JPH02175148A - Long-sized composite molding - Google Patents

Abstract

PURPOSE:To prevent interlaminar peeling and to enhance durability by bonding a skin layer to a core material layer with an adhesive of synthetic resin incorporating a filler for making linear expansion coefficient small. CONSTITUTION:A skin layer of thermoplastic resin is coated on a core material layer wherein reinforcing fiber is fixed by synthetic resin. Both the core material layer and the skin layer are bonded by an adhesive of synthetic resin which incorporates a filler for making linear expansion coefficient small. As the adhesive of synthetic resin for bonding the core material layer and the skin layer, a curing type adhesive such as epoxy system, urethan system and acryl system and a hot melt adhesive such as ethylene-vinyl acetate system, polyester system and polyamide system and utilized. As the filler for making linear expansion coefficient small, inorganic salt such as calcium carbonate and calcium silicate, pulverized metallic articles of aluminum and iron, ceramic such as silicon carbide and silicon nitride, short fiber of glass and carbon, woodmeal and resin powder, etc., are utilized.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a long composite molded article that has improved thermal expansion/contraction, rigidity, and delamination, and has excellent durability.

(Prior Art) Building materials such as rain gutters are molded into long lengths from thermoplastic resin such as vinyl chloride resin and are widely used. However, such thermoplastic resin molded articles have large thermal expansion and contraction and low rigidity, and therefore have the disadvantage that they are easily deformed due to the seasons and changes in temperature between day and night, and are prone to cracking.

As a molded product that has improved on these drawbacks, a rain molded product is made by covering a core material layer in which reinforcing fibers are fixed with a synthetic resin such as unsaturated polyester resin and an outer skin layer of a thermoplastic resin such as vinyl chloride resin. Long composite molded bodies such as gutters have been proposed (Japanese Unexamined Patent Application Publication No. 58-209560, Utility Model Application No. 59-1983)
(See Publication No. 147823).

(Problem to be Solved by the Invention) However, in such a long composite molded article, the adhesion between the core material layer and the outer skin layer is insufficient, and even if there is no problem in short-term use, it may not last for a long time. During use, the core material layer and the outer skin layer undergo repeated thermal expansion and contraction, and the difference in thermal expansion and contraction between the two layers creates a large interfacial stress at the adhesive interface, which causes delamination and durability problems.

The present invention solves the above problems, and its purpose is to provide a long composite molded article with improved deformation, rigidity, and glabella peeling due to thermal expansion and contraction, and excellent durability. .

(Means for Solving the Problems) A long composite molded article of the present invention is a long composite molded article in which a core layer in which reinforcing fibers are fixed with a synthetic resin is covered with an outer skin layer of a thermoplastic resin. The core material layer and the outer skin layer are bonded together using a synthetic resin adhesive containing a filler to reduce the coefficient of linear expansion, thereby achieving the above object.

In the present invention, as reinforcing fibers, rovings, nonwoven fabrics, mats, woven fabrics, nets, etc., such as glass fibers, carbon fibers, alumina fibers, and aramid fibers, are used. Thermal expansion and contraction in the longitudinal direction is a major problem in long bodies, and in particular, when roving is used as reinforcing fiber and many rovings are arranged in the longitudinal direction, the coefficient of linear expansion of the resulting molded body closely matches the theoretical value. Therefore, in the present invention, it is preferable to arrange the rovings in the longitudinal direction.

As the synthetic resin for the core material layer that fixes the reinforcing fibers, thermosetting resins such as unsaturated polyester resins, diallyl phthalate resins, and epoxy resins are used.

This thermosetting resin usually contains a thermosetting agent such as an organic peroxide, a photocuring agent such as a benzoin derivative, and other accelerators. In addition, examples of the synthetic resin for the core material layer include vinyl chloride resin, acrylic resin, vinyl acetate resin,
Thermoplastic resins such as ethylene-vinyl acetate copolymer resins and olefin resins can also be used.

The above-mentioned reinforcing fibers are generally 6
It is preferable to use it in a range of 0% by volume or less. If more than 60% by volume is used, the core material layer is likely to crack or delaminate due to impact.

Further, as the thermoplastic resin for the outer skin layer, vinyl chloride resin, acrylic resin, olefin resin such as polyethylene or polypropylene, polyamide resin, engineering resin such as polyphenylene sulfide or polyether sulfone, etc. are used.

Furthermore, synthetic resin adhesives for bonding the core material layer and the outer skin layer include hardening adhesives such as epoxy, urethane, and acrylic adhesives, and hot melt adhesives such as ethylene-vinyl acetate, polyester, and polyamide. A mold adhesive or the like is used.

The adhesive contains a filler to reduce the coefficient of linear expansion. Such fillers include:
Inorganic or organic fillers are used. Inorganic fillers include inorganic salts such as calcium carbonate and calcium silicate, crushed metals such as aluminum and iron, ceramics such as silicon carbide and silicon nitride, and short fibers such as glass and carbon.

Furthermore, organic fillers include wood flour and resin powder.

Such fillers generally have a smaller coefficient of linear expansion than the synthetic resin used for the outer skin layer or adhesive. The average particle diameter of such a filler is preferably about 30 to 100 μm from the viewpoint of dispersibility.

In addition, the filler is generally 3 times the synthetic resin of the adhesive.
It is preferably contained in an amount of about 0 to 70% by volume. If it is less than 30% by volume, the effect of improving delamination will be reduced. On the other hand, if it is more than 70% by volume, the contact force will decrease.

The elongated composite molded article of the present invention is manufactured, for example, by the following method. First, reinforcing fibers are impregnated with a synthetic resin liquid and then dried to form a sheet prepreg. This is shaped into a desired shape such as a rain gutter, corrugated plate, decking material, etc. and hardened or solidified to form a core material layer. Form. Next, a synthetic resin adhesive containing a filler is applied to the surface of the core layer using an adhesive applicator. Thereafter, using an extruder equipped with a crosshead mold, a thermoplastic resin is melt-extruded to cover and solidify to form an outer skin layer. In this way,
A long composite molded article of the present invention is obtained.

(Function) In the elongated composite molded article of the present invention, the core layer has high rigidity and a small linear expansion coefficient due to the reinforcing fibers, but the outer skin layer has a large linear expansion coefficient, and there is a difference in thermal expansion and contraction between the two layers. Large interfacial stress occurs due to However, the core material layer and the outer skin layer are
When bonded with a synthetic resin adhesive containing a filler with a small coefficient of linear expansion, the coefficient of linear expansion of this adhesive layer will be an intermediate value between that of the core layer and the outer skin layer, and the interfacial stress will be lower than that of the adhesive. The layer is relatively relaxed and becomes smaller.

(Example) Examples and comparative examples of the present invention are shown below.

Scrap ±1 100 parts by weight of unsaturated polyester resin (++7510: manufactured by Yubika Japan) (linear expansion coefficient: 6.0xlO-5/''C) and benzoyl peroxide (Vercure 0:
A resin liquid was prepared by mixing 2 parts by weight of the following products (manufactured by NOF). Glass roving (It4400: manufactured by Nittobo Co., Ltd.) in which this resin liquid is arranged in many strips in the longitudinal direction (linear expansion coefficient: 0.5
Impregnated with X10-'/'C) to a thickness of 0.5 mm,
A sheet prepreg having a width of 3001 Wm and a glass roving content of 60% by volume was obtained. The above sheet prepreg is softened by heating at 60 to 80°C using a roll forming device, shaped into a square eaves gutter shape, and then hardened, and then completely hardened in a thermosetting zone to form core material N10 as shown in the figure. did. In this core material layer 10, a glass roving 11 is fixed with an unsaturated polyester resin 12.

Next, calcium carbonate (linear expansion coefficient: 0.3×10
-'/'C) ethylene-vinyl acetate copolymer resin containing 50% by volume (linear expansion coefficient: 20X10-'/'C)
) hot melt adhesive (Takemelt XM223
: Sokoen Yakuhin Co., Ltd.) 30 was applied to a thickness of 50 μm at 170°C.

After that, it was introduced into the crosshead mold of the extruder, and the vinyl chloride resin (linear expansion coefficient near, 0X10-'/'C) mixed with stabilizers was heated to 0.51 at 180°C.
It was melt-extruded and coated to a thickness of n1w to form an outer skin layer 20 as shown. After that, the surface is finished using a sizing device, cooled, and pulled out using a tensile machine to a thickness of approximately 1.5 mm.
A long mIIIO eave gutter composite molded body was manufactured. The line speed at this time was 3 m/min. Thermal stretchability and durability of the twenty-eight gutter composite molded article were evaluated using the following methods. The results are shown in Table 1.

(1) A heat-stretchable eaves gutter molded body was cut into a length of 4 m to make a test piece, and this was placed in a constant temperature constant temperature room and the length L2° was measured at 20°C.
Next, increase the temperature to 60°C and length L6 at 60°C.
Measure ゜ and calculate the linear expansion coefficient α using the following formula. (r=(
Lao Lzo)/(40”CXLzo).

(2) Durability The eaves gutter molded body was cut to a length of 111 cm to obtain a test piece, and this test piece was subjected to 1000 cycles of repeated heating and cooling tests at 110°C to 70°C in a constant temperature room. was cut and the cross section was observed using an electron microscope.

In addition, the test piece before and after the above test was 20 mm wide,
It was cut into a length of 200 mm, the end of the outer skin layer on one side was peeled off, and the T-peel strength was measured, and the strength after the test relative to the strength before the test was expressed as the adhesion retention rate. Note that the T-peel strength before the above test was 2.5 kg/cm in all cases.

50% by volume of wood flour (coefficient of linear expansion: 4.0X10-'/'C) in place of 50% by volume of calcium carbonate as a filler.
Example 1 was carried out in the same manner as in Example 1, except that the adhesive layer contained . The results are shown in Table 1.

Example 1 except that the adhesive layer did not contain a filler.
I did the same thing. The results are shown in Table 1.

Table 1 (Effects of the Invention) As mentioned above, in the elongated composite molded article of the present invention, the core material layer is reinforced with reinforcing fibers, so the thermal expansion and contraction as a whole is small (
Deformation and rigidity due to temperature changes are improved. Moreover, since the core material layer and the outer skin layer are bonded together with a synthetic resin adhesive containing a filler to reduce the coefficient of linear expansion, the interfacial stress caused by thermal expansion and contraction is reduced, and temperature changes are prevented. Even if used for a long time in a harsh environment, there will be no peeling between the eyebrows and the durability will be improved.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway perspective view showing an example of the elongated composite molded article of the present invention, and FIG. 2 is an enlarged view of the part (A) in FIG. 1. DESCRIPTION OF SYMBOLS 10... Core material layer, 11... Reinforced fiber, 12... Synthetic resin, 20... Outer skin layer, 30... Adhesive.

Claims (1)

[Claims] 1. In a long composite molded article in which a core material layer in which reinforcing fibers are fixed with a synthetic resin is covered with an outer skin layer of thermoplastic resin, the core material layer and the outer skin layer are used to reduce the coefficient of linear expansion. A long composite molded article, characterized in that it is adhered with a synthetic resin adhesive containing a filler.