JPH0136417B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a phenolic FRP that greatly improves the adhesion between an unsaturated polyester gel coat resin and a fiber-reinforced phenolic resin. Conventionally, in order to color the appearance of reinforced plastics using phenolic resins, unsaturated polyester gel coat resins were not often used on the surface, and it was common to rely on post-painting.

Ordinary unsaturated polyester gel coat resin does not contain wax as an air-curing agent (which completely cures the surface by blocking air), so even if it is sufficiently cured using peroxide, Since its surface is constantly in contact with oxygen in the air, it is in a partially cured state due to the polymerization inhibiting effect.

On the other hand, unlike unsaturated polyester resin, phenol resin undergoes an ionic reaction, and the condensation water and phenol itself from the reaction act as a polymerization inhibitor for unsaturated polyester resin, so this phenol resin is used next to the unsaturated polyester gel coat resin. When FRP is laminated, it is considered natural that the adhesion is poor and peeling occurs at the interface, and this is the main cause of peeling of the gel coat layer when molded products are made.

Furthermore, in order to improve this adhesion, a furan resin-based primer has often been used between the gel coat layer and the phenol FRP layer.
However, in this case as well, since the air-curing agent wax is not added to the unsaturated polyester gel coat resin, the gel coat surface remains uncured due to oxygen in the air, and the reaction pattern is different from that of the unsaturated polyester resin. Even when a furan resin (ionically reactive) was used as a primer, peeling between the gel coat layer and the primer layer often occurred.

For the above reasons, unsaturated polyester gel coat resin is not often used as a means of coloring the appearance of phenol FRP, which is convenient for the production process because it eliminates the need for post-painting. It was common to rely on Therefore, the advantages of phenol FRP (high flame retardancy and very little strength loss at high temperatures)
Although this is acknowledged, phenol FRP has not been actively taken up in the market due to the fact that it requires more man-hours to manufacture than unsaturated polyester FRP and is more expensive, as well as appearance defects (pinholes, etc.) caused by post-painting. It was one of the.

The present invention was developed as a result of various studies to improve the adhesion between unsaturated polyester gel coat resin and phenol FRP.
In the case of FRP, wax, which is not generally added because it deteriorates the adhesion between the gel coat layer and the FRP layer, is added at a ratio of 0.03 to 0.6 parts by weight to 100 parts by weight of gel coat resin, and air cured. After completely curing the surface, a base material made of resol type phenolic resin and inorganic or organic fiber is laminated on top of the wax directly or via a primer made of furan resin. It has been found that by heating and curing, the adhesion between the unsaturated polyester gel coat resin and the phenol FRP or furan resin as a primer is significantly improved. If it is necessary to use a general gel coat resin that does not contain wax, add wax as a primer after gel coat at a ratio of 0.03 to 0.6 parts by weight per 100 parts by weight of the resin to make it air-curable. After applying a saturated polyester resin and completely curing it to the surface, phenol FRP is laminated and cured at a temperature higher than the melting point of the wax used. This improves the adhesion between the primer and the phenol FRP, and as a result, the wax It has been found that the adhesion between gel coat resin and phenol FRP, which is not added, is also generally improved. The reason for the improved adhesion is that the thin wax layer formed on the surface of the unsaturated polyester (gel coat) resin melts when heated above the melting point of the wax, and a portion of it melts into the phenolic resin or furan resin. This is thought to be because the unsaturated polyester (gel coat) resin and the phenol resin or furan resin came into direct contact with each other and hardened.

The unsaturated polyester (gel coat) resin used in the present invention may be a commercially available unsaturated polyester resin, but it is more desirable that a phenol derivative such as bisphenol A be contained in the polyester molecule.

Further, the wax added to the unsaturated polyester (gel coat) resin as an air curability imparting agent is preferably made of petroleum wax or mineral wax, such as paraffin wax or montan wax, which has a melting point of 40 to 86°C. It is necessary that it does not dissolve in saturated polyester resin (styrene solution). If the melting point of wax is below 40℃, it will be difficult to form a solid, uniform air barrier layer on the surface of the unsaturated polyester resin, and if it is above 86℃, after laminating phenol FRP, the unsaturated polyester ( This is because there is a risk of cracks entering the resin (gel coat). Also, as for the amount of wax added,
A good range is 0.03 to 0.6%, preferably 0.08 to 0.2%. If it is less than 0.03%, the air barrier effect will be insufficient and uncured components will remain on the surface of the unsaturated polyester (gel coat) resin.
If the amount is more than 1, it becomes effective as a mold release agent, and in either case, the adhesion between the unsaturated polyester (gel coat) resin and the phenol FRP deteriorates. The phenol resin used in phenol FRP is a general acid-curing resol type phenol resin. Furan resin consisting of furfuryl alcohol and formaldehyde is generally used as a primer for unsaturated polyester gel coat resin and phenolic resin. As curing agents, organic or inorganic acids such as benzenesulfonic acid, para-toluenesulfonic acid, xylene sulfonic acid, phenolsulfonic acid, sulfuric acid, and phosphoric acid, which are commonly used for resol type phenolic resins and furan resins, may be used alone or in combination. It is.

The base materials for phenol FRP include inorganic fibers such as glass and carbon, as well as Kevlar, nylon,
Organic fibers such as vinylon are used.

In the present invention, 0.03 to 0.6 parts by weight of wax is added to 100 parts by weight of unsaturated polyester resin to make it air curable, and after completely curing the surface of the gel coat resin after application, it is applied directly or with a primer. After laminating a resol-type phenolic resin and inorganic or organic fibers through the process, the adhesion between the unsaturated polyester gel coat resin and the phenolic FRP or primer is significantly improved by heating at a temperature higher than the melting point of the wax used. It is characterized by this. Furthermore, by using the present invention, it is possible to significantly improve the adhesion between a general gel coat resin to which wax is not added and phenol FRP.

That is, after gel coat resin to which wax is not added, wax is added as a primer from 0.03 to 0.03.
It has been found that adhesion can be improved by completely curing using an unsaturated polyester resin containing 0.6 parts by weight, then laminating phenol FRP and curing it by heating at a temperature higher than the melting point of the wax. As the molding method, known methods such as hand lay-up, spray-up, and resin injection can be employed. By using the method of the present invention, there is no fear that the gel coat layer of the finished molded product will peel off, and abnormal troubles after product delivery can be prevented.
There are many advantages as there is no need to color finish FRP products by post-painting.

Examples and comparative examples will be shown below.

Example 1 Ortho-type unsaturated polyester gel coat resin made air-curable by adding 0.03 parts by weight of paraffin wax with a melting point of 40°C was placed in an FRP mold.
It was sprayed and completely cured to a thickness of ~0.3mm. On top of that, 60% of the curing agent para-toluenesulfonic acid is added to 100 parts by weight of the resol type phenolic resin.
After adding 10 parts by weight of % aqueous solution, molded by hand lay-up method using chopped strand mat (300 g/m ² ), gelled, and cured at 50°C for 3 hours to form a product of approximately 3 mm.
A thick gel coated phenol FRP board was obtained. When this FRP board was subjected to a plane tensile test according to JAS (Japanese Agricultural and Forestry Standards for Special Plywood), it showed a tensile strength of 12.1 Kg/cm ² , and the fracture occurred between the phenol FRP layers.

Comparative Example 1 FRP obtained in the same manner as Example 1 using gel coat resin without adding paraffin wax
When the plate was subjected to a plane tensile test, the tensile strength was 4.5Kg/cm ²
Peeling occurred at the interface between the gel coat layer and the phenol FRP layer.

Example 2 Paraffin wax with a melting point of 50°C was applied to the gel coat.
A bisphenol type unsaturated polyester resin containing 0.15% was molded in the same manner as in Example 1, and then heated and cured at 60° C. for 3 hours to obtain a gel coated phenol FRP plate having a thickness of about 4 mm. The planar tensile strength of this FRP plate was 23.3 Kg/cm ² , and the fracture occurred between the phenol FRP layers.

Comparative Example 2 The planar tensile strength of a gel coated phenol FRP board obtained in the same manner as in Example 2 using a gel coat resin to which no paraffin wax was added was 6.7.
Peeling occurred at the interface between the gel coat layer and the phenol FRP layer at Kg/cm ² .

Example 3 An iso-unsaturated polyester gel coat resin made air-curable by adding 0.3 parts by weight of Montan wax with a melting point of 80°C was sprayed onto an FRP mold and completely cured, followed by furan resin (alcohol) as a primer. 4 parts by weight of a 60% aqueous solution of para-toluenesulfonic acid was added as a curing agent to 100 parts by weight (approximately 70% solution), and the mixture was heated and cured at 90°C for 2 hours.

Furthermore, phenol was added on top of it in the same manner as in Example 1.
FRP was laminated to obtain a phenol FRP board with gel coat and primer. The planar tensile strength of this FRP plate was 17.9 Kg/cm ² , and the fracture occurred between the phenol FRP layers.

Comparative Example 3 The planar tensile strength of an FRP board with gel coat and primer obtained in the same manner as in Example 3 using gel coat resin without adding Montan wax is
Peeling occurred at the interface between the gel coat layer and the primer layer at 5.8 kg/cm ² .

Example 4 Spray unsaturated polyester gel coat resin with no wax added onto an FRP mold to approximately 0.2 mm.
After curing, a bisphenolic unsaturated polyester resin to which 0.55% of paraffin wax with a melting point of 60°C was added was applied as a primer and completely cured.
was molded, and after gelation, it was heated and cured at 70°C for 3 hours to obtain a phenol FRP board with gel coat and primer. The planar tensile strength of this FRP plate was 27.0 Kg/cm ² and the fracture occurred between the phenol FRP layers.

Comparative Example 4 The planar tensile strength of a phenol FRP board with gel coat and primer obtained in the same manner as in Example 4 using bisphenol type unsaturated polyester resin to which no parafine wax was added as the primer was 6.2 Kg/cm ² The primer layer and phenol FRP layer peeled off at the interface.

Claims (1)

[Claims] 1. Add 0.03 to 0.6 parts by weight of petroleum wax or mineral wax with a melting point of 40 to 86°C to 100 parts by weight of the resin to make it air hardenable and completely form the surface of the unsaturated polyester gel coat resin. A method for producing phenolic FRP, which is characterized in that after being cured, a resol-type phenolic resin and a base material made of inorganic or organic fibers are directly layered on top of the resin, followed by heat curing at a temperature higher than the melting point of the wax. 2 Add 0.03 to 0.6 parts by weight of petroleum wax or mineral wax with a melting point of 40 to 86°C to 100 parts by weight of the resin to unsaturated polyester gel coat resin to make it air curable and completely harden the surface. A method for producing phenolic FRP, which comprises laminating a phenolic resin and a base material made of an inorganic or organic fiber through a primer made of a furan resin, and then heating and curing the wax at a temperature higher than the melting point of the wax. 3. Cured using an unsaturated polyester gel coat resin to which no wax is added, then adding 0.03 to 0.6 parts by weight of wax made of petroleum wax or mineral wax with a melting point of 40 to 86°C per 100 parts by weight of the resin and curing in air. After completely curing the surface of the primer, a phenol resin and a base material made of inorganic or organic fibers are layered and cured by heating at a temperature above the melting point of the wax. A method for producing phenol FRP, which is characterized by: