JPH0530783B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a fiber reinforced thermoplastic resin body (FRTP).
The present invention relates to a method of manufacturing a molding material useful for manufacturing.

[Conventional technology]

FRTP is manufactured by injection molding using pellets (fiber-containing pellets) containing reinforcing fibers such as glass fibers and thermoplastic resin.

Fiber-containing pellets are usually produced by kneading cut reinforcing fibers (for example, chopped strands, abbreviated as CS) and thermoplastic resin under heat, but the reinforcing fibers are likely to be shredded during the kneading operation. , therefore, the FRTP obtained using this pellet
The problem is that the strength of the material decreases.

In order to overcome the above-mentioned difficulties, a method has been proposed in which continuous glass fiber bundles such as strands or rovings are coated with thermoplastic resin and then cut to produce fiber-containing pellets (referred to as the long length method). Continuous glass fiber bundles are used in the long method, but industrially, a cylindrical wound body (cylindrical wound body) of glass fiber bundles is used; It is drawn out from the roll and continuously fed to a thermoplastic resin coating device.

If the glass fiber bundle contains moisture, this moisture will evaporate during FRTP molding and the performance of FRTP will deteriorate. Therefore, the cylindrical wound body should be a pre-dried one, such as a direct-wound roving such as Type 30. A rolled body is used.

[Problem to be solved by the invention]

The conventional long length method has the following problems.

While the glass fiber bundle is pulled out from the dried cylindrical roll and sent to the thermoplastic resin coating device, the glass fibers also become fluffy, resulting in uneven adhesion of the resin to the glass fiber bundle, which may affect the quality of the FRTP. It is easy to cause variations in the glass fiber bundles, and the glass fiber bundles may be broken. This tendency is particularly noticeable when a sizing agent containing acrylic resin, urethane resin, or AS resin is used. Furthermore, when pulling out the glass fiber bundle, the glass fiber bundle is not perfectly straight, and distortions such as twisting and curving remain, resulting in uneven adhesion of the thermoplastic resin and variations in the quality of the FRTP. It causes the occurrence of Such strain occurs when a glass fiber bundle is pulled out from a cylindrical wound body in the longitudinal direction of the cylindrical body. This is thought to be due to this, and attempts have been made to prevent the twisting caused by the above-mentioned drawing process by supporting the cylindrical wound body rotatably around the axis of the cylinder and performing the drawing process. , it is difficult to completely remove the residual strain and obtain a homogeneous FRTP.

Furthermore, the prior art has the following problems.

As the number of bundled glass fiber bundles increases and the thickness of the glass fiber bundles increases (the weight per 1000m increases), productivity improves, but when the fiber bundles are made thicker, the thermoplastic resin attached to the fiber bundles FRTP obtained using this fiber bundle becomes difficult to seep into the inside of the fiber bundle.
This causes variations in quality.

For this purpose, glass fibers to which a sizing agent has been added are divided into multiple groups and bundled into multiple thin fiber bundles.
It has also been proposed to simultaneously wind a plurality of fiber bundles into a rolled body, but when using this method, the lengths of the fiber bundles cannot be made completely the same,
Loops may occur, making it difficult to smoothly pull out the fiber bundle from the wound body, and may cause the fiber bundle to get caught on the guide used to send the fiber bundle to the next process, causing it to break or fuzz. Easy to do.

Attempts have also been made to draw out a thick fiber bundle and then divide it into a plurality of fiber bundles, but fluffing occurs during division and good results could not be obtained.

The present invention uses heat to uniformly permeate the thermoplastic resin to the inside without causing fuzzing or cutting when pulling out the glass fiber bundle, and without impairing productivity, resulting in a homogeneous FRTP. The purpose of this invention is to provide a method for manufacturing a molded material for FRTP coated with a plastic resin.

[Means to solve the problem]

In order to achieve the above object, the present invention includes a step of applying a sizing agent to a large number of glass fibers drawn from a bushing and converging them into a glass fiber bundle, and a step of reciprocating the glass fiber bundle along a rotating axis. The step of engaging the guide member and winding it around the shaft to form a cylindrical rolled body, the moisture content of the rolled body being
A process of drawing out a glass fiber bundle from a rolled body in a state of 0.5 to 13 wt%, a process of dividing the drawn glass fiber bundle into a plurality of fiber bundles, drying the divided glass fiber bundle in a traveling state, and then converting it into thermoplastic A molding material is manufactured by a step of applying resin.

The thickness of the divided glass fiber bundles should preferably be 10 to 500g per 1000m in dry condition.
It should be 50-300gr.

Next, the present invention will be explained in more detail.

A sizing agent is applied to a large number of glass fibers pulled out from the bushing, and the fibers are bundled by a sizing member.

Glass fibers having a diameter of 3 to 23 microns, preferably 9 to 16 microns can be suitably used.

Prevents fuzzing and thread breakage when manufacturing glass fiber bundles or when pulling out glass fiber bundles from rolled bodies to improve workability, and improves compatibility between glass fibers and thermoplastic resin. Get used to it
In order to improve the strength of FRTP, a sizing agent containing a coupling agent, lubricant, and film forming agent is used.

As the coupling agent, silane coupling agents such as aminosilane, epoxysilane, and vinylsilane, or titanium-based coupling agents, particularly silane coupling agents, are preferably used.

As the lubricant, it is preferable to use fatty acid amide, nonionic surfactant, etc., and as the film forming agent, it is preferable to use urethane resin, acrylic resin, or AS resin.

The concentrations of the coupling agent, lubricant, and film forming agent in the sizing agent are 0.05 to 0.8 wt%, 0.05 to 5 wt%, respectively.
It is appropriate to add 0.01 to 2 wt%, preferably 0.1 to 0.8 wt% of the sizing agent to the glass fiber as a solid content. The glass fibers to which a sizing agent has been added are bundled into a glass fiber bundle according to a conventional method and guided to a guide member.

The guide member is reciprocated along the rotating shaft, the glass fiber bundle is wound into a cylindrical shape to form a roll, and the glass fiber bundle is then pulled out from the roll and sent to the next step.

If the rolled body contains a large amount of moisture, it should be pre-dried before being pulled out to reduce the moisture content to 0.5-13wt%.
The content is desirably 3 to 8 wt%.

If this moisture content is too high, drying in the drying process described below will be insufficient, which tends to cause quality defects in FRTP.If this moisture content is too low, effects such as preventing fluffing will be insufficient, and migration tends to become large.

Then, the drawn glass fiber bundle is divided.

There is no particular limitation on the means of division, but the tip of the glass fiber bundle is manually divided into a plurality of pieces, a comb-like dividing member having a plurality of grooves is used, and the divided glass fiber bundle is pulled through the grooves. As a result, the division can be performed smoothly without causing fuzz, and fiber bundles with equal length and no loops can be obtained.

The number of divisions is based on the weight of each divided fiber bundle in the dry state of 10 to 500g per 1000m,
Desirably, it is appropriate to set the amount to 50 to 300 gr. By drying the divided glass fiber bundles while running, drying can be performed uniformly and glass fiber bundles free from distortion can be obtained.

Drying is preferably carried out in an oven maintained at 100-300°C, preferably 120-200°C, at 5-200 m/min.
It is preferable to dry the fiber bundle while running it at a speed of about 10 to 100 m/min, but it is also possible to dry by high frequency heating or the like.

The glass fiber bundle is then coated with a thermoplastic resin.

Although there is no particular limitation on the method of application, it is preferable to run the glass fiber bundle through a thermoplastic resin melt, apply the melt to the surface of the fiber bundle, and squeeze out excess resin. can be dressed.
The amount of resin deposited is determined depending on the type of resin and the use of the molding material produced by the above method, but the glass fiber content is preferably 20 to 80 wt%, preferably 30 to 60 wt.
It is appropriate to set it as %.

[Effect]

Although the function of the present invention is not fully clear, it is thought to be approximately as follows. When a large number of glass fibers drawn from a bushing are added with a sizing agent and converged to form a glass fiber bundle, the glass fibers in the fiber bundle are tightly and tightly attached to each other in parallel to each other.

When this glass fiber bundle is engaged with a guide member that reciprocates along a rotating shaft and wound around the shaft to form a cylindrical wound body, the glass fibers are wound in a state in which they are in close contact with each other.

If the wound body is dried in this state as in the prior art, a migration phenomenon occurs in which the sizing agent migrates to the surface as the moisture evaporates.

Due to migration, from a macroscopic perspective, the content of the sizing agent increases in a portion closer to the surface of the wound body.

In addition, although moisture moves through capillary action, the distribution of fibers in the rolled body is not uniform, so passages where moisture can easily move and areas where moisture cannot move are mixed irregularly in the rolled body. Therefore, the distribution of the focus that moves with this moisture becomes microscopically non-uniform.

In this state, the glass fiber bundles are wound into a cylindrical shape in a curved shape, dried in close contact with each other, and fixed together with a sizing agent.

For this reason, the glass fiber bundle pulled out from the wound body has variations in the content of the sizing agent along the length direction, and the sizing agent is dried and solidified while remaining in a curved shape, resulting in twisting, The curve remains, and when it is pulled out, it receives a large stress locally, and the part with a lot of sizing agent is difficult to peel off, so the fibers are partially cut, and the curved part is rubbed by the guide, etc. For,
It is thought that it causes fluff.

On the other hand, when using the method of the present invention, the glass fiber bundle is drawn out with a moisture content of 0.5 to 13 wt%, and the sizing agent is not dried and solidified, so the drawn glass fiber bundle is easily drawn out. It is considered that the fibers are deformed into a straight shape, the fibers are not cut, and the variation in the distribution of the sizing agent during the drying process is small, resulting in a uniform fiber bundle.

Furthermore, by splitting the glass fiber bundles in a wet state where the sizing agent has not dried and solidified as described above, fluffing during splitting can be prevented, and the lengths can be made equal without impeding productivity. It is possible to produce thin glass fiber bundles without loops.

〔Example〕

Add 4wt% of PP emulsion and 0.5wt% of lubricant to the 13μ thick glass fiber pulled out from the bushing.
A sizing agent containing 0.6 wt% of aminosilane was added as a solid content of 0.4 wt%, and 3200 fibers were bundled to form a glass fiber bundle.

This glass fiber bundle has an inner diameter of 16 cm, an outer diameter of 26 cm, and a height of
It was wound into a 26 cm cylinder, pulled out at a speed of 30 m/min with a water content of 8 wt%, guided through a comb-shaped guide, and divided into 22 glass fiber bundles each weighing 100 gr. Then, it is passed through an oven kept at 200℃ to dry it, and the PP is bonded to the glass fiber.
It was coated at 150wt% and cut into 1cm pieces to be used as a molding material.

No fluffing or thread breakage occurred during the production of the molding material. Also, using this molding material, ASTM.
A test piece of No. D-256 was manufactured and the measured impact strength was 50 kg-cm/cm.

[Comparative example]

The same experiment as in the example was carried out by drying the same rolled body as in the example until the water content was 0.1 wt% or less, applying resin to the drawn glass fiber bundle as it was.

Fuzzing frequently occurred, and the impact strength of the test piece obtained was 40 kg-cm/cm.

〔Effect of the invention〕

A homogeneous molding material can be obtained without fluffing or thread breakage during the production of the molding material, and high-strength FRTP can be obtained using this molding material.

Further, it is possible to obtain thin glass fiber bundles having equal lengths and no loops without hindering productivity.

Claims (1)

[Scope of Claims] 1. A step of applying a sizing agent to a large number of glass fibers pulled out from a bushing and converging them into a glass fiber bundle, and engaging the glass fiber bundle with a guide member that reciprocates along a rotating axis. In the process of tightening and winding it around the shaft to form a cylindrical roll, the water content of the roll is
A process of drawing out a glass fiber bundle from a rolled body in a state of 0.5 to 13 wt%, a process of dividing the drawn glass fiber bundle into a plurality of fiber bundles, drying the divided fiber bundles in a running state, and then adding a thermoplastic resin A method for producing a molding material, including a step of adhering the molding material. 2. The method for producing a molding material according to claim 1, wherein the weight of the divided glass fiber bundle in a dry state is 10 to 500 gr/1000 m.