JPH03114706A - Molding material and its mixture - Google Patents

Abstract

PURPOSE:To improve drastically mechanical strength by making fiber dispersion favor able and reducing a breakage or a rapture of a fiber at the time of molding irrespec tive of a fact that a fiber reinforcement material is filled in high density into the title material, by a method wherein melt viscosity of polycarbonate resin is made into 3000 poise or more and 7000 poise or less under the condition that a temperature and shearing stress are respectively 300 deg.C and 10<6>dyn/cm<2>. CONSTITUTION:A fibrous reinforcement material constituted of a single fiber 22 is covered with polycarbonate resin 21. Furthermore, a boardlike body comprised by infiltrating the polycarbonate resin 21 into the fibrous reinforcement material 22 is cut off and a desired molding material 20 is obtained. In this instance, a loading of the fibrous reinforcement material 22 to the molding material 20 is made into 50wt.% or more and 90wt.% or less and a length of the fibrous reinforcement is made into 1-30mm. Furthermore, at least one side of the boardlike material and a specific surface area of the molding material 20 are made into respectively 1mm or less and at least 20cm<2>/g. In this instance, melt viscosity of the polycarbonate resin 21 is made into 3000 poise or more and 7000 poise or less under the condition that a temperature and shearing stress are respectively 300 deg.C and 10<6>dyn/cm<2>.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a molding material and a mixture thereof, and more specifically, it is used in injection molding, extrusion molding, compression molding, etc., and has good dispersibility during molding, and The present invention relates to a molding material and a mixture thereof that can provide a molded product with less fiber breakage and significantly improved mechanical strength.

[Conventional technology]

Conventionally, methods for producing polycarbonate resin compositions reinforced with fibers can be roughly divided into the following two types.

■One method is to add, for example, 3 to polycarbonate resin.
This method involves tri-blending glass fibers with a length of approximately 11 ml to produce a tri-blend product, which is then kneaded and granulated using an extruder to form pellets.

■Another method is to pass a continuous body such as glass fiber through a die hole, introduce polycarbonate resin melted by an extruder into the die hole, cover the fiber bundle, and cut it into a certain length after cooling. This is a method to obtain a cylindrical molding material.

[Problem to be solved by the invention]

In the former case, the upper limit of the filling rate of glass m-fibers in the molding material obtained as described above was usually set at 30% by weight due to problems with the dispersibility of the fibers during kneading. Also in the latter case, the upper limit is usually set at 40% by weight due to the problem of resistance to pulling out the fibers within the die hole. Therefore, there was a problem that it was not possible to obtain a molding material with a higher filling rate.

Conventionally, polycarbonate resins used as molding materials generally have a high molecular weight, that is, high melt viscosity, considering the physical properties of the molded product after molding. There was a problem that the fibers were broken due to the shear force generated, and the average fiber length in the resulting molding material was shortened to 0.3 to 0.5).

On the other hand, even in the case of Gonagisa, the fiber length in the molding material is
Although it is the same as that of the molding material and is maintained for a long time, it has the above-mentioned high melt viscosity and the shape of the molding material is generally cylindrical, and the lining area of the molding material per unit weight, that is, the specific surface area is small, making it difficult to extrude. Because it takes time to plasticize the polycarbonate resin in the machine feeding zone, the fibers break during molding, resulting in an average fiber size of 0.3 to 0.5 m in the molded product.
In addition to being short (m), there is also the problem of poor dispersion of the fibers fdt.

As described above, the conventional technology has a problem in that the reinforcing effect of the fibers cannot be sufficiently exerted from the viewpoints of the filling rate, breakage, and dispersibility of the fibers.

Therefore, the object of the present invention is to achieve good fiber dispersibility during molding despite being filled with a high concentration of fiber reinforcing material.
It is an object of the present invention to provide a molding material and a mixture thereof, from which a molded article with less fiber breakage and significantly improved mechanical strength can be obtained.

[Means to solve the problem]

As a result of intensive studies to solve the above problems, the inventors of the present invention found that the problem of poor dispersion of m-fibers that occurs in the extruder during molding, or H&
The issue of fiber breakage is closely related to the melt viscosity and specific surface area of the resin in the molding material, and by setting these melt viscosity and specific surface area to satisfy certain conditions,
The present invention was completed based on the discovery that fiber dispersibility during molding is good, there is little fiber breakage, and mechanical strength is significantly improved without impairing the physical properties of the molded product.

That is, the molding material according to the present invention has a plate-like structure in which a fibrous reinforcing material made of single fibers (filaments) is covered with a polycarbonate resin, and the polycarbonate resin is impregnated into the male reinforcing material. Get the body #
In the molding material obtained by cutting the plate-shaped body filled with the sleeve-shaped reinforcing material, (i) the filling ratio of the m male reinforcing material to the molding material is 50
(ii) The length of the fibrous reinforcing material is 1 to 30 mm.

(iii) At least one side of the plate-like body is 1 mm or less.

(iv) The specific surface area of the molding material is 20cm27g or more (
v) The melt viscosity of the polycarbonate resin is at a temperature of 3
It is characterized by being 3000 poise or more and 7000 poise or less under the conditions of 00°C and a shear stress of 106 dyn/cm'.

Furthermore, the molding material mixture according to the present invention comprises the above-mentioned molding material and a non-fiber-reinforced polycarbonate resin, and the melt viscosity of the non-fiber-reinforced polycarbonate resin is 1 to 4 times the melt viscosity of the polycarbonate resin that is the molding material. (measured under the same conditions).

The present invention will be explained in detail below.

First, an example of the molding material of the present invention will be explained based on FIGS. 1 and 2. In the figure, 20 is a molding material, 21 is a polycarbonate resin, and 22 is a single fiber.

L is the length of the molding material, that is, the fiber length, 1.0 to 3
It is 0 mm. If the fiber length is less than 1.0 mm, the fiber length is short and a sufficient reinforcing effect cannot be obtained, whereas if it exceeds 30 m+n, bridging etc. occur in the hopper, making molding difficult, which is not preferable.

W and H are the width and thickness of the molding material, respectively, and are determined so that the specific surface area of the following formula is greater than or equal to a certain value.

In the formula, L = length of the molding material (cm) W: width of the molding material (cm) H: thickness of the molding material (am) p: specific gravity of the molding material (g/cm3) , it is preferable to set at least one of them to 1.0 mm or less, preferably less than 0.5 mm, in order to set a large specific surface area.

In the present invention, the specific surface area is 20 cm2/g or more, preferably 30 cm2/g, more preferably 40 cm2/g.
This is 2. If the specific surface area is less than 20 cm2/g, it will take a long time for the polycarbonate resin in the molding material to become molten in the extruder during injection molding, extrusion molding, etc., resulting in poor fiber dispersion and poor fiber dispersion in the extruder supply zone.
This is not preferable as it may cause problems such as fiber breakage.

Note that the thickness 11 is preferably set to 0.1 mm or more in terms of classification in the hopper and ease of handling.

Examples of the method for producing the polycarbonate resin used in the present invention include the phosgene method in which hisphenol A and phosgene are reacted, and the transesterification method in which bisphenol A and diphenyl carbonate are reacted at high temperature and reduced pressure.

The melt viscosity of the polycarbonate resin used in the present invention was measured using a Koka type flow tester having a die with a diameter of 1 mm and a length of 10 mm at a temperature of 300°C and a shear stress of 06 dy.
n/cm' (hereinafter referred to as "measurement conditions of the present invention"), it is 3000 poise or more and 7000 poise or less. If it is less than 3000 poise, the mechanical strength of the molded product obtained will be greatly reduced, which is not preferable. Moreover, if it exceeds 7,000 poise, it is not preferable because it causes poor fiber dispersion and fiber breakage during molding, impairing the reinforcing effect of the fibers. Generally, the melt viscosity of polycarbonate resin is in the range of 2,000 to 15,000 poise when measured under the measurement conditions of the present invention. That is, the present inventor found a specific melt viscosity range within the general melt viscosity range in relation to other requirements of the present invention.

The types of fibrous reinforcing materials used in the present invention include glass fibers such as E-glass and S-glass, carbon fibers such as polyacrylonitrile, pitch, and rayon, and DuPont's "Kefler" (trademark). Examples include aromatic polyamide fibers, silicon carbide fibers such as Nippon Carbon Co., Ltd.'s "Nicalon" (trademark), and metal fibers. These fibrous reinforcing materials can be used alone or in combination.

In the present invention, the fiber diameter varies depending on the type of fiber, but for example, in the case of glass fiber, it is usually 5 to 25 gm, but from the viewpoint of mechanical properties, the smaller the diameter is, the better. In addition, it is preferable to surface-treat the fibrous reinforcing material from the viewpoint of adhesion to the polycarbonate resin. For example, in the case of glass fiber, it is particularly preferable to treat it with a silane-based or titanate-based coupling agent.

In the present invention, the filling rate of the fibrous reinforcing material in the molding material is
50% by weight or more and 90% by weight or less. If it is less than 50% by weight, the effect of the present invention of high fiber filling cannot be achieved, and it is also unfavorable from the economic point of view when used as a master hatch as described below. On the other hand, if it exceeds 90% by weight, the surface of the single fiber cannot be sufficiently covered with the polycarbonate resin, which is not preferable.

The molding material according to the present invention is a plate-shaped body having a structure in which a female reinforcing material composed of a single fiber a (filament) is coated with a polycarbonate resin, and the polycarbonate resin is impregnated in the fibrous reinforcing material. is obtained by cutting the plate-shaped body filled with the fibrous reinforcing material into a certain length.

In the present invention, it is preferable to obtain a molding material in which 90% or more of the surface of single fibers (filaments) which are the constituent units of the fibrous reinforcing material are coated with the polycarbonate resin.

In the present invention, the method of impregnating polycarbonate resin into the fibrous reinforcing material and coating the surface of a single fiber (filament), which is a structural unit of the fiber, with polycarbonate resin is not particularly limited. For example, melting Examples include a melt impregnation method in which a fibrous reinforcing material is impregnated with a polycarbonate resin in the form of a powder, and a fluidized bed method in which a powdered polycarbonate resin is impregnated while suspended in the air or suspended in a liquid such as water.

Representative examples of the melt impregnation method are disclosed in Japanese Patent Application Laid-open Nos. 61-229534, 6]-229535, 61-229536, and Japanese Patent Application No. 61-215253.

An example of the melt impregnation method that can be employed in the present invention will be explained based on FIG. 3.

Long male roving 2 pulled out from multiple bobbins 1
are aligned in one direction by an aligner 3, and then passed through tension adjustment rolls 4, 5.6 to form a fiber sheet 7. In the present invention, in addition to the fiber sheet aligned in one direction, multidirectional continuous fibers of woven fabric can also be used.

On the other hand, the extruder (not shown) heats and melts the resin into a die 8.
It is applied to the surface of the sheet heated by the heating roll 9 via the heating roll 9. The upper belt 12 is heated by a heating roll 11.

Next, the seams 1 to 7 are connected to the lower belt 1o and the upper belt 1o.
2, it passes between heated impregnating rolls 13 without any tension being applied.

The continuous fiber/polycarbonate resin composite 14 thus obtained can be used as it is or, if necessary, after laminating and hot pressing the required number of sheets to a desired thickness, the composite is slittered with a slitter 17 in parallel with the fibers to a desired width. After slitting, cut perpendicular to the fiber to the desired length! By cutting at j&18, a rectangular molding material 20 can be obtained. In addition, in FIG. 3, 15 and 16 are take-up rolls.

As the method of laminating and hot pressing, for example, the composite 1
After heating the surface of No. 4 to a temperature above the softening point of the polycarbonate resin, the polycarbonate resin is laminated. Alternatively, after lamination, the surface of the polycarbonate resin is heated to a temperature above the softening point of the resin in a heating furnace. Next, the composite 14 is cooled under pressure to a temperature below the solidification temperature of the resin, such as by passing it between cold nip rolls.

2 The molding material thus obtained can be used as it is, or by dry-zulenting it with a non-fiber-reinforced polycarbonate resin to obtain the desired fiber filling rate, a molding material mixture can be obtained and used as a so-called masterbatch.
Can be used for injection molding and extrusion molding.

There is no particular restriction on the tulend ratio between the molding material and the non-fiber-reinforced polycarbonate resin, and it should be determined by the set value of the fiber filling rate of the molded product obtained by molding the mixture.

The melt viscosity of the fiber-unreinforced polycarbonate resin used in the present invention is 1 to 4 times the melt viscosity of the polycarbonate resin in the molding material described above under the measurement conditions of the present invention. If it is less than 1 time, it is not preferable because the physical properties of the molded article will be greatly deteriorated, and if it exceeds 4 times, it is not preferable because the effects of the present invention cannot be exhibited due to poor fiber dispersion or fiber breakage in the molded article.

In addition to the above injection molding and extrusion molding, the above molding material or molding material mixture can also be applied to, for example, compression molding. Even when applied to compression molding, the molding material has a plate-like shape, that is, a scale-like shape, so that it fits well with the mold. Also, because the specific surface precision is high, the resin in the material melts quickly, allowing molding to take place in a shorter time than with conventional methods. In this case, whereas conventional molding materials are usually cylindrical, the material is scale-shaped, which has the secondary effect of facilitating positioning on the mold.

(Examples) Examples of the present invention will be described below, but the scope of the present invention should not be construed as being limited by these Examples.

Example 1 Using the apparatus shown in FIG. 3, polycarbonate resin and glass #I! A molding material was obtained from the fiber in the following manner. The melt viscosity of polycarbonate resin is: diameter Inon, length 1
Using a Koka type flow tester with a tie of 0 mm, the temperature is 300° C. and the shear stress is 106 dyn/crn'', that is, the measurement condition of the present invention is 3000 poise.

4 1 Low pink 21 of glass fiber (fiber diameter 13 pLm, convergence number 1600) drawn from Enki's bobbin 1
After aligning the 00 pieces in one direction using the aligner 3, they are passed through the tension adjustment rolls 4 and 5.
fiber sheet 7.

On the other hand, a polycarbonate resin heated and melted to 2106C in an extruder (not shown) is passed through ties 8 and rolled at 220° with lower belt rolls 9 (here, two rolls, 9' is not heated).
It was applied to the surface of the lower belt 1o heated to C to a thickness of 145 lm.

Next, the sheet 7 is attached to the lower belt 10 and the upper belt 12 (
It is heated to 220'C by two upper belt rolls 11. Note that the roll 11' is not heated. ) with a tension of 150 kg applied between three wooden impregnated rolls 13 with a diameter of 240 mm heated to 220°C.
It was passed at a speed of 0 cn+/min.

The glass fiber/polycarbonate resin composite 14 thus obtained was cooled to 100°C, taken off by take-up rolls 15 and 16, and then cut into a 5 m width by a slitter 17.
After slitting at intervals of m, the material was cut into 3 mm pieces using a cutting machine 18 to obtain a molding material having a thickness of 0.24 mm and a glass fiber filling rate of 70% by weight.

The specific surface area of the molding material obtained was found to be 55CII.
It was 12/g.

Next, 43 parts by weight of the molding material and 57 parts by weight of the non-fiber-reinforced polycarbonate resin were mixed to obtain a molding material mixture, and a molded product having a glass filling rate of 30% by weight was produced using an injection molding machine.

When the cross section of the molded article was observed using a scanning electron microscope, the dispersibility of the fibers was good and no phenomena such as blocking were observed.

Moreover, the tensile strength and average fiber length were measured using the molded product. The results are shown in Table 1.

Compared to the conventional technology, fewer fibers were broken during injection molding, and the tensile strength was greatly improved.

Example 2 The thickness of polycarbonate resin applied to the belt was 210 pm.
The process was carried out in the same manner as in Example 1 except that the fiber filling rate was 5.
A 0% molding material was obtained. Then, the molding material thus obtained was molded as it was in the same manner as in Example 1 to obtain a molded product with a fiber filling rate of 50%.

When the cross section of the molded article was examined using a scanning electron microscope, the dispersibility of the fibers was good and no phenomenon such as blocking was observed. Furthermore, the tensile strength and average fiber length of the molded product were measured. The results are shown in Table 1.

Comparative Example 1 The melt viscosity under the 31σ constant conditions of the present invention was 8 (l[l[
A molding material having a glass fiber filling rate of 70% by weight and a specific surface area of 55 cm 2 /H was obtained in the same manner as in Example 1, except that a polycarbonate resin of 1 poise was used.

Next, 43 parts by weight of the molding material and 57 parts by weight of the non-fiber-reinforced polycarbonate resin used in Example 1 were triblended to obtain a molding material mixture, and a molded product with a glass fiber filling rate of 30% by weight was made using an injection molding machine. Created.

When the cross section of the molded product was observed using a scanning electron microscope, it was found that the dispersibility of the m-fibers was insufficient and a blocking phenomenon was observed.

In addition, using the molded product, tensile strength and average fiber 7 The length was measured. The results are shown in Table 1.

Compared to Example 1, fiber breakage during injection molding was severe;
The tensile strength also decreased significantly [1].

Examples 3 to 5 Molding materials were obtained in the same manner as in Example 1, except that the polycarbonate resin shown in Table 1 was used in Example 1. Next, the mixture was triblended with a non-fiber-reinforced polycarbonate resin in the proportions shown in Table 1, and then molded to obtain the molded products shown in Table 1.

Using the molded article, tensile strength and average fiber length were measured.

The results are shown in Table 1.

Comparative Examples 3 to 4 Molding materials were obtained in the same manner as in Example 1, except that the polycarbonate resin shown in Table 1 was used in Example 1. Next, fiber-unreinforced polycarbonate resin was used in the proportions shown in Table 1).
After the rectification, the molded products shown in Table 1 were obtained by molding.

Using the molded article, tensile strength and average fiber length were measured. The results are shown in Table 1.

Example 6 The molding material obtained in Example 1 was adjusted to a fiber filling rate of 30% by blending the molding material with unreinforced fiber-reinforced poly 8 carbonate resin. This Treitzlend product was molded into a round bar with a diameter of 30 mm using a conventional extrusion molding machine.

When the cross section of this molded article was observed using a scanning electron microscope, it was found that the fibers had good dispersibility and no phenomenon such as locking was observed.

Example 7 Mold release agent (FREKOTE44, FREKOTE, USA)
After uniformly placing 300 g of the molding material 20 obtained in Example 1 into the female mold 30 shown in FIG.
A male mold 31 coated with the above mold release agent was set.

Next, the mold was left in a heating furnace heated to 300°C until the mold temperature reached 280°C, and then quickly transferred to a compression molding machine equipped with a pressure plate at room temperature, and molded at a pressure of 50kg/cba for 20 minutes. Pressurize for 300 x 300 x 2, Omm
A molded product was obtained.

When the surface of the molded product was visually observed, it was found that no fibers were visible on the surface, the fibers were well dispersed, and the molded product had good surface gloss.

9 [Effects of the Invention] According to the present invention, despite being filled with a high concentration of fiber reinforcing material, the fiber dispersibility during molding is good, there is little breakage or breakage of fibers, and the mechanical strength is high. It is possible to provide molding materials and mixtures thereof that yield significantly improved molded articles.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing an example of the structure of the molding material of the present invention;
Fig. 2 is a partially enlarged view of the molding material, Fig. 3 is a schematic diagram showing an example of an apparatus for manufacturing the molding material of the present invention, and Fig. 4 is an example of a mold for compression molding to which the present invention is applied. FIG. 20: Molding material 21: Polycarbonate resin 22: Single fiber 30: Female mold 31: Male mold

Claims (1)

[Claims] 1. To obtain a plate-shaped body having a structure in which a fibrous reinforcing material composed of single fibers (filaments) is covered with a polycarbonate resin, and the polycarbonate resin is impregnated into the fibrous reinforcing material. , in the molding material obtained by cutting the plate-shaped body filled with the fibrous reinforcing material, (i) the filling ratio of the fibrous reinforcing material to the molding material is 50
% by weight or more and 90% by weight or less, (ii) the length of the fibrous reinforcing material is 1 to 30 mm, (ii)
i) at least one side of the plate-like body is 1 mm or less; (iv)
The specific surface area of the molding material is 20 cm^2/g or more (v) The melt viscosity of the polycarbonate resin is 300 at a temperature of 300°C and a shear stress of 10^6 dyn/cm^2.
A molding material characterized by having a poise of 0 poise or more and 7000 poise or less. 2. It consists of the molding material according to claim 1 and a fiber-unreinforced polycarbonate resin, and the melt viscosity of the fiber-unreinforced polycarbonate resin is 1 to 4 times the melt viscosity of the polycarbonate resin (measured under the same conditions). A molding material mixture characterized by: