JPH01250458A - Manufacturing method of fiber reinforced resin body - Google Patents

Abstract

PURPOSE:To obtain the subject mat capable of giving a fiber-reinforced resin material having uniform deep-drawn form, by depositing long glass fiber bundles in curved states and integrating the glass fiber bundles with each other using a thermoplastic resin binder. CONSTITUTION:Long glass fiber bundles having a length of >=30cm, preferably >=60cm are randomly deposited on a conveyor in curved form (curved with a radius of curvature of 1.5-20cm, preferably 2-15cm in >=70%, preferably >=80% of the length of the glass fiber bundle). The glass fibers are integrated with each other using a binder composed of a thermoplastic resin to form the objective mat.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention provides glass Fpcm mats and fiber reinforced resin bodies (FRP) useful as reinforcing fibers for fiber reinforced resin bodies (FRP).
This relates to a method for producing P).

[Prior Art] Fiber-reinforced resin bodies (FRP), which are made by impregnating reinforcing fibers such as glass fiber mats with liquid thermosetting resin and curing the resin, are used in various applications such as automobile parts, hastubs, boat hulls, etc. The injection molding method is the resin injection molding method (RI method), and the press molding method is the matte tie method (RI method).
The MD method is mainly used for mass production.

In order to obtain FRP of a certain quality, chopped strand mats (CM) made of short cut glass fiber bundles and continuous strand mats (CSM) made of long glass fiber bundles are widely used as reinforcing fibers.

[Problems to be solved by the invention] When attempting to manufacture FRP with a deeply curved shape (hereinafter referred to as deep-drawn shape) using CM or C3M as reinforcing fibers by the RI method or MD method, the compatibility between the mat and the mold becomes poor. Due to defects or external forces received during molding, the glass fiber bundles constituting the mat move, making the distribution of the glass fiber bundles in the mat uneven, or tending to arrange them in one direction. This phenomenon is particularly likely to occur at the corners of deep-drawn shapes, and sometimes the mat breaks, creating areas where no glass fiber bundles are present, reducing the strength of the resulting FRP, and causing quality defects such as cracks that occur in some corners. It causes.

In order to solve these difficulties, cut glass fiber bundles (
A preform mat obtained by spraying chopped strands (hereinafter referred to as C8) together with a binder into a mold having a predetermined shape has been used as reinforcing am. The foam mat method) has the following drawbacks.

When using the preform mat method, it is possible to prevent the distribution of the reinforced uA males from becoming uneven to some extent.

This method is laborious and expensive, and has the disadvantage that it is difficult to achieve a completely uniform distribution of reinforcing fibers. That is,
Preform mats are manufactured by simultaneously spraying C8 and a binder onto a mold having a predetermined shape, but in the case of a mold with a deep drawing shape, the resistance of C3 to the corners of the mold or the vertical parts of the mold is Adhesion and deposition are likely to be insufficient.

In addition, in order to disperse C8 along a predetermined curved surface, the preform mat has a C8 of 25 to 50111.
It may be necessary to use a shorter one.

If C3 becomes short, CS tends to move and be arranged in one direction during FRP molding, which tends to reduce the strength of FRP. Holding such a short CS on the surface of the mold, and also FR
In order to prevent the movement of CS during P molding, it is necessary to add a larger amount of binder (about 10 wt % to C8) to the preform mat than to CM and CSM. Therefore, when a preform mat is used as a reinforcing fiber, the transparency and water resistance of the obtained FRP tend to decrease.

The present invention is a new proposal based on research to solve these problems of the prior art, and it provides a glass fiber mat and a homogeneous fiber reinforced plastic mat that facilitates the production of homogeneous deep-drawn FRP (fiber reinforced resin). The object of the present invention is to provide a method for manufacturing FRP having a deep drawing shape.

[Means for Solving the Problems] In order to achieve the above object, the present invention uses long glass fibers with a length of 30 cm or more as reinforcing fibers for FRP, and 70% or more of the fibers along the length direction. A glass fiber mat mat is used, in which the glass fiber bundles are deposited in a curved shape with a radius of curvature of 1.5 to 20 cm and are bonded together with a binder made of thermoplastic resin. In addition, long glass fiber bundles with a length of 30 cm or more are deposited in a curved shape with a radius of curvature of 1.5 to 20 cm in more than 70% of the length. A glass fiber mat in which glass fiber bundles are bonded together with a binder made of a thermoplastic resin is formed into a desired curved shape by softening the binder, and then impregnated with a liquid thermosetting resin to form the mat. FRP is manufactured by curing the resin.

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

In the present invention, the length is 30 cm or more, preferably 60 cm.
A long glass fiber bundle of m or more is used. If this length is too short, the glass fiber bundle will move easily during FRP molding, and it will be necessary to use a large amount of binder. A suitably suitable glass fiber bundle is a 20 to 200, preferably 30 to 150 glass fibers with a thickness of 9 to 25 JL, preferably 13 to 22 mm.

If the thickness of the glass fiber bundle is too small, the glass fiber bundle will tend to move when impregnated with resin, and if the thickness is too large, the surface smoothness of the obtained FRP will be easily lost.

The sizing agent to be added to the glass fibers includes 0.02 to 0.3 wt% of a lubricant such as Earth 185 (trade name), preferably 0.05 to 0.2 wt%, and a self-emulsifying polyester resin. It is desirable to use a liquid material containing 1.5 to 5 wt%, preferably 0.2 to 4 wt%, of a film forming agent, and 0.1 to 0.3 wt% of a coupling agent such as a silane coupling agent. The amount of sizing agent added is 0 as a solid content.
．． It is appropriate to set it at 1 to 0.5 wt%.

In addition, when transparency is required for FRP, it is also possible to use a sizing agent containing only a coupling agent.

In the present invention, the above-mentioned long glass fiber bundles are deposited in a mat shape, and a binder described later is added to bond the glass fibers together.

Industrially, a 1 mm bundle of glass is fed onto a conveyor moving at a predetermined speed in the longitudinal direction and allowed to fall and deposit, and preferably about 40 to 200 mesh powder binder is added. The binder can be added at the same time as the glass fiber bundle or after the glass fiber bundle is supplied. The amount of deposited glass fiber bundles is 300 to 500 gr/rrr', preferably 4
00 to 5 (] Ogr/m'' is appropriate. If this amount is too large, it will be difficult to carry out the reforming process (preforming process) to make the glass fiber mat into the desired curved shape.
Also, if this amount is too small, productivity will decrease.

The long glass fiber bundles are randomly deposited in a curved shape on the conveyor, or the radius of curvature depends on the moving speed of the conveyor, the falling speed of the glass fiber bundle, the thickness of the glass fiber bundle, the rigidity, etc. Determined. In the present invention, the above radius of curvature,
7C% or more in the length direction of the glass fiber bundle, preferably 80%
1.5 to 20c11 in the above parts, preferably 2
These conditions are set so that it becomes ~15C11.

Note that such conditions can be determined experimentally.

If the radius of curvature is larger than the above range, the glass fiber bundles are likely to shift during FRP manufacturing, and if the radius of curvature is smaller than the above range, it will be difficult to renovate, and when renovating,
It is easy to cause partial cuts in the mat.

As a binder, the softening point measured by the Ba1l Ring method is 60 to 200°C, preferably 80 to 150°C.
is appropriate.

Also, it is not desirable to use a binder that has a high solubility in the matrix resin, and the binding strength of the binder is significantly reduced when the mat is impregnated with the matrix resin.

The binder is selected depending on the type of resin (matrix resin) with which the mat of the present invention is impregnated, and the following are suitable binders that satisfy the above conditions.

When the matrix resin is an unsaturated polyester resin or a polyurethane resin, a polyester resin, preferably an isophthalic acid-modified alkyd resin or a bisphenol-modified alkyd resin,
Particularly preferably, isophthalic acid-modified alkyd resin When the matrix resin is Metone resin (trade name) Polyethylene or polypropylene When the matrix resin is phenol resin Novolac resin By using such a binder, during FRP molding, or The effect that the mat can be preformed into a desired deep-drawn shape becomes even more remarkable without shifting the glass fiber bundles and making the distribution of the glass fiber bundles non-uniform when performing the preforming described later.

The mat of the present invention is produced by heating the glass fiber bundles to which a binder has been added to soften the binder and bonding the glass fiber bundles together. At this time, it is preferable to use a pair of rolls or the like to compress the material.

The bulk density of the mat in an unloaded state and the bulk density when a predetermined pressure is applied to the mat are determined by the above-mentioned squeezing force during mat production and the elastic repulsion force of the glass fiber bundles that make up the mat, or by the measurement method described below. It is especially desirable that the bulk density of the mat is within the following range.

Bulk density (mat weight/area x thickness) measured with a 3 mm thick iron plate placed on the entire surface of a mat with a size of 30 cm x 30 cm or more (in this case, the load the mat receives is approximately 3 gr/crn') No load on actual purchase) is 0
．． 08-0.25gr/Cm' preferably 0.10-0
．． 18gr/crn', about 30gr/mat
The bulk density when applying crn' load is 0.3 to 0.4
2gr/cm″ preferably 0.36~0.4gr/c
rn''s.

The elastic repulsion force of the glass fiber bundle is determined by the thickness of the glass fibers, the number of bundles, the type and amount of the sizing agent, the type and amount of the binder, and the length of the glass fiber bundle. The dimensions of the mat having bulk density can be easily determined experimentally.

Since the mat of the present invention is composed of long glass fibers, and the mat itself has a substantially planar shape, it is sufficient to add the binder in an amount of about 2 to 6 wt% based on the glass fi&m bundle.
The glass fiber bundles are sufficiently firmly bonded to each other, and no movement (weld) of the glass fiber bundles occurs during FRP molding.

When manufacturing FRP having a deep drawing shape using the glass fiber mat of the present invention as reinforcement m fibers, the above mat is
Is it appropriate to perform pre-forming by heating the mat to 10°C, preferably 150 to 180°C and applying pressure using a pair of molds to give it a predetermined shape? Alternatively, the mat may be sprayed with a solvent to soften the binder and the mat may be bent manually. .

Using the mat of the present invention, FRP is manufactured by a known RI method or MD method. The liquid thermosetting resin used in this case may be unsaturated polyester resin, epoxy resin, metone resin, polyurethane resin, phenol resin, etc., or it is practical to use unsaturated polyester resin. The amount of resin added is based on the glass ma in FRP.
The proportion of matte is 20 to 70 wt%, preferably 30 to 6
It is appropriate to set it to 0wL%.

By using the binder as described above, it is possible to prevent a decrease in the bonding strength of the binder due to the liquid thermosetting resin during FRP production, and to further reduce welding of the glass fiber bundle.

[Operation] A long glass fiber bundle with a length of 30 cm or more has a radius of curvature of 1.5 in 70% or more of its length.
By depositing the fiber bundles in a curved shape of ~20 cm and bonding them with a binder made of thermoplastic resin, the glass fiber bundles are bonded together with a small amount of binder to form a matrix. Furthermore, when this mat is used as a reinforcing material for FRP, welding of glass fiber bundles is reduced, and preforming of this mat is facilitated.

Furthermore, by pre-forming such a mat into a desired shape with the binder softened, and then impregnating it with a liquid thermosetting resin, and then curing the resin, the shape of the glass fiber bundle during molding is improved. Minimize the misalignment (weld).

[Example] 3.5 wt% of self-emulsifying polyester emulsion and 0.1 w of Arco 185 were added to glass fiber with a diameter of 20 pots.
A continuous glass fiber bundle formed by bundling a sizing agent containing 0.2 wt% of A174 and 0.35 wt% of solid content is dropped onto a traveling conveyor at a rate of 450 gr/rn'', 9 along the length of the glass fiber bundle.
A mat-like material was obtained which was deposited in a curved shape having a radius of curvature of 2 to 10 cm in a portion of 0% or more.

Thermoplastic resin powder (50 to 150 mesh) made of isophthalic polyester resin is added to this mat-like material.
When 4 wt% of is added and heated to 210'C, the bulk density when no load is 0.14gr/crn', and the bulk density when a load of 30 gr/g is applied is 0.38gr/crrr'.
I got the mat.

The softening point of the thermoplastic resin binder was 150'C by the Ba1l Ring method.

This mat was heated to 180°C and pressed between a pair of molds.
To obtain FRP with good water resistance and little welding by preforming into a dish shape of 0 cm x 80 cm and height 10 cm+++, impregnating it with unsaturated polyester resin so that the weight of the mat in the FRP is 35 wt%, and using the MD method. I was able to do it.

[Example 2] A glass fiber bundle cut into a length of 60 cm was used instead of the continuous glass fiber bundle of Example, and the same results as in Example 1 were obtained.

Effects of the Invention It is possible to obtain a homogeneous FRP with small cowelt and good transparency and water resistance.

Claims (2)

[Claims] (1) A long glass fiber bundle with a length of 30 cm or more has a radius of curvature of 1.
Glass fibers for reinforcing thermosetting resin, characterized in that they are deposited in a curved shape of 5 to 20 cm, and these glass fiber bundles are integrally bonded with a binder made of thermoplastic resin. male mat. (2) A long glass fiber bundle with a length of 30 cm or more has a radius of curvature of 1.5 at 70% or more along its length.
The glass fiber mat is deposited in a curved shape of ~20 cm, and these glass fiber bundles are bonded together with a binder made of thermoplastic resin. A method for producing a fiber-reinforced resin body, which comprises forming a fiber-reinforced resin body into a curved shape, and then impregnating it with a liquid thermosetting resin and curing the resin.