B) are used, good waterproof properties, antistatic properties, and moisture permeability are exhibited.

Examples 3 to 5 Comparative Examples 4 to 5 The ratio of compounds represented by chemical formula [I] and chemical formula CI [) as a fiber treatment agent to the polyethylene nonwoven sheet obtained in Example 1, that is, monohexyl potassium hydrogen phosphate and The antistatic and waterproof effects of varying the ratio of dihexyl potassium phosphate were investigated. Incidentally, the same amount of an oil repellent (B) consisting of a fluorocarbon compound; a perfluoroalkyl acrylate compound was contained in the treatment liquid. The amount of adhesion of fiber treatment agent and oil repellent is 0.
It was 2% by weight.

The greater the ratio of monohexyl potassium hydrogen phosphate, the greater the waterproof effect.

Examples 6 to 10 Comparative Examples 6 to 7 A fiber treatment agent consisting of a mixture of monohexyl potassium hydrogen phosphate and dihexyl potassium hydrogen phosphate in a molar ratio of 3=1 was applied to the polyethylene nonwoven sheet obtained in Example 1 as a fiber treatment agent. was applied to the nonwoven sheet in varying amounts. As an oil repellent added to the treatment bath, a perfluoroalkyl acrylate compound was added to the nonwoven sheet in an amount of 0.2% by weight.

A fiber treatment agent consisting of a mixture of monohexyl potassium hydrogen phosphate in a molar ratio of 3:1 was applied to the nonwoven sheet at a concentration of 0.
Sufficient antistatic properties can be obtained by adding 0.05% by weight or more.

Examples 11 to 14 Comparative Example 8 The polyethylene nonwoven sheet obtained in Example 1 was treated with different fiber treating agents containing different metals and ammonium in monohexyl phosphate salt and dihexyl phosphate salt. 0.2% by weight was added to the woven sheet. The oil repellent added to the treatment bath was a perfluoroalkyl acrylate compound added to the nonwoven sheet in an amount of 0.2% by weight.

It was found that the antistatic effect and waterproof property did not substantially change even if the metal (M) was changed.

Examples 15-20 A deposit sheet of fibrillated reticulated polypropylene fibers was obtained in the same manner as in Example 1. 15 sheets of this
Partially crimped with an embossing roll at 5℃, date 69
g/m" and a thickness of 0.22111 [11] was obtained. This sheet was previously subjected to a corona discharge treatment, and a mixture of monohexyl potassium hydrogen phosphate and dihexyl potassium hydrogen phosphate in a molar ratio of 3=1 was obtained. 0.5% by weight of each of a fiber treatment agent consisting of a fiber treatment agent and an oil repellent consisting of a fluorocarbon compound shown in the table below were applied.

Table 5 It was found that the waterproofing effect did not change even if the oil repellent made of fluorocarbon compound was changed.

Examples 21 to 26 Comparative Example 9 0.2% by weight of a fiber treatment agent consisting of 3 moles of monohexyl potassium hydrogen phosphate and 1 mole of dihexyl potassium phosphate and a polytetrafluoroethylene polymer were added to the polyethylene nonwoven sheet obtained in Example 1. was applied by varying the amount of adhesion.

Table 7 The amount of fiber treatment agent consisting of 3 moles of monohexyl potassium hydrogen phosphate and 1 mole of dihexyl potassium phosphate was kept constant, and the amount of polyfluoroethylene polymer dispersion was increased to 0.05% by weight on the nonwoven sheet. It was found that complete waterproofing was achieved when the above amount was applied.

〔Effect of the invention〕

Since the present invention is constructed as described above, it is a polyolefin non-woven sheet with improved anti-icing coal and excellent anti-static properties, resulting in packaging materials, protective clothing, windbreakers, raincoats, sleeping bags, etc. It can be usefully used as a sheet for packaging, etc.

Claims (1)

[Claims] Consists of a compound represented by the following chemical formula [I] and a compound represented by the following chemical formula [II], wherein the molar ratio of the compound [I] is [
The fiber treatment agent (II) is more than twice the molar ratio of the compound in
A polyolefin nonwoven sheet RM_2PO_4...[I] R_2MPO_4...[II] M is characterized by containing 0.05% by weight or more of A) and 0.05% by weight or more of an oil repellent (B) consisting of a fluorocarbon compound. Lithium, sodium, potassium, hydrogen or ammonium, R is an alkyl group having 6 or 7 carbon atoms.