JPH0332836A - Composite molding sheet - Google Patents

Abstract

PURPOSE:To obtain good appearance, excellent heat-resistant dimensional stability and mechanical strength by providing an intermediate layer containing a fiber whose diameter is smaller than the diameter of the fiber bundle or monofilament constituting a fibrous reinforcing material between a core material composed of a thermoplastic resin layer containing the fibrous reinforcing material and an outer layer material composed of a thermoplastic resin containing an inorg. filler. CONSTITUTION:A sheet-like intermediate layer containing a fiber whose diameter is smaller than the diameter of the fiber bundle or monofilament constituting a fibrous reinforcing material is integrally laminated between a sheet-like core material composed of a thermoplastic resin layer containing the fibrous reinforcing material composed of a bundled fiber and/or a monofilament and a sheet-like outer layer material composed of a thermoplastic resin layer containing an inorg. filler. In case of a continuous fiber as the fibrous reinforcing material, there are a continuous strand mat, roving cloth or the like and, in case of a discontinuous fiber, there is a chopped strand mat and the core material is composed of a glass fiber. As the intermediate layer, there are a commercial surfacing mat, natural fiber cloth, knitted cloth, a nonwoven fabric or paper.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a stampable sheet with a thermoplastic resin layer, particularly for use in automobile exterior parts, housing materials, etc., with good appearance, excellent heat-resistant dimensional stability, and mechanical properties. The present invention relates to a thermoplastic resin layer stampable sheet that can be used to stamp molded products that require high mechanical strength.

[Conventional technology]

Conventional thermoplastic resin stampable sheets have poor surface properties after stamping. For example, by laminating a layer containing relatively short glass fibers or granular fillers on the surface layer of a thermosetting resin sheet, the surface can be smoothed. (Japanese Patent Publication No. 52-40588), an attempt to improve surface properties by dispersing short fibers in a thermosetting resin reinforced with long fiber strands (Japanese Patent Publication No. 54-36193); Although there are methods to improve the appearance by reducing the diameter of the glass fibers used in reinforcing mats (Japanese Unexamined Patent Publication No. 168731/1983), the surfaces of molded products obtained using these methods are still not satisfactory, and Method of using curable resin in combination (JP-A-54-30
No. 264) and a method of sandwiching the upper and lower surfaces of a thermoplastic stampable sheet with thin metal plates to ensure surface smoothness (Japanese Patent Laid-Open No. 57-201650) have been proposed. In this case, even if good surface properties are obtained, the cost is high and it is not practical. As described above, even with these methods, problems such as protrusion of the glass reinforcing material on the surface, fine surface cracks, racks, warping, etc. have not been solved, and this is especially true for fields that require a good appearance. The surface characteristics that molded products should have are not fully satisfied.

[Problem to be solved by the invention]

An object of the present invention is to provide a stampable sheet made of thermoplastic resin that has improved the above-mentioned drawbacks and can be used to form a stamp-molded product having a good appearance.

[Means to solve the problem]

The inventors of the present invention focused on this problem and completed the present invention as a result of intensive research to develop a stampable sheet that does not have the above-mentioned defects.

That is, the present invention comprises a sheet-like core material made of a thermoplastic resin layer containing a fibrous reinforcing material made of bundled fibers and/or single fibers, and a thermoplastic resin sheet-like outer layer material containing an inorganic filler. The present invention relates to a sheet for a composite bottom shape, characterized in that a sheet-like intermediate layer containing fibers having a smaller diameter than the bundled fiber diameter or single fiber diameter constituting the fiber reinforcing material is laminated and integrated therebetween. be.

In the case of continuous fibers, the fibrous reinforcing material contained in the sheet-like core material in the sheet for composite bottom shapes of the present invention includes continuous strand mat, roving cloth,
There are glass cloths, etc., and in the case of discontinuous fibers, there are chopped strand mats, surfering mats, etc., and there are laminate mats, etc. that use a combination of both. The fibers used for the core material are preferably glass fibers, but it is not necessary that all of them are glass fibers, and depending on the required performance, inorganic and organic U& fibers such as OF (carbon fiber) and AP (aramid fiber) can be used. Can be used in combination. Further, the fibers may be either bundled fibers or single fibers. The mixing ratio is preferably 50% or less of the reinforcing fibers constituting the core material. This percentage is
Selected from physical properties and/or controls.

The thickness of such fibers is, for example, in the case of bundled fibers, about 60 to 70 μm as a bundle diameter, and in the case of single #am, about 18 to 20 μm.
μi. The length is preferably 5 m or more, more preferably 10 m or more. 5W! Below R, the reinforcing effect of the fibers is insufficient.

The content of reinforcing fibers relative to the resin in the sheet-like core material is preferably 20 to 70% by weight, more preferably 30 to 6% by weight.
It is 0% by weight. If it is less than 20%, the strength is insufficient7
If it exceeds 0%, the fluidity becomes poor.

Examples of the sheet of fibers with a relatively small diameter used as the intermediate layer in the composite bottom sheet of the present invention include commercially available surfing mats, cloths made of natural fibers, knits, non-woven fabrics, papers, etc. . however,
The diameter of the fibers that make up these fibers is smaller than the fibers of the reinforcing material of the core material, for example, about 18 to 20 μm in the case of fiber bundles, and about 9 to 1 μm in the case of single fibers.
It is 1 μm.

In the present invention, a thermoplastic resin sheet-like outer layer material containing an inorganic filler is provided on this sheet-like intermediate layer. Such inorganic fillers may be commonly used ones such as commercially available wollastonite, clay, and calcium carbonate. The amount of the filler added is preferably in the range of 10 to 60% by weight, more preferably 20 to 50% by weight of the resin forming the outer layer material.

If it is less than 10% by weight, it will not exhibit an auxiliary concealing effect;
If it is 0% by weight or more, the hiding effect is excellent, but the fluidity of the resin is inhibited.

Further, the above-mentioned inorganic filler can also be included in the core material, if desired.

The type of thermoplastic resin used as a matrix in the core material and the outer layer material is not particularly specified.
Those described in Japanese Patent Publication No. 1-14557, Japanese Patent Publication No. 58-17720, etc. may be used. Specifically, polyolefin resins such as polyethylene and polypropylene, polyester resins such as polyethylene terephthalate and polybutylene terephthalate, nylon 6, and nylon 66
Polyamide resins such as PS, PPo,
Examples include heat-resistant resins such as PEEK. Of course, the thermoplastic resin matrix may be a homopolymer, a keyaki copolymer such as an ethylene-vinyl acetate copolymer or an ethylene-acrylic copolymer, a modified polymer, a graft copolymer, etc. It is also possible to blend them as appropriate. Furthermore, the thermoplastic resin matrix contains fillers other than the core material,
Reinforcing agents, plasticizers, stabilizers, flame retardants, crystal nucleating agents, etc. may be added, or additions such as silane coupling agents and titanate coupling agents to improve the adhesion of the matrix resin to the reinforcing materials. An agent may be added. The amount added is selected depending on the purpose.

The degree of IJ lux polymerization of the thermoplastic resin used in the present invention is not restricted in any way and is preferably selected depending on the purpose. In particular, the ratio of the melt viscosity of the relatively high degree of polymerization resin used for the outer layer material to the matrix resin used for the sheet body is preferably 1.2 or more, and more preferably 1.4 or more. This is because if it is less than 1.2, the resin layer will wash away during stamping, making it difficult to form the outer layer material.

In the present invention, if necessary, an outer layer material can be provided on the opposite (back) side of the core material via an intermediate layer in the same manner as described above. In this case, there is an outer layer material on both the front and back sides of the core material.

In the present invention, in preparing a composite sheet in which these layered bodies are laminated and integrated, the laminated bodies laminated as described above are unified by heating and pressing. In this case, the resins in the outer layer material and the core material are melted and flowed and impregnated into the fiber reinforcing material to form an integrated composite molding sheet.

The thickness of the core material, middle layer, and outer layer material is 1ooo each.
~50f')O (preferably 2000-4000), 1
00~200 (130~180 in old times), 100~
500 (preferably 150 to 450) μ. When there is an outer layer material on both the front and back surfaces, it is preferable that the thicknesses of both are the same.

The thus obtained composite molding sheet (stampable sheet) of the present invention can be easily molded using a general molding machine for thermoplastic resin stampable sheets by a normal molding method. The mold temperature is preferably 160° C. or less, and the molded product obtained from the present stampable sheet has better physical properties than conventional products, especially in terms of appearance.

EXAMPLES The present invention will be explained in detail below with reference to Examples, but the present invention is not limited to these Examples.

〔Example〕

The θ11 constant of each microscopic characteristic in the examples was determined by the following method.

(1) Surface smoothness The surface smoothness of the flat stamp molded product was measured in accordance with the surface roughness standard J.E. 0601-1982 using a Tokyo Seimitsu ■Flash surface roughness profile measuring machine Surfcom 300B. The surface roughness was represented by the center line average roughness Ra.

Ra is expressed by the following formula.

The roughness was evaluated by a relative comparison with the roughness of the face milling plate of the comparison roughness standard piece of Model 5S-03-2 made by Metrol@.
It was as follows.

Table 1 (2) The sled molded plate was cut into 10clIX 10c*X 1.5 to 2 shoulders and evaluated based on the average value of the distance from the plane of the two points farthest from the plane. The evaluation criteria were as follows.

Table 2 Examples 1 to 6 Comparative Examples 1 to 9 Polyethylene terephthalate with an intrinsic viscosity of 0.63, polypropylene with M = 48, and nylon 6 with an intrinsic viscosity of 1.21 were each coated with wollastonite (manufactured by NYAD325 Linhua Kai). Blend 30 vol % and heat each at 280°C, 1200°C, 250″C using a 30mφ twin-screw extruder.
After vacuum drying the pellets at 120°C for 6 hours, they were pelletized using a 40Ilaφ extruder, the same as the above 2111f.
Extrude it into a sheet from a die at high temperature, cool it, and make it into a sheet with a thickness of 20 mm.
A sheet of 0 μm was obtained (this is used as the outer layer material and the sheet in the core material).

Next, the obtained sheet was combined with a glass mat (A: 8 bundles made of MO45QA fibers with a diameter of 11 to 13 μm).
1 Glass mat consisting of bundled fibers m (diameter 60-701 zm), B: σFG24 made of E1 sheet glass ■ fiber diameter 18-20
10! After the glass mat is sandwiched between Ell-thick flat metal molds and hot pressed to completely melt the resin, the pressure is gradually increased to fully impregnate the resin into the glass mat.
Immediately, it was poured into water and rapidly cooled to obtain a sheet-like core material with a thickness of 2 days.

Next, the sheet-like core material is placed in the center, and an intermediate layer is formed between Cumulus DHM-5030 (F
A! Glass paper made of a single fiber with a diameter of 9 to IJμ and a length of 25m) or aya 24C manufactured by Nippon Sheet Glass ■
A layered sheet of glass paper with a fiber diameter of 18 to 20μ is heated with an infrared heater to elute the resin in the outer layer material and sheet-like core material, and then heated in a cooling mold kept at room temperature. A stampable sheet was obtained by applying a breath cooling force.

Next, the stampable sheet was 1100mm x 100t.
After cutting the sheet into a size of
A flat plate measuring 110 x 2 to 3 thick was molded.

The results are shown in the table below.

Single fiber diameter (μ), 9 to 11 indicate the single calf diameter (μ).

Description 1, Title of the invention Composite bottom sheet 2, Claim 1, A sheet-like core material consisting of a thermoplastic resin layer containing a fibrous reinforcing material consisting of bundled fibers and/or single fibers, and an inorganic A sheet-like intermediate layer containing fibers having a smaller diameter than the fiber bundle diameter or single fiber diameter constituting the fiber reinforcement material is laminated and integrated between the thermoplastic resin sheet-like outer layer material containing a filler. A composite molding sheet characterized by:

3. Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a stampable sheet with a thermoplastic resin layer, and is particularly applicable to automobile exterior parts, housing materials, etc., with good appearance, excellent heat-resistant dimensional stability, and mechanical properties. The present invention relates to a thermoplastic resin layer stampable sheet that can be used to stamp molded products that require high mechanical strength.

[Conventional technology]

Conventional thermoplastic resin stampable sheets have poor surface properties after stamping. For example, by laminating a layer containing relatively short glass fibers or granular fillers on the surface layer of a thermosetting resin sheet, the surface can be smoothed. (Japanese Patent Publication No. 52-40588), an attempt to improve surface properties by dispersing short fibers in a thermosetting resin reinforced with long fiber strands (Japanese Patent Publication No. 54-36193); Although there are methods to improve the appearance by reducing the diameter of the glass fibers used in reinforcing mats (Japanese Unexamined Patent Publication No. 168731/1983), the surfaces of molded products obtained using these methods are still not satisfactory, and Method of using curable resin in combination (JP-A-54-30
No. 264) and a method of sandwiching the upper and lower surfaces of a thermoplastic stampable sheet with thin metal plates to ensure surface smoothness (Japanese Patent Laid-Open No. 57-201650) have been proposed. In this case, even if good surface properties are obtained, the cost is high and it is not practical. As described above, even with these methods, problems such as protrusion of the glass reinforcing material on the surface, fine surface cracks, racks, warping, etc. have not been solved, and this is especially true for fields that require a good appearance. The surface characteristics that molded products should have are not fully satisfied.

[Problem to be solved by the invention]

An object of the present invention is to provide a stampable sheet made of thermoplastic resin that has improved the above-mentioned drawbacks and can be used to form a stamp-molded product having a good appearance.

[Means to solve the problem]

The inventors of the present invention focused on this problem and completed the present invention as a result of intensive research to develop a stampable sheet that does not have the above-mentioned defects.

That is, the present invention comprises a sheet-like core material made of a thermoplastic resin layer containing a fibrous reinforcing material made of bundled fibers and/or single fibers, and a thermoplastic resin sheet-like outer layer material containing an inorganic filler. The present invention relates to a sheet for a composite bottom shape, characterized in that a sheet-like intermediate layer containing fibers having a smaller diameter than the bundled fiber diameter or single fiber diameter constituting the fiber reinforcing material is laminated and integrated therebetween. be.

In the case of continuous fibers, the fibrous reinforcing material contained in the sheet-like core material in the sheet for composite bottom shapes of the present invention includes continuous strand mat, roving cloth,
There are glass cloths, etc., and in the case of discontinuous fibers, there are chopped strand mats, surfering mats, etc., and there are laminate mats, etc. that use a combination of both. The fibers used for the core material are preferably glass fibers, but it is not necessary that all of them are glass fibers, and depending on the required performance, inorganic and organic U& fibers such as OF (carbon fiber) and AP (aramid fiber) can be used. Can be used in combination. Further, the fibers may be either bundled fibers or single fibers. The mixing ratio is preferably 50% or less of the reinforcing fibers constituting the core material. This percentage is
Selected from physical properties and/or controls.

The thickness of such fibers is, for example, in the case of bundled fibers, about 60 to 70 μm as a bundle diameter, and in the case of single #am, about 18 to 20 μm.
μi. The length is preferably 5 m or more, more preferably 10 m or more. 5W! Below R, the reinforcing effect of the fibers is insufficient.

The content of reinforcing fibers relative to the resin in the sheet-like core material is preferably 20 to 70% by weight, more preferably 30 to 6% by weight.
It is 0% by weight. If it is less than 20%, the strength is insufficient7
If it exceeds 0%, the fluidity becomes poor.

Examples of the sheet of fibers with a relatively small diameter used as the intermediate layer in the composite bottom sheet of the present invention include commercially available surfing mats, cloths made of natural fibers, knits, non-woven fabrics, papers, etc. . however,
The diameter of the fibers that make up these fibers is smaller than the fibers of the reinforcing material of the core material, for example, about 18 to 20 μm in the case of fiber bundles, and about 9 to 1 μm in the case of single fibers.
It is 1 μm.

In the present invention, a thermoplastic resin sheet-like outer layer material containing an inorganic filler is provided on this sheet-like intermediate layer. Such inorganic fillers may be commonly used ones such as commercially available wollastonite, clay, and calcium carbonate. The amount of the filler added is preferably in the range of 10 to 60% by weight, more preferably 20 to 50% by weight of the resin forming the outer layer material.

If it is less than 10% by weight, it will not exhibit an auxiliary concealing effect;
If it is 0% by weight or more, the hiding effect is excellent, but the fluidity of the resin is inhibited.

Further, the above-mentioned inorganic filler can also be included in the core material, if desired.

The type of thermoplastic resin used as a matrix in the core material and the outer layer material is not particularly specified.
Those described in Japanese Patent Publication No. 1-14557, Japanese Patent Publication No. 58-17720, etc. may be used. Specifically, polyolefin resins such as polyethylene and polypropylene, polyester resins such as polyethylene terephthalate and polybutylene terephthalate, nylon 6, and nylon 66
Polyamide resins such as PS, PPo,
Examples include heat-resistant resins such as PEEK. Of course, the thermoplastic resin matrix may be a homopolymer, a keyaki copolymer such as an ethylene-vinyl acetate copolymer or an ethylene-acrylic copolymer, a modified polymer, a graft copolymer, etc. It is also possible to blend them as appropriate. Furthermore, the thermoplastic resin matrix contains fillers other than the core material,
Reinforcing agents, plasticizers, stabilizers, flame retardants, crystal nucleating agents, etc. may be added, or additions such as silane coupling agents and titanate coupling agents to improve the adhesion of the matrix resin to the reinforcing materials. An agent may be added. The amount added is selected depending on the purpose.

The degree of IJ lux polymerization of the thermoplastic resin used in the present invention is not restricted in any way and is preferably selected depending on the purpose. In particular, the ratio of the melt viscosity of the relatively high degree of polymerization resin used for the outer layer material to the matrix resin used for the sheet body is preferably 1.2 or more, and more preferably 1.4 or more. This is because if it is less than 1.2, the resin layer will wash away during stamping, making it difficult to form the outer layer material.

In the present invention, if necessary, an outer layer material can be provided on the opposite (back) side of the core material via an intermediate layer in the same manner as described above. In this case, there is an outer layer material on both the front and back sides of the core material.

In the present invention, in preparing a composite sheet in which these layered bodies are laminated and integrated, the laminated bodies laminated as described above are unified by heating and pressing. In this case, the resins in the outer layer material and the core material are melted and flowed and impregnated into the fiber reinforcing material to form an integrated composite molding sheet.

The thickness of the core material, middle layer, and outer layer material is 1ooo each.
~50f')O (preferably 2000-4000), 1
00~200 (130~180 in old times), 100~
500 (preferably 150 to 450) μ. When there is an outer layer material on both the front and back surfaces, it is preferable that the thicknesses of both are the same.

The thus obtained composite molding sheet (stampable sheet) of the present invention can be easily molded using a general molding machine for thermoplastic resin stampable sheets by a normal molding method. The mold temperature is preferably 160° C. or less, and the molded product obtained from the present stampable sheet has better physical properties than conventional products, especially in terms of appearance.

EXAMPLES The present invention will be described in detail below with reference to Examples, but the present invention is not limited to these Examples.

〔Example〕

The θ11 constant of each microscopic characteristic in the examples was determined by the following method.

(1) Surface smoothness The surface smoothness of the flat stamp molded product was measured in accordance with the surface roughness standard J.E. 0601-1982 using a Tokyo Seimitsu ■Flash surface roughness profile measuring machine Surfcom 300B. The surface roughness was represented by the center line average roughness Ra.

Ra is expressed by the following formula.

The roughness was evaluated by a relative comparison with the roughness of the face milling plate of the comparison roughness standard piece of Model 5S-03-2 made by Metrol@.
It was as follows.

Table 1 (2) The sled molded plate was cut into 10clIX 10c*X 1.5 to 2 shoulders and evaluated based on the average value of the distance from the plane of the two points farthest from the plane. The evaluation criteria were as follows.

Table 2 Examples 1 to 6 Comparative Examples 1 to 9 Polyethylene terephthalate with an intrinsic viscosity of 0.63, polypropylene with M = 48, and nylon 6 with an intrinsic viscosity of 1.21 were each coated with wollastonite (manufactured by NYAD325 Linhua Kai). Blend 30 vol % and heat each at 280°C, 1200°C, 250″C using a 30mφ twin-screw extruder.
After vacuum drying the pellets at 120°C for 6 hours, they were pelletized using a 40Ilaφ extruder, the same as the above 2111f.
Extrude it into a sheet from a die at high temperature, cool it, and make it into a sheet with a thickness of 20 mm.
A sheet of 0 μm was obtained (this is used as the outer layer material and the sheet in the core material).

Next, the obtained sheet was combined with a glass mat (A: 8 bundles made of MO45QA fibers with a diameter of 11 to 13 μm).
1 Glass mat consisting of bundled fibers m (diameter 60-701 zm), B: σFG24 made of E1 sheet glass ■ fiber diameter 18-20
10! After the glass mat is sandwiched between Ell-thick flat metal molds and hot pressed to completely melt the resin, the pressure is gradually increased to fully impregnate the resin into the glass mat.
Immediately, it was poured into water and rapidly cooled to obtain a sheet-like core material with a thickness of 2 days.

Next, the sheet-like core material is placed in the center, and an intermediate layer is formed between Cumulus DHM-5030 (F
A! Glass paper made of a single fiber with a diameter of 9 to IJμ and a length of 25m) or aya 24C manufactured by Nippon Sheet Glass ■
A layered sheet of glass paper with a fiber diameter of 18 to 20μ is heated with an infrared heater to elute the resin in the outer layer material and sheet-like core material, and then heated in a cooling mold kept at room temperature. A stampable sheet was obtained by applying a breath cooling force.

Next, the stampable sheet was 1100mm x 100t.
After cutting the sheet into a size of
A flat plate measuring 110 x 2 to 3 thick was molded.

The results are shown in the table below.

Single fiber diameter (μ), 9 to 11 indicate the single calf diameter (μ).

Claims (1)

[Claims] 1. A sheet-like core material made of a thermoplastic resin layer containing a fibrous reinforcing material made of bundled fibers and/or single fibers;
A sheet-like intermediate layer containing fibers having a smaller diameter than the fiber bundle diameter or single fiber diameter constituting the fiber reinforcement material is laminated and integrated between the thermoplastic resin sheet-like outer layer material containing an inorganic filler. A composite molding sheet characterized by: