JP2948730B2 - Method for producing SMC and method for producing molded body using this SMC - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automobile interior material, an automobile outer panel, an automobile part such as a spoiler, a bathroom wall panel,
The present invention relates to a method of manufacturing an SMC useful as a molding material for manufacturing a building material such as a ceiling material and a housing of an OA device, and a method of manufacturing a molded body using the SMC.

[0002]

2. Description of the Related Art In place of the SMC (sheet molding compound) composed of polyester and glass fiber, which has been conventionally used in recent years, an SMC composed of an initial condensate of phenolic resin having excellent strength and heat resistance and glass fiber is used. Is used as a material for manufacturing automobile interior materials, automobile outer panels, automotive parts such as spoilers, bathroom wall panels, housing materials such as ceiling materials, and housings for OA equipment and the like. I have. Further, in the above-described various fields, it is desired to reduce the weight of parts. However, a molded article having a low specific gravity tends to deteriorate in strength and rigidity as the weight is reduced.

[0003]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an SMC capable of obtaining a light-weight molded article excellent in strength and rigidity.
And a method for producing a molded article using the SMC.

[0004]

A feature of the method for producing an SMC according to claims 1 to 3 of the present invention is that the one side surface of the first layer comprising a phenolic resin composition and glass fiber has a reduced weight. Forming a second layer made of a phenolic resin composition containing a material to form an unreacted phenolic resin sheet, and heating the unreacted phenolic resin sheet to bring the phenolic resin composition into the B-stage state. The initial condensation reaction.

[0005] A feature of the method for producing a molded article using SMC according to claim 4 of the present invention lies in that the SMC is molded by heating and pressing.

A feature of the method for producing a molded article using SMC according to claim 5 of the present invention is that the second layers of the SMC are laminated inwardly and formed by heating and pressing. .

Hereinafter, the present invention will be described in detail. FIG. 2 is a side view showing an example of the method of manufacturing an SMC of the present invention, and FIG. 1A is a cross-sectional view of the SMC obtained by the method of manufacturing an SMC of the present invention. For example, as shown in FIG. 2, the method for producing SMC of the present invention comprises applying a phenolic resin composition (6) onto a release film (51) made of polypropylene, polyester, vinyl, etc. The glass fiber (8) is sprayed on (6) to form a first phenolic resin layer (11). Separately from this, a release film (52) similar to the release film (51) is formed. A phenol resin composition (7) containing a weight-reducing material is applied thereon to form a second phenol resin layer (21), and then the phenol resin layer (21) is formed on the phenol resin layer (11). Are placed face-to-face to form an unreacted phenolic resin sheet (4) having release films (51) and (52) on both upper and lower surfaces. In the phenolic resin sheet (4), the phenolic resin layer (11) and the phenolic resin layer (21) become a first layer (10) and a second layer (20) in which the phenolic resin composition has not reacted. . At this time, the glass fiber (8) is contained in the first layer (10), and the viscosity of the phenol resin composition (7) containing the weight-reducing material of the second layer (20) is reduced to the first level. If the viscosity of the phenolic resin composition (6) of one layer (10) is adjusted to be larger than that of the phenolic resin composition (6) of the first layer (10) having a lower viscosity, the glass fiber (8) is preferentially added. Can be buried. Alternatively, the phenol resin layer (11) may be formed by applying a mixture of a glass fiber (8) and a phenol resin composition (6) on a release film (51).

When the phenolic resin sheet (4) is primarily cured at a temperature of 70 ° C., preferably in a range of 30 to 50 ° C. for 1 to 7 days, as shown in FIG. Is in B-stage state, SMC with release films (51) (52) on both upper and lower surfaces
(3) can be obtained. The SMC (3) is composed of the first layer (10) and the second layer (20) of the phenolic resin sheet (4) in which the phenolic resin composition is in the B-stage state and the second layer (1a). (2a). The SMC (3) is formed of the release film (51)
(52) is peeled off and used.

The phenol resin composition (6) and the glass fiber (8) constituting the first layer (1a) of the SMC (3) will be described. As the phenol resin used in the phenol resin composition (6), a novolak-type or resol-type phenol resin obtained by reacting various phenol compounds such as phenol, alkylphenol, biphenol, bisphenol A and bisphenol F with formaldehyde is used. be able to. The phenolic resin composition (6) is prepared by appropriately adding additives such as a curing agent, a curing accelerator, a flame retardant, a viscosity modifier, a coloring agent, a foam stabilizer, a surfactant, and a filler to the phenolic resin. May be prepared. As the glass fiber (8), a glass fiber having a fiber length of 0.5 to 300 mm can be used, and a glass fiber having a fiber length of 10 to 50 mm is preferably used.

The phenolic resin composition (7) containing a weight-reducing material, constituting the second layer (2a) on the first layer (1a) of the SMC (3) will be described. As the phenol resin used in the phenol resin composition (7), the same phenol resin as used in the first layer (1a) can be used, and is the same resin as the first layer (1a). Or different resins, and is not particularly limited. The phenol resin composition (7)
Similar to the first layer (1a), it can be prepared by appropriately adding additives such as a curing agent, a curing accelerator, a flame retardant, a viscosity modifier, a coloring agent, a foam stabilizer, a surfactant, and a filler. . As the lightening material, for example, a foaming agent, an inflation balloon, a hollow sphere, or the like can be used. In this foaming agent, for example,
Nitrosotetramines such as dinitrosopentamethylenetetramine (DPT), benzenesulfonylhydrazide,
Sulfonyl hydrazides such as p-toluenesulfonyl hydrazide and p, p'-oxybisbenzenesulfonyl hydrazide, and azo compounds such as azobisisobutyronitrile and azodicarbonamide can be arbitrarily used. The inflation balloon is a resin particle containing a low-boiling compound such as a hydrocarbon compound. When heated, the low-boiling compound is gasified and expanded inside, and the inside becomes hollow. As the inflatable balloon, for example, a granular material made of vinylidene chloride, acrylonitrile resin, or the like, enclosing microcapsules in which isobutane is encapsulated can be used. As the hollow sphere, a glass balloon, a silica balloon, a shirasu balloon, a resin balloon and the like can be used.

FIG. 1B is a sectional view of a molded article (9) obtained by using the SMC of the present invention. This molded body (9)
Can be obtained by setting the above SMC (3) in a desired molding die and subjecting it to heat and pressure molding. The first layer (1) of the SMC (3)
a) and the second layer (2a) become the first layer (1b) and the second layer (2b) where the phenol resin composition is cured. At this time, when the second layers (2a) and (2a) of the SMC (3) are laminated and formed inward to each other, a second layer (2b) is provided on the inside and a first layer ( A molded article (9) having the structure provided with 1b) is obtained. The molding conditions for obtaining the molded body (9) are as follows: the mold temperature is 130 to 190 ° C., and the pressure is 40.
It is good to carry out in the range up to 0 kg / cm ² . The ratio of the thickness of the first layer (1b) to the thickness of the second layer (2b) of the molded body (9) is such that the thickness ratio of the second layer (2b) is 0.5 with the thickness of the molded body (9) being 1. It is preferably in the range of 0.95 to 0.95. If the ratio of the thickness of the second layer (2b) is less than 0.5, the weight reduction of the molded article (9) cannot be sufficiently achieved. Strength and rigidity cannot be maintained.

[0012]

According to a first aspect of the present invention, there is provided a method for producing an SMC, comprising the steps of: forming a phenol resin composition containing a lightening material on one surface of a first layer comprising a phenol resin composition and glass fiber; Forming a second layer to form an unreacted phenolic resin composition sheet, and heating the unreacted phenolic resin composition sheet to convert the phenolic resin composition to B
Since the initial condensation reaction is performed in the stage state, the resulting SM
C is provided integrally with a second layer contributing to weight reduction and a first layer for imparting strength and rigidity. When molding, it is troublesome to separately laminate the lightened layer and the reinforced layer. I do not need.

In the method for manufacturing a molded article using SMC according to claim 4 of the present invention, the SMC is formed by heating and pressing, so that the obtained molded article is formed by the second layer lightened by the lightening material. The weight and weight are reduced, and strength and rigidity are provided by the first layer reinforced by glass fiber.

According to a fifth aspect of the present invention, in the method of manufacturing a molded body using SMC, the second layers of the SMC are laminated inwardly and formed by heating and pressing. The body has a second layer on the inside and a first layer on the outside, and has excellent surface strength.

[0015]

Embodiments of the present invention will be described below. (Example 1) 100 weight of resol type liquid phenol resin
2 parts by weight of zinc stearate as a release agent
And 10 parts by weight of wollastonite and magnesium oxide
Phenolic resin composition prepared by adding 3 parts by weight of
Apply on a polypropylene release film, and further
50 mm fiber length glass on phenolic resin composition
The first phenol with a fiber ratio of 50% by weight by spraying fibers
A resin layer, and separately,
Stearic acid as a release agent in 100 parts by weight of
Lead 2 weight parts, wollastonite 40 weight as filler
Parts, 3 parts by weight of magnesium oxide, and Gini as a foaming agent.
Adjust by adding 4 parts by weight of tolsopentamethylenetetramine
Phenolic resin composition
To form a second phenolic resin layer on top of the film.
Was. The phenol tree used for this second phenol resin layer
Fat composition used for the first phenolic resin layer
The amount of wollastonite is greater than that of the resin composition.
Thus, a high viscosity was prepared. And the first fenault
Face the second phenolic resin layer on the resin layer
And the first phenolic resin layer is used as the first layer.
And a second phenolic resin layer as a second layer.
Unreacted phenol with release films on both upper and lower sides
A resin sheet was formed. Made of this unreacted phenolic resin
The sheet is first cured at 40 ° C for 4 days, and the above resol type
When the liquid phenol resin is in the B-stage state,
An SMC with film was obtained. This SMC with release film
After peeling off the release film, the second layers
After lamination, the SMC was set on a press molding machine,
0 ° C, pressure 10 to 20 kg / cm^Two3 minutes under the molding conditions
During the heating and pressing, the whole thickness was 5.0 mm and was cured.
A flat molded body having a thickness ratio of the second layer of 0.8 was obtained. (Example 2) 100 weight of resol type liquid phenol resin
2 parts by weight of zinc stearate as a release agent
And 10 parts by weight of wollastonite and magnesium oxide
Phenolic resin composition prepared by adding 3 parts by weight of
Apply on a polypropylene release film, and further
50 mm fiber length glass on phenolic resin composition
The first phenol with a fiber ratio of 50% by weight by spraying fibers
A resin layer, and separately,
Stearic acid as a release agent in 100 parts by weight of
Lead 2 weight parts, wollastonite 40 weight as filler
Parts, magnesium oxide 3 parts by weight, and an inflation balloon (pine)
Adjusted by adding 5 parts by weight of this oil and fats pharmaceutical company, product number F-82D)
Phenolic resin composition
Apply on film to form a second phenolic resin layer
did. Phenol used for this second phenolic resin layer
The phenolic resin used for the first phenolic resin layer was used as the resin composition.
The amount of wollastonite is lower than that of the wool resin composition.
The viscosity was adjusted to a higher value. And the first pheno
A second phenolic resin layer over the phenolic resin layer
With the first phenolic resin layer as the first layer.
And a second phenolic resin layer as a second layer.
Unreacted phenol with release films on both upper and lower sides
A resin sheet was formed. Made of this unreacted phenolic resin
The sheet is first cured at 40 ° C for 4 days, and the above resol type
When the liquid phenol resin is in the B-stage state,
An SMC with film was obtained. This SMC with release film
After peeling off the release film, the second layers
After lamination, the SMC was set on a press molding machine,
0 ° C, pressure 10 to 20 kg / cm^Two3 minutes under the molding conditions
During the heating and pressing, the whole thickness was 5.0 mm and was cured.
A flat molded body having a thickness ratio of the second layer of 0.8 was obtained. (Embodiment 3) In the same manner as in Embodiment 2, curing is performed in the same manner as in Embodiment 2.
Only the thickness ratio of the second layer differs, the overall thickness is 5.0 m.
m, flat plate-shaped molding with the cured second layer having a thickness ratio of 0 or 5
I got a body. (Comparative Example 1) 100 weight of resol type liquid phenol resin
2 parts by weight of zinc stearate as a release agent
And 10 parts by weight of wollastonite and magnesium oxide
Phenolic resin composition prepared by adding 3 parts by weight of
Apply on a release film made of polypropylene
A glass fiber with a fiber length of 50 mm is placed on the knol resin composition.
Spray, and on top of this, release film made of polypropylene
Fiber ratio with release films on both upper and lower sides
To form unreacted phenolic resin sheet with 50% by weight
did. This unreacted phenolic resin sheet is
It has the same composition as the first layer. Made of this unreacted phenolic resin
The sheet is first cured at 40 ° C for 4 days, and the above resol type
When the liquid phenol resin is in the B-stage state,
An SMC with film was obtained. This SMC with release film
After peeling off the release film, the SMC is pressed into a press molding machine.
At 150 ° C, pressure 10 to 20kg / c
m ^TwoHeat and pressure molding for 3 minutes under the molding conditions of
5.0 mm, 100% first layer of Example 1
I got a body. (Comparative Example 2) 100 weight of resol type liquid phenol resin
2 parts by weight of zinc stearate as a release agent
And wollastonite 40 parts by weight, magnesium oxide 3
Parts by weight, and dinitrosopentamethylene te as a foaming agent
Phenolic resin composition adjusted by adding 4 parts by weight of tramine
Is applied on a polypropylene release film, and
Then put a polypropylene release film on top of this
Unreacted phenol with release films on both sides
A resin sheet was formed. Made of this unreacted phenolic resin
The sheet has the same composition as the second layer of Example 1. This not
Primary curing of reactive phenolic resin sheet at 40 ° C for 4 days
The resol type liquid phenol resin is B stage
An SMC with a release film in a state was obtained. This release
After peeling off the release film of SMC with mold film,
Set the SMC on the press molding machine, temperature 150 ℃, pressure
10 to 20 kg / cm^TwoHeating for 3 minutes under the molding conditions
The second layer 1 of Example 1 was pressed and formed to have a total thickness of 5.0 mm.
A flat molded article of 00% was obtained. (Evaluation of performance) Compared with the above Examples 1 to 3 and Comparative Example 1.
Measure the specific gravity, specific strength and specific rigidity of the molded product obtained in Comparative Example 2.
did. The specific strength is represented by the square root of the bending strength,
The specific stiffness is a value represented by the cube root of the bending elastic modulus. ratio
As shown in FIG. 3, AST was used to measure the strength and specific rigidity.
The phenolic resin obtained in the test method for bending strength of M
A test stand (15) formed by cutting out a formed body
(16) Adjust the span to 100mm on (16)
And apply a load speed of 5 to the center of the test piece (15) from above.
Press at 0 mm / min to measure flexural strength and flexural modulus.
And the square root of the bending strength as the specific strength
The third root of the modulus was defined as the specific rigidity.

The results of these measurements are shown in Table 1.

[0017]

[Table 1]

As shown in Table 1, Examples 1 to 3 are smaller in specific gravity and higher in specific strength and specific rigidity than Comparative Example 1. Further, in Examples 1 to 3, as compared with Comparative Example 2, although the specific gravity is large, the specific strength is greatly superior, and the specific rigidity is large. Therefore, although the molded articles of Examples 1 to 3 cannot be expected to be as lightweight as Comparative Example 2, they are much lighter than Comparative Example 1, and the specific strength does not decrease as in Comparative Example 2. Things. That is, the molded articles of Examples 1 to 3 were lightweight and excellent in strength and rigidity.

[0019]

According to the method for producing SMC of the present invention, a second layer made of a phenol resin composition containing a lightening material is formed on one surface of a first layer made of a phenol resin composition and glass fibers. An unreacted phenolic resin composition sheet is formed, and the unreacted phenolic resin composition sheet is heated to cause an initial condensation reaction of the phenolic resin composition in the B-stage state. Since the two layers and the first layer for imparting strength and rigidity are integrally provided, there is no need to separately laminate the lightened layer and the reinforced layer during molding. Therefore, the work product is good.

In the method for producing a molded article of the present invention, the SMC is molded under heat and pressure, so that the resulting molded article is reduced in weight by the second layer reduced in weight by the lightening material, and The first layer reinforced with glass fibers provides strength and rigidity. Therefore, the molded body is lightweight and has excellent strength and rigidity.

Further, in the method for producing a molded article of the present invention, the second layer of the SMC is laminated inwardly and molded under heat and pressure. And the first layer is provided on the outside, so that the surface strength is excellent.

[Brief description of the drawings]

FIG. 1A is a cross-sectional view of an SMC obtained by a method of manufacturing an SMC of the present invention, and FIG. 1B is a cross-sectional view showing a structure of a molded article of the present invention.

FIG. 2 is a side view illustrating an example of a method for manufacturing an SMC of the present invention.

FIG. 3 is a side view showing a method for measuring specific strength and specific rigidity in an example of the present invention.

[Explanation of symbols]

 1a first layer 1b first layer 2a second layer 2b second layer 3 SMC 9 molded article

Continuation of the front page (58) Field surveyed (Int. Cl. ⁶ , DB name) B32B 1/00-35/00 B29B 11/16 B29B 15/08-15/14 C08J 5/04-5/10 C08J 5 / 24 B29C 43/00-43/58

Claims (5)

(57) [Claims] An unreacted phenol resin sheet is formed by forming a second layer made of a phenol resin composition containing a lightening material on one surface of a first layer made of a phenol resin composition and glass fibers. A method for producing an SMC, comprising: heating the unreacted phenolic resin composition sheet to cause an initial condensation reaction of the phenolic resin composition in a B-stage state. 2. The method according to claim 1, wherein the lightening material is a foaming agent. 3. The method for producing an SMC according to claim 1, wherein the weight-reducing material is a resin-made inflation balloon whose gas expands and increases in volume when heated. 4. The S according to claim 1, wherein
A method for producing a molded body using SMC, characterized in that MC is heated and pressed. 5. The method according to claim 1, wherein the SMC is formed by laminating a second layer inward to each other and subjecting the second layer to heat and pressure molding.
The method for producing a molded article according to claim 4, wherein MC is used.