JPH03146442A - Production of molding material - Google Patents

Abstract

PURPOSE:To obtain the molding material for fiber reinforced thermoplastic resin which is free from fluffing and thread breakage and homogeneous by applying a sizing agent to glass fiber to make a glass fiber bundle and forming this bundle into a cylindrically wound body and pulling out the glass fiber bundle in a state of specified water content, dividing and drying it and thereafter coating thermoplastic resin thereon. CONSTITUTION:A sizing agent such as a coupling agent, a lubricator and a film forming agent is applied to many glass fibers pulled out from a bushing to make a glass fiber bundle. This bundle is led to a guiding member. This guide member is moved back and forth along a rotary shaft and the glass fiber bundle is wound into a cylindrical shape to make a wound body. When this wound body contains large amounts of water, it is preliminarily dried before pulling out it and moisture content is regulated to 0.5-13wt.% preferably 3-8wt.%. Then the glass fiber bundle is pulled out from the wound body and divided (preferably 50-300g weight per 1000m) by utilizing a sinking comblike dividing member having a plurality of grooves. This divided fiber bundle is dried while allowing it to run and passed through the melt of thermoplastic resin to coat resin thereon.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for producing a molding material useful for producing fiber-reinforced thermoplastic bodies (FRTP).

[Conventional technology]

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

Fiber-containing pellets are usually produced by kneading cut reinforcing fibers (for example, chopped strands, abbreviated as C8) and a thermoplastic resin under heating, but the reinforcing fibers are likely to be shredded during the cross-crossing operation. Therefore, there is a problem that the strength of FRTP obtained using this pellet is reduced.

In order to solve the above-mentioned difficulties, a method (referred to as the long 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. 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 cause the FR
Since FRTP performance deteriorates due to vaporization during TP molding, the cylindrical wound body should be dried in advance, such as type 3.
Directly wound roving turns such as 0 are 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 deteriorates 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 remarkable when a sizing agent containing acrylic resin, urethane resin, or AS resin is used. Furthermore, when the glass fiber bundle is pulled out, 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 FRTP. This may cause Such strain occurs when a glass fiber bundle is pulled out from a cylindrical wound body in the longitudinal direction of the cylindrical body. It is thought that this is due to this, and attempts have been made to prevent the twisting caused by the above-mentioned drawing by supporting the cylindrical wound body rotatably around the axis of the cylinder and pulling it out. Completely removes distortion and produces a homogeneous F
Obtaining RTP is difficult.

Furthermore, the prior art has the following problems.

Increase the number of glass fiber bundles and make the glass fiber bundles thicker.
(The larger the weight per 1,000m), the higher the productivity, but when the fiber bundle is made thicker, it becomes difficult for the thermoplastic resin adhered to the fiber bundle to seep into the inside of the fiber bundle. This causes variations in the quality of FRTP obtained using FRTP.

For this reason, it has also been proposed to divide glass fibers to which a sizing agent has been added into multiple groups and bundle them into multiple thin fiber bundles, and to simultaneously wind these multiple fiber bundles to form a wound body. However, when using this method, the length of the fiber bundle cannot be made completely the same, and loops occur, making it difficult to smoothly pull out the fiber bundle from the wound body. The fiber bundles tend to get caught on the guides used when sending the fibers to the process, causing them to break or become fluffy.

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

The present invention provides a homogeneous FRT in which the thermoplastic resin permeates into the internal material without causing fuzz or cutting when pulling out the glass fiber bundle, and without impeding productivity.
It is an object of the present invention to provide a method for manufacturing a molding material for FRTP coated with a thermoplastic resin that can be replaced with P.

[Means to solve the problem]

In order to achieve the above object, the present invention includes a step of adding a sizing agent to a large number of glass fibers pulled out from a bushing and converging them into a glass fiber bundle, and a step of reciprocating the glass fiber bundle along a rotating axis. A step of engaging the guide member to form a cylindrical wound body by winding it around the shaft, and removing the glass fiber bundle from the wound body in a state where the moisture content of the wound body is 0.5 to 13-1%. A molding material is manufactured by a drawing process, a process of dividing the drawn glass fiber bundle into a plurality of fiber bundles, a process of drying the divided glass fiber bundle in a running state, and then a process of covering it with a thermoplastic resin.

Also, the thickness of the divided glass fiber bundles is 1 in the dry state.
The weight per ,000 m is 10 to 500 gr, preferably 50 to 300 gr.

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 a bushing, and the fibers are bundled by a sizing member.

The glass fiber has a diameter of 3 to 23 μm, preferably 9 to 1 μm.
A material having a diameter of 6μ 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. In order to smoothen and improve the strength of FRTP, a binding agent containing a coupling agent, lubricant, and film forming agent is used as a sizing agent.

As the coupling agent, a silane coupling agent such as aminosilane, epoxysilane, 3-vinylsilane, or a titanium-based coupling agent, particularly a silane coupling agent, is 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.

Concentrations of the compacting agent, lubricant, and film forming agent in the sizing agent are 0.05 to 0.8 wt% and 0.05 to 0.8 wt%, respectively.
5 wt%, 0.5 to 10 wt%, and the solid content of the sizing agent to the glass fiber is 0.01 to 2 wt%, preferably 0.
．． It is appropriate to add 1 to 0.8-t%. 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 up into a cylindrical shape, and the glass fiber bundle is then pulled out from this roll and sent to the next process.

If the rolled body contains a large amount of water, it is pre-dried before being drawn out to reduce the water content to 0.5 to 13 wt%, preferably 3 to 8&4 t%.

If this water content is too high, drying in the drying process described below will be insufficient, which will likely result in poor quality of FRTP.
Furthermore, if this water content is too small, the effect of preventing fluffing etc. will be insufficient, and migration will tend 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 a group of fiber bundles with equal length and no loops can be obtained.

In addition, the number of divisions is such that the weight of each divided fiber bundle in a dry state per 1,000 m is 10 to 500 gr,
Desirably, it is appropriate to set the amount to 50 to 300 gr. By drying the divided glass fiber bundle while it is running, the drying can be performed uniformly, and the glass fiber bundle can be rolled without distortion.

Drying at 100-300°C, preferably 120-200°C
It is preferable to run the fiber bundle at a speed of about 5 to 200 m/min, preferably about 10 to 100 m/sin, while drying is maintained at a constant temperature, but drying can also be carried out by high frequency heating or the like.

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

Although there are no particular limitations on the method of adhesion, adhesion is suitably achieved by running a glass fiber bundle through a thermoplastic resin melt, adhering the melt to the surface of the fiber bundle, and squeezing out excess resin. can be done.

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 it is appropriate to set it so that the glass fiber content is 20 to 80 wt%, preferably 30 to 600%. It is.

[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 out from the bushing are added with a sizing agent and converged to form a glass fiber bundle, the glass fibers in the fiber bundle are brought into close contact with each other in parallel and integrally.

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 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 a 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 dries and solidifies while remaining in a curved shape, so that it cannot be twisted. ,
Curves remain, and when the fibers are pulled out, they are subjected to large local stresses, and areas with a large amount of sizing agent are difficult to peel off, resulting in local fiber breakage, and curved areas are rubbed by guides, etc. 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 wL%, and the sizing agent is not dried and solidified, so the drawn glass fiber bundle is It is believed that the fibers are easily 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, fuzzing during splitting can be prevented, and the lengths can be made to be equal without impeding productivity. It is possible to produce thin glass fiber bundles without loops.

〔Example〕

PP is applied to the 13μ thick glass fiber pulled out from the bushing.
4wt% emulsion, 0.5wt% lubricant, 0.6% 1t% aminosilane sizing agent as solid content
．． 4 wt% was added and 200 fibers were bundled to form a glass fiber bundle.

This glass fiber bundle has an inner diameter of 16mm. J, rolled into a cylindrical shape with an outer diameter of 26 cm and a height of 26 cm, water content 8 ivt.
% at a speed of 30 m/l 1 lin, guided through a comb-shaped guide, and divided into 22 glass fiber bundles each having a weight of IQOgr per t,ooo. The glass fibers were then dried by passing through an open chamber kept at 200° C., and 150 wt % of PP was applied to the glass fibers, and the glass fibers were cut into one piece to obtain 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 5.
0 g-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 -cn+/ca+.

〔Effect of the invention〕

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

In addition, thin glass fiber bundles with equal length and no loops can be rolled without hindering productivity.

Claims (2)

[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, in which the glass fiber bundle is engaged with a guide member that reciprocates along a rotating shaft and attached to the shaft. A process of winding the glass fiber bundle into a cylindrical body, a step of drawing out the glass fiber bundle from the body in a state where the moisture content of the body is 0.5 to 13 wt%, and a step of pulling out the glass fiber bundle into a plurality of layers. A method for producing a molding material, comprising the steps of dividing into fiber bundles, drying the divided fiber bundles in a running state, and then coating them with a thermoplastic resin. (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/1,000 m.