JPH01201518A - Production of pulpy material consisting of thermotropic polyester - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention is a method for producing a pulp material made of thermotropic polyester. Fields such as backing materials, gasket materials, filtration materials, and abrasive materials for wear materials (mixed with other fibers and resins),
It is widely used in paper products for industrial materials (e.g., vibration materials for speaker cones, insulating paper, heat-resistant paper, etc.).

[Prior art]

Although there are several published techniques for producing pulp-like short fibers made of aramid, no practical method for producing them from thermotropic polyester is known.

[Problems to be Solved by the Invention] Generally, it is very difficult to produce a pulp-like material by applying shearing force to a thermoplastic polymer and pulverizing it, as it also causes agglutination and fusion. In the case of thermotropic polyester, the present inventors have found that this possibility is somewhat high, but the conventional method causes stagnation and powdery substances as well as fibrils. (The fiber length is too short).

On the other hand, there was also the problem that the obtained pulp-like material had poor dispersibility in other media, making it impossible to obtain a product strength sufficient to withstand use.

[Means for solving problems]

In the present invention, an aromatic polyester capable of forming an anisotropic melt is discharged from a nozzle at a temperature higher than the flow temperature of the chopped polymer by 910 C or more and at a shear rate of 103 sec-' or more. This is a method for producing a pulp-like material made of thermotropic polyester, which is characterized in that fibers and/or strands are crushed and fibrillated.

Preferred examples of aromatic polyesters capable of forming anisotropic melts according to the present invention are those consisting of a plurality of combinations of the following repeating components, and other components include polyethylene terephthalate, polyolefins, polycarbonates, and other polyesters. Thermoplastic polymers such as arylates and polyamides, or
It may contain titanium oxide, kaolin, silica, 5 [barium, carbon black, pigments, etc., or 10 or less of antioxidants, ultraviolet absorbers, light stabilizers, etc.].

The effects of the present invention are most clearly exhibited in the system of
In particular, it is an aromatic polymer containing 5 to 45 moles of naphthoic acid component.

The melt anisotropy referred to in the present invention refers to optical anisotropy in the melt phase. Such characteristics can be easily recognized by a known method, for example, by heating a sample placed on a hot stage in a nitrogen atmosphere and observing the transmitted light. It is necessary to discharge from the nozzle at a high temperature and at a shear rate (f) of 103Sec-1 or more. Anisotropic melts develop orientation when expelled from a nozzle under shear. If t is less than 10"aec-', it becomes powdery during crushing, the fiber length is short, and strength cannot be obtained when used as a product. If t is 10 sec or more, good fibril shearing is achieved. Velocity (log?) and melt viscosity (logη)
It shows the relationship between This shows that the higher tK is, the lower η is. The preferred range of t is 10'' to 10'
sec.

In the case of a circular nozzle, the shear rate t referred to in the present invention is determined by the following equation.

t=tan(5ea-') πr3 However, r: Radius of nozzle hole (CM) Q: Poly of single hole ib! - Discharge amount (cTVaec) The obtained fibers and/or strands are transferred to a pulverization process, but for operational reasons, they can be cut into 10 to 1000 s+s+ for use. Further, preferably, heat treatment is performed at a temperature below the flow temperature in air or in an inert atmosphere before pulverization, so that heat resistance is improved and fibrillation is facilitated (powdery material is difficult to form).

Examples of mechanical operations for fibrillating fibers and/or strands according to the present invention include various grinders, mills, beaters, dijordans, Refiners and the like are effectively used, but in either case it is necessary to carry out the process in a wet state.

A preferable wet state condition is a wet state in which the amount of emulsion containing water or an oil agent is 1 or more (weight ratio) to 1 fiber and/or strand-like material.

If mechanical shearing is applied in a dry state or in a state with a low wetness rate, partially agglomerated crumbs and powdery debris are produced, and the good pulp-like material targeted by the present invention cannot be obtained. The preferred wetting ratio is 1:1 to l:100.

Examples of preferred oils used in the present invention include the following A
, L) A: Ho9 ethylene glycol alkyl ether B: Copolymer of propylene oxide and ethylene oxide Φ side C: Polyethylene glycol D: XM alkyl phosphate, sulfonate, sulfosuccinate and/or their salts alone or in combination At least 30% of total oil
%. Preferred molecule of component B -fi(
MW) is 1,000 to 10,000, and the C component is 1 to 10,000.
It is 200,000.

As other oil components, fluorine-based activators, silicone-based activators, epoxy-based emulsions, etc. may be added, taking into account the intended use of the product. A preferred oil concentration is 0.5% or more and 30% or less. Further, the preferable amount of the oil agent attached to the valve-shaped object is O,OS to 1.0%.

When fibrillated in the above-mentioned oil, it is possible to significantly prevent the formation of stickiness and powdery substances, and when used as a product, dispersion in water or resin provides good interfacial layering properties. The strength and durability of the secondary layer product is improved.

Hereinafter, the present invention will be explained more specifically using Examples.
The present invention is not limited to these examples.

Example 1 A wholly aromatic polyester polymer was prepared in which the structural units (1) and (n) were 7=3. The properties of this polymer are η1nh=6. l dll f MP = 279°C. However, the measurement of the logarithmic viscosity ηinh was performed as follows.

The sample was dissolved in 0.1% by weight of pentafluorophenol (60 to 80°C), and this polymer was measured using an Utsuberohde viscometer in a constant temperature bath at 60°C. This polymer was attached to the tip of the extruder: & 0.6 φ The nozzle i) discharged the polymer at 300° C. with a single hole discharge rate of 20 v/min. The shear rate at this time is 1.1
3XIQ'5ec-1.

The discharged fibrous material was sucked with an air sucker, further finely cut, and then cut into a length of 25 m.

When this material was treated with a beader for 6 hours at a wet ratio of 1:50 with water, a pulp-like material that was well formed into fibrils was obtained.

Comparative Example 1, Examples 2 to 7 Using the polymer of Example 1, spinning was performed by changing the nozzle diameter and suctioning with an air sucker, and the obtained fibrous material was cut into 25 m+. 12 at 270℃
After being treated in an N2 gas atmosphere for a period of time, each sample was treated multiple times in a refiner under the conditions shown in Table 1 to form fibrils.

Table 1 [Oil agent] W; Water.

W-1: Polyether modified silicone oil W-2: P
OE (8) Phosphate, anionic oil agent W-3 mainly composed of K: POE (3) Nonylphenyl ether, PO/
EO (oil agent containing MWW20O58 and anionic surfactant [judgment of fibrillation]) X: Fibers are crushed or powdered.

Δ: Slight sticking areas and poorly fibrillated areas 00: Relatively good fibrillation.

◎: Fiber lengths are relatively uniform and fibrillation is good.

[Determination of dispersibility]

For pulp 1, water is 100%, and the nullary material stirred with a mixer is 10000% and put into a υ test tube and observe the state after 1 hour.

Δ: A considerable layer of separated water is formed at the top.

O: Separated water layer is 10% or less.

◎: There is almost no separated water layer.

In Comparative Example 1, there were few fibrils and the fiber length was 1 m.
The following powdery substance was obtained.

In Example 2, there were some parts where fibrillation was not sufficiently performed. Further, when treated with a refiner, some of the particles stuck and became bead-like, and the water dispersibility was also poor.

In Examples 3 and 4, the water dispersibility was relatively improved, but the water dispersibility was not significantly improved.

Examples 5 and 6 had good fibrillation and improved 91 dispersibility, and Example 6 was particularly good.

In Example 7, in which the wetting ratio was reduced, fibrillation was not sufficient, and as a result, the dispersibility was also slightly lowered.

Example 8 An anisotropic melt with a flow temperature of 230 °C and a melt viscosity (250 °C, day 1000) of 400 voids, which is 0.2-φ
For X500H nozzle, 'r = 2.3 x 10
It was discharged at '5ea-' and wound up at 1000 m/min. This material was cut into 5 square pieces, treated at 220°C for 10 hours and at 240°C for an additional 10 hours in a nitrogen atmosphere, and then fibrillated under the conditions of Example 6. Fibrillation was evaluated as (○), and dispersibility was also evaluated as (0).

Compared to the polymer of Example 6, it was somewhat difficult to fibrillate, and as the number of treatments was increased, it tended to become powder.

[Brief explanation of the drawing]

Figure 1 shows the shear rate (logte) and melt viscosity (
10g7). Patent applicant RiRa Shi Co., Ltd.

Claims (1)

[Claims] 1) An aromatic polyester capable of forming an anisotropic melt,
The polymer is discharged from a nozzle at a temperature 10°C or more higher than the flow temperature of the polymer and at a shear rate of 10^3sec^-^1 or more, and the resulting fibers and/or strands are machined in a wet state. 1. A method for producing a pulp-like material made of thermotropic polyester, which comprises applying a shearing force through manual operation to crush the fibers and/or strand-like material to form fibrils. 2) The aromatic polyester capable of forming an anisotropic melt is
The portion consisting essentially of the following repeating structural units [I] and [II] is 90% by weight or more, and the unit [II] is 5 to 5% by weight.
A method for producing a pulp-like material made of thermotropic polyester according to claim 1), wherein the content is 50 mol%. ▲There are mathematical formulas, chemical formulas, tables, etc.▼・・・・・・・・・
[I] ▲There are mathematical formulas, chemical formulas, tables, etc.▼・・・・・・・・・
[II] 3) Claim 1, wherein the wet state is 1 or more (weight ratio) of water to 1 of fibers and/or strands.
) A method for producing a pulp-like material made of thermotropic polyester according to item 2. 4) The wet state is 1 part fiber and/or strand-like material to 1 part or more of an emulsion containing the following oil agent (weight ratio)
A method for producing a pulp-like material made of thermotropic polyester according to claim 1). [Emulsion] Emulsion A in which the following oils A, B, C, and D are used alone or in combination, accounting for at least 30% of the total oil and having a total oil concentration of 0.5% by weight or more: polyethylene glycol, alkyl ether B: Copolymer of propylene oxide and ethylene oxide C: Polyethylene glycol D: Higher alkyl phosphate, sulfonate, sulfosuccinate and/or salts thereof