JP2554708B2 - Method for manufacturing long composite molded body - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for producing a long-sized composite molded body which is less deformed by thermal expansion and contraction and has excellent weather resistance.

(Prior Art) Conventionally, as a long composite molded body, for example, a gutter body made of vinyl chloride resin is generally used, but a vinyl chloride resin rain gutter has a large linear expansion coefficient, so The expansion and contraction is large, and due to changes in the temperature of the four seasons and the temperature difference between day and night,
When it was attached to a building together with a joint, it could fall out of the joint due to thermal expansion and contraction, or be bent and deformed and damaged.

Therefore, in order to make up for these drawbacks, for example, in
As described in JP-A-58-209560, a fibrous base material composed of an inorganic fiber or an organic fiber is pre-impregnated with a thermosetting resin to form a core material layer of a sheet-like prepreg, and the core material layer is formed of a thermoplastic resin layer. It is known to obtain a molded product by composite-integrating in a sandwich form.

(Problems to be solved by the invention) However, in the above-mentioned conventional technique, when adopting a method of coating a thermoplastic resin on a core layer of a thermosetting resin by extrusion molding, a sheet-shaped prepreg is formed into a predetermined shape while being heated. In the semi-cured state, it is led to the crosshead die and the thermoplastic resin is covered by extrusion molding. In this case, the unreacted portion is volatilized from the thermosetting resin serving as the core material layer to cause foaming, and bubbles are formed between the thermosetting resin layer and the thermoplastic resin layer. The presence of the air bubbles makes the resulting composite molded article more susceptible to cracking than the air bubbles and has a low impact strength. If it is attempted to reduce the generation of bubbles, the molding rate of the extrusion coating becomes slow. Even if the material is completely cured in the heating furnace and then extrusion-coated, it takes a long time for the heating and curing, so that the heating zone of the heating furnace becomes long and the equipment becomes large.

In addition, when a prepreg that has been formed into a predetermined shape is completely heat-cured in a heating furnace, the temperature of the heat-curing is higher than the softening temperature, so the prepreg with the predetermined shape may lose its shape or retain it in the predetermined shape. However, it was difficult to obtain a long composite molded product having a predetermined shape and size by extrusion coating as a core layer having a large dimensional change.

The present invention has been made to solve the above-mentioned problems, and the object thereof is that there is no dimensional change or generation of bubbles during molding, and there is little heat stretchability that can improve the molding speed and excellent weather resistance. Another object of the present invention is to provide a method for producing a long composite molded body.

(Means for Solving the Problem) The method for producing a long-sized composite molded article of the present invention is to impregnate a reinforcing fiber with a thermosetting resin to form a sheet-like prepreg, and heat the prepreg as a core layer on both sides thereof. In a method for producing a long composite molded article in which a skin layer is formed by coating a plastic resin by extrusion molding, the sheet-shaped prepreg is molded into a predetermined shape while being softened by heating, and then a curing reaction is performed by ultraviolet irradiation to cure the sheet. After being completed, an adhesive is applied to both surfaces thereof, the thermoplastic resin is covered by extrusion molding, and the core material layer and the outer layer of the thermoplastic resin are adhered via the adhesive.

As the reinforcing fibers in the present invention, glass fibers, carbon fibers, alumina fibers, aramid fibers and the like can be used alone or in combination of roving long fibers, non-woven fabrics, woven fabrics, mats, processed products such as nets. Further, it is also possible to have a multi-layer structure in which these are combined.

In the present invention, as the thermosetting resin, unsaturated polyester resin, epoxy resin, phenol resin or the like is used. A photo-curing agent, a sensitizer and the like are added to the thermosetting resin depending on the properties of the thermosetting resin.

As the photocuring agent, there are a radical cleavage type and a hydrogen abstraction type, and a benzoyl derivative, a benzyl ketal, an aminoacetophenone, a benzophenone derivative + amine, a dicarbonyl + amine, a thioxanthone + amine are used, respectively.

Further, as the thermoplastic resin, an olefin resin such as vinyl chloride resin, polyethylene, polypropylene, or an engineering plastic such as polyphenylene sulfide is used.

The sheet-shaped prepreg in the present invention is obtained by impregnating the reinforcing fibers with the above-mentioned raw material resin solution of the thermosetting resin and allowing the impregnated resin solution to stand at room temperature to dry the resin component. The content ratio of the reinforcing fiber and the thermosetting resin in this prepreg can be appropriately selected, but the content of the reinforcing fiber is 90
Vol% is the upper limit, and if the content is more than that, the binding between the fibers is incomplete, and the desired molded article having low thermal expansion and contraction cannot be obtained. The thickness and width of the sheet-like prepreg are appropriately selected according to the shape and dimensions of the long composite molded body. The sheet-like prepreg may be transparent or opaque, but it is preferable to use a transparent sheet-like prepreg in order to transmit ultraviolet rays to the inside of the sheet-like prepreg and completely cure it.

Ultraviolet irradiation in the present invention can be performed using a high pressure mercury lamp, the irradiation amount can be adjusted by the intensity of the irradiation lamp, the irradiation distance, the production line speed, etc., the type of thermosetting resin, the light It is appropriately selected depending on the composition and amount of the curing agent.

As the adhesive in the present invention, a one-component or two-component adhesive or a hot-melt adhesive is used. One-component or two-component adhesives include, for example, epoxy-based, urethane-based, acrylic-based, etc. adhesives, and hot-melt adhesives include styrene-butadiene rubber-based, ethylene vinyl acetate-based adhesives, etc. . These adhesives can be coated or coated by extrusion. In addition, the adhesiveness of the adhesive is appropriately selected and adjusted by the composition, the catalyst and the like according to the types of the thermosetting resin of the sheet-like prepreg to be the core material layer and the thermoplastic resin of the outer skin layer. Further, the temperature and speed at which the adhesive is applied or coated are appropriately selected depending on the type of the adhesive.

(Function) According to the present invention, when the sheet-like prepreg to be the core material layer is formed into a predetermined shape while being softened by heating and then subjected to ultraviolet irradiation, the invention is cured by an ultraviolet curing reaction without heating at a low temperature. can do. Therefore, the sheet-shaped prepreg having a predetermined shape does not cause deformation such as deformation due to heating, and it is possible to coat the thermoplastic resin with dimensional accuracy by extrusion molding while maintaining the formed shape. .

(Example) Next, an example of the method for producing a long-sized composite molded article of the present invention will be described with reference to FIGS. 1 and 2.

FIG. 1 is a schematic diagram of an apparatus used in a process of manufacturing a sheet-like prepreg by a wet impregnation method, and FIG. 2 is a diagram showing a long composite molded body formed by forming a sheet-like prepreg, curing by ultraviolet irradiation, and extrusion coating. It is the schematic of the apparatus which shape | molds continuously.

In FIG. 1, glass rovings 1, 1, ... Are supplied to the impregnation tank 5 of the raw material resin liquid 4 as sheet-like reinforcing fibers 3 while being defibrated by the rotor 2. Incidentally, the impregnation tank 5 is replenished with the raw material resin liquid 4 in which a photocuring agent, a sensitizer and the like are added and mixed to the unsaturated polyester resin.
In this impregnated layer 5, the raw resin solution 4 is impregnated into the reinforcing fiber 3 made of glass fiber. The reinforcing fiber 3 is pulled up in a state where the resin solution is impregnated and adhered, and the rolling rolls 6, 6
Thus, the raw material resin liquid 4 may be sufficiently impregnated into the sheet-shaped reinforcing fiber 3. Subsequently, the sheet-shaped reinforcing fiber 3 impregnated with the raw material resin liquid 4 is passed through a drier 7 to dry the resin component and form a sheet-shaped prepreg 8. The sheet-shaped prepreg 8 is wound into a roll.

Next, as shown in FIG. 2, the roll-formed sheet-like prepreg 8 is continuously fed to a roll forming device 9, and the roll forming device 9 heats and softens it to bend it into a predetermined shape such as a gutter. .

Then, the flex-molded prepreg 8 is introduced into a reaction curing tank 10 in which ultraviolet lamps (not shown) are arranged, and ultraviolet rays are irradiated by the ultraviolet lamps to completely cure the unsaturated polyester resin to form a gutter or the like. A core material layer 11 is obtained. In the next step of applying the adhesive, the adhesive 13 is applied to both surfaces of the core layer 11 by the coating die 12 and is guided to the crosshead die 14 of the extruder as it is, and the thermoplastic resin such as vinyl chloride resin is coated on the outer layer. Cover as 15. Then sizing mold
After passing through 16, it is cooled and solidified while finishing the surface, and then pulled by a tensioner 17.

The long composite molded body thus obtained has a cross-sectional structure as shown in FIG.

Next, the evaluation results of the thermal expansion coefficient and the like of the long composite molded body obtained by the method of the present invention will be described based on specific examples.

The linear expansion coefficient α [1 / ° C] was measured by cutting the obtained gutter molded body into a length of 4 m to give an evaluation sample, and placing this evaluation sample in a constant temperature and humidity chamber at 20 ° C. The L ₂₀ was measured, then the temperature was raised to 60 ° C., the dimension L ₆₀ was measured, and the amount of change in the dimension was measured to calculate by the following formula.

α = (L ₆₀ −L ₂₀ ) / (40 × L ₂₀ ) (1) Further, the impact strength [kg · cm] is measured by cutting the obtained sample into a test piece of 20 mm × 20 mm, The DuPont impact tester was used to spontaneously drop the test piece using a 1.5 kg weight, and the presence or absence of damage to the test piece and the drop distance were examined to measure the damage energy.

[Example 1] Unsaturated polyester resin (# 7510, manufactured by Nippon Yupica) 100
2.0 parts by weight of a photo-curing agent (Irgacure # 651, manufactured by Nippon Ciba Kaigi) was added to parts by weight to prepare a raw material resin solution. A glass roving (# 4400, Nitto Boseki) was impregnated with this raw material resin liquid to obtain a transparent sheet-like prepreg. At this time, the thickness of the sheet-like prepreg is 0.5 mm,
The width of the sheet was 300 mm, and the glass fiber content was 60 vol%.

As shown in FIG. 2, the sheet-like prepreg was bent and formed into a gutter shape while being softened by heating at 60 to 80 ° C. by a roll forming device 9.

Then, the bent prepreg 8 is not heated, and it is led to the reaction curing tank 10 with a running line of 0.5 m in a state as it is, and irradiated with ultraviolet rays of 1000 mJ / cm ² by a high pressure mercury lamp to obtain unsaturated polyester. The resin was cured by reaction to obtain a completely cured trough-shaped core material layer 11. An ethylene vinyl acetate-based hot melt adhesive (Takemelt XM223, manufactured by Takeda Yakuhin) is coated on both sides of this core layer 11 with a coating die 12.
Apply at 170 ℃, crosshead die 14 of extruder as it is
Then, a commercially available vinyl chloride resin for rain gutter was coated as a skin layer 15 at a mold temperature of 180 ° C. Then sizing mold 16
While being surface-finished by passing through, it was cooled to about room temperature and solidified, and then pulled by a tensioner 17. The molding speed of the running line at this time was 3.0 m / min. The obtained gutter molded body had a thickness of 1.4 mm, good appearance and dimensional accuracy, a linear expansion coefficient of 1.6 × 10 ⁻⁵ , and an impact strength of 20.0 kg · cm.

Comparative Example 1 A gutter molded body was obtained in the same manner as in Example 1 except that no adhesive was used. The linear expansion coefficient of this molded product was 7.0 × 10 ⁻⁵ , which was substantially the same as the linear expansion coefficient of vinyl chloride resin. When the sample after evaluation is observed, the interface between the core material layer and the outer skin layer is hardly adhered, so the outer skin layer can be peeled off by hand, and the impact strength is as low as 5.0 kgcm, and the outer skin layer and the core material are The layer had cracks.

[Comparative Example 2] A sheet-like prepreg was obtained in the same manner as in Example 1 except that benzoyl peroxide was added instead of the photo-curing agent.
As shown in FIG. 2, the sheet-shaped prepreg is bent and formed into a trough shape while being softened by heating at 60 to 80 ° C. by a roll forming device 9 to form a semi-cured core material layer,
As it was, it was guided to the crosshead die 14 of the extruder, and a commercially available vinyl chloride resin for rain gutter was coated as the outer skin layer 15 at a mold temperature of 180 ° C. The molding speed of the running line at this time is 1.0 m / min
Met.

The thickness of the obtained gutter molded body was 1.4 mm, and air bubbles were partially observed between the core material layer and the outer skin layer. It is presumed that this is because volatile components such as styrene monomer remain and foaming occurs during molding in the extrusion coating mold. The linear expansion coefficient of this gutter molded body was 1.6 × 10 ⁻⁵ , and the impact strength was 5.0 kg · cm. When the sample after the impact test was observed, cracks were generated in the bubble portion.

[Comparative Example 3] Example 1 was repeated except that the same sheet-like prepreg as in Comparative Example 2 was used and the curing reaction was introduced into a reaction-curing tank 10 having a line length of 2.0 m in which infrared heaters were arranged and heat-cured at 100 ° C. A gutter molded body was obtained in the same manner as in. The molding speed was 1.0 m / min in spite of the length of the reaction hardening tank 10 being four times as long as the running line.

The linear expansion coefficient of this gutter molded body is 1.8 × 10 ^-5 , and the impact strength is 2
At 0.0 kg · cm, the appearance was good, but the shape was deformed.

The theoretical value α _{c of the} coefficient of linear expansion generally satisfies the following equation (2) in the case of a long fiber reinforced composite material.

α _c = [α _m × E _m × φ _m + α _f × E _f × (1-φ _m )] / [E _m × φ _m + E _f × (1-φ _m )] (2) α _c : Composite material Coefficient of linear expansion α _m : coefficient of linear expansion of matrix resin α _f : coefficient of linear expansion of fiber E _m : modulus of elasticity of matrix resin E _f : modulus of elasticity of fiber φ _m : volume fraction of matrix resin Theoretical value of linear expansion coefficient α _c
Was calculated to be 1.5 × 10 ⁻⁵ , and the value obtained in Example 1 is close to the theoretical value.

(Effects of the Invention) A method for producing a long composite molded article of the present invention is to impregnate a reinforcing fiber with a thermosetting resin to form a sheet-like prepreg, and extruding a thermoplastic resin on both surfaces of the prepreg as a core material layer. In the method for producing a long composite molded body in which the outer skin layer is formed by coating by molding, after molding into a predetermined shape while heating and softening the sheet-like prepreg, the curing reaction is performed by ultraviolet irradiation to complete curing. , Because both sides are coated with an adhesive and the thermoplastic resin is covered by extrusion molding to bond the core material layer and the outer layer of the thermoplastic resin via the adhesive,
It is possible to obtain a low heat-stretchable long-length composite molded article which does not generate bubbles during molding, has little dimensional change, and has excellent appearance and dimensional accuracy. In addition, since the molding speed can be increased, the equipment can be downsized, and the production method has high production efficiency.

[Brief description of drawings]

FIG. 1 is a schematic view showing an example of an apparatus for producing a sheet-like prepreg used in the production method of the present invention, and FIG. 2 is a sheet-like prepreg obtained by the apparatus shown in FIG. FIG. 3 is a schematic view showing an example of an apparatus for continuously molding, and FIG. 3 is a sectional view of a gutter molded body obtained by the manufacturing method of the present invention. Explanation of symbols 1 ... Glass roving, 3 ... Reinforcing fiber, 4 ... Raw material resin liquid, 5 ... Impregnation tank, 8 ... Sheet prepreg, 9
…… Roll forming device, 10 …… Curing reaction tank, 11…
… Core layer, 12 …… Coating die, 13 …… Adhesive, 14 …… Crosshead die, 15 …… Skin layer.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location // B29K 105: 06 105: 24

Claims (1)

(57) [Claims] 1. A long sheet in which a reinforcing fiber is impregnated with a thermosetting resin to form a sheet-like prepreg, and a thermoplastic resin is extruded on both surfaces of the prepreg as a core layer to form a skin layer. In the method for producing a shaku composite molded body, after the sheet-shaped prepreg is molded into a predetermined shape while being softened by heating, a curing reaction is performed by ultraviolet irradiation to complete the curing, and then an adhesive is applied to both surfaces of the thermoplastic resin. A method for producing a long-sized composite molded article, characterized in that the core material layer and the outer layer of the thermoplastic resin are adhered to each other by an extrusion method, and the core material layer and the outer layer of the thermoplastic resin are bonded to each other via an adhesive.