JPH0359169A - Hot-weldable fiber - Google Patents

Abstract

PURPOSE:To obtain a hot-weldable fiber exhibiting hydrophilic nature and having good process stability by applying a treatment agent consisting of a specific polyoxyalkylene-modified silicone and an alkyl phosphate to a surface of a hot-weldable fiber composed of a specific polymer. CONSTITUTION:The hot-weldable fiber used as a raw material for the subject fiber contains a thermoplastic polymer having a melting point of 50-200 deg.C as the hot-weldable component wherein >=50wt.% of the thermoplastic polymer is a polyolefin polymer. The hot-weldable fiber is coated with a treatment agent consisting of (A) 5-20wt.% of a polyoxyalkylene-modified silicone containing <=50wt.% of silicone in the resin and >=40wt.% of polyoxyethylene in the polyoxyalkylene and having a molecular weight of 1,000-100,000 and (B) 25-95wt.% of a (polyoxyethylene)alkyl phosphate composed of a (polyoxyethylene)alkyl group wherein the average carbon number of the alkyl group is 8-10 and the molar number of added oxyethylene units is 0-15 and having a phosphatization degree of 0.5-1 and an acid value of 0-150. The amount of the treatment agent attached to the fabric is 0.05-5wt.%. The obtained hot- weldable fiber gives a non-woven fabric having high quality and free from web unevenness.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a thermoadhesive fiber that has a soft feel and exhibits hydrophilic properties with excellent water wash durability. More specifically, scum occurs in the cotton manufacturing process, carding process, etc.

The present invention relates to a heat-adhesive fiber that generates little static electricity, has good process stability, and provides a high-quality nonwoven fabric without web unevenness.

<Prior art> Various heat-adhesive fibers have been proposed for use in nonwoven fabrics, mainly sheath/core type composite fibers, such as low-melting point polyester/polyethylene terephthalate, polyethylene/polypropylene, polyethylene/polyethylene terephthalate, etc. It is used. In recent years, the fields in which they are used have been expanding, particularly as surface materials for tea bags for food and household use, cosmetic puffs, wet tissues, sanitary napkins, disposable diapers, etc. for hygiene and medical use.

Heat-adhesive fibers used for diaper liners, poultice base fabrics, etc. are required to have hydrophilic properties with excellent washability and a soft texture.

In general, heat-adhesive fibers that can be soft-finished use polymer-modified heat-adhesive component polymers, so they are easily deformed and cannot be attached to thread guides such as guides, rollers, and clothing.
The contact area is much larger than that of ordinary synthetic fibers. As a result, the friction between the fibers and the metal increases significantly, making it extremely easy to generate scum, which causes a decrease in the stability of the cotton-making process and, ultimately, a decrease in the quality of the nonwoven fabric finally obtained. Furthermore, in post-processes such as spinning, static electricity tends to be generated and winding around cards, cylinder rollers, etc. tends to occur frequently.

On the other hand, in order to impart hydrophilicity to heat-adhesive fibers, a method of attaching a hydrophilic compound to the fiber surface is simple and generally employed. As such a method, for example, JP-A-54-153872 discloses that one selected from sulfuric acid ester salts, phosphoric acid ester salts, and sulfonic acid salts.
5. With an anionic surfactant containing a species compound. A method of treating a porous polypropylene membrane is disclosed. However, in this case, there is a problem that the durability of hydrophilicity is poor. Furthermore, JP-A No. 64-6173 discloses a treatment method using a sorbitan trifatty acid ester compound, etc., but there is a problem that the treatment agent tends to be unevenly distributed at the adhesive interface, inhibiting adhesion. . Also, JP-A-63-30
Publication No. 3184 discloses treating polyolefin thermal adhesive fibers with a treatment agent containing 30% by weight or more of polyoxyalkylene-modified silicone. According to this method, a heat-adhesive fiber can be obtained which exhibits hydrophilicity with excellent water washing durability and has improved passability through a carding process. However, according to studies conducted by the present inventors, scum generation was large in the cotton manufacturing process and the nonwoven fabric manufacturing process, and the process stability was still insufficient. Furthermore,
There are also problems in that mechanical crimp cannot be stably applied to the fibers, or that it is difficult to obtain nonwoven fabrics of stable quality without date spots.

<Purpose of the Invention> The present invention was made in view of the above background, and its purpose is to provide a soft texture and hydrophilicity with excellent water washing durability, while providing a material that can be used in cotton manufacturing processes, nonwoven fabric manufacturing processes, etc. It is an object of the present invention to provide a thermally bondable fiber from which a nonwoven fabric with excellent stability and good quality (unevenness and adhesive strength) can be obtained.

<Structure of the Invention> As a result of intensive studies to achieve the above object, the present inventors have surprisingly found that the amount of polyoxyalkylene-modified silicone can be significantly reduced compared to conventionally known silicones, and that polyoxyalkylene-modified silicone can be used within a very specific range. It was discovered that the above objectives can be achieved at the same time by applying a treatment agent containing an alkali metal salt of polyoxyalkylene>alkyl phosphate ester, and the present invention was achieved.

That is, according to the present invention, a thermoplastic polymer having a melting point of 50 to 200° C. is used as a thermal adhesive component, and at least 5
In a heat-adhesive fiber in which 0% by weight is a polyolefin polymer, a treatment agent containing the following components (A) and (B) adheres to the surface of the fiber in an amount of 0.05 to 5% by weight as an active ingredient of the treatment agent. A thermoadhesive fiber characterized by:

(A) Polyoxyalkylene-modified silicone with silicon content of 50% or less, polyoxyethylene content in polyoxyalkylene of 40% or more, and molecular weight of i, ooo to 100.000 = 5 to 20% by weight (B ) A <polyoxyethylene> alkyl group having an average carbon number of 8 to 10 and an oxyethylene addition mole number of 0 to 15,
An alkali metal salt of (polyoxyethylene>alkyl phosphate ester=25 to 95% by weight) having a degree of phosphorylation of 0.5 to 1.0 and an acid value of θ to 150 is provided.

Examples of the polyoxyalkylene-modified silicone (component A) used in the present invention include those represented by the following general formula.

MeX-RMe (wherein, Me is a methyl group, X is methylene, propylene,
N-(aminoethyl>methylimino, or N-(aminopropyl>propylimino), R is a polyoxyalkylene group, n and m are in the range where the silicon content is 50% or less and the molecular weight is 1.000 to 100.000. (The selected number is shown.) The silicon content in such modified silicone must be 50% or less; if it exceeds 50%, sufficient hydrophilicity cannot be obtained and is not preferred.

Examples of the polyoxyalkylene groups include polyoxyethylene groups, polyoxypropylene groups, polyoxybutylene groups, and copolymerized monomers of these. The content must be 40% by weight or more based on the oxyalkylene. If it is less than this, sufficient hydrophilicity cannot be obtained, which is not preferable.

Further, the molecular weight of the modified silicon is i, ooo to io
o, ooo, and if it is out of this range, the hydrophilicity decreases, and this tendency is particularly noticeable when it is less than 1.000.

In the present invention, it is important to use a processing agent containing a very small amount of 5 to 20% by weight, preferably 5 to 15% by weight of the polyoxyalkylene-modified silicone described above. If the blending amount exceeds 20% by weight, although it exhibits excellent durability and hydrophilicity, scum will be generated in the cotton manufacturing process, nonwoven fabric manufacturing process, etc., and crimping will occur during cotton manufacturing. This is undesirable as it tends to reduce the process stability and the process stability during sliver production (the cause of non-woven fabric unevenness).Furthermore, adhesion failure may occur and the adhesive strength of the non-woven fabric may decrease, or static electricity may be generated. In some cases, the suppressing effect is insufficient and the card passage property is impaired.On the other hand, if the amount is less than 5% by weight, hydrophilicity with water washing durability cannot be obtained9. In addition, the following specific <polyoxyalkylene> alkyl phosphate ester alkali metal salt (B
It is important to use these components in combination, and by doing so, the process stability and quality of the nonwoven fabric can be significantly improved without impairing the hydrophilicity, which has excellent water washing durability.

The average carbon number of the alkyl group in the (polyoxyalkylene)alkyl phosphate ester alkali metal salt used in the present invention is extremely important and needs to be 8 to 10, preferably 8. If the average carbon number is less than 8,
The surfactant ability decreases and the stability of the processing agent decreases, while if it exceeds 10, sufficient hydrophilicity cannot be obtained and the tackiness of the processing agent tends to increase, making it difficult to wind the card. This is not preferable because it may cause problems such as sticking or winding around the heat roller.

In addition, the average degree of polymerization of the polyoxyethylene group in the polyoxyethylene alkyl group is 0 to 15, preferably 0 to 5 (
When the degree of polymerization is 0, it shows that it is a simple alkyl group〉
It is necessary to do so. If the degree of polymerization exceeds 15, the hydrophilicity decreases and the generation of static electricity increases, which tends to reduce the ability to pass through the carding process, which is not preferable.

Moreover, the degree of phosphorylation needs to be 0.5 to 1.0.

If this value is less than 0.5, scum will occur frequently,
Moreover, the cohesiveness is also reduced, and the stability of the cotton manufacturing process and the nonwoven fabric manufacturing process is impaired. As a result, the obtained nonwoven fabric has insufficient quality such as date spots. Also,
It also has the disadvantage that it has a strong odor, which is unfavorable in terms of production, since there is a large amount of unreacted alcohol. On the other hand, the degree of phosphorylation is 1
．． When it exceeds 0, the performance as a surfactant is impaired.

Since the compatibility with the component A decreases, the treatment agent cannot be uniformly attached to the surface of the heat-adhesive fiber.

As a result, the obtained hydrophilicity becomes unstable and the water washing durability becomes extremely poor, which is not preferable. In addition, in the present invention, the degree of phosphorylation is a value calculated by calculating how many moles of phosphorus atoms are bonded to the (oxyethylene addition) alcohol used, and on average, when this value is 1, the phosphoric acid monoester , and when it is 0 or 5, it indicates a phosphoric acid diester (phosphorus atoms are determined by the phosphomolybdic acid colorimetric method).

In addition, the degree of neutralization by an alkali metal compound has a large effect on process stability, and when the acid value exceeds 150, heat resistance decreases and scum formation increases, and solubility becomes poor, causing odor generation. It also becomes. Therefore, the acid value is 0
The lower it is in the range of ~150, the more preferable it is, but if it becomes too low, the compatibility with component A tends to decrease.
Preferably, it is in the range of 10 to 100. Incidentally, examples of the alkali metal include sodium, potassium, lithium, etc., and among them, potassium is preferably used.

In this way, the properties of the (polyoxyalkylene)alkyl phosphate ester salt are important, including the number of carbon atoms in the alkyl group,
The object of the present invention can only be achieved by using a material in which the number of moles of oxyalkylene added, the degree of phosphorylation, and the acid value are within appropriate ranges.

In the present invention, two or more of the above (polyoxyethylene>alkyl phosphate ester alkali metal salts)
It is necessary to use a processing agent containing 5 to 95% by weight, preferably 40 to 95% by weight. If this amount is less than 25% by weight, the effect of the combination with component A is reduced, process stability is deteriorated, and hydrophilicity and durability are reduced. As the component B, it is preferable to use an alkali phosphate salt and a polyoxyethylene alkyl phosphate salt in combination, and it is particularly desirable that the mixing ratio be 1=3 to 3:1. By doing so, it has excellent water washing durability.
The purpose of the present application, which is to simultaneously provide SM4 with aqueous properties and improve process stability and quality of nonwoven fabrics, can be highly achieved.

The processing agent used in the present invention described above may contain other additives within the range that does not impair the effects of the present invention, such as nonionic surfactants, anionic surfactants other than component B, antistatic agents, whitening agents, etc. Agents, antioxidants, ultraviolet absorbers, dyes, pigments, etc. can also be added.

The heat-adhesive fiber of the present invention is prepared by applying the above-mentioned treatment agent to the fiber at 0.00%.
05 to 5% by weight, preferably 0.3 to 1.0% by weight. If the amount of adhesion is less than 0.05% by weight, sufficient hydrophilicity will not be obtained, and the lubricity and cohesiveness will also be insufficient, leading to troubles in the carding process, etc. On the other hand, if it exceeds 5% by weight, there is a tendency for scum generation and roller rolling to increase, and adhesive strength also tends to decrease.

To attach the treatment agent, a conventional method such as dipping or spraying in the spinning and stretching steps may be applied as a water-washed emulsion.

In the present invention, the heat-adhesive fiber to which the treatment agent is attached is a non-polymer with a softening point of 50 to 20.
It is important that the thermoadhesive component is a thermoplastic polymer at 0° C., and that at least 50% by weight thereof is a polyolefin polymer. The processing agent, especially the modified silicone, has a specific high affinity with polyolefin polymers, so when 50% by weight or more of the adhesive component is polyolefin polymer, the processing agent can extremely firmly bond the thermal adhesive fibers. It is presumed that it is fixed to the surface, resulting in hydrophilicity with excellent washing durability, and at the same time, the generation of scum is reduced.

The heat-adhesive fiber may be a fiber consisting of an adhesive component alone, or may be a composite fiber (core-sheath type, side-by-side type, etc.) with another fiber-forming polymer. The cross-sectional shape may be any form such as a round cross-section, a flattened cross-section, a T-shape, a Y-shape, a medium shape, a multi-lobed irregular cross-section such as an irregular shape, a hollow cross-section, and an irregular hollow cross-section. Those having hollow portions improve the electrical properties of the nonwoven fabric.

Next, polyolefin polymers preferably used as adhesive components include, for example, polyethylene, polypropylene, polybutene-1, polypentene-1, and random or block copolymers thereof, or methacrylic acid, acrylic acid, and maleic acid. , fumaric acid,
Examples include polyolefin polymers (referred to as modified olefins) that are copolymerized with at least one selected from unsaturated carboxylic acids such as crotonic acid and itaconic acid, and derivatives such as esters and acid anhydrides thereof. Further examples include graft polymers in which at least one of the unsaturated carboxylic acids or derivatives thereof is grafted onto the polyolefin polymer. Among them, one or more unsaturated carboxylic acids and ethylene, propylene, butene-1 are used from the viewpoint of process stability during cotton manufacturing and the texture (flexibility) of nonwoven fabrics.
Modified polyolefins copolymerized with at least one kind of α-olefins such as the following are preferred.

Thermal adhesive components other than polyolefin polymers include:
As mentioned above, there is no particular limitation as long as the melting point is in the range of 50 to 200°C, and polyvinyl acetate, polyacrylic acid ester, or copolymers thereof, polyamides such as nylon 10 and nylon 12, or copolymerized polyamides may be used. , polyester, copolyester, etc., and those having a melting point of 90 to 150°C are particularly preferred.

On the other hand, as other fiber-forming polymers for forming composite fibers, thermoplastic polymers having a melting point of 150° C. or higher and higher than that of the thermoadhesive component, such as PET, PBT, nylon-6, nylon-66, etc. , polypropylene, etc., especially the bulkiness of the final nonwoven fabric,
PET or PBT is preferable in terms of resistance to set, elasticity, and soft texture. The ratio of the fiber-forming polymer to the total circumference of the composite fiber cross section, that is, the fiber cross-sectional circumference is 60% or less (the ratio of the thermal adhesive component is 40%).
If the affinity between the fiber-forming polymer and the heat-adhesive component is insufficient and interfacial peeling is likely to occur, the heat-adhesive component should preferably be Alternatively, it is preferable to blend a polymer having high affinity with the fiber-forming polymer with the fiber-forming polymer in order to improve adhesive strength.

The thermoadhesive fiber of the present invention described in detail above has a fineness of 0.0000.000.
It is desirable to set it as 1-20 deniers.

The fiber length and number of crimps vary depending on the application, for example, for paper making, 35 mm+ or less, 0 to 10 strands/25 mm, and for dry nonwoven fabric, 20 to 150 mm, 6 to 25 strands/2.
At 5 mm, the crimp degree and crimp elasticity (JIS L
1015) and heat shrinkage rate (80℃> are respectively 8% or more, 7
0% or more and 10% or less are suitable.

The heat-adhesive fiber of the present invention may be used alone as a nonwoven fabric, or may be used in combination with ordinary fibers such as polyester short fibers, polypropylene short fibers, etc., and may be selected as appropriate depending on the purpose. I can do it.

(Actions and Effects of the Invention) The heat-adhesive fiber of the present invention has good affinity with the treatment agent and the adhesive component, so it exhibits hydrophilicity with excellent water washing durability. When used in combination, the amount of polyoxyalkylene-modified silicone used can be reduced to an extremely small amount without reducing hydrophilicity, thereby reducing the occurrence of scum in the cotton manufacturing process, nonwoven fabric manufacturing process, etc. and the quality unevenness of nonwoven fabrics ( Date spots) can be significantly improved.

Furthermore, the compatibility between the phosphoric acid ester salt and the modified silicone is extremely good, and uniform adhesion of the treatment agent can be obtained, and stable hydrophilic water washing durability and excellent process passability can be achieved.

As mentioned above, the thermoadhesive fiber of the present invention has durable hydrophilic properties, so it can be used in tea bags.

It can be suitably used for nonwoven fabrics for food and household use such as cosmetic puffs and wet tissues, surface materials for sanitary napkins and paper diapers, and hygiene and medical use such as diaper liners and poultice base fabrics. In addition, the occurrence of troubles such as scum generation in the cotton manufacturing process, nonwoven fabric manufacturing process, etc. is significantly reduced, and nonwoven fabrics of good quality can be obtained with high productivity, so its industrial significance is extremely large.

<Examples> The present invention will now be described in more detail with reference to Examples. In addition, evaluation of each physical property followed the following method.

(1) Stability of processing agent solution An aqueous solution with a concentration of 10% was prepared and evaluated based on the state of the liquid (precipitation, layer separation, etc.) after being left at 20° C. for 3 days.

(2) Passability through the push crimper When applying crimps with the push crimper, the case where the push crimper can operate normally and provide good crimp is rated as good (○).
A case in which the push-in crimper could not be operated normally due to looseness or the like and only crimps with large spots could be applied was evaluated as poor (×>), and a case in which it could be operated somehow between the two was evaluated as almost good (△>).

(3) Hydrophilic fiber 1. Collect Og, make a spherical fiber mass with a diameter of 4 cm, and place it 5 cm above the water surface in a beaker containing 10,100 O of water.
The fiber mass was allowed to fall naturally from a height of m, and the immersion time until the fiber mass sank below the water surface was measured to evaluate the hydrophilicity.

(4) Durability of hydrophilic water washing After the fiber mass immersed under water was taken out and dehydrated and dried using a centrifuge, the immersion time was measured again using the above-mentioned hydrophilicity evaluation method.

Repeat until the soaking time exceeds 60 seconds, and the soaking time exceeds 60 seconds.
The number of immersion times during which the immersion time was maintained at 0 seconds or less was determined as the durability against water washing of water immersion performance.

(5) Scum generation 50 kg of raw cotton was applied to a roller card under the conditions of 25°C x 65% RH, and 30 g/lr? 30m of eye-sized web
Evaluation was made based on the presence or absence of scum during spinning at a speed of /min. No scum occurred, which was considered good (O), cases where scum occurred and carding was impossible were judged poor (x), and cases where carding was barely possible between the two were judged good (Δ).

(6) Static electricity generation 50 kg of raw cotton was applied to a roller card under the conditions of 25°C x 65% RH, and 30 g/rr? 'The web with a weight of 30
Evaluation was made based on whether or not static electricity was generated during spinning at m/min.

A case where static electricity was not generated was judged as good (O), a case where static electricity was generated and carding was impossible was judged as poor (x), and a case where carding was possible as much as possible between the two was judged as good (Δ).

(7) Using a roller card under 25℃ x 65%RH conditions with card winding
When spinning a web with a basis weight of 0 g/rrr at 30 m/min, those that could be operated normally were rated Good (○), and those that could not be operated due to frequent winding of the card on the clothing were rated Bad ×. 〉
, and those that managed to operate between the two were judged as intermediate (Δ〉).

(8) A web of nonwoven fabric having a grain size of 30 g/- is heat treated at 165°C for 20 seconds to produce a nonwoven fabric. 10cm x 10cm from this non-woven fabric
100 test pieces of size m were cut and weighed, and the weight was determined based on the σ value of the measured values.

σ value less than 0.003 is good (○>, σ value is 0, 003
~0.006 was indicated as almost good (Δ), and a case where the σ value exceeded 0.006 was indicated as poor (×).

(9) Adhesive Strength A test piece with a width of 6 cm and a length of 20 cm was cut in the machine direction from the nonwoven fabric prepared in the same manner as above, and the tensile strength at break was measured at a gripping interval of 10 cm and an elongation rate of 20 cm/min.

The adhesive strength was determined by dividing the tensile strength at break by the weight of the test piece.

((0) When the odor web was heat-treated at 140°C for 1 minute, those with no odor were evaluated as good (O), those with a strong odor that caused discomfort were evaluated as poor (×), and those in between the two were evaluated as good. It was evaluated as △).

Example 1 Polyethylene terephthalate (melting point 260°C) with an intrinsic viscosity of 0.64 was used as the core component, 80 parts of high-density polyethylene (i! point 130°C) and ethylene/methyl methacrylate/maleic anhydride copolymer were used as the sheath component. Copolymerization molar ratio 90/6/4, melt index 8, melting point 95
Using a heat-adhesive component consisting of 20 parts of a heat-adhesive component having 210 holes, the material was spun at a spinning temperature of 280°C, a spinning speed of 1000 m/min, and a composite ratio of 50150 (weight ratio). Collect the obtained undrawn yarn and
After forming tow of 10,000 denier, 3.
Stretched to 0 times, various processing agents shown in Tables 1 and 2 (10
% aqueous emulsion) was applied at the adhesion rate (as the active ingredient) shown in Tables 3 and 4. After this drawn yarn was fed to a push crimper and crimped, it was subjected to relaxation heat treatment at 100°C to form a 51 mm When cut to a fiber length of Obtained fiber.

Tables 3 and 4 show the results of evaluation using these heat-adhesive fibers according to the evaluation method described above.

Note that the adhesive strength is the one when the nonwoven fabric is made of heat-adhesive fiber alone.

Example 2 A thermoadhesive fiber was obtained in the same manner as in Example 1 except that the thermoadhesive component listed in Table 5 was used as the sheath component. <obstruction,
For the treatment agent, use ■ listed in Table 1, and the amount per inch is 0.5w.
It was set as t%. ) The obtained thermal adhesive fibers were evaluated in the same manner as in Example 1.

The results are shown in Table-6.

t MA MAΩ AA MG G : Ethylene, : Methyl methacrylate, : Maleic anhydride, : Terephthalic acid, : Isophthalic acid, : Hexamethylene glycol : Ethylene glycol Table 6 Ne: Comparative example implementation (Ijlj3 High density with melting point of 130°C Polyethylene melting temperature 250
After melting at ℃, spinning was carried out at a spinning speed of 800 m/min using a die having 210 holes, and the drawing temperature was 80 ℃.
It was stretched 5 times. Next, the processing agent (10
% aqueous emulsion> was applied at a deposition rate of 0.5 wt% (as the active ingredient), crimped with a push crimper, and then subjected to relaxation heat treatment with IOO'C to form fully adhesive fibers. Obtained.

Table 7 shows the results of evaluation according to the above evaluation method. In addition, when creating the web, use regular polyethylene
- It was evaluated by mixing it with terephthalate short fibers (single filament fineness 3.0 denier, fiber length 51 mm) at a ratio of 50,150.

Claims (1)

[Scope of Claims] A thermoadhesive fiber whose thermoadhesive component is a thermoplastic polymer having a melting point of 50 to 200°C, and at least 50% by weight of which is a polyolefin polymer, the fiber surface having the following (A): A heat-adhesive fiber characterized in that a processing agent containing component (B) is attached in an amount of 0.05 to 5% by weight as an active ingredient of the processing agent. (A) Polyoxyalkylene-modified silicone with a silicon content of 50% or less, a polyoxyethylene content in polyoxyalkylene of 40% or more, and a molecular weight of 1,000 to 100,000: 5 to 20% by weight (B ) an alkyl group having an average carbon number of 8 to 10 and a (polyoxyethylene) alkyl group having an added mole of oxyethylene of 0 to 15;
Alkali metal salt of (polyoxyethylene) alkyl phosphoric acid ester having a degree of phosphorylation of 0.5 to 1.0 and an acid value of 0 to 150: 25
~95% by weight