JP3398976B2 - Resin composition - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel resin composition, and more particularly to a novel soft polypropylene resin composition having both flexibility at room temperature and sufficient mechanical strength at high temperature.

[0002]

2. Description of the Related Art In recent years, a soft vinyl chloride resin containing a plasticizer has been widely used as a soft resin used for a sheet or a film. However, for soft vinyl chloride resin,
Toxicity issues due to bleed-out of plasticizers and monomers,
In addition, there are social factors such as acid rain caused by the generation of hydrogen chloride during incineration.

On the other hand, as the soft resin comparable to the soft vinyl chloride resin, ethylene / vinyl acetate copolymer, ethylene / ethyl acrylate copolymer, ionomer,
There are those mainly composed of ethylene such as linear low density polyethylene, extremely low density polyethylene and ethylene / propylene copolymer. However, these soft resins mainly composed of ethylene lack the balance between flexibility and mechanical strength. That is,
A resin having sufficient flexibility near room temperature tends to have a reduced mechanical strength at about 80 ° C., on the other hand, at about 80 ° C.
A resin having excellent mechanical strength at around 0 ° C has a drawback that it lacks flexibility at around room temperature.

In addition, the softening of the polypropylene resin, which is excellent in mechanical strength, lowers the melting point by randomly copolymerizing propylene and ethylene, so that it has flexibility while maintaining sufficient mechanical strength. Is being done in. However, with the current technology, the ethylene concentration can be increased up to 5 to 6% by weight at most, and it is difficult for the polypropylene resin to have flexibility comparable to that of the soft vinyl chloride resin.

[0005]

In view of the above situation, the present invention provides a soft resin composition other than the soft vinyl chloride resin, particularly a resin composition which is rich in flexibility and mechanical strength from room temperature to high temperature. The purpose is to provide goods. Further, the present invention has cost advantages and is used in various applications, for example, packaging films and sheets, sheets for building materials in the field of civil engineering and construction, carpet backing materials in the field of automobiles and construction, insulators for cables, fibers, tapes. It is an object of the present invention to provide a resin composition that is a material that is preferably used as a base material for use. As a result of intensive studies conducted by the inventors for the above purpose, a soft polypropylene resin composition obtained by blending an amorphous polyolefin having a specific composition and a crystalline polypropylene in a predetermined ratio is suitable for the above purpose. And completed the present invention.

[0006]

According to the present invention, (a)
The content of propylene and / or butene-1 component is 50% by weight or more, and the amorphous polyolefin is propylene.
It is a butene-1 copolymer, the heat of fusion of crystal of the amorphous polyolefin is 20 Joule / g or less, and the number average molecular weight of the amorphous polyolefin is 1000 to 20000,
The boiling n-heptane insoluble content of the amorphous polyolefin is 20.
% Or less and amorphous polyolefin 2
0-80% by weight and (b) crystalline polypropylene 80
To 20% by weight, and (a)
An amorphous polyolefin having a propylene component content of 50% by weight or more and an ethylene component content of 0 to 30% by weight (not including 0% by weight), wherein the amorphous polyolefin is a propylene-ethylene copolymer. And the heat of fusion of crystal of the amorphous polyolefin is 20 Joule / g or less,
The number average molecular weight of the amorphous polyolefin is 4500 to 20
000, the weight average molecular weight of the amorphous polyolefin
Between Mw and the number average molecular weight Mn of the amorphous polyolefin
The ratio Mw / Mn is 6 to 16, the boiling n-heptane insoluble content of the amorphous polyolefin is 20% by weight or less,
Then, a resin composition containing 20 to 80% by weight of amorphous polyolefin and 80 to 20% by weight of (b) crystalline polypropylene is provided.

[0007]

The resin composition of the present invention is constituted as described above, and by mixing the amorphous polymer containing propylene and / or butene-1 and the crystalline polypropylene in a predetermined ratio, the original polypropylene It is possible to obtain a resin composition having high flexibility while maintaining the desired mechanical strength.

The present invention will be described in detail below. The amorphous polyolefin of the component (a) of the present invention may be an amorphous olefin polymer having a propylene and / or butene-1 component content of 50% by weight or more. For example, amorphous polypropylene or a copolymer of propylene and another α-olefin can be used. Propylene and / or amorphous polyolefin of the component (a) of the present invention
Or, when the butene-1 component content is less than 50% by weight,
It is not preferable because the compatibility with the crystalline polypropylene as the component (b) decreases.

Further, the amorphous polyolefin of the present invention is
It is preferable that the heat of fusion of crystal is not more than a predetermined value. That is,
When the amorphous polyolefin is a propylene / butene-1 copolymer, the heat of fusion of crystallization is preferably less than 10 Joule / g.
In the case of ethylene copolymer, the heat of fusion of crystal is 20 Jou
It is preferably le / g or less. If the heat of fusion of crystals is out of the above range, the flexibility is deteriorated, which is not preferable.

The heat of fusion of crystal was measured as follows. That is, this heat of crystal fusion is a value calculated using a straight line obtained by directly extrapolating the specific heat curve of the polymer in a completely molten state by a differential scanning calorimeter to the low temperature side as a baseline. The measurement was carried out by using a DSC-50 manufactured by Shimadzu Corporation as a differential scanning calorimeter, and the sample amount was about 10 mg.
The measurement atmosphere was a nitrogen atmosphere, and indium was used as a heat quantity standard. The heating program was as follows. That is, the sample was heated up to 210 ° C. at a heating rate of 50 ° C./min and left at 210 ° C. for 5 minutes, and then 10
Cool to -42 ° C at a cooling rate of ° C / min, and cool at -42 ° C for 5
Leave for a minute. After that, at a temperature rising rate of 20 ° C / min, -40 ° C
From 200 to 200 ° C.

The amorphous polyolefin of the component (a) of the present invention further comprises a boiling n-heptane-insoluble component, that is, a boiling n-.
It is desirable that the soxhlet-extractable insoluble matter with heptane is 70% by weight or less, preferably 60% by weight or less, particularly preferably 10% by weight or less. When the boiling n-heptane insoluble content is more than 70% by weight, the ratio of the amorphous portion is small, and it is not possible to impart the desired sufficient flexibility to the obtained resin composition. The above-mentioned amorphous polyolefin of the component (a) preferably has a number average molecular weight of 1,0.
00-200,000, preferably 1,500-10
It is 10,000. Here, the boiling n-heptane insoluble matter was measured by using a Soxhlet extraction method and using about 2 g of a dice-shaped sample of 3 to 5 mm square. In the present invention, the amorphous polyolefin may be used alone or in combination of two or more.

As the amorphous polypropylene, atactic polypropylene produced as a by-product during the production of crystalline polypropylene may be used, or it may be produced from raw materials and used. Further, the copolymer of propylene and other α-olefin can be used by purposely producing it from a raw material so as to contain a predetermined propylene component. When producing for the purpose,
For example, it can be obtained by polymerizing a raw material monomer in the presence / absence of hydrogen using a titanium-supported catalyst supported on magnesium chloride and triethylaluminum. From the viewpoint of the stability of supply and the stability of quality, it is preferable to use a predetermined amorphous polyolefin produced in a targeted manner. Moreover, if there is a suitable and suitable commercial product, a commercially available product can be appropriately selected and used.

[0013] As (a) the amorphous polyolefin component of the present invention, specifically, the propylene component content or the like having a predetermined characteristic Help propylene-ethylene copolymer or a flop <br/> propylene- An amorphous polyolefin whose main component is a propylene component such as butene-1 copolymer can be mentioned. When the amorphous polyolefin is a propylene / ethylene copolymer, it is desirable that the ethylene component content is 0 to 30% by weight, preferably 1 to 20% by weight. When the ethylene component content is more than 30% by weight, the resulting resin composition becomes too soft, and the surface tackiness becomes large, which is unfavorable in handling. Also, propylene
In the case of a butene-1 copolymer, the butene-1 component content is preferably 0 to 50% by weight, preferably 1 to 50% by weight, particularly preferably 10 to 50% by weight. Butene-
When the content of the one component is more than 50% by weight, the softening point of the obtained resin composition becomes too low, which is not preferable.

As the amorphous polyolefin of the component (a) of the present invention, a propylene / butene-1 copolymer containing 10 to 50% by weight of a butene-1 component has tensile elongation, impact resilience and cohesive force. Since it is large, it can be preferably used. For example, American Rexene
Commercially available products such as REXTAC of the company can be used.

The crystalline polypropylene of the component (b) of the present invention refers to boiling n-heptane-insoluble isotactic polypropylene including polypropylene which is usually commercially available for extrusion molding, injection molding, blow molding and the like. In this case, a propylene homopolymer may be used, and isotactic polypropylene having other stereoregularity and other α
-It may be a copolymer with an olefin. The crystalline polypropylene may be a commercially available product, or may be produced and used. The production of crystalline polypropylene is not particularly limited and can be appropriately selected and applied from the conventional methods for producing crystalline polypropylene.

The α-olefin used for copolymerization with the crystalline polypropylene is α-olefin having 2 to 8 carbon atoms.
-Olefins such as ethylene, butene-1, pentene-1, hexene-1, heptene-1, octene-1 etc. are preferred. Among these, ethylene or butene-1 is particularly preferable.

In the present invention, the crystalline polypropylene as the component (b) is preferably a propylene homopolymer and an ethylene component in an amount of 1 to 30% by weight, preferably 2 to 2.
Examples thereof include a propylene / ethylene random copolymer or a block copolymer containing 5% by weight, and a propylene / butene-1 random copolymer or a block copolymer containing 1 to 20% by weight of butene-1. Among these,
A copolymer of ethylene or butene-1 and propylene from applications such as films and sheets of the resin composition of the present invention,
Particularly preferred. The crystalline polypropylene as the component (b) may be used alone or in combination of two or more.

Furthermore, modified components (a) and / or (b) in the present invention can be used. The above (a) or (b) is, for example, acrylic acid,
Unsaturated carboxylic acids such as methacrylic acid, ethacrylic acid, maleic acid, fumaric acid, itaconic acid and / or their esters, acid anhydrides, and their derivatives such as metal salts can be modified for use. Of these modified products,
Those modified with maleic anhydride or itaconic anhydride are preferably used, and those modified with maleic anhydride are more preferably used.

In the present invention, the method for preparing the resin composition containing the above-mentioned components (a) and (b) is not particularly limited, and a method conventionally used in the conventional method for producing polypropylene compositions, For example, the kneader, the Banbury mixer, a kneader such as a roll, a single-screw or twin-screw extruder, and the like can be used for heat melting and kneading. Also,
In the present invention, if desired, various additives, reinforcing materials,
Fillers such as heat stabilizers, antioxidants, light stabilizers,
Antistatic agents, lubricants, nucleating agents, flame retardants, pigments or dyes, glass fibers, carbon fibers, calcium carbonate, calcium sulfate, barium sulfate, magnesium hydroxide, mica, talc, clay and the like can be added. Furthermore, other thermoplastic resins, thermoplastic elastomers, rubbers and the like can be blended as necessary, and these can also be crosslinked and blended.

The resin composition of the present invention contains the above-mentioned components (a) and (b) in a proportion such that the content of the component (a) is 20 to 80% by weight, preferably 25 to 75% by weight. It can be obtained by blending. When the content of the component (a) is less than 20% by weight, the Shore hardness Hs (23 ° C.) at room temperature exceeds 60, and sufficient flexibility cannot be obtained. On the other hand, (a)
When the component content exceeds 80% by weight, the Shore hardness Hs (23 ° C) at 23 ° C becomes less than 8, it is too soft at normal temperature, and the tensile elastic modulus (80 ° C) becomes less than 30 kg / cm ² and the shape is sufficiently retained. Cannot be achieved and the mechanical strength cannot be maintained.

The resin composition of the present invention is obtained by blending the components (a) and (b) within the above range, and preferably has a Shore D hardness Hs (23 ° C.) of 8 or more and 60 or less, 2,000k when the elastic modulus (80 ° C) is 30kg / cm ² or more
It is prepared so as to be in the range of less than g / cm ² . Further, when the Shore D hardness Hs (23 ° C.) and the common logarithmic value y of the tensile elastic modulus (80 ° C.) satisfy the following formulas (1) and (2), the flexibility near room temperature is It is even more preferable, the mechanical strength is not lowered at around 80 ° C., and the flexibility and the mechanical balance are excellent, which is particularly preferable. 10 ≦ Hs (23 ° C.) ≦ 55 (1) y ≧ 0.04163 Hs (23 ° C.) +0.8665 (2)

In the present invention, Shore D hardness Hs
(23 ° C) and tensile modulus (80 ° C) were measured by the following methods. The resin composition is press-molded using a press temperature of 180 ° C. and a press pressure of 100 kg / cm ² for 2 minutes of preheating, 1 minute of pressing, and 3 minutes of cooling to form a sheet having a thickness of 2 mm. (Shore D Hardness Hs (23 ° C.)) The sheet obtained as described above was adjusted in a thermostatic chamber at 23 ° C., and a hardness tester was pressed from the top of 6 sheets, and the value after 5 seconds was measured.

(Tensile Elastic Modulus (80 ° C.)) The sheet obtained as described above was punched with a JIS No. 2 dumbbell to obtain a tensile test piece. The test piece having the obtained cross-sectional area Scm ² was
In a constant temperature bath at 0 ° C, a tensile test is performed at a crosshead speed of 50 mm / min, a chuck distance of 5 cm, and a chart speed of 50 cm / min. While reading the displacement between chucks on the chart, measure the tensile load Xkg at 2% deformation. did. From the obtained results, the tensile elastic modulus (80 ° C.) was calculated by the following formula (3). Tensile modulus (80 ° C) (kg / cm) = X / S / 2/100 = 100X / 2S (3)

The resin composition of the present invention is excellent in flexibility at room temperature as described above and has high mechanical strength at around 80 ° C., and it is a film, a sheet, a bottle using a conventional soft polymer, As a resin for pipes, fibrous materials, porous films and other general molded products, it can be used alone,
For these moldings, general molding methods such as extrusion molding, injection molding, blow molding, press molding and stretching can be applied. The film, sheet and blowbin molded from a single layer of the resin composition of the present invention can be used for various purposes.

The resin composition of the present invention is a laminate with leather or vinyl chloride, polypropylene, polyethylene,
It can also be used as a laminate with nylon, polyester or the like, or as a complex with another polymer such as a laminate with woven or non-woven fabric. For example, as a multilayer body of crystalline polypropylene / resin composition of the present invention, crystalline polypropylene / resin composition of the present invention / crystalline polypropylene, crystalline polypropylene / resin composition of the present invention / polyethylene, etc., prevention of surface tackiness, surface hardness Can be improved. Also,
A resin having a better gas barrier property, for example, EVAL (trade name, manufactured by Kuraray Co., Ltd.) may be laminated on the above-mentioned multilayer body to impart selective gas permeability to form a multilayer film, a multilayer sheet or a multilayer bottle. it can. Furthermore, it may be used as a foam. Further, the molded product made of the resin composition of the present invention can be subjected to known surface treatments such as coating and vapor deposition.

[0026]

EXAMPLES The present invention will be described in detail below with reference to examples. However, the present invention is not limited to the following examples. In the following examples, the melting point was measured using a differential scanning calorimeter (DSC) at a temperature rising rate of 10 ° C / min and helium ventilation of 100 ml / min.

Examples 1 to 4 As the amorphous polyolefin of the component (a), propylene / butene-1 produced by Lexen, USA, weight ratio of 65/35, number average molecular weight Mn of 6,500, and heat of fusion of crystal of 7.2 Jou.
REXTAC RT is a propylene / butene-1 copolymer with le / g and boiling n-heptane insoluble content of 5% by weight.
2780 as a component (b) crystalline polypropylene, a trade name polypropylene RF35 manufactured by Ube Industries, Ltd.
5B (MFR = 2.7, ethylene content 4% by weight) was melt-stirred and mixed in a stainless beaker heated to 180 ° C. at a composition ratio shown in Table 1 to obtain a resin composition.
The composition obtained was subjected to Shore D hardness Hs (23
℃), tensile modulus (80 ℃) and melting point were measured. The results are shown in Table 1.

[0028]

[Table 1]

Examples 5 to 8 As component (a), a propylene / ethylene weight ratio of 85/15 manufactured by Lexen, USA, and a number average molecular weight Mn710.
0, a crystal fusion heat amount of 4.7 Joule / g, and a boiling n-heptane insoluble content of 0.7% by weight, which is a propylene / ethylene copolymer, trade name REXTAC RT2585, and a union polymer (b) as a component (b). A polypropylene resin manufactured by K.K. was used in the same manner as in Example 1 except that FM801 (MFR = 9, ethylene content: 5.7% by weight) having a composition ratio shown in Table 2 was used. Obtained. The composition obtained was treated with Shore D hardness Hs (23
C.), tensile modulus (80.degree. C.) and melting point were measured. The results are shown in Table 2.

[0030]

[Table 2]

Examples 9 to 12 Trade name REXTAC R used in Example 1 for component (a)
A resin composition was obtained in the same manner as in Example 1 except that T2780 was used and the component (b) and the trade name FM801 used in Example 5 were used in the composition ratios shown in Table 3, respectively. The composition obtained was treated with Shore D hardness Hs (23
C.), tensile modulus (80.degree. C.) and melting point were measured. The results are shown in Table 3.

[0032]

[Table 3]

Comparative Example 1 A sheet having a thickness of 2 mm was prepared in the same manner as in the above-described method for producing a sample piece, using as a resin only polypropylene RF355B (trade name) used as the component (b) in Example 1. Using the obtained sheet, the Shore D hardness Hs (23 ° C.), the tensile elastic modulus (80 ° C.) and the melting point were measured in the same manner as in Example 1. The results are shown in Table 4.

[0034]

[Table 4]

Comparative Examples 2 to 3 Resin compositions were obtained in the same manner as in Example 1 except that the compositions of the components (a) and (b) were changed to the ratios shown in Table 4.
The obtained composition was measured for Shore D hardness Hs (23 ° C.), tensile modulus (80 ° C.) and melting point in the same manner as in Example 1.
The results are shown in Table 4.

Comparative Example 4 A sheet having a thickness of 2 mm was prepared in the same manner as in the production method of the above-described sample piece, using only the FM801 product name used as the component (b) in Example 5 as the resin. Using the obtained sheet, the Shore D hardness Hs (23 ° C.), the tensile elastic modulus (80 ° C.) and the melting point were measured in the same manner as in Example 1. The results are shown in Table 4.
It was shown to.

Comparative Examples 5 to 10 As resin, low-density polyethylene (VLDPE) trade name Z517 (MI = 2.0 g / 10) manufactured by Ube Industries, Ltd.
Min, density = 0.906 g / cm ³⁾ (Comparative Example 5), Idemitsu Petrochemical Industry Co., Ltd. of high density polyethylene (HDP
E) Trade name 640UF (MI = 0.05 g / 10 min, density = 0.955 g / cm ³ ) (Comparative Example 6), linear low density polyethylene (LLDPE) trade name FA120N (MI) manufactured by Ube Industries, Ltd. = 1.0 g / 10 min, density = 0.
920 g / cm ³ ) (Comparative Example 7), low-density polyethylene (LDPE) manufactured by Ube Industries, Ltd., trade name L719 (MI
= 7.5 g / 10 minutes, density = 0.918 g / cm ³ )
(Comparative Example 8), ethylene-vinyl acetate copolymer (EVA) manufactured by Ube Industries, Ltd., trade name V315 (MI = 17 g /
10 minutes, vinyl acetate concentration 15% by weight) (Comparative Example 9), homopolypropylene (PP) trade name J manufactured by Ube Industries, Ltd.
109 (MFR = 9 g / 10 min) (Comparative Example 10) was used alone to prepare a 2 mm thick sheet in the same manner as in Comparative Example 1. Using the obtained sheet, in the same manner as in Example 1, Shore D hardness Hs (23 ° C.) and tensile modulus (80
C.) and melting point were measured. The results are shown in Table 5.

[0038]

[Table 5]

From the results of the above examples, it is understood that the resin composition of the present invention has flexibility at room temperature and has a tensile modulus at 80 ° C. of 30 kg / cm ² or more. Also,
Based on the results of the above Examples and Comparative Examples, the horizontal axis shows Shore D
Hardness Hs (23 ℃), the vertical axis is the tensile modulus (80 ℃),
It is shown in FIG. 1 as a semilogarithmic graph. As a result, it can be seen that the resin composition of the present invention satisfies the above formulas (1) and (2) and is excellent in the balance between flexibility and mechanical strength.
In Tables 1 to 5, the common logarithmic value y of the tensile elastic modulus (80 ° C) and the right side (0.04163Hs (23 ° C) + 0 of the above formula (2) corresponding to the straight line Z shown in Fig. 1 are shown. The value of 0.865) was shown.

[0040]

Industrial Applicability The resin composition of the present invention comprises crystalline polypropylene and an amorphous polyolefin containing propylene and / or butene-1 as a main component, and is a soft resin which is the mainstream of conventional soft resins. It does not cause the problem of environmental pollution such as vinyl chloride. Further, it has flexibility while maintaining the mechanical strength of polypropylene, and has a good balance between mechanical strength and flexibility, and is extremely useful industrially.

[Brief description of drawings]

FIG. 1 is a graph showing the relationship between the Shore D hardness Hs (23 ° C.) and the tensile elastic modulus (80 ° C.) of the resin compositions of Examples and Comparative Examples of the present invention.

Continuation of the front page (56) Reference JP-A-2-135244 (JP, A) JP-A-61-155435 (JP, A) JP-A-60-258238 (JP, A) JP-A-3-14851 (JP , A) JP-A-3-250040 (JP, A) The Melt Compatibilities of Blends of Polypropylene and Ethylene-Propylene Copolymers, POLYMER 508, 1986, 1986, 1986, 1986, 1986, 1986 Field (Int.Cl. ⁷ , DB name) C08L 23/00-23/36

Claims (8)

(57) [Claims] 1. (a) Propylene and / or butene-1
An amorphous polyolefin having a component content of 50% by weight or more, the amorphous polyolefin is a propylene-butene-1 copolymer, and the amorphous polyolefin has a heat of fusion of crystal of 20 Joule / g or less, The number average molecular weight of the amorphous polyolefin is 1000 to 20.
And the boiling n-heptane insoluble content of the amorphous polyolefin is 20.
A resin composition containing 20 to 80% by weight of an amorphous polyolefin and 80 to 20% by weight of (b) a crystalline polypropylene. 2. The (a) propylene component content is 50% by weight or more, and the ethylene component content is 0 to 30% by weight (0
The amorphous polyolefin is a propylene-ethylene copolymer, the amorphous polyolefin has a heat of fusion of crystal of 20 Joule / g or less, and the amorphous polyolefin is Number average molecular weight of 4500-20
000, the weight average molecular weight Mw of the amorphous polyolefin and the amorphous po
The ratio of the number average molecular weight Mn of the re-olefin, Mw / Mn
6 to 16, and the boiling n-heptane insoluble content of the amorphous polyolefin is 20.
A resin composition containing 20 to 80% by weight of an amorphous polyolefin and 80 to 20% by weight of (b) a crystalline polypropylene. 3. The resin composition has a tensile elastic modulus (80 ° C.) of 3
The resin composition according to claim 1 or 2, which is 0 kg / cm ² or more and less than 2000 kg / cm ² . 4. The resin according to claim 1, wherein the propylene / butene-1 copolymer has a butene-1 component content of 0 to 50% by weight (not including 0% by weight). Composition. 5. The resin composition according to claim 1, wherein the Shore D hardness Hs (23 ° C.) of the resin composition is 8 or more and 60 or less. 6. The resin composition according to claim 1, wherein the amorphous polyolefin has a boiling n-heptane insoluble content of 15% by weight or less. 7. The resin composition according to claim 1, wherein the amorphous polyolefin has a heat of crystal fusion of 15 Joule / g or less. 8. The Shore D hardness Hs (23 ° C.) and the common logarithmic value y of the tensile elastic modulus (80 ° C.) at 80 ° C. satisfy the following equations (1) and (2). The resin composition according to any one of 1 to 7. 10 ≦ Hs (23 ° C.) ≦ 55 (1) y ≧ 0.04163 Hs (23 ° C.) +0.8665 (2)