JPH0643659B2 - FRP press molding continuous strand mat - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to a continuous strand mat for FRP press molding.

(Prior Art) When manufacturing an FRP (FRP) product such as a structure panel or a waist panel by a press molding method, a glass fiber mat is placed on a lower mold and a liquid thermosetting resin is placed on the mat. , The lower mold and the upper mold forming a male and female pair are lowered, and the mat is heat-pressed with the mold to cure the resin.

CSM (Continuous Strand Mat) and CM (Chyopp Strand Mat) as glass fiber mats
Etc. are widely used.

(Problems to be solved by the invention) In order to obtain an FRP molded product having a uniform predetermined strength,
It is necessary to keep the distribution of the glass fiber mat and the liquid resin, that is, the ratio between them (or the content ratio of the glass fibers, called GC) at a design value (or a desired value).

When the GC varies and a portion with a small amount of GC or a portion with defective resin content occurs, the molded product becomes non-uniform and a predetermined strength cannot be obtained. Normally, the GC is constant over the entire molded product. When it is necessary to partially increase the strength, G
In some cases, C may be larger in this portion than in other portions, but in this case as well, it is necessary to keep GC within a predetermined range constant.

Place the glass fiber mat evenly over the entire surface of the lower mold,
Although it is effective to pour the resin uniformly, lower the upper mold so that the glass fiber mat does not shift, and then heat the mold, it is effective to make the GC uniform, but such a method requires labor and Since the time required for molding becomes long and the production efficiency decreases, it is not practical, and the following method is adopted in industrial production.

A preheated lower mold is covered with a glass fiber mat, a predetermined amount of liquid resin is poured into this substantially central portion, the preheated upper mold is rapidly lowered, and the resin is generated by the pressure generated by the lowering of the upper mold. Allow to flow and cure throughout the glass fiber mat.

In this method, since the mold is preheated, the viscosity of the resin poured into the glass fiber mat rises rapidly, and the part where the resin is not sufficiently spread or the resin is not spread at all. In addition, the glass fiber mat moves rapidly due to the upper mold moving rapidly to form a tear, the glass fiber bundles forming the mat move and the distribution becomes non-uniform, or There is a case where they are arranged in a direction along the moving direction of, and the strength in a direction directly opposite thereto is reduced, and it often happens that a homogeneous FRP molded product cannot be obtained, which causes a reduction in yield.

In order to solve such a problem, a glass fiber mat having the following properties is required.

(1) The resistance to the flow of the liquid resin poured into the glass fiber mat is small, and the resin easily permeates. (Wet th
ru is good. If the wet thru is poor, the resin viscosity will increase by the time the resin is spread over the entire mat, and the resin distribution will be around the same level.

(2) The distribution of the glass fiber bundles forming the mat in the thickness direction is uneven, or the position of the glass fiber bundles is displaced as the upper mold descends, or the mat is torn, or the glass fibers are formed. The glass fiber bundles are firmly bonded so that they are not arranged in one direction in the moving direction of the bundle type.

As such a mat, CSM is suitable, and
27μ of glass fiber with a sizing agent as a solid content of 0.1 to
Concentrated 20 wt.% With 1.5 wt%
A long glass fiber bundle having a weight per 1,000 m of 3 to 145 gr has a curved shape and is deposited in a mat shape. The glass fiber bundles are 2 to 6 wt% of binder at the intersection. They are connected to each other and have a thickness without load of 3.5 to 6.5 mm / 450 gr /
The thickness when applying a load of m ² 40 gr / m ² is 1.5 to
We have found that particularly suitable results can be obtained by using CSM that is 3.5 mm / 450 gr / m ² , and filed a patent application.

The CSM applies a sizing agent to the glass fibers pulled out from the bushing to bundle them into a glass fiber bundle, which is brought into contact with a rotating cylindrical surface and pulled to be randomly curved on a moving conveyor. It can be suitably manufactured by forming it into a shape and then dropping and accumulating it.

Alternatively, glass fiber bundles drawn from the cake can be used to make a continuous strand mat similar to that made by the method described above. These CSMs need to be fixed so that the glass fiber bundles forming the CSM do not move during press molding, and it is necessary to add a binder to bond the glass fiber bundles together.

Unsaturated polyester resins are most widely used as thermosetting resins to be reinforced with CSM. As a binder,
An alkyd resin whose binding strength is not lowered by styrene contained in the unsaturated polyester resin can be preferably used.

Such a binder is applied to the long glass fiber bundles having a curved shape and accumulated in a mat-like shape, so that the heating effect is exerted. It is practical that the heating is continuously carried out by passing it through a heating furnace maintained at a predetermined temperature, but in order to improve the production efficiency, the curing speed is fast and the above-mentioned various properties are satisfied. A binder is desired.

The present invention is a new proposal for solving the above-mentioned problems of the prior art and providing a CSM suitable for FPR press molding.

[Structure of the Invention] (Means for Solving Problems) The present invention has been made to solve the above-mentioned problems, and has a curved shape of a glass fiber bundle focused with a styrene-insoluble sizing agent. And the glass fiber bundles are bound together by a binder consisting of alkyd resin powder of high unsaturation mainly composed of the reaction product of fumaric acid or maleic acid and ethylene glycol. The present invention relates to a characterized continuous strand mat for FR press molding.

Next, the present invention will be described more specifically.

A sizing agent is attached to the glass fibers drawn from the bushing to bundle them, and the glass fibers are made to fall on a moving conveyor in a curved shape, and then deposited on a mat. As a mat manufacturing device for this purpose, the one described in Japanese Utility Model Publication No. 43-234 can be preferably used, and the glass fiber bundle can be formed into a curved shape and uniformly distributed.

In the present invention, a glass fiber bundle bundled with a styrene-insoluble sizing agent is used. Here, styrene-insoluble means that the fiber bundle does not collapse even if the glass fiber bundle is immersed in styrene for 30 seconds and pinched with a finger.

It has been found that a mat using such a fiber bundle has a good wet thru.

The thickness (diameter) of the glass fiber is 9 to 27 μ, preferably 13 to 23 μ, the number of bundles is 20 to 100, preferably 30 to 70, and the weight per 1,000 m of the fiber bundle (g
r) (hereinafter referred to as tex) is 3 to 145, preferably 7 to 75, and the amount of the sizing agent added is 0.
1 to 1.5 wt%, preferably 0.5 to 1 wt% is appropriate.

As the glass fiber sizing agent, a solution containing a silane coupling agent, a film former and a lubricant can be preferably used, and the solution is added by a known method.

As film former, unsaturated polyester resin,
A styrene-insoluble sizing agent suitable for the present invention can be obtained by using an epoxy resin, a phenol resin, a melamine resin, or the like.

As a silane coupling agent, acrylic silane (A1
74), unsaturated polyester resin as a film former, and Arco 185 as a lubricant.
Are particularly preferred.

A binder is applied to the above-mentioned mat.

In the present invention, powder of a highly unsaturated alkyd resin (hereinafter referred to as the binder) which is a reaction product of fumaric acid or maleic acid and ethylene glycol is used as the fiber bundle binder.

The binder has a high curing rate, and the binding strength is not lowered by styrene, and the glass fiber bundle can be fixed so that the position of the glass fiber bundle does not shift during press molding.

It is preferable to add about 0.2 to 1.5 wt% of peroxide such as BPO to the resin powder,
The curing speed can be further increased.

Since this binder consists of the reaction product of fumaric acid or maleic acid, which is an unsaturated dibasic acid, and ethylene glycol, it is a reaction product obtained by reacting a glycol with an unsaturated dibasic acid and a saturated dibasic acid in combination. Compared with some "unsaturated alkyd resins" or "unsaturated polyester resins", the degree of unsaturation is extremely high. When the degree of unsaturation of the unsaturated polyester resin for FRP is 1, this binder has a degree of unsaturation more than double.

Maleic acid is an isomer of fumaric acid. The binder mainly composed of the reaction product of maleic acid and ethylene glycol has the same properties as the binder mainly composed of the reaction product of fumaric acid and ethylene glycol used in Examples, and the effects of both Are the same.

The method of applying the binder is not particularly limited, but suitable results can be obtained by dropping 50 to 200 mesh of the binder powder onto the upper surface of the mat wet with water.

The binder powder adheres to the intersections of the glass fiber bundles in a particularly large amount, and as described later, is hardened by heating the mat to which the binder powders are adhered, and the glass fiber bundles at the intersections. Join.

The amount of the binder added is 2 to 6 wt%, preferably 3 to 5
It is suitable to set it to wt%.

If this amount is too small, the bonding between the glass fibers will be insufficient and the position of the glass fiber bundle will shift during press molding,
The resulting FRP molded product tends to be non-uniform.

Further, if this amount is too large, spots due to the binder are likely to occur on the surface of the FRP molded product.

The glass fiber mat provided with the binder is continuously fed to a heating furnace, and while the mat passes through the heating furnace, the mat is heated to cure the binder.

The heating temperature and the heating time are determined in correlation with each other.
It is about 0.5 to 1 min at 0 to 350 ° C., and the curing time can be shortened to about 1/2 as compared with the case of using the unsaturated polyester resin for molding.

Further, since the binder of the present invention is in powder form, a binder film is formed on the surface of the fiber bundle as in the case of using a liquid unsaturated polyester for molding, which causes a whitening phenomenon of FPR, or No impregnation of the resin occurs.

The thickness of the mat having a predetermined weight per unit area is mainly determined by the thickness of the glass fibers, the number of bundles, tex, and the conditions for applying a binder to the glass fiber bundle and heating it. For example, if tex is small, the mat becomes bulky,
It tends to be thick. Further, the thickness of the mat can be reduced by pinching the mat with rolls during heating. The thickness of the mat can be increased by blowing hot air from the lower surface of the mat during heating.

By appropriately selecting such conditions, the thickness of the mat is set to 3.5 to
It is particularly preferable that the thickness is 6.5 mm / 450 gr / m ^2, and the wet thru can be improved.

(Example) A glass fiber having a thickness of 18 μm contains 3.4 wt% of unsaturated polyester resin emulsion, 0.2 wt% of gamma-methacryloyloxypropyltrimethoxysilane, and 0.1 wt% of Arco 185 as a lubricant. 0.35 wt% of a sizing agent was added as a solid content, and a continuous glass fiber bundle formed by 40 bundles was dropped onto a continuously moving conveyor at a rate of 450 gr / m ^{2 to} give a mat. It was deposited in a shape.

As a binder, 50 to 50% of a highly unsaturated alkyd resin mainly composed of a reaction product of fumaric acid and ethylene glycol.
Using 200 mesh powder (1% BPO powder added), 3.5 wt% was added to this mat and heated to form a long 26 tex glass fiber bundle in a curved shape, and the intersections of them Thicknesses bonded together at 5.
An 8 mm mat was obtained.

The heating time was 0.5 to 1 min at 280 ° C to 300 ° C, and the heating time could be shortened to about 45%.

The sizing agent used to make this mat is insoluble in styrene, and the wet thru of this mat is good, and when unsaturated polyester resin is poured, as described below, ensure that the resin is evenly distributed throughout the mat. I was able to.

The size of the above mat of 100 cm x 100 cm is 8
One piece, stacked on the lower mold kept at 115 ℃, pour unsaturated polyester resin, lower the upper mold kept at 120 ℃,
It heated at that temperature for 10 minutes and obtained FRP of 8 mm thickness.
A homogeneous FRP was obtained without any deviation of the glass fiber bundle during molding. The bending strength of this FRP is 19.5K
The tensile strength was g / mm ² , and the tensile strength was 9.7 Kg / mm ² . In addition, the panel had no defects.

(Comparative Example 1, an example in which neither the sizing agent nor the binder satisfies the constitutional requirements of the present invention) 3.4 wt% vinyl acetate resin emulsion and 0 gamma-methacryloyloxypropyltrimethoxysilane were used instead of the sizing agent in the examples .2 wt%, Arco 1 as lubricant
Experiments were carried out under the same conditions as in Example except that a sizing agent containing 0.1 wt% of 85 was used and a reaction product of propylene glycol and an equimolar mixture of fumaric acid and phthalic acid was used as a binder. The results were as follows.

The sizing agent used in Comparative Example 1 was not insoluble in styrene, the wet thru was not good, and when the mat was made to contain the resin, the impregnation of the resin was uneven.

The thickness of the obtained mat was 3.8 mm, and the time required for heating to obtain this mat was about 2.2 times the heating time of the example.

During the FRP molding, the glass fiber bundles often shift, resulting in a uniform F
I couldn't get an RP.

FRP has a bending strength of 14.2 Kg / mm ² and a tensile strength of 6.1 Kg / mm ² , FRP has an unimpregnated portion of the molding resin, and warpage due to deviation of the glass fiber occurs. The rejected product occurrence rate was 80%.

(Comparative Example 2, an example in which only the binder does not satisfy the constitutional requirements of the present invention) Same as the example except that a reaction product of an equimolar mixture of fumaric acid and phthalic acid and propylene glycol was used instead of the binder of the example. An experimental example was conducted under the condition of. The results were as follows.

The obtained mat had a thickness of 4.3 mm, and the time required for heating to obtain this mat was about 2.2 times the time required for heating in the example.

The mat of Comparative Example 2 had a good wet thru, and the resin was impregnated uniformly, but the glass fiber bundle was frequently displaced during FRP molding, and a uniform FRP could not be obtained.

The bending strength of the obtained FRP was 15.3 Kg / mm ² , and the tensile strength was 6.5 Kg / mm ^{2. The} FRP was warped due to the deviation of the glass fiber, and the rejection rate was 50%. Met.

(Comparative Example 3, an example in which only the sizing agent does not satisfy the constituent requirements of the present invention) A vinyl acetate resin emulsion is used in an amount of 3.4 wt% and a gamma-methacryloyloxypropyltrimethoxysilane is used in an amount of 0.2 wt% in place of the sizing agent of the embodiment. Arco 1 as a lubricant
An experiment was conducted under the same conditions as in Example except that a sizing agent containing 0.1 wt% of 85 was used. The results were as follows.

The sizing agent used in Comparative Example 3 was not styrene-insoluble, the wet thru was not good, and the impregnation when the mat was impregnated with the resin was non-uniform, and a uniform FRP could not be obtained. .

The thickness of the obtained mat was 5.3 mm, and the time required for heating to obtain this mat was almost the same as the time required for heating in the examples.

The bending strength of the obtained FRP was 14.9 Kg / mm ² , and the tensile strength was 6.3 Kg / mm ² , and the FRP had an unimpregnated portion of the molding resin, and the rejection rate was 50%. .

The data of the above-mentioned examples and comparative examples can be summarized as shown in a separate table.

(Effect of the invention) The wet thru is good, and it is possible to produce a homogeneous and high-strength FRP with a good yield without moving the fiber bundles constituting the mat during press molding. Further, the curing speed of the binder is high, and the productivity of the mat can be improved.

Claims (2)

[Claims] 1. A long glass fiber bundle focused with a styrene-insoluble sizing agent is deposited in a curved shape, and the glass fiber bundles are produced by the reaction of fumaric acid or maleic acid with ethylene glycol. A continuous strand mat for F / P press molding, characterized in that it is bound by a binder composed of alkyd resin powder having a high degree of unsaturation, which is mainly composed of materials. 2. A glass fiber bundle is a glass fiber having a diameter of 9 to 27 μm, which is bundled with a sizing agent as a solid component in an amount of 0.1 to 1.5 wt%, and has a weight per 1,000 m of 3 to 3.
145 gr, and the thickness of the mat is 3.5 to 6.5 m.
The continuous strand mat for FPR press molding according to claim 1, which has a m / 450 gr / m ² .