JPH053832B2 - - Google Patents

Description

[Detailed description of the invention]

(Field of Industrial Application) The present invention relates to a polypropylene resin laminate sheet with improved scratch resistance, gloss, rigidity, dimensional stability, and thermoformability such as vacuum forming, pressure forming, and press forming. (Prior art and its problems) Polypropylene resin sheets have excellent properties such as impact resistance, abrasion resistance, chemical resistance, heat deformation resistance, creep resistance, and hinge resistance, and are relatively inexpensive. Therefore, it is widely used in fields such as home appliances, automobile parts, stationery, office supplies, and packaging materials. However, the polypropylene resin sheet still has many drawbacks in terms of thermoformability in vacuum forming, pressure forming, press forming, etc., scratch resistance, gloss, rigidity, dimensional stability, etc. In order to improve this drawback, polypropylene resins are supplemented with polymeric compounds such as polyethylene and synthetic rubber and/or
Alternatively, sheets containing fillers are generally known. However, although sheets made of compositions made by blending polypropylene resin with polyethylene and synthetic rubber have some improvement in impact resistance and thermoformability, they have poor scratch resistance, gloss, rigidity, dimensional stability, and heat deformation resistance. Various properties such as creep resistance and hinge resistance deteriorate. In addition, sheets made of polypropylene resin with fillers generally have improved heat deformation resistance, rigidity, dimensional stability, etc., but they also have improved thermoformability, scratch resistance, gloss, impact resistance, etc. Various properties such as creep resistance and hinge resistance deteriorate. As described above, sheets made of compositions containing polypropylene resin, polyethylene, synthetic rubber, and/or fillers have not yet achieved various properties such as scratch resistance, gloss, creep resistance, and hinge resistance. Not improved. The inventors of the present invention have conducted intensive research to improve the conventional drawbacks of polypropylene resin sheets, namely thermoformability, scratch resistance, gloss, rigidity, and dimensional stability. As a result, crystallinity and
The A layer or C layer is made of a specific polypropylene resin whose MFR is within a specific range and the MFR and Q value have a certain relationship; and the MFR is within a specific range and the MFR and Q value have a certain relationship. A/B, C/B, A/
We discovered that laminated sheets like B/A or C/B/C (however, the thickness of the C layer is less than 50% of the total thickness) can improve the various drawbacks of conventional sheets, and completed the present invention. . As is clear from the above description, an object of the present invention is to provide a polypropylene resin laminate sheet with improved thermoformability, scratch resistance, gloss, rigidity, and dimensional stability. (Means for solving the problems) The present invention has the following configuration. (1) Crystallinity is 0.945 or more, melt flow rate (MFR) is 0.3 to 2.5 g/10 minutes, and the MFR(x)
Layer A (hereinafter referred to as A
It's called a layer. ) and a polypropylene resin with an MFR of 0.3 to 2.5 g/10 minutes and a relationship between the MFR (x) and Q value (y) of y≧15x.
Layer B consisting of a composition containing ~70% by weight (hereinafter referred to as
It is called B layer. ) in two layers of A/B or A/
A laminated sheet of polypropylene resin characterized by laminating three layers of B/A. (2) Crystallinity is 0.945 or higher, MFR is 0.3-2.5g/
10 minutes, and a layer C (hereinafter referred to as layer C) made of a polypropylene resin whose MFR (x) and Q value (y) have a relationship represented by the formula y <15x;
When MFR is 0.3 to 2.5g/10 minutes, the MFR(x) and Q value
Layer B (hereinafter referred to as layer B) consisting of a composition in which 10 to 70 wt. Or a sheet laminated in three layers of C/B/C, where the thickness of the C layer is 50% of the total thickness.
A laminated sheet of polypropylene resin characterized by the following: The polypropylene resin used for each layer of A, B, and C of the present invention includes propylene homopolymer,
α- with propylene as the main component selected from propylene and ethylene, butene-1, 4-methylpentene-1, hexene-1, and octene-1
Examples include copolymers with one or more types of olefins, modified polypropylene resins obtained by modifying these homopolymers or copolymers with unsaturated carboxylic acids or their anhydrides, and mixtures of two or more of these. can. The polypropylene resin used for the A layer of the present invention has a crystallinity of 0.945 or more, an MFR of 0.3 to 2.5 g/10 minutes, and the MFR (x) and Q value (y) are expressed by the formula y≧15x. It is a related polypropylene resin. Crystallinity is generally measured by infrared analysis or nuclear magnetic resonance, and in the present invention, infrared analysis was used. The specific measurement method of this infrared analysis method is to use a test piece with a preferable thickness (for example, 40μ) as a sample, take an infrared absorption spectrum of this test piece, and calculate the absorbance at wave numbers 977 cm ^-1 and 997 cm ^-1 of the absorption spectrum. This is a value expressed as a ratio (997cm ^-1 /977cm ^-1 ). A larger value indicates a higher degree of crystallinity, and a higher degree of crystallinity improves scratch resistance, gloss, and rigidity. However, the degree of crystallinity of commercially available polypropylene resins is approximately 0.80 to 0.935. Further, the MFR of the polypropylene resin used for the A layer is 0.3 to 2.5 g/10 minutes. If the MFR is less than 0.3 g/10 minutes, the fluidity of the molten resin during melt-kneading will deteriorate, making it difficult to extrude into a sheet and reducing gloss.
Moreover, if it exceeds 2.5 g/10 minutes, the thermoformability of the obtained sheet deteriorates, making it impossible to perform secondary forming such as vacuum forming or pressure forming, which is not preferable. The Q value is a characteristic value indicating the molecular weight distribution of the resin, and specifically, it is the ratio (Mw/Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) of the resin. Q value and
MFR is a characteristic value that has nothing to do with it, but
The present inventors have discovered that the thermoformability of the obtained sheet is further improved by using a polypropylene resin in which the Q value (y) and MFR (x) have the relationship expressed by the formula y≧15x. . The polypropylene resin used for layer A is a solid obtained by the method described in JP-A No. 58-219207, that is, by reacting an organoaluminum compound or a reaction product of an organoaluminum compound and an electron donor with titanium tetrachloride. The solid product () obtained by further reacting the product with an electron donor and an electron acceptor is combined with an organoaluminum compound and an aromatic carboxylic acid ester () to form the aromatic carboxylic acid ester and the solid product (). ) Propylene is polymerized in multiple stages in the presence of a catalyst with a molar ratio ()/() = 0.1 to 10.0, and in the first stage, 35 to 65% by weight of the total polymerization amount is added in the second stage and subsequent stages. In the same way, 65 to 35% by weight is polymerized, and the intrinsic viscosity of the middle-high molecular weight portion of each polymer portion produced in the first stage and the second stage and subsequent stages is [η] _H The intrinsic viscosity of the lower one is [η] ] _L is 3.0 [η] _H − [η] _L 6.5 ...(1) It can be obtained by adjusting the intrinsic viscosity of each polymer part. A copolymer of propylene and one or more α-olefins is produced by polymerizing propylene in the first stage in the presence of the catalyst described above, and then polymerizing propylene and It can be obtained by copolymerizing with α-olefin, or by copolymerizing propylene and α-olefin from the first stage. In addition, modified polypropylene resins modified with unsaturated carboxylic acids such as acrylic acid and maleic anhydride or their anhydrides can be prepared using known methods such as organic peroxidation. It can be obtained by heat treatment with an unsaturated carboxylic acid or its anhydride in the presence of a compound. At this time, the amount of the unsaturated carboxylic acid used is not particularly limited, but it is preferably about 0.5 to 2.0% by weight, and the modified polypropylene resin modified with the unsaturated carboxylic acid or its anhydride in an amount exceeding 2.0% by weight is preferably used. When used, it is preferable to mix and adjust unmodified polypropylene resin. In any case, the polypropylene resin used for the A layer has a crystallinity of 0.945 or more as a whole,
It is sufficient to use one in which the MFR(x) and the Q value (y) have a relationship expressed by the equation y≧15x. At this time, the thickness of layer A is not particularly limited. The polypropylene resin used for the B layer of the present invention has an MFR of 0.3 to 2.5 g/10 minutes, and the MFR(x) and Q value
(y) is a polypropylene resin having the relationship shown by the formula y≧15x. MFR is 0.1 to 5.0 g/10
The reason for using a resin having the relationship expressed by the equation y≧15x between MFR(x) and Q value (y) is the same as in the case of the A layer described above. Further, for layer B, it is necessary to use a composition containing the above-mentioned polypropylene resin and a filler in an amount of 10 to 70% by weight, preferably 20 to 50% by weight. If the filler content is less than 10% by weight, the effect of improving the stiffness and dimensional stability of the resulting laminated sheet will be small, and if it exceeds 70% by weight, the properties such as thermoformability and impact resistance of the resulting laminated sheet will be reduced. This is not preferable because the fluidity of the molten resin of the B layer decreases and the press moldability deteriorates. In addition, the above-mentioned fillers include commonly used inorganic fillers such as talc, calcium carbonate, barium sulfate, calcium silicate, calcium sulfate, aluminum hydroxide, and mica, as well as wood flour, rice husk flour, cellulose short fibers, and synthetic Examples include organic fillers such as fibers, natural fibers, and carbon fibers, and these can be used alone or in combination. The shape of the filler is preferably 50 μm or less in particle size for inorganic fillers, 50 mesh or less for powdered organic fillers, and 5 mm or less in fiber length for fibrous fillers. Preferable in terms of ease of handling. In addition, the polypropylene resin used for the B layer is composed of propylene and α-
It is preferable to use a copolymer with one or more olefins and a modified propylene copolymer obtained by modifying the copolymer with an unsaturated carboxylic acid or its anhydride. In addition, the polypropylene resin used for the B layer is produced by polymerizing propylene or propylene and α-olefin in multiple stages using a catalyst and a molecular weight regulator consisting of a titanium trichloride composition and an organoaluminum compound. It can be obtained by a method of polymerization while changing the amount of a regulator. The polypropylene resin used for the C layer of the present invention has a crystallinity of 0.945 or more and an MFR of 0.3 to 2.5 g/10.
It is a polypropylene resin in which the MFR (x) and the Q value (y) have a relationship expressed by the formula y<15x. Such polypropylene resins are disclosed in, for example, Japanese Patent Application Laid-Open No.
It can be obtained by the method described in JP-A-104907. That is, a solid product obtained by reacting an organoaluminum compound or a reaction product of an organoaluminum compound and an electron donor with titanium tetrachloride, and further reacting an electron donor and an electron acceptor. substances (), organoaluminium compounds and aromatic carboxylic acid esters ()
in combination, the molar ratio ()/() of the aromatic carboxylic acid ester and the solid product () = 0.2 to
It can be obtained by polymerizing propylene in the presence of a catalyst with a concentration of 10.0 or by random copolymerization or block copolymerization of propylene and one or more α-olefins. In addition, the propylene homopolymer or copolymer obtained by the above method is mixed with an unsaturated carboxylic acid such as acrylic acid or maleic anhydride or its anhydride in accordance with the method for producing the modified polypropylene resin of layer A described above. A modified polypropylene resin can be obtained by modifying the polypropylene resin. In addition, the polypropylene resin used for the C layer has a crystallinity of 0.945 or more and an MFR of 0.3 to 2.5.
The reason for using the polypropylene resin of g/10 min is the same as in the case of layer A. In the case of layer A made of polypropylene resin in which MFR(x) and Q value (y) have the relationship expressed by the formula y≧15x, the thickness of layer A is not particularly limited as described above, but MFR( x) and Q
The thickness of the C layer made of the above-mentioned polypropylene resin, where the value (y) is expressed by the formula y<15x, is 50% of the total thickness.
Below, it is necessary to preferably set it to 40% or less. At this time, in the case of a sheet laminated in three layers such as C/B/C, the total thickness of the two C layers must be 50% or less of the total thickness. If the thickness of the C layer or the total thickness of the C layers exceeds 50%, the thermoformability of the resulting sheet will deteriorate and practicality will not be lost, which is not preferable. The polypropylene resin used in each of the A, B, and C layers of the present invention includes stabilizers, lubricants, nucleating agents, gloss improvers, antistatic agents, ultraviolet absorbers, flame retardants,
Coupling agents, etc. can be added, and synthetic rubbers such as polyethylene, ethylene-propylene rubber and styrene-butadiene rubber, styrene-based resins such as ABS resin, polystyrene, and acrylonitrile can be used as long as the purpose of the present invention is not impaired. - Styrene resin etc. can be added. Furthermore, an inorganic filler may be added to the polypropylene resin used for the A layer and C layer of the present invention, if necessary. Although the total thickness of the laminated sheet of the present invention is not particularly limited, it is practically 0.5 to 3 mm, particularly 0.8 mm.
A thickness of ~2.5 mm is preferred. Methods for producing the laminated sheet of the present invention include coextrusion, extrusion lamination, dry lamination,
An example of a method is to laminate each layer using a generally known method such as a heat lamination method. Among these, it is preferable to use a coextrusion method in order to simplify the manufacturing process of the laminated sheet. (Examples) Hereinafter, the present invention will be specifically explained using Examples and Comparative Examples. The various test methods used in Examples and Comparative Examples were as follows. 1 MFR: Compliant with JIS K 6758. 2 Crystallinity: Based on infrared analysis. 3 Q value: Based on gel permeation chromatography method (GPC method). 4 Gloss: Compliant with ASTMD 523. 5 Surface hardness: Compliant with JIS K 5401. 6 Young's modulus: Based on ASTMD882. 7 Thermoformability After heating the laminated sheet with a far-infrared heater in an oven controlled at 220°C for 30 seconds, the heated sheet is molded into a sheet with an opening of 30 mm in length and width.
200mm, bottom length 280mm, width 180mm and depth 100mm
This was placed in a box-shaped mold and vacuum-formed to form a box-shaped molded product. The resulting molded product was examined for thickness unevenness, wrinkles, and surface roughness to determine whether the thermoformability was good or bad. 8 Shrinkage rate (dimensional stability) Using a box-shaped molded product of a predetermined shape formed by a vacuum forming method in accordance with the molding method for molded products for thermoformability testing, the longitudinal direction of the opening of the molded product is The dimensions of the mold were measured, and the dimensional change rate (%) with respect to the mold dimension (300 mm) was calculated using the following formula. Dimensions of molded product/mold dimensions x 100 9 Method of making a laminated sheet To each of the compounds listed in Table 1, 0.15 PHR of BHT and 0.15 PHR of calcium stearate were added as stabilizers to 100 parts by weight of the compound. , also A-
1 to A-4 and A′-1 further contain aluminum salt of para-t-butylbenzoic acid as a nucleating agent.
After adding 0.2 PHR and stirring and mixing each blend for 3 minutes using a Hensel mixer, the mixture was melt-kneaded and extruded into pellets using a 65 mm twin-screw extruder at a melt-kneading temperature of 230°C. Using the obtained pellets, co-extrusion was carried out at a melt-kneading temperature of 230°C using two extruders equipped with T-dies each having a diameter of 65 mm and a diameter of 30 mm and a T-die width of 800 mm.
A laminated sheet with a total thickness of 1.0 mm was created by extruding it between two metal rolls with a diameter of 350 mm and cooling and solidifying it.

【table】

[Table] *1 Calcium carbonate with an average particle size of 2μ Examples 1 to 8, Comparative Examples 1 to 5 The materials listed in Table 1 above were used to create the laminated sheet described in Table 2 using the method for creating the laminated sheet described above. A two-layer sheet was created. Using the obtained sheet, the surface hardness and gloss of the A and A' sides, Young's modulus, shrinkage rate, and thermoformability were tested. The results are shown in Table 2.

【table】

[Table] Examples 9 to 13, Comparative Examples 6 and 7 Using the materials listed in Table 1, three-layer sheets listed in Table 3 were prepared by the method for making a laminated sheet. Using the obtained sheet, the surface hardness and gloss of sides A and A', Young's modulus, shrinkage rate, and thermoformability were tested. The results are summarized in Table 3.

[Table] Examples 14 to 20, Comparative Examples 8 to 13 Using the materials listed in Table 1, two-layer and three-layer sheets listed in Table 4 were produced by the method for producing laminated sheets. Using the obtained sheet, surface hardening of the A, C, and C' sides, gloss, Young's modulus, shrinkage rate, and thermoformability were tested. The results are shown in Table 4.

[Table] (Effects of the Invention) As is clear from Table 2, the laminated sheet of the present invention has good surface hardness, gloss, rigidity, shrinkability, and thermoformability, and is well-balanced. On the other hand, it can be seen that the laminated sheet obtained in the comparative example that satisfies the present invention has a problem with any of the above-mentioned properties. Further, as is clear from Table 3, it can be seen that the laminate sheet of the present invention has excellent properties even in a three-layer structure. As is clear from Table 4, all of the laminated sheets of the present invention in which the thickness of the C layer is 50% or less of the total thickness have excellent properties in surface hardness, gloss, Young's modulus, shrinkage rate, and thermoformability, and are well-balanced. You can see that it has been removed. As is clear from the above description, the laminated sheet of the present invention has excellent surface hardening, gloss, rigidity, shrinkability, and thermoformability, and is used for home appliance parts such as electric refrigerators, and as interior material for automobiles. It can be suitably used to manufacture parts that require physical properties such as gloss, scratch resistance, rigidity, and dimensional accuracy.

Claims (1)

[Claims] 1. Crystallinity is 0.945 or more, melt flow rate (MFR) is 0.3 to 2.5 g/10 minutes, and the relationship between the MFR(x) and Q value is expressed by the formula y≧15x. Layer A (hereinafter referred to as A layer) made of polypropylene resin in
Layer B (hereinafter referred to as layer B), which is made of a composition in which 10 to 70% by weight of a filler is blended with a polypropylene resin whose Q value (y) has the relationship shown by the formula y≧15x, is A/B. A laminated sheet of polypropylene resin, characterized in that it is laminated in two layers or three layers, A/B/A. 2 The polypropylene resin used for the A layer and the B layer is a propylene homopolymer, with propylene as the main component, propylene, ethylene, butene-1, 4-
Methylpentene-1, hexene-1, octene-1
A copolymer with one or more α-olefins selected from 1, a modified polypropylene resin obtained by modifying these with an unsaturated carboxylic acid or its anhydride, or a mixture of two or more of these. Laminated sheet of polypropylene resin according to item 1. 3. As a filler, an inorganic filler selected from talc, calcium carbonate, barium sulfate, calcium silicate, calcium sulfate, aluminum hydroxide, mica, and mixtures of two or more of these, or wood flour, rice husk flour, and cellulose. type fiber,
The polypropylene resin according to claim 1, which uses an organic filler selected from synthetic fibers, natural fibers, carbon fibers, and mixtures of two or more thereof, or a mixture of the inorganic filler and the organic filler. Laminated sheet. 4 Crystallinity is 0.945 or more, MFR is 0.3-2.5g/
10 minutes, a layer C (hereinafter referred to as C layer) made of a polypropylene resin whose MFR (x) and Q value (y) have a relationship expressed by the formula y<15x, and an MFR of 0.3.
~2.5g/10min, the MFR (x) and Q value (y) are y≧15x
Layer B (hereinafter referred to as B layer) consisting of a composition in which 10 to 70% by weight of a filler is blended with a polypropylene resin having the relationship shown by the formula: C/B two layers or C/B/C. It is a sheet laminated in three layers and C
A laminated sheet of polypropylene resin, characterized in that the layer thickness is 50% or less of the total thickness. 5 The polypropylene resin used in the C layer is a propylene homopolymer, an α-olefin mainly composed of propylene and selected from propylene and ethylene, butene-1, 4-methylpentene-1, hexene-1, and octene-1. A laminated sheet of a polypropylene resin according to claim 4, which is a copolymer with one or more of the above, a modified polypropylene resin obtained by modifying these with an unsaturated carboxylic acid or anhydride thereof, or a mixture of two or more of these. . 6. As a filler, an inorganic filler selected from talc, calcium carbonate, barium sulfate, calcium silicate, calcium sulfate, aluminum hydroxide, mica, and mixtures of two or more of these, or wood flour, rice husk flour, and cellulose. type fiber,
The polypropylene resin according to claim 4, which uses an organic filler selected from synthetic fibers, natural fibers, carbon fibers, and mixtures of two or more thereof, or a mixture of the inorganic filler and the organic filler. Laminated sheet.