JPH0533215A - Polyolefin fiber having low specific gravity and nonwoven fabric using the same fiber - Google Patents

Abstract

PURPOSE:To obtain the title fiber useful for ceiling covering material for automobiles, packing material, interior materials, sanitary materials, etc., having a special specific gravity and a pearly feeling, containing a cyclopentadiene- based petroleum resin having a specific softening point (ring and ball method). CONSTITUTION:A polyolefinic resin (e.g. polypropylene resin) containing 3-40wt.% cyclopentadiene-based petroleum resin having >=160 deg.C softening point (ring and ball method) is subjected to melt spinning at 230 deg.C to give undrawn fiber. The undrawn fiber is drawn at 70 deg.C at 4.6 times draw ratio, provided with crimps by a crimper and cut into stable fibers to give polyolefin fiber having <=0.89 ratio of microvoids produced in the fiber, a pearly feeling and low specific gravity. Then the fiber is sent to a carding machine, made into a web having 100g/cm<2> weight and needle punched.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a polyolefin fiber having a low specific gravity. More specifically, a composition obtained by blending a polyolefin resin with a petroleum resin having a specific high softening point is spun and stretched to generate a large number of microvoids inside the fiber, thereby giving a fiber having a low specific gravity and a pearly feeling, and A non-woven fabric using the fiber.

[0002]

2. Description of the Related Art Polyolefin fibers are generally used in the fields of non-woven fabrics, woven fabrics, fillers, etc. because of their characteristics such as low specific gravity, softness and high strength. As a method for lowering the specific gravity of fibers, a method of adding a foaming agent to one component of the composite fibers and subjecting them to composite spinning to form foamed fibers (Japanese Patent Laid-Open No. 5-6980)
2-85513, JP-A-59-76959), a method in which a foaming agent is added to the sheath component of the core-sheath type composite component, and the mixture is spun from a hollow fiber spinneret to form a large number of bubbles on the sheath side with a hollow core side. Kosho 43-19616) and the like are known. Also known is a method in which an inorganic filler is added to a thermoplastic resin, melt-spun, and then stretched to generate microvoids inside the fiber. However, these methods have the following drawbacks. That is, in the method of adding a foaming agent, regardless of whether it is a non-composite spinning method or a composite spinning method, the bubbles generated by the decomposition of the foaming agent are cleaved on the fiber surface, and the bubbles are aggregated in the fiber to form bubbles. It is not possible to stably produce low specific gravity fibers because of the large diameter, the necessity of adding a large amount of foaming agent, and the like. In addition, a fiber having a pearly feeling can be obtained by the method of adding an inorganic filler, but a low specific gravity fiber is not preferable because the inorganic filler has a high specific gravity and needs to be added in a large amount. I can't get it.

[0003]

SUMMARY OF THE INVENTION The object of the present invention is to solve the above-mentioned problems with the conventional polyolefin fibers, and to achieve a low specific gravity.
An object of the present invention is to provide a polyolefin fiber which has a feeling of rubbing and is capable of stably producing a fine fiber and a nonwoven fabric using this fiber.

[0004]

Means for Solving the Problems As a result of studying various production methods for the purpose of imparting a low specific gravity and a feeling of pearl to the fiber, the present inventor has found that a cyclopentadiene-based petroleum resin having a specific softening point is used as a polyolefin resin. The present inventors have reached the present invention by knowing that the above-mentioned object can be achieved more effectively by the addition thereof than in the case of adding a conventional foaming agent or inorganic filler. That is, the present invention comprises (1) a polyolefin resin containing 3 to 40% by weight of a cyclopentadiene-based petroleum resin having a softening point (ring and ball method) of 160 ° C. or more, a specific gravity of 0.89 or less, and a palle feeling. Low specific gravity polyolefin fibers, (2) Low specific gravity polyolefin fibers, wherein the polyolefin fibers described in (1) above are composite fibers composed of a plurality of polyolefin resins. (3) Each component of the composite fiber has a difference in melting point or softening point of 20 ° C.
Polyolefin composite fiber according to the above item 2, comprising a plurality of polyolefin resins as described above, and the low melting point resin forms the majority of the surface of the fiber, (4) Polyolefin with low specific gravity according to the above item 1 or 2. A non-woven fabric comprising 30% by weight or more of fibers and 70% by weight or less of other fibers, (5) comprising 30% by weight or more of the polyolefin olefin composite fiber having a low specific gravity described in the above item 3 and 70% by weight or less of other fibers, Is a non-woven fabric in which the contact points are bonded by a low melting point resin of a composite fiber.

The polyolefin resin used in the present invention is a polyolefin resin having a drawing temperature of less than 160 ° C. when drawing an undrawn yarn obtained by melt-spinning it by a factor of 2 or more, such as polypropylene, polyethylene and polybutene.
1, a binary or terpolymer of propylene and another α-olefin, or a mixture thereof.

The cyclopentadiene-based petroleum resin used in the present invention is a cyclopentadiene obtained from steam cracking of petroleum naphtha, dicyclopentadiene, and multimers thereof, or a mixture containing them as a main component. Minutes in the presence or absence of a solvent, preferably 22
At a temperature of 0 to 320 ° C., a high molecular weight high softening point containing 50% by weight or more of a cyclopentadiene-based component obtained by thermal polymerization for several hours or more under a pressure sufficient to keep the polymerization system in a liquid phase. A cyclopentadiene-based petroleum resin, a hydrogenated cyclopentadiene-based petroleum resin obtained by hydrogenating this petroleum resin by a conventionally known method, or a mixture thereof. Among the cyclopentadiene-based petroleum resins thus obtained, those having a softening point (ring and ball method) of 160 ° C. or higher are used in the present invention. When the softening point is less than 160 ° C., the fibers become transparent and do not generate a pal sensation as in Japanese Patent Publication No. Sho 41-7958 and conventionally known hydrogenated petroleum resins, and the fibers intended by the present invention are obtained. Can't get Among such cyclopentadiene-based petroleum resins, hydrogenated cyclopentadiene-based petroleum resins are preferable, and the softening point is particularly 17
Hydrogenated cyclopentadiene-based petroleum resin having an average molecular weight of 1200 or more and an iodine value of 20 or less measured at 0 to 200 ° C. by gel permeation chromatography method has excellent compatibility with polyolefin and is uniformly dispersed. Is preferable because it is possible to obtain fibers having excellent productivity such as spinnability and drawability, and having fineness and evenness in fineness.

In the present invention, the above cyclopentadiene-based petroleum resin (hereinafter sometimes simply referred to as petroleum resin) is added to the polyolefin resin in an amount of 3 to 4 with respect to the entire fiber.
Add 0% by weight. When the content of the petroleum resin is less than 3% by weight, the feeling of palling can be improved to some extent, but the specific gravity is 0.
It is not preferable because a polyolefin fiber having a low specific gravity of 89 or less cannot be obtained. Further, if the amount of the petroleum resin compounded exceeds 40% by weight, the spinnability and drawability of the fine-fine yarn are deteriorated, which is also not preferable. When the fiber is a composite fiber composed of multiple components, petroleum resin may be evenly mixed with each component,
Further, fibers having different color tones can be obtained by changing the blending amount for each component. Furthermore, when the composite fiber is a so-called heat-fusible composite fiber in which polyolefin resins having different melting points are used in combination, a polyolefin resin having a melting point equal to or lower than the softening point of the petroleum resin is used as the low melting point component,
As the high melting point component, a polyolefin resin having a melting point higher than that of the low melting point component by 20 ° C. or more is used, and the petroleum resin is blended only on the high melting point component side. As a result, the heat treatment for bonding the fibers can be carried out at a temperature equal to or lower than the softening point of the petroleum resin without eliminating the microvoids existing in the fibers. To the polyolefin fiber of the present invention, a small amount of an inorganic filler such as titanium oxide, mica, calcium carbonate, and various coloring materials are added for the purpose of changing the tone of the pearly feeling within a range that does not impair the effects of the present invention. You can also

The polyolefin fiber of the present invention is obtained by spinning a polyolefin resin blended with the above-mentioned petroleum resin by a conventionally known method (or composite spinning) and then doubling the temperature at a temperature not higher than the softening point of the petroleum resin, preferably 3-fold. It is obtained by stretching 9 times. When the stretching temperature is equal to or higher than the softening point of the petroleum resin or when the stretching ratio is less than 2 times, micro voids do not occur and fibers having low specific gravity and a pearly feeling cannot be obtained. The drawn yarn thus obtained may be crimped or not crimped, and may be a strand tip having a fiber length of 3 to 25 mm and a staple fiber having a fiber length of 25 to 120 mm.
It is widely used as a pull or multifilament for textile materials, non-woven materials or fillers, filling materials and the like.

The low specific gravity polyolefin fiber of the present invention is
By itself or as a mixed fiber of 30% by weight or more of this polyolefin fiber and 70% by weight or less of other fibers,
A non-woven fabric can be obtained by a conventionally known non-woven fabric manufacturing method. As a conventionally known non-woven fabric manufacturing method, a non-heat-bonding non-woven fabric manufacturing method such as a needle punch method, a water-needle method, a binder method, etc., further, a heat calendar roll method, a hot embossing roll method, a hot air method. A dryer method etc. can be illustrated. The non-woven fabric obtained by these methods is used alone or in combination with other materials as a composite material or the like.

[0010]

The present invention will be described in more detail with reference to Examples. The evaluation methods of physical properties in each example are shown below. Softening point: According to JIS K2207 (ring and ball method), (unit: ° C). Iodine value: According to JIS K0070. It refers to the number of grams of iodine added to unsaturated components in 100 g of a sample. Density: According to JIS L1015 (density gradient tube method). MFR: Melt Float Polypropylene: JIS K7210 Condition 14 (23
0 ° C., 2160 g). Polyethylene: JIS K7210 condition 4 (190
C., 2160 g). Peel: Polypropylene fiber without petroleum resin (2.
5d / f × 51mm) needle punch non-woven fabric (unit weight 100g / m ² , 10cm × 10cm) and non-woven fabrics or fibers (card webs) of each example are compared, and there is no or very little feeling of palling. It was judged that the sample had no palle and the sample having a marked pallet had a palle. Nonwoven fabric strength: A test piece with a width of 5 cm and a length of 15 cm is cut out from the nonwoven fabric, and the gripping interval is 10 cm, and the extension speed is 10 cm / mi.
The breaking strength (g / 50 mm) was measured by n (machine direction of the nonwoven fabric).

[0011]

Examples 1 to 5, Comparative Examples 1 to 4 Polypropylene having a melting point of 163 ° C. (softening point of 153 ° C.) MFR16 was mixed with various petroleum resins shown in Table 1 at the compounding amounts shown in Table 2. In each case, melt spinning was performed at a spinning temperature of 230 ° C. to obtain an undrawn yarn. These undrawn yarns were drawn 4.6 times at 70 ° C., crimped with crimps of 12 threads / 25 mm and then cut to obtain staple fibers of 18 d / f × 64 mm. The spinnability and stretchability were good in both Examples and Comparative Examples. These staple fibers were passed through a carding machine to make a web having a basis weight of 100 g / m ² , and then nidle punched to obtain a nonwoven fabric. The properties of the fibers and nonwovens are shown in Table 2. From Table 2, it can be seen that the one to which 3% by weight or more of the petroleum resin having a softening point of 160 [deg.] C. or more is added to the whole fiber has a specific gravity of 0.89 or less and is excellent in a feeling of pal ( Examples 1-5). On the other hand, it can be seen that the one to which no petroleum resin is added or the one to which a petroleum resin having a softening point of less than 160 ° C. is added does not have a lower specific gravity and has no pearly feeling (Comparative Examples 1 to 4).

[0012]

[Examples 6 to 7 and Comparative Examples 5 to 6] Polypropylene having a melting point of 163 ° C (softening point of 153 ° C) MFR38 was mixed with various petroleum resins shown in Table 1 at the compounding amounts shown in Table 3. In each case, melt spinning was performed at a spinning temperature of 240 ° C. to obtain an undrawn yarn. These undrawn yarns were drawn at 85 times at 4.0 times, crimped with crimps of 15 ridges / 25 mm and then cut to obtain staple fibers of 2.5 d / f × 51 mm. The spinnability and stretchability were good in both Examples and Comparative Examples. These staple fibers were made into a web having a basis weight of 20 g / m ² through a carding machine, and then thermocompression bonded at a temperature of 140 ° C. using a hot embossing roll to obtain a nonwoven fabric.
The properties of the fibers and nonwovens are shown in Table 3. It can be seen from Table 3 that 12% by weight of a petroleum resin having a softening point of 160 ° C. or higher has a specific gravity of 0.89 or less and is excellent in pearly feeling (Examples 6 and 7). . On the other hand, it can be seen that the ones to which the same amount of petroleum resin having a softening point of 160 ° C. or less is added do not have a lowered specific gravity and have no pearly feeling (Comparative Examples 5 and 6).

[0013]

Examples 8 to 10 and Comparative Example 7 Polypropylene fiber obtained in Example 7 and rayon of 1.5 d / f × 51 mm or polypropylene (core) of 2.0 d / f × 51 mm
/ Polyethylene (sheath) composite fibers are mixed in various ratios,
A web having a basis weight of 20 g / m ² was obtained through a carding machine. The webs are then heated to a temperature of 13 using a hot embossing roll.
By thermocompression bonding at 6 ° C., a nonwoven fabric having a basis weight of 20 g / m ² was obtained. The characteristics of the non-woven fabric are shown in Table 4. From this table, it is understood that a non-woven fabric having a pearly feel can be obtained by mixing 30% by weight or more of fibers having a low specific gravity and a pearly feel.

[0014]

[Table 1]

[0015]

[Table 2]

[0016]

[Table 3]

[0017]

[Table 4]

[0018]

Examples 11 to 16 and Comparative Examples 8 to 10 Polypropylene having a melting point of 163 ° C. (softening point 153 ° C.) MFR12 was used as the first component, and a melting point of 133 ° C. (softening point 1 was used as the second component.
16 ° C.) high-density polyethylene was used, and various petroleum resins shown in Table 1 were added and mixed in the respective components at the compounding amounts shown in Table 5, and the spinning temperature was 230 for both the first component and the second component. Melt-spinning is carried out by a composite spinning method at a temperature of ℃ and the first component is the core component and the second component is the sheath component, and the composite ratio is 1: 1.
A core-sheath type composite fiber undrawn yarn was obtained. These unstretched yarns were stretched 5.6 times at 80 ° C, and the crimper 12 threads / 2.
14d / f × 64m after cutting with 5mm crimp
m staple fibers were obtained. The spinnability and stretchability were good in both Examples and Comparative Examples. These staple fibers were passed through a carding machine to make a web having a basis weight of 100 g / m ² ,
Next, needle punching was performed to obtain a nonwoven fabric. The properties of the composite fiber and the non-woven fabric are shown in Table 6. From Table 6, 3 petroleum resins with a softening point of 160 ° C.
It can be seen that those added in an amount of not less than wt% have a specific gravity of 0.89 or less and are excellent in pearly feeling (Examples 11 to 11).
16). On the other hand, it can be seen that the one without addition of petroleum resin or the one with addition of petroleum resin having a softening point of less than 160 ° C. does not decrease in specific gravity and has no palle feeling (Comparative Examples 8 to 1).
0).

[0019]

Example 17, Comparative Examples 11 to 12 Polypropylene having a melting point of 163 ° C. (softening point 153 ° C.) MFR20 was used as the first component, and a melting point of 138 ° C. (softening point 125 was used as the second component.
Ethylene butene-1 containing propylene as the main component
Using the ternary copolymer of No. 3, the various petroleum resins shown in Table 1 were added and mixed only in the first component at the compounding amounts shown in Table 6, and the spinning temperature was 240 ° C as the first component and the second component as the second component. Is 2
Melt spinning was performed by a composite spinning method at 80 ° C. to obtain a core-sheath type composite fiber undrawn yarn having a composite ratio of 1: 1 in which the first component was a core component and the second component was a sheath component. 7 of these undrawn yarns
Stretched at 3.9 times at 0 ° C, 14 peaks / 25m in crimper
2.5 d / f × 51 mm after cutting after crimping m
To obtain staple fiber. The spinnability and stretchability were good in both Examples and Comparative Examples. These staple fibers were made into a web having a basis weight of 20 g / m ² through a carding machine, and then thermocompression bonded at a temperature of 130 ° C. using an embossing roll to obtain a nonwoven fabric. The properties of the composite fiber and the non-woven fabric are shown in Table 6. From Table 6, the softening point is 160 ° C for the entire composite component.
If the above petroleum resin is added in an amount of 3% by weight or more, the specific gravity is 0.
It can be seen that it is 89 or less and is excellent in pearly feeling (Example 7). On the other hand, it can be seen that the specific gravity of the petroleum resin added amount of less than 3% by weight or the addition of the petroleum resin having a softening point of less than 160 ° C. does not decrease, and there is no feeling of pal. (Comparative examples 11-12).

[0020]

Example 18, Comparative Examples 13 to 14 The polypropylene used in Example 17 was used as the first component, and 50% high density polyethylene having a melting point of 133 ° C. and a melting point of 128 were used as the second component.
Using a mixture of 50% linear low-density polyethylene at 50 ° C., a core-sheath type composite fiber was produced under the same conditions as in Example 17, and 2.5 d / f × 51 mm staple fiber was obtained.
The spinnability and stretchability were good in both Examples and Comparative Examples. These staple fibers were made into a web in the same manner as in Example 17, and thermocompression bonded at a temperature of 125 ° C. using an embossing roll to obtain a nonwoven fabric having a basis weight of 20 g / m ² . The properties of the composite fiber and the non-woven fabric are shown in Table 6. From Table 6, it can be seen that the one to which 3% by weight or more of the petroleum resin having a softening point of 160 ° C. or more is added to the entire composite component has a low specific gravity and is excellent in a pal feeling (Example 18). . On the other hand, it can be seen that those having a petroleum resin content of less than 3% by weight or petroleum resin having a softening point of less than 160 ° C. do not have a reduced specific gravity and have no pearly feeling (Comparative Examples 13 to 14). ).

[0021]

Examples 19 to 21 and Comparative Example 15 The composite fiber obtained in Example 18 was mixed with 1.5 d / f × 51 mm rayon at various ratios, and a basis weight of 20 g / m was passed through a carding machine.
Got ² webs. Next, these webs were thermocompression bonded at a temperature of 130 ° C. using an embossing roll to give a basis weight of 20 g / m ^2.
A non-woven fabric was obtained. The characteristics of the non-woven fabric are shown in Table 7. From Table 7, it can be seen that a non-woven fabric having a pearly feel can be obtained by mixing 30% by weight or more of the composite fiber having a low specific gravity and having a pearly feel.

[0022]

[Table 5]

[0022]

[Table 6]

[0023]

[Table 7]

[0024]

Industrial Applicability The fibers and nonwoven fabrics of the present invention have a lower specific gravity than ordinary polyolefin fibers and the like, and are excellent in pearly feeling. The fiber of the present invention can be knitted or woven after spinning, or can be used as a non-woven fabric, and the fiber product can be used alone or in combination with other materials for a wide range of applications such as vehicle ceiling materials, packaging materials, interior materials, and sanitary materials.

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Claims (5)

[Claims] 1. A softening point (ring and ball method) comprising a polyolefin resin containing 3 to 40% by weight of a cyclopentadiene-based petroleum resin having a temperature of 160 ° C. or higher, and having a specific gravity of 0.89 or less and a low specific gravity with a pearly feel. Polyolefin fiber. 2. The polyolefin fiber according to claim 1,
A low specific gravity polyolefin fiber that is a composite fiber composed of multiple polyolefin resins. 3. Each component of the composite fiber comprises a plurality of polyolefin resins having a difference in melting point or softening point of 20 ° C. or more,
The low melting point resin forms the majority of the fiber surface.
Polyolefin composite fiber as described. 4. The low specific gravity polyolefin fiber according to claim 1 or 2, and 30% by weight or more of the other fiber and 70% by weight of the other fiber.
A non-woven fabric consisting of: 5. A non-woven fabric comprising 30% by weight or more of the low specific gravity polyolefin composite fiber according to claim 3 and 70% by weight or less of other fibers, and the contact points of the fibers are bonded by a low melting point resin of the composite fiber.