JPH01221507A - Production of split fiber and production of split fiber aggregate using same - Google Patents

Abstract

PURPOSE:To obtain highly crimpy fibrillar fiber without causing interlaminar debonding and little forming powdery product, by splitting a drawn tape of multilayered film with each layer made up of a mixture of polyethylene and polypropylene. CONSTITUTION:A double-layered film consisting of polypropylene and polyethylene is slitted and drawn, or vice versa, to produce a drawn tape, which is then split into the objective fibrillar fiber. The structure of said film is as follows: one layer is made up of a blend of (1) 70-95wt.% of polypropylene with a MI of 0.5-10 and (2) 5-30wt.% of polyethylene with a MI of 0.5-20 and the other layer is made up of a second blend is (3) 70-95wt.% of polyethylene with a MI of 0.5-20 and (4) 5-30wt.% of polypropylene with a MI of 0.5-10.

Description

[Detailed Description of the Invention] The present invention relates to a method for producing defibrated fibers and a method for producing a defibrated aggregate using the defibrated fibers, and more particularly, to a method for producing defibrillated aggregates using a composite synthetic resin film. The present invention relates to a method for producing defibrated fibers having crimpability and a fibrillar structure, and a method for producing a defibrated aggregate using the defibrated fibers.

Day's technique 01 view and the. The subject.

M, tli, so-called composite fibers, which are made by combining at least two types of synthetic resins with different properties, are chemical fibers that have crimpability and a fibril structure.

Conventionally, one method for producing composite fibers is to stretch and slit a composite synthetic resin film composed of two layers of raw materials of two different properties, such as polypropylene and polyethylene, to produce a stretched tape. There is no method for producing composite fibers from defibrated fibers obtained by defibrating a stretched tape (Japanese Patent Application Laid-Open No. 149905/1983).

However, the defibrated fibers obtained by defibrating conventionally known composite synthetic resin films have the problem that delamination easily occurs;
There is a problem that it is easy to peel off during stretching, and for example, a composite synthetic resin film consisting of a polypropylene layer and a polyethylene layer has a problem that the polyethylene falls off during fibrillation, causing so-called powder drop.

The present invention aims to solve the problems associated with the conventional technology as described above, and aims to improve the interlayer adhesion of a composite synthetic resin film, improve its stretchability, and improve its stretchability during defibration. Eliminate powder fall-off and high l? ! It is an object of the present invention to provide a method for producing defibrillated fibers having m-character and fibrillar structure. Another object of the present invention is to provide a network-like defibrated aggregate using the above-described defibrated fibers.

The method for producing defibrated fibers according to the present invention involves slitting and stretching a composite synthetic resin film consisting of at least two layers, or stretching and slitting to produce a stretched tape, and defibrating the stretched tape. When producing defibrillated fibers, one layer has zero melt index as a composite synthetic resin film.
．． The polypropylene layer is made by mixing 70 to 95% by weight of polypropylene with a melt index of 0.5 to 10 and 5 to 30% by weight of polyethylene with a melt index of 0.5 to 20, and the other layer is made of 70 to 95% by weight of polyethylene with a melt index of 0.5 to 20. 9
It is characterized by using a composite synthetic resin film which is a polyethylene layer made by mixing 5% by weight of polypropylene with 5% to 30% by weight of polypropylene having a melt index of 0.5 to 10.

In addition, the method for producing a defibrated aggregate according to the present invention includes slitting and then stretching a composite synthetic resin film consisting of at least two layers, or stretching and then slitting to produce a stretched tape, and defibrating this stretched tape. Either the resulting defibrated fibers are mixed alone, or the defibrated fibers and a vegetable fiber material are mixed, and then heated at a temperature between the melting points of polyethylene and polypropylene, so that the defibrated fibers can be mixed with each other or the defibrated fibers can be mixed with the vegetable fiber material. It is characterized by being integrated with a synthetic fiber material.

Hereinafter, the method for producing defibrated fibers and the method for producing a defibrated aggregate using the defibrated fibers according to the present invention will be specifically explained.

First, the defibrillation according to the present invention will be explained.

In order to produce the defibrated fiber according to the present invention, a composite synthetic resin film is first prepared. In addition, "composite synthetic resin film"
The term ``'' is used in a meaning that also includes composite synthetic resin sheets.

The composite synthetic resin film used in the present invention is composed of at least two layers, and the composite synthetic resin film composed of two layers will be described below.

Specifically, the two-layer composite synthetic resin film used in the present invention includes a first layer made of polypropylene 70 to
The polypropylene layer has a high polypropylene content, which is made by mixing 95% by weight of polyethylene and 5 to 30% by weight of polyethylene, and the second layer is made of polyethylene, which is made by mixing 70 to 95% by weight of polyethylene and 5 to 30% by weight of polypropylene. A composite synthetic resin film with a high content polyethylene layer is used. Among them, the first layer is polypropylene 88
The polypropylene layer is a mixture of ~92% by weight of polyethylene and 8-12% by weight of polyethylene, and the second layer is a polyethylene layer made of a mixture of 88-92% by weight of polyethylene and 8-12% by weight of polypropylene. A composite synthetic resin film is preferred.

The properties of the polypropylene constituting the first layer used in the present invention and the properties of the polypropylene constituting the second layer used in the present invention are within the same range, and the properties of the polypropylene constituting the first layer used in the present invention are within the same range. The properties of the polyethylene used in the present invention and the properties of the polyethylene constituting the second layer used in the present invention are within the same range.

As the polypropylene used in the present invention, specifically, polypropylene having a melt index (according to JIS K6760, the same applies hereinafter) of 0.5 to 10 is used, and among them, polypropylene having a melt index of 2 to 8 is preferable. used. Furthermore, the polyethylene used in the present invention has a melt index of 0.
．． 5 to 20 polyethylene is used, especially 1
-8 polyethylene is preferably used.

As the polyethylene used in the present invention, low density polyethylene is preferably used.

The composite synthetic resin film used in the present invention is composed of a first polypropylene layer and a second polyethylene layer, and the first layer is made of polyethylene, and the second layer is made of polypropylene, respectively. Because it is blended in a specific ratio, the interlayer adhesion between the first layer and the second layer is good, and the stretchability of the composite synthetic resin film can be improved. Falling can be prevented.

Further, the first layer and the second layer constituting the composite synthetic resin film used in the present invention are usually 40 to 75% by weight of the first layer.
, are laminated to a thickness such that the second layer contains 125 to 60% by weight of N, and in particular, with respect to 50 to 70% by weight of the first layer,
A composite synthetic resin film containing 30 to 50% by weight of the second layer is preferably used.

In this way, when the weight of the first layer is greater than the weight of the second layer, the defibrated aggregate has a greater elastic recovery force and tends to be bulkier. In general, a composite synthetic resin film in which the weight ratio of the first layer to the second layer is 5=5 is preferred because it is easy to produce.

Further, in the present invention, although the total thickness of the composite synthetic resin film is not particularly limited, a composite synthetic resin film having a thickness of 27 to 150 μm is preferably used.

In addition to polypropylene and polyethylene, which are the components of the composite synthetic resin film, pigments, dyes, lubricants, ultraviolet absorbers, flame retardants, etc. can be added to the extent that they do not impair the object of the present invention.

Next, a method for producing defibrillated fibers according to the present invention will be explained.

The composite synthetic resin film used in the present invention can be manufactured by conventionally known film forming methods such as melt extrusion, calendering, and casting. Among these, extrusion methods using an inflation method and a T-die method are preferred.

Next, the prepared composite synthetic resin film is slit and then stretched, or stretched and then slit to produce a stretched tape.

For stretching the composite synthetic resin film, conventionally known stretching machines such as a nip roll type, a clover roll type, or a continuous stretching type can be used.

The stretching temperature and stretching ratio when stretching a composite synthetic face fat film vary depending on the stretching method, the composition of the composite synthetic resin film, etc., but for example, when stretching a composite synthetic resin film with a hot roll, the stretching temperature is usually 97°C. ~138℃
The stretching ratio is 3 to 10 times.

Furthermore, the stretched tape obtained through the slitting and stretching process described above is finely defibrated by passing it between rollers with serrated knives or needles, for example, to obtain defibrated fibers in the form of a fine network. It will be done.

Further, if necessary, the above-mentioned defibrillated fibers can be cut using a cutter or the like.

As mentioned above, the defibrated fiber obtained by the production method according to the present invention is made of two different synthetic resins, and is made of rj &
Because it is defibrated into a fine mesh, it has high crimpability.
It also has a fibrillar structure.

Next, a method for producing a defibrated aggregate according to the present invention will be explained.

The method for producing a defibrillated aggregate according to the present invention includes a case in which a waste fiber aggregate is produced by mixing the fine network-shaped defibrated fibers obtained as described above alone, and a case in which a waste fiber aggregate is produced by mixing the fine network-shaped defibrillated fibers obtained as described above alone. There are cases where a waste fiber aggregate is produced by mixing defibrillated fibers and a vegetable fiber material.

Specifically, the vegetable fiber materials used in the present invention include cotton, hemp, jute, hemp, pulp, and the like.

The size of the vegetable fiber material used in the present invention varies depending on the use of the waste fiber aggregate, etc., but usually the fiber length is 1 to 1.
5fi and a fiber diameter of 5 to 15 μm is used.

Next, the network-like dissolved fibers are mixed alone, or the network-like dissolved fibers and a vegetable fiber material are mixed using a cotton blending machine or the like, and then heated at a temperature between the melting points of polyethylene and polypropylene, When the disintegrated fibers or the disintegrated fibers and the vegetable fiber material are integrated, a waste fiber aggregate is obtained.

The waste fiber aggregate obtained by the production method according to the present invention is
It consists of fine mesh-like dissolved fibers and a vegetable fiber material, and the vegetable fiber material is fixed in the mesh-like dissolved fibers. Moreover, this waste fiber aggregate has excellent adhesiveness with other materials,
Since the fibers with a high melting point, ie, polypropylene, maintain their shape even when bonded, they have elasticity and have a sublime quality. The monolysed fibers are water repellent and do not lose their rigidity when wet.

EXAMPLES The present invention will be explained below with reference to Examples, but the present invention is not limited to these Examples.

Resins to be used in the polypropylene layer and polyethylene layer constituting the K-barrel composite synthetic resin film were each prepared in the following manner.

Polypropylene with a melt index of 2.4 [Product number F-
401, manufactured by Mitsui Petrochemical Industries ■] and 5 parts by weight of polyethylene with a melt index of 2.0 [product number M-27, manufactured by Mitsui Petrochemical Industries ■] to obtain a resin for the polypropylene layer, and A resin for the polyethylene layer was obtained by mixing 95'M parts of the above polyethylene and 5 parts by weight of polypropylene.

Using 50 parts by weight of the prepared resin for the polypropylene layer and 50 parts by weight of the resin for the polyethylene layer, a composite synthetic resin film was produced under the following conditions.

[Manufacturing conditions for composite synthetic resin film - Resin blending ratio used in the first layer (polypropylene layer) - Resin blending ratio above F-401/M-27 = 9515 (weight ratio) Resin blending ratio used in the second layer (polyethylene layer) 2 above F
-401/M-27=5/95 (weight ratio) T-die extruder die diameter...300■X300+m Screen-'-80 Mash, 100 Mash, 1
50 Mesh, 200 Mesh, 100 Mesh
, 80 Mesh Resin extrusion speed: 14 m/min Film winding speed: 102 m/min [Temperature conditions] Using the obtained composite synthetic resin film, powder fallout during fibrillation of the stretched tape, stretching The properties, thermal adhesion, and degree of crimp of the defibrillated fibers were evaluated by the following methods.

[Evaluation method for powder fall] After slitting a composite synthetic resin film to a width of 30 In+, the stretched tape obtained by stretching at a stretching ratio of 7.3 times was defibrated with a serrated knife, and the state at the time of defibration was evaluated. Observe and evaluate.

[Method for evaluating stretchability] A composite synthetic resin film slit to a width of 30 times is stretched at a stretching ratio of 7 times and 9 times, and the number of breaks in the stretch is observed for a stretching time of 10 minutes to evaluate the stretchability.

(Display of evaluation) (Number of stretching breaks) O Δ 1 to 3 times × 5 times or more [Method for evaluating thermal adhesiveness] Crimp-defibrated yarn obtained by defibrating a stretched tape with a stretching ratio of 7.3 times 0 .5 g was sandwiched between two sheets of polypropylene nonwoven fabric [trade name "Syntex", manufactured by Mitsui Petrochemical Industries, Ltd.] and press-molded under the following molding conditions to produce a sample of size 2013AX 20 tx.

(Press forming conditions) Manual hot press, iron plate temperature 150°C (no press pressure, only iron plate weight), forming time 10 minutes The sample prepared as above was cut into a size of 15 mm wide and 10 mm long. The peel strength was measured using Tensilon manufactured by Shimadzu Corporation at a tensile rate of 20 mm/min to evaluate thermal adhesion.

[Method for evaluating the degree of crimp] The degree of crimp is evaluated by the crimp rate. The crimp rate is determined by the length jl when the initial load W1 (fiber denier
■/d), find the difference between the two (J
2-Jl) is divided by the latter 1□ and expressed as a percentage.

The results are shown in Table 1.

Example 1 was repeated in the same manner as in Example 1, except that the compounding ratio of the components of the composite synthetic resin film was set to the ratio shown in Table 1. ,
Thermal adhesion and the degree of crimp of the defibrillated fibers were evaluated.

The results are shown in Table 1.

In Example 1, a stretched tape was produced in the same manner as in Example 1, except that a composite synthetic resin film was prepared using only polypropylene as the resin for the polypropylene layer and using only polyethylene as the resin for the polyethylene layer. The powder shedding, stretchability, thermal adhesion, and degree of crimp of the defibrated fibers during defibration were evaluated.

The results are shown in Table 1.

Yokasa Plate 1 In the same manner as in Example 1, except that the blending ratios of the polypropylene layer and polyethylene layer constituting the composite synthetic resin film were both 50 parts by weight of polypropylene and 50 parts by weight of polyethylene. Evaluate the powder shedding, stretchability, thermal adhesion, and degree of crimp of the defibrated fibers during defibration of the stretched tape.

The results are shown in Table 1.

According to the method for producing defibrated fibers and the method for producing a defibrated aggregate using the defibrated fibers according to the present invention, the composite synthetic resin film has a first layer containing polypropylene as a main component,
It consists of a second layer containing polyethylene as a main component, and the first layer contains polyethylene, and the second layer contains polypropylene in the specific ratios mentioned above, so they are different from the first layer. The interlayer adhesion with the second layer is good, and the stretchability of the composite synthetic resin film can be improved, and powder falling off during fibrillation of the stretched tape can be prevented.

In addition, the defibrated fibers and defibrated aggregates obtained by the production method according to the present invention are made of 1aISI mesh-like defibrated fibers (and vegetable fiber materials) obtained from the composite synthetic resin film as described above, which are entangled with each other. Because of this, it has high crimpability and has a fibrillar structure, and has excellent elasticity and bulk.

Therefore, products using defibrillated fibers or defibrated aggregates having such characteristics have excellent bulkiness, a voluminous feel, a soft feel, and excellent heat retention.

Furthermore, since the composite synthetic resin film made of polypropylene and polyethylene has casing properties, the defibrated fibers and defibrated aggregates obtained by the production method according to the present invention do not lose their rigidity even when wet.

As described above, the defibrated fibers and defibrated aggregates obtained by the production method according to the present invention can be used for interior materials such as curtains, carpets, etc., clothing materials such as sweaters, diapers, etc. having the above-mentioned characteristics. It can be widely used for absorbing materials, vibration damping materials, exterior materials, packaging materials, etc.

Agent: Patent Attorney: Shunbetsu Suzuki

Claims (1)

[Claims] 1) A composite synthetic resin film consisting of at least two layers is slit and then stretched, or a stretched tape is produced by stretching and then slit, and the stretched tape is defibrated to produce defibrillated fibers. In this case, as a composite synthetic resin film, one layer is made of polypropylene 70 with a melt index of 0.5 to 10.
It is a polypropylene layer made of a mixture of ~95% by weight and 5-30% by weight of polyethylene with a melt index of 0.5-20, and the other layer is a mixture of 70-95% by weight of polyethylene with a melt index of 0.5-20 and a melt index of 0.5-20. 0
．． A method for producing defibrated fibers, which comprises using a composite synthetic resin film having a polyethylene layer formed by mixing 5 to 30% by weight of 5 to 10% polypropylene. 2) A composite synthetic resin film consisting of at least two layers is slit and then stretched, or a stretched tape is produced by stretching and then slit, and the defibrated fibers obtained by defibrating this stretched tape are mixed alone, or Alternatively, the defibrated fibers and the vegetable fiber material are mixed and then heated at a temperature between the melting points of polyethylene and polypropylene to integrate the defibrated fibers or the defibrated fibers and the vegetable fiber material. Method for producing defibrillated aggregate.