JPH0443503B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a sandwich structure in which an unsaturated polyester resin foam containing glass fibers is sandwiched between FRP (general term for glass fiber reinforced plastics). [Prior art] JP-A-56-90840, JP-A-58-29330, JP-A-58-145737, JP-A-58-145738, JP-A-58
-154735, JP-A-59-81346 and JP-A-60
-115637 and other specifications disclose methods for producing foamed polyester, but these methods involve foaming and curing unsaturated polyester resin in a beaker or plastic container, or using chopped strand mats. The material is impregnated with unsaturated polyester resin and cured by foaming. Moreover, those manufactured using a spray device are sprayed onto a glass plate and foamed and cured, and do not contain glass fibers. Conventionally, FRP and FRP were used for the hull and deck of FRP ships.
Laminated boards are used in the sanderch structure with balsar wood in between. [Problems to be solved by the invention] However, all balsar wood is imported from overseas, and there is a risk that it may not be able to be imported due to weather or disasters, making it extremely unsafe to use. Moreover, balsar wood easily absorbs moisture, so if cracks or cracks form in the FRP that makes up the exterior, the balsar wood inside will absorb moisture and rot, making the structure unable to maintain its strength. Furthermore, if balsar material can be used during construction, the balsar material must be laid on top of the FRP so that there are no gaps, and then sprayed on top using a spray device, which is very time-consuming. Therefore, in recent years, there has been a strong desire to develop a structure that uses balsar wood as a core material and that can be used as a substitute for FRP sandwich structures and that is easy to manufacture. [Means for Solving the Problems] As a result of intensive studies in view of the above points, the present inventors have developed a novel sandwich structure in which both sides of a foamed cured product layer of an unsaturated polyester resin containing glass fibers are sandwiched between FRP. The present invention was completed based on the discovery that this material has excellent strength, durability, and processing characteristics. That is, the present invention is made by foaming and curing unsaturated polyester containing glass fiber with a mixed aqueous solution of tert-butylhydrazine hydrochloride and ferric chloride and methyl ethyl ketone peroxide, and sandwiching both sides of the foamed cured product layer with FRP. Regarding the characteristic Sanderutsch structure. More specifically, the content of glass fiber in the unsaturated polyester resin foam cured product is 13 to 18%,
The glass fiber is a silanized glass roving, the impregnation time is about 60 seconds, and the miscut rate is 15-17.
% and has a stiffness of 50 to 60 g and is cut into long fibers of 1/2 inch or more. Further, the unsaturated polyester resin is an orthophthalic acid resin containing 45 to 70 mol% of maleic acid. The glass fiber-containing unsaturated polyester resin foam of the present invention does not easily absorb water, so there is no need to worry about it rotting, and even if cracks or cracks form in the FRP that makes up the outer surface, the strength of the part will only be compromised. The glass fiber-containing unsaturated polyester resin foam of the present invention can be applied in a very short time by simply spraying it onto the FRP using a spray device and then impregnating the roving cloth. Can be done. The sanderch structure of the present invention can be manufactured by the following method. FRP was manufactured using spray equipment.
While mixing unsaturated polyester resin with a blowing agent and ketone peroxide (such as methyl ethyl ketone peroxide) as a hardening agent on top of the FRP using a separate spray device, glass roving cut into pieces of 1/2 inch or more is simultaneously sprayed. and create a glass fiber-filled foamed polyester resin.
Then, using the same spray device, only the resin and curing agent were sprayed onto it, and a roving cloth was placed on it to impregnate and harden it, creating a sandwich structure in which the target object, an unsaturated polyester resin foam containing glass fibers, was sandwiched between FRP. Obtainable. When making the structure of the present invention, glass roving cut into 1/2 inch or more is made of FRP on both sides.
It has very good adhesion to layers and has high strength. The blowing agent for unsaturated polyester resins used in the present invention is a mixed aqueous solution of tert-butylhydrazine hydrochloride and ferric chloride (trade name: Lupaform).
329 (manufactured by Lucidor Yoshitomi) and can be easily dispersed in unsaturated polyester resins by using it in combination with a surfactant. Furthermore, the glass fibers (glass roving cut into pieces of 1/2 inch or more) contained in the unsaturated polyester resin foam cured product of the present invention are silane-treated, and the impregnation time is about 60 seconds, and the miscut rate is low. 15 to 17% and a stiffness of 50 to 60 g are best; those treated with the same silane but with other characteristics have drawbacks such as insufficient curing and poor adhesion to roving cloth. Not suitable for use. Also,
Generally, those using chromium-treated glass roving are not suitable for use because the area around the glass fibers hardens first, creating an uneven surface. The most suitable unsaturated polyester resin used in the present invention is an orthophthalic acid resin containing 45 to 70 mol% of maleic acid, and those containing 45 mol% or less of maleic acid have sufficient hardness after curing. No, 70
If the amount exceeds mol%, the activity of the resin is high, so heat generation is too high, and cracks are likely to occur in the foam. Furthermore, isophthalic acid-based and vinyl ester-based resins have the disadvantage of a lower expansion ratio than orthophthalic acid-based resins. [Example] The present invention will be explained in more detail with reference to Examples below, but the present invention is not limited in any way. Example 1 Decorative board with polyester resin surface (height 180cm width)
90cm), apply a sufficient amount of mold release agent and wipe it off.
Orthophthalic acid-based unsaturated polyester resin adjusted to have a glass content of 30% and methyl ethyl ketone peroxide (trade name, Lupazol)
DDM, manufactured by Sildor Yoshitomi) was sprayed using a spray device (trade name, Venus Spray Gun HIS80,
(manufactured by Venus Corporation) to form a 2 mm thick FRP layer. Next, in a 5-gallon can, orthophthalic acid-based unsaturated polyester resin (trade name, Polymer 810 Note 1,
15 kg of 6% cobalt naphthenate (trade name, P-106, manufactured by Takeda Pharmaceutical Co., Ltd.) 30
ml and 262 g of a foaming agent (trade name, Lupaform 329, manufactured by Lucidor Yoshitomi) were added and thoroughly stirred with an air stirrer. After that, spray equipment (trade name, Vinx
B8 (manufactured by Vinx), hardening agent methyl ethyl ketone peroxide (trade name, Lupasol)
DELTA-X-9 (manufactured by Lucidor Yoshitomi) was set so that 3% by weight of the resin mixture was supplied.
In addition, a 1 inch long glass roving (trade name, SP-9A, manufactured by Asahi Fiberglass Co., Ltd.) was set so that it would supply 18% of the resin mixture, and was placed on top of the above FRP layer to a thickness of approximately 4 mm. I sprayed it up to get it right. After about 2 minutes, the polyester resin began to foam and harden, and after about 20 minutes, the glass fiber-containing unsaturated polyester resin had a thickness of about 8 mm and was fully cured. Thereafter, a resin mixture having the same composition was sprayed onto the foam, and immediately a roving cloth was placed on top of it to fully impregnate it with the resin. Also about 2
After a few minutes, the resin began to foam and harden, and the roving cloth and the underlying glass fiber-containing polyester resin foam were completely bonded. The magnification of the unsaturated polyester resin foam thus produced was approximately 2 times. Note 1: Polymer 810 contains approximately 55% maleic acid.
It is an unsaturated polyester resin containing a thixotropic agent and a surfactant. Comparative Examples 1 to 4 The same procedure as in Example 1 was conducted except that SP-9A was replaced with another grade of glass roving in the foamed polyester resin. [Effect of the invention] Obtained in Example 1 and Comparative Examples 1 to 4 above
Regarding the FRP sandwich structure, we compared and examined the degree of foaming and curing of the resin, as well as the degree of adhesion between the resin and the FRP layers on both sides. The results are shown in Table 1.

[Table] Table 2 shows a comparison of the properties of only the core material (glass fiber-containing foamed unsaturated polyester resin) with no FRP layer adhered to both sides of the core material (glass fiber-containing foamed unsaturated polyester resin) with FRP and balcer material, in addition to the examples.

[Table] As is clear from Table 2, the core material of the present invention is
It has lower thermal conductivity than FRP, so it has excellent heat retention, and it also has higher bending strength than balsar material. In addition, since it contains glass fiber, it has no directional strength or weakness compared to balsar material, and has good vibration absorption properties, so it can be used as a substitute for balsar material as part of the hull or deck of an FRP ship. In addition, Table 3 shows the results of measuring the change in bending strength due to the difference in glass fiber content of the core material (glass fiber-containing foamed unsaturated polyester resin) on which FRP is not bonded on both sides, which is different from the example.

[Table] As is clear from Table 3, the glass fiber content is 15
If it is too low or too high, the bending strength will decrease. From this, the most appropriate glass fiber content is 13 to 18%. As described above, the unsaturated polyester resin foam cured product containing glass fiber of the present invention is sandwiched between FRP and has a sandwich structure, which is easy to manufacture.
It has excellent heat insulation and sound insulation properties, as well as low density strength, so it is suitable for manufacturing FRP ships, various heat insulation materials, insulation materials, construction panels, reinforcement materials for the back of bathtubs, septic tanks, etc.

Claims (1)

[Claims] 1 Glass fibers made by cutting silane-treated glass roving into long fibers of 1/2 inch or more with an impregnation time of 60 seconds, a miscut rate of 15 to 17%, and a stiffness of 50 to 60 g. A foam made by foaming and curing an unsaturated polyester resin, which is an orthophthalic acid-based resin containing 18% maleic acid and 45 to 70 mol% maleic acid, with a mixed aqueous solution of tert-butylhydrazine hydrochloride and ferric chloride and methyl ethyl ketone peroxide. A sandwich structure consisting of a cured material layer sandwiched between FRP on both sides.