JP2002292800A - Release sheet for molding prepreg material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a release sheet for molding a prepreg material excellent in mechanical strength and preventing the contamination of a mold caused by the oligomer or fretting powder precipitated from the release sheet at the time of thermoforming. SOLUTION: The release sheet for molding the prepreg material is constituted by laminating a polyolefin resin film having heat resistance and releasability, a resin film, and a heat-resistant engineering plastic film having a phenyl group in its skeleton in this order.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a release sheet for molding a prepreg material which can be suitably used for continuously heating and molding various shapes of carbon fiber reinforced plastic such as a cylinder, a U-shape and an H-shape. It is.

2. Description of the Related Art A prepreg material in which a reinforcing material such as carbon fiber or glass fiber is impregnated with a thermosetting resin such as an epoxy resin or a phenol resin is heat-formed to continuously obtain a molded product having an arbitrary cross-sectional shape. However, so far, as a release sheet between the prepreg material and the mold, a fluorine sheet or a polymethylpentene resin sheet (including TPX),
Alternatively, a composite sheet obtained by laminating a polymethylpentene resin sheet and polyethylene terephthalate (PET) has been used. However, when a fluorine sheet is used, the transfer of fluorine to a molded article adversely affects the subsequent processability, such as lowering the adhesiveness, and there is a disadvantage that the cost becomes high.On the other hand, a polymethylpentene resin sheet is used. In addition, there is a disadvantage that mechanical properties such as bending elasticity and tensile strength during heating are insufficient. On the other hand, if a laminated sheet in which PET and a polymethylpentene-based resin sheet are bonded to each other to compensate for mechanical strength is used,
Although the mechanical strength is improved, there is a new drawback that the mold is contaminated by oligomers and abrasion powder precipitated from PET when heated.

[0002]

DISCLOSURE OF THE INVENTION The present invention relates to a release sheet for molding a prepreg material, which has excellent mechanical strength and is not contaminated by a mold due to oligomers and abrasion powder precipitated from the release sheet during heat molding. The purpose is to provide.

[0003]

SUMMARY OF THE INVENTION The present invention is directed to a laminate of a resin film such as a polyester resin film and a polyolefin resin film having heat resistance and releasability, such as a polymethylpentene resin sheet, and a polyphenylene sulfide film. The heat-resistant engineering plastic film having a phenyl group in the skeleton such as the above resin film, especially when provided and laminated on a polyester resin film, it was made based on the knowledge that the above problems can be solved efficiently. is there. That is, the present invention provides a prepreg material characterized in that a polyolefin resin film having heat resistance and mold release properties, a resin film and a heat-resistant engineering plastic film having a phenyl group in a skeleton are laminated in this order. A mold release sheet is provided. The present invention is also characterized in that a prepreg material is disposed on a polyolefin resin film layer having heat resistance and release properties of the release sheet, heated and pressed, and then the release sheet is peeled off. A method of molding a material is provided.

[0004]

BEST MODE FOR CARRYING OUT THE INVENTION The polyolefin resin film having heat resistance and releasability used in the present invention has heat resistance and releasability from a prepreg material. Specific examples include a polymethylpentene resin film and a cycloolefin resin film. Among these, a polymethylpentene resin film is preferable, and a 4-methyl-1-pentene resin film is particularly preferable. These can be easily obtained as Opulan TPX manufactured by Mitsui Chemicals, Inc. Although the thickness is arbitrary, it is preferably from 10 to 150 μm, and more preferably from 15 to 100 μm. In the present invention, the polyolefin resin film on one side or both sides (preferably on one side), a corona treatment,
It is preferable to use one that has been subjected to an easy adhesion treatment such as a plasma treatment or a blast treatment, preferably a corona treatment. The resin film used in the present invention can be used without any particular limitation, and polyethylene terephthalate (P
ET), polybutylene terephthalate, polycarbonate, acrylic resin and other films. Among them, polyester resin films such as polyethylene terephthalate (PET) and polybutylene terephthalate are preferable, and PET is particularly preferable. These can be easily obtained as Lumirror manufactured by Toray Industries, Inc.
The thickness is arbitrary, but is preferably less than 500 μm, more preferably 5 to 120 μm.

The heat-resistant engineering plastic film used in the present invention preferably has a low oligomer precipitation amount during heating and has excellent mechanical properties during heating. As such a film, a polyphenylene sulfide film is preferable, and Torelina manufactured by Toray Industries, Inc. can be mentioned. The thickness is optional, but is preferably less than 100 μm, more preferably 5 to 20 μm. In the present invention, a polyolefin resin film having heat resistance and release properties, a resin film, and a heat-resistant engineering plastic film having a phenyl group in the skeleton are laminated in this order. At this time, it is preferable to laminate the heat-resistant plastic film such that the surface of the plastic film which has been subjected to the easy adhesion treatment faces the polyester resin film. or,
Any laminating method can be used without particular limitation as long as it imparts heat resistance to the laminated release sheets. When an adhesive is not used, there are an ultrasonic fusion method and a heat fusion method. In particular, it is preferable to apply an adhesive layer between the adhesive films.

Here, the adhesion between the surface of the heat-resistant plastic film which has been subjected to the easy adhesion treatment and the resin film is as follows.
Polyester resin, urethane resin, polyester
Polyurethane-based resins, acrylic-polyol-based resins, polyolefin-based resins, polyisocyanate-based resins, and the like can be used in any combination, but it is particularly preferable to use polyester polyol-based resins and polyisocyanate-based resins in combination. On the other hand, polyester resin, urethane resin, polyester-polyurethane resin, acrylic-
Polyol-based resins, polyolefin-based resins, polyisocyanate-based resins and the like can be used in any combination, but it is particularly preferable to use polyester polyol-based resins and polyisocyanate-based resins in combination.
Specifically, an aliphatic isocyanate is preferable as the isocyanate resin. In particular, HDI isocyanates are desirable.

More specifically, it is preferable to use an adhesive composition comprising a polyester polyol resin and a polyisocyanate resin for bonding the polyester resin film and the polyphenylene sulfide film.
As the polyisocyanate-based resin, aliphatic polyisocyanate and the like are preferably used, and HDI-based polyisocyanate is particularly preferable. In the present invention, it is particularly preferable to use a solution in which the adhesive is dissolved or dispersed, apply the solution to one surface of the resin film, dry the solvent, and then bond the adherends to each other. Such a solution adhesive is formed on a film substrate by a conventional method using a Meyer bar,
It can be applied by a method using various coating devices such as an applicator, silk screen, comma, reverse, direct gravure, microgravure, die, air knife, bar, curtain, spray, blade and the like.

In the present invention, the thickness of the adhesive layer is not particularly limited, but is preferably about 0.05 to 20 μm, more preferably 0.1 to 10 μm, and particularly preferably 0.5 to 5 μm. is there. The laminate prepared in this manner has a 90 ° bending heat resistance (180 ° C. × 2 hours),
It is preferable that the film does not float between the films, has high bending elasticity, and does not easily curl. The thickness of the laminate of the present invention is arbitrary, but is preferably from 10 to 800 µm, more preferably from 25 to 250 µm, and still more preferably from 100 to less than 200 µm. In the present invention, the prepreg material is formed by arranging a prepreg material on a polyolefin resin film layer having heat resistance and releasability of the release sheet, heating and pressing, and then peeling the release sheet. Good to do. At this time, two release sheets are prepared, and the heat-resistant engineering films of the respective sheets are arranged so as to face each other, and a prepreg material is sandwiched between the sheets, and then heated and pressed, and then the release sheet is peeled off. Good. The heat and pressure molding is preferably performed by applying a hot press in a mold, but the molding method can be used without any particular limitation, and it is particularly preferable to use a molding method, and more preferably a pultrusion method.

The prepreg material used here may be any material that can be suitably used for forming a fiber-reinforced plastic, for example, a phenol-epoxy resin, a bismaleimide-triazine resin, a polyimide resin, an epoxy resin, Any of phenol resin, triazine resin, and polyamide resin may be used alone or in combination, and may be combined with carbon fiber, synthetic fiber, glass fiber, or the like. In addition, when forming a multilayer, they may be combined.
Among them, particularly, it can be suitably used for a prepreg using an epoxy resin. In the above molding method, one or more release sheets may be used depending on the shape of the final molded product.

[0010]

According to the present invention, there is provided a release sheet for molding a prepreg material which has excellent mechanical properties and is not contaminated by a mold due to oligomers and abrasion powder precipitated from the release sheet during heat molding. Is done. By using the release sheet and the prepreg, reinforcing members of various forms can be efficiently molded. Next, the present invention will be described with reference to examples.

[0011]

EXAMPLES Example 1 The following three-layered laminate was prepared as follows. (1) Lowermost layer As a polyolefin resin film having heat resistance and mold release property, TPX: manufactured by Mitsui Chemicals, Inc., Opulan TP
X and X44B # 50 (thickness: 50 μm) were used. (2) Intermediate layer PET: Lumirror # 100S10 (100 μm thickness) manufactured by Toray Industries, Inc. was used as the resin film.

(3) Top layer As a heat-resistant engineering plastic film having a phenyl group in the skeleton, a polyphenylene sulfide film (PPS: manufactured by Toray Industries, Inc., Torelina, #
9-3030 corona (9 μm thickness) was used. First,
Polyester-polyol resin (Adlock RU-77, manufactured by Rock Paint Co., Ltd.) / Aliphatic polyisocyanate (H-7, manufactured by Rock Paint Co., Ltd.) = 87/13 in terms of solid content mass ratio, and toluene / diluent / Methyl ethyl ketone = 1/1 mixed solvent by weight ratio 26/7
The solution was prepared by stirring and dissolving so as to obtain the composition No. 4. This was applied to a PET film as an intermediate layer by a usual method using a Meyer bar, and dried (4 μm in thickness).
The S films were stacked and heated and pressed to form a two-layer laminate.
Next, a polyether polyurethane resin (Takerac A-610, manufactured by Takeda Pharmaceutical Co., Ltd.)
HMDI-based isocyanate (Coronate HL, manufactured by Nippon Polyurethane Industry Co., Ltd.) = 87.8 / 12.2 and a mixed solvent of ethyl acetate / toluene = 1/1 as a diluting solvent are stirred and dissolved in a weight ratio of 26/74. Prepared. This was applied to the PET film layer side of the previously formed three-layer laminate using a Meyer bar by a usual method, and dried (4 μm in thickness). A release film having adhesiveness (NT25, manufactured by Panac Co., Ltd.) is attached to one side of the TPX film to prevent show-through of the corona, and a corona discharge treatment is performed on the TPX film side.
The treated surfaces of the PX films were stacked and heated and pressed, and the release film having adhesiveness was peeled off to prepare a release sheet composed of a five-layer laminate.

A 180 ° turn-back test on the PPS side showed 3.82 N / 15 mm at room temperature and 1.67 N / 15 mm in hot air at 100 ° C. The evaluation result of 100 ° C. tearing was 8 under the aging condition (45 ° C. × 2 days).
5 ° and 85 ° even under aging conditions (45 ° C. × 7 days). After heating in hot air at 190 ° C for 3 hours, PPS
The surface of the film was visually observed, and the surface states before and after heating were compared. As a result, there was no change.

Example 2 A release sheet comprising a three-layer laminate of the present invention was prepared in the same manner as in Example 1 except that the amount of the aliphatic isocyanate (manufactured by Adlock Co., Ltd.) was changed to 20 parts by weight. . PP
A 180 ° turn-back test was performed on the S side.
/ 15mm, 1.47N / 15mm in hot air of 100 ℃
Met. The evaluation result of 100 ° C. tearing was 90 ° under the aging condition (45 ° C. × 2 days) and 85 ° under the aging condition (45 ° C. × 7 days).

Comparative Example 1 In the same manner as in the example, a release sheet composed of a two-layer laminate comprising a lowermost layer and an intermediate layer was prepared. After heating in hot air at 190 ° C. for 3 hours, the PET film surface was visually observed, and the surface state before and after heating was compared. As a result, white powder oligomers were precipitated on the entire surface of the intermediate layer. Was.

Example 3 Using the release sheets prepared in Examples 1 and 2, an epoxy prepreg using a roll-shaped carbon fiber cloth was continuously molded by a conventionally known method. The prepreg had good adhesion, and could be processed without causing a large air entrapment that would cause inconvenience in practical use and appearance. On the other hand, the mold exhibited good releasability. After molding, the release film could be easily peeled off from between the molded products, and showed good release properties. Also, the mold was not soiled.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Minoru Nakahara 1120 Matsuda-cho, Matsuda-machi, Ashigarashimo-gun, Kanagawa Prefecture Room No. 202, Ichidananaka Heights Room (72) Inventor Takashi Watanabe 2-4 Otemachi, Oimachi, Ashigara-gun, Kanagawa Prefecture Leo Palace 21 Cosmos No3 Room No. 303 F term (reference) 4F100 AK01B AK03A AK08 AK42A AK51 AK51G AK56B BA02 EH46 EH462 EJ17 EJ173 EJ42 EJ422 EJ55 EJ552 EJ86 EJ862 GB90 JJ03A JJ03B JL06 FE034204

Claims (5)

[Claims] 1. A prepreg material molding comprising a heat-resistant and mold-releasing polyolefin resin film, a resin film and a heat-resistant engineering plastic film having a phenyl group in the skeleton laminated in this order. Release sheet. 2. The release sheet according to claim 1, wherein the heat-resistant engineering film is a polyphenylene sulfide film. 3. The release sheet according to claim 1, wherein the polyolefin resin film has one surface subjected to an easy adhesion treatment. 4. The release sheet according to claim 1, wherein the resin film is a polyester resin film. 5. The release sheet according to claim 1, wherein each of the films is bonded with an adhesive.