JPH0822933B2 - Thermoplastic polyurethane prepreg and method for producing the same - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel fiber-reinforced prepreg and a method for producing the same, and more particularly to a thermoplastic polyurethane prepreg and a method for producing the same.

[0002]

2. Description of the Related Art Generally, a prepreg is obtained by uniformly impregnating a thermosetting resin obtained by mixing a reinforcing material such as reinforcing fibers or a woven fabric thereof with a curing agent, a coloring agent and a filler at an appropriate ratio, drying and semi-curing. It is an intermediate composite material formed so that it can be further processed. Resins used for forming such prepregs are mainly unsaturated polyester resins,
A thermosetting resin such as an epoxy resin is used.

In the conventional formation of prepregs, the resin impregnated with the thermosetting resin is subjected to a suitable heat treatment so that the resin is partially reacted, that is, B-staged, and finally the secondary processing is performed. Was taken. However, with a prepreg using a thermosetting resin, the storage period is short,
Refrigerant storage is required, and the waste product of the prepreg has a drawback that it causes environmental pollution because there is still no effective recovery method.

Further, as a method for producing a prepreg using a thermosetting resin, there are generally the following three types: (1) solvent type, (2) heat fusion type, and (3) film type.
When applying these manufacturing methods to the continuous forming method,
There are problems as described below, and none of the manufacturing methods can be said to be sufficient.

(1) Solvent type: This method is very slow in the production process for removing the solvent, and it is necessary to remove the solvent as much as possible. In order to do so, the solvent must be completely removed in a very short time, which is practically impossible, and there is a problem that the residual solvent greatly affects the quality of the product.

(2) Heat-melting type: This method requires that the thermosetting resin be retained in the resin tank at a high temperature for a long time, so that the deterioration of the resin is very likely to occur and the quality of the product is greatly affected. In addition, there is a problem that the resin in a molten state has a high viscosity and it is difficult to impregnate the fiber.

(3) Film type: In this method, a polymer film and a fiber woven fabric are used by continuous lamination, and after the heated polymer film is melted, the viscosity of the film is increased to give the fiber woven fabric. There is a problem that it is difficult to impregnate.

Despite the demand for a prepreg and a method for producing the same (continuous formation) that solves the above problems, the present situation is that the prepreg has not yet been sufficiently obtained.

[0009]

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide reworkability, waste reusability, repairability, weldability, good thermal stability and long storage time. The present invention provides a thermoplastic resin pull prepreg.

Another object of the invention is the unique abrasion resistance, elasticity, flexibility, puncture resistance, oil resistance of polyurethane polymers,
The present invention provides a thermoplastic resin polyurethane pull prepreg having excellent properties such as solvent resistance.

Yet another object of the present invention is to provide a method for producing a thermoplastic resin polyurethane pull prepreg capable of completely removing a solvent in a short time without deterioration of an impregnated resin even when it is retained in a resin tank at a high temperature for a long time. To do.

Another object of the present invention is to provide a method for producing a thermoplastic resin polyurethane pull prepreg having a sufficiently long resin pot life at a viscosity such that the polyurethane resin used can obtain good impregnation with fibers.

[0013]

In view of the above circumstances, the present inventors have earnestly studied prepreg and a method for producing the same, and as a result, have used a thermoplastic polyurethane resin instead of a thermosetting resin. The present invention has been completed by finding a thermoplastic polyurethane prepreg having the excellent urethane properties of the resin and a manufacturing method capable of forming the prepreg.

[0014]

That is, in the present invention, a fiber composed of a plurality of fibers is pulled by a polyurethane elastomer emulsion having a viscosity of 150 to 4000 cps, the fiber impregnated with the emulsion is wound around a core shaft, and the water content therein is heated. removed, after forming the polyurethane elastomer composites of fiber reinforced, removed, is achieved Ri by the method for producing a thermoplastic polyurethane prepreg consists in cutting the composite material along the axial direction.

[0016]

[0017]

The thermoplastic polyurethane resin used in the present invention has a urethane group in the unit molecule of the resin, and the structure of the resin has a hard chain step (hard segment, represented by B) and a soft chain. Chain stage (soft segment, A
It is a kind of artificial elastomer which is a (AB) n type block copolymer consisting of

Further, the hard chain stage is a urethane or urethane urea low molecular weight polymer produced by reacting a diisocyanate with a low molecular weight diol or diamine as a chain extender, and has a molecular weight of 300 to 3000. is there. The soft chain has a molecular weight of 500 to 5000, which is formed by combining a polyalkyl diol and a diisocyanate. The polyurethane elastomer has unprecedentedly high elasticity due to its network structure, and basically has a sufficiently long resin pot life, and is apparent even when it is retained in a resin tank at a high temperature for a long time. It has a viscosity that does not increase.

Next, as a method of using the polyurethane resin by impregnating fibers with the present invention, an aqueous method can be used. This method will be described below.

[0020]

[0021]

In the aqueous method according to the present invention , the polyurethane elastomer is dispersed in water to form a water emulsion of the polyurethane elastomer, and the viscosity is suitable for processing.
The viscosity of the water emulsion is adjusted and controlled so as to be in the range of 50 to 4000 cps. When the fibers thus obtained, which are impregnated with the water-based emulsion of the polyurethane elastomer, are heated, water is expelled, and a polyurethane elastomer composite material as a prepreg is obtained. Actually, the polyurethane elastomer is not dissolved in water, but it is "water-based" because it is different from water-insoluble polyurethane.
I decided to call it.

As the form of the water-based emulsion of the polyurethane elastomer, those dispersed in water using (a) an emulsifier method, (b) an ionic group introduction method, or (c) a nonionic hydrophilic group introduction method are used. Is mentioned. As such a method, it can be manufactured by many methods shown below.

(A) A method for producing a polyurethane group using the method of using an emulsifier is described in Hepburn, C. "Polyurethane Elas.
tomer ", Applied Science Publishers, New York, pp.268-
278 (1982), T. Tokuyo, Kagaku Kogyo Kogyo monthly report, 9th term
(1986) and the like, and can be obtained by these methods.

(B) As a method for producing a polyurethane group using the ionic group introduction method, Dieterich, D. and Reiff, H. "
Advances in Urethane Science & Technology "Vol.4, Te
chnomic Publishing Co. Inc., PA. USA, pp. 112-131 (197
6) and Spekhard, TA, et al., J. Macromol. Sci. Phy.
s., B23, pp.175-199 (1984) and the like, and the method can be used.

(C) A method for producing a polyurethane group using the method of introducing a nonionic hydrophilic group includes Miller, JA, et a.
l., J. Macromol. Sci. Phys., B22, p.322 (1983) and H.
wang, KKS, et al., Polym. Eng. Sci., 21, pp.1027-1
The methods described in 036 (1981) and the like can be mentioned, and they can be obtained by these methods.

The water-based emulsion of the polyurethane elastomer preferably contains 25 to 60% by weight of solid components.

[0028]

[0029]

[0030]

[0031]

[0032]

[0033]

Next, as the shape of the fiber used in the method of the present invention, a continuous type comprising at least one selected from filament, yard bundle, linear, cord, cloth or blanket shape is used. Reinforcing fibers are mentioned.

The material of the fiber may be either inorganic or organic fiber and is not particularly limited, and examples thereof include glass fiber, carbon fiber, aramid fiber and blended fiber.

The winding tension of the fibers in the method of the present invention is in the range of 30 to 120 Newtons (N). If the tension exceeds 120 N, the fiber cannot withstand the tension and breaks, which is not preferable. On the other hand, when the tension is less than 30 N, the content of fibers contained in the obtained thermoplastic polyurethane prepreg is reduced, the impact and bending strength, which are its physical properties, are also reduced, and since a large amount of resin is contained, the solvent contained in the resin. It is not preferable because it takes a relatively long time to remove such substances.

The fiber content in the thermoplastic polyurethane prepreg of the present invention is in the range of 30 to 75% by volume. If the fiber content exceeds 75% by volume, the winding tension in the process needs to be extremely high,
Therefore, the yield deteriorates, such as the fiber itself breaking,
Further, the quality becomes unstable, which is not preferable. On the other hand, if it is less than 30% by volume, the physical properties of the prepreg, such as impact and bending strength, are deteriorated, and since a large amount of resin is contained, it takes a relatively long time to remove the solvent and the like contained in the resin, which is not preferable. .

[0038]

EXAMPLES Next, the present invention will be described in more detail with reference to Examples, but it goes without saying that the present invention is not limited to these Examples.

Example 1 (1) Preparation of Impregnating Resin: A polyurethane resin used as the impregnating resin was prepared so as to have the constituent components shown in Table 1 below. Among them, in the preparation of the solvent-type polyurethane, the polyurethane resin content is dissolved in dimethylformamide as a solvent so that the content of the polyurethane resin is 30% by weight, and a solvent of methylethylketone having a higher volatility is further added to obtain a viscosity suitable for processing. Prepared.

[0040]

[Table 1]

In Table 1 above; polyester-based polyurethane is Taiwan Dao No. D
E1090 polyester thermoplastic polyurethane, polyvinylene adipate (molecular weight 200
0), diphenylmethane diisocyanate (MDI) and 1,4-butylene glycol (chain extender), and the molecular weight measured by GPC is 126,700.

The polyether-based polyurethane is a polyether-based thermoplastic polyurethane of Taiwan Daiho No. DE3090, which includes H-[(CH ₂ ) ₄ ] _n OH polyol (molecular weight 2000), diphenylmethane diisocyanate (MDI) and Synthesized from 1,4-butylene glycol (chain extender), the molecular weight measured by GPC is 14
It is 0,400.

Dimethylformamide (DMF) is a special grade product manufactured by Fisher Chemical Company, USA.

Methyl ethyl ketone (MEK) is a special grade product manufactured by Fisher Chemical Company, USA.

Aqueous polyurethane is manufactured by Taiwan Shimei Co., Ltd.
Anionic water-based polyurethane, the composition of which is an aromatic isocyanate and a polyester polyol, and the solid component is 40% by weight.

Block type isocyanate is BASF
It is a block type aromatic isocyanate of No. Desmodur BL1100 manufactured by Kagaku Kagaku Co., which has a molecular weight of 4,219 as measured by GPC and a viscosity of 4000 at 25 ° C.
It is 0 cps.

The chain extender is a cycloaliphatic diamine of No. Laromin C260 manufactured by Shell Chemical Company.

(2) Operating method of winding process The above-prepared impregnated resin was put in a resin tank, and then glass fiber (manufactured by Nippon Glass Co., Ltd., ER 1150 F-56).
RA) is a constant value in which the winding tension of the fiber is in the range of 30 to 120 Newton (30 and 6 in this example, respectively).
0, 90 and 120, 200 N) while controlling the tension to pass through the resin tank to impregnate the fibers with the resin, and subsequently (continuously), a diameter of 0.6 m and a length of 1.5 m.
Wrap it around the core shaft and heat with an IR heater at a temperature of 100 to 13
It was heated in the range of 0 ° C. for 30 minutes to obtain a sheet-shaped thermoplastic polyurethane prepreg having a thickness of 0.5 to 2 mm. The glass fiber has a specific gravity of 2.54 and a fiber diameter of 13.5.
μm and tensile strength 1310 MPa (190 kps
i) was used.

In the sheet-like thermoplastic polyurethane prepreg thus obtained, the winding tension of the fiber and the fiber content in the prepreg after processing were measured, and the results are shown in Table 2.

[0050]

[Table 2]

From Table 2 above, it can be seen that there is a clear correlation between the fiber winding tension and the fiber content in the prepreg material. That is, the higher the winding tension, the higher the fiber content in the prepreg. Further, it is understood that in the case of the same winding tension, the fiber content in the prepreg is highest when the solvent type polyester polyurethane resin is used, and decreases in the order of the solvent type polyether polyurethane and the aqueous polyurethane. Further, an attempt was made to form a prepreg by setting the winding tension of the fiber to 200 N, but the fiber was broken in any of the resins and could not be processed.

(3) Test after secondary processing of the above prepreg The obtained sheet-like thermoplastic polyurethane prepreg was further subjected to secondary processing by a thermocompression molding method to produce a sample, and its mechanical properties were tested. It was evaluated by.

Bending strength test: Using a sample obtained by secondary processing, a bending strength of the sample was measured by a test method according to ASTM D790, and the obtained results are shown in Table 3 below.

[0054]

[Table 3]

Impact strength test: The sample obtained by the secondary processing was made to have a length of 6.3 so that it was suitable for the Izod method.
5 cm wide, 1.27 cm wide, depth of 0.
After forming the 25 cm V-shaped groove, ASTM D256
The bending strength of the sample was measured according to the test method according to 1. and the obtained results are shown in Table 4 below.

[0056]

[Table 4]

From the above Tables 3 and 4, it is understood that both the bending strength and the impact strength increase as the fiber content in the prepreg increases.

From the above examples, it was found that the obtained thermoplastic polyurethane prepreg can be manufactured into a fiber-reinforced composite material product having excellent mechanical properties by secondary processing.

[0059]

The method for producing a thermoplastic polyurethane prepreg of the present invention, unlike the method for producing a prepreg using a thermosetting resin, can completely remove a solvent, water or the like in a short period of time, so that stable and high quality can be obtained. This is an economically excellent method because the polyurethane-impregnated resin has a sufficiently long resin pot life without deterioration when used for a long time at high temperature.

Further, the thermoplastic polyurethane prepreg of the present invention thus obtained, unlike the prepreg using a thermosetting resin, utilizes the formation of a urethane bond having a strong intermolecular cohesive force, so that the bending and impact energy are prevented. It has the property of being easily absorbed. In addition, the polyurethane polymer has excellent properties such as abrasion resistance, elasticity, flexibility, breakage resistance, oil resistance, and solvent resistance, which are unique to polyurethane polymers. The prepreg also has reworkability, waste reusability, repairability, weldability, excellent thermal stability and long storage time.

Therefore, the product obtained by further secondary processing using the thermoplastic polyurethane prepreg can be widely applied to the shoe industry, automobile tire industry, building materials and the like.

Claims (6)

[Claims] 1. A plurality of fibers having a viscosity of 150 to
It is pulled with a water-based emulsion of a polyurethane elastomer of 4000 cps, the fiber impregnated with the water-based emulsion is wound around a core shaft, and the water therein is removed by heating to form a fiber-reinforced polyurethane elastomer composite material.
A method for producing a thermoplastic polyurethane prepreg, which comprises taking out and cutting the composite material along the axial direction. 2. A water emulsion of polyurethane elastomer, The method of claim 1 obtained by forming so that the range of the solid component of 25 to 60% by weight by emulsion polymerization. 3. The method according to claim 1 , wherein the winding tension of the fiber is 30 to 120 Newton. Wherein said composite material, method of claim 1, including a 30 to 75 volume percent of said fibers. Shape according to claim 5, wherein the fibers, filamentary, yard bundle, linear, cord-shaped, according to claim 1, wherein the cloth-like or reinforcing fibers of a continuous consisting of at least one selected from a blanket-like Method. Wherein the material of said fibers The process of claim 1, wherein those of at least one selected from the group consisting of organic or inorganic fibers.