JPS58215446A - Improved molding resin composition - Google Patents

Abstract

PURPOSE:To provide the titled resin compsn. having good moldability, transparency, strength flexibility, resistance to heat, weather and cold, etc., by using, as a base resin, a blend obtd. by blending a specified polypropylene polymer with a specified block copolymer which is used as a base. CONSTITUTION:A block copolymer wherein both terminal blocks are composed of an arom. vinyl compd. polymer and the intermediate block is composed of a conjugated diene polymer, is prepd. As said terminal block, those having a number-average MW of 5,000-125,000 are suitable. For example, polystyrene is preferred, and accounts for 10-40wt% of the block copolymer, and not more than 10% of the block is hydrogenated. As the intermediate block, polybutadiene having a number-average MW of 10,000-300,000 is preferred and not less than 10% thereof is hydrogenated. The titled compsn. consists of 60-98wt% said block copolymer and 40-2wt% isotactic polypropylene or copolymr mainly composed of the same.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a resin composition. More specifically, the present invention relates to an improved molding resin composition that is flexible, has excellent strength, heat resistance and transparency, and is non-toxic.

Conventionally, various molding resin compositions for obtaining flexible molded products using transparent IJI have been proposed and put into practical use. However, (~ these t) 1 also had the following problems.

In other words, one of them, enalene-vinyl acetate mh
Molded products made from metal salts of 11iPI products, enalene-1/-acrylate copolymers, 1,2-polybutadiene, enalene-acrylic acid or methacrylic acid copolymers have good flexibility and transparency. , tensile strength is 200
Kg/l! 1Q because the level is below JI and heat resistance is insufficient
1) Thermoplastic polyurethane f, L has excellent flexibility, tensile strength, and heat resistance, and has good transparency. However, it has the drawbacks of hygienic problems if the monomer remains and high 6111-tb, but silicone yarn -L Shirasu 7- also has excellent flexibility, tensile strength, and heat resistance. Although it has good transparency and 1411 properties, it is extremely expensive.

Furthermore, molded products using base resins such as Sunalene-butadiene-J-block copolymer, Sterene-butadiene-Sterene block copolymer, Styrene-Isoprene-Styrene block copolymer, etc. have excellent flexibility and transparency, and can reach up to 200Kf/ Although it is known to have a tensile strength of ct1 or more, it has had the problem that it has insufficient heat resistance and softens even below 100°C, making it impossible to maintain its shape.

On the other hand, molded products using soft polyvinyl chloride/l/ have excellent flexibility and transparency, and have a tensile strength of 200 kg/c.
xd or higher, maintains its shape even at high temperatures of about 120°C, and has sufficient strength, making it possible to sterilize at high temperatures, and is widely used in food packaging, medical instruments, etc. However, since soft polyvinyl chloride usually contains a large amount of plasticizer, the plasticizer gradually evaporates and hardens, and especially in packaging bags, tubes, etc., the plasticizer transfers to all objects that come in contact with the contents. May cause hygiene problems. In addition, there was a risk of hygienic problems unless the amount of vinyl chloride monomer remaining in the molded product was extremely reduced.

Therefore, a resin molded product that satisfies flexibility, strength, heat resistance, and transparency, and does not contain highly toxic rIJ plastic T monomers (r^) such as soft polysalts has long been desired. The present invention 191 solves the above-mentioned problems that were difficult to solve with conventional 04# fat compositions.The present inventors have developed a specific 11# copolymer. As a base material, a relatively small amount of a specific borino-mesh pyrene thread M (combined as a modifier) is used as a base resin. We obtained a molded product in which the point was eliminated, and after further investigation, we arrived at 1ν1 (7, 7).

Thus, from the present invention, a block copolymer K consisting of both end blocks made of a polymer of an aromatic vinyl/vinyl compound and an intermediate block made of a conjugated diene polymer is produced.
> both ends are closed) (lO to 40% in polymer)
A block copolymer of 60 to 98 mm ml 96 in which 1096-1 is enriched with water and the middle block is 9 (>96-1-1M), and a melting point 15 (, There is provided an improved molding resin composition comprising 40 to 2% by weight of a ulili compound mainly consisting of 1° C. or lower -σ)' f-1 Someknak Polypropylene or -tJL.

A proposal to include a specific block copolymer used in the present invention as a component of a resin composition was published in Japanese Patent Application Laid-Open No. 53-13845.
Publication No. 1% JP-A-53-138453, JP-A-Sho 5
3-138454, JP-A-53-138456, JP-A-53-13845843, JP-A-53
-138460 publication and JP-A-1111q 53-13
Although it has already been proposed in Publication No. 8461, etc., all of them are resin compositions consisting of at least three components, and the block copolymer is only used in a relatively small amount as a modifier for other resins. This is completely different from the technical concept of improving the properties of a block copolymer as in the present invention by blending a small amount of isotactic polypropylene. Furthermore, JP-A-53-124559 proposes a three-component resin composition containing the block copolymer and polypropylene used in the present invention, but it also contains various engineering resins as essential components. Furthermore, as mentioned above, we are interested in a mixed resin that is completely different from the technical idea of EllJ.

A molded article using the resin composition of the present invention has transparency, strength,
It has good heat resistance, weather resistance, cold resistance, flexibility, etc., and the moldability of the composition itself is also good, especially high flexibility, transparency, and 13
It has a heat resistance of about 0 U, making it unique. In addition, soft polychloride and plasticizers such as 2μ are used.
1.1.It is hygienic because it does not contain any harmful substances and does not contain highly toxic monomers. do not have.

The base of the block copolymer used in the present invention is an intermediate block (90 to 6
0mJ16) and both ends of block A consisting of a polymer of an aromatic vinyl compound (10 to 40 weight 96). Examples of the polymer include styrenic polymers such as polystyrene, poly-α-methylstyrene, and polychlorsnarene.
00 to 125,000 are suitable, with polystyrene being particularly preferred.

On the other hand, examples of the conjugated diene polymer constituting the intermediate block include polybutadiene, polyisogrene, polychloroprene, etc., and a number average molecular weight of 10,000 to 300,000 is suitable, with polybutadiene being particularly preferred.

The end blocks in the block copolymer serve as high-hardness components of a molded article obtained using the composition of the present invention, that is, a thermoplastic elastomer, and the middle block serves as a flexible component. If the content of both end blocks in the copolymer is less than 10% by weight, the hardness and strength will be insufficient, and if it exceeds 40% by weight, the flexibility of the molded product will be insufficient. Particularly preferred is 15 to 25% by weight of the end blocks.

By hydrogenating the block copolymer,
A block copolymer used in the present invention is obtained. In this case, the hydrogenation ratio of both end blocks is required to be 10% or less, and the hydrogenation ratio of the middle block is required to be 90% or more. In particular, the hydrogenation ratio of the intermediate block is important and is preferably 95% or more. This means that, for example, when the intermediate block is polybutadiene, the hydrogenated product has an ethylene-butylene copolymer structure, and when the intermediate block is polyisoprene, it has an ethylene-[1-pyrene copolymer structure, and the overall This is because the heat resistance and weather resistance are improved, and in particular, this leads to the excellent heat resistance of the composition of j.

The block copolymer used in the present invention 1ν1 is Kraton G-1650 + Kraton A-1675.
It is easily available under the brand name (manufactured by Shell Chemical).

On the other hand, Bolig [1-pyrene used in IJJK of the present invention is isotactic polypropylene with a melting point of 150°C or higher or a co-11 combination mainly composed of it, and is generally used with molding materials.
What is used in ~ can be used as is.

Also, copolymer and 1. 65, block polymers and syndam polymers of polypropylene and α-olefins such as ethylene and l-butene can be used, but in order to maintain flexibility, K is preferably flexible, and a random copolymer is particularly suitable. .

The melting point of the polymer must be 150° C. or higher in order to maintain the heat resistance of the molded product obtained.

The molding resin composition of the present invention can be obtained by blending the isotactic polypropylene with the block copolymer. At this time, it is necessary that the proportion of the block copolymer in the composition is 60 to 98% by weight, and 70 to 98% by weight.
~92% by weight is preferred.

If it is less than 60% by weight, the flexibility of the molded article obtained using this composition will be insufficient, and if it exceeds 98% by weight, the heat resistance will be insufficient. Conversely, the proportion of isotactic polypropylene needs to be 2 to 40% by weight, and 8 to 40% by weight.
30% by weight is preferred. If the amount is less than 2% by weight, the heat resistance of the molded product will be insufficient and blocking phenomenon may often occur, and if it exceeds 40% by weight, the flexibility of the molded product will be insufficient and the transparency will be significantly reduced.

In addition to the above-mentioned essential components, the composition of the present invention may contain various plasticizers, anti-blocking agents, sea μ property improvers, heat stabilizers, antioxidants, ultraviolet absorbers, lubricants, and crystal nuclei depending on the purpose. 8-1 may also contain small amounts of agents, colorants, etc. j (Noh.

The composition of the present invention can be molded by conventional methods.

In other words, various raw materials are mixed according to the formulation of the composition.
, After mixing in a blender, it can be further kneaded by heating μ in θ♂ and then kneaded in a press to create a sheet.[7.
It is also possible to extrude shaped articles, tubes, nets, etc. In addition, various parts, bottles, etc. can be made entirely from pellets by injection molding or blow molding. In addition, various molded products can also be subjected to secondary processing such as cutting, painting, and gluing.

Composition d1, I of the present invention 1v1] As stated above, it has various characteristics that have not been seen before, so it can be used in the fields of general industrial materials, household goods, etc., but especially It can be suitably used in the fields of food packaging materials and medical equipment.

The IJllt of the present invention will be described below with reference to Examples, but the present invention is not limited thereto.

Example-1 A water bulk block Jlt'M body and Kraton G-J (ib () manufactured by Shell Chemical Co., Ltd.) were used. This is a copolymer in which the prongs at both ends are polystyrene and the central water block is ethylene butylene. , and the ratio of songwriters to latter is 28.
/72. Further, as the isotactic polypropylene, a homopolymer having a melting point of 172°C was used.

A hydrogenated block copolymer in the form of flakes and a polypropylene homopolymer in the form of pellets are mixed in the proportions shown in the table below, kneaded in a two-wheel machine to make a bare sheet, which is compression molded to a thickness of approximately 0. -4 m/rrL sheet was produced.

The results of measuring the physical properties of the sheet are shown in the table below. The high temperature resistance in the table is measured by the shape retention when the sheet is left in an oven at 125C for 15 minutes and the deformation tR' of the sheet when a load of 1.4 KgZ- is applied at this temperature. be.

= 11-]2- Note that the above tensile strength is JIS K 6732 (tensile speed 200+u+/min), total light transmittance and haze are ASTM D-1003VC, and Shore hardness is A8TM.
D-1706 type DK was measured respectively.

Furthermore, as a reference example, the results of measurements made in the same manner on an ethylene-vinyl acetate copolymer sheet with a vinyl acetate content of 18% are also shown.

Grades 3 to B in the above table are within the scope of the present invention, and sheets using these compositions are all good in terms of strength, flexibility, and transparency, and in addition, high temperature properties are better than Na1Nc2 and Reference. It is clear that this is significantly superior to the example. 1. As a matter of course, it was significantly superior to Yo9 (polypropylene/single) K in terms of transparency and flexibility.

Example-2 Shell Chemical's Claydoor G as a hydrogenated block copolymer
-1650 (the composition is shown in Example 1) and Kraton G-1657 (Kraton G-: Like L650, both end blocks are polystyrene and the central water temperature block is a copolymer of ethylene and butylene, the former versus the latter.
A sheet metal was produced in the same manner as in Example 1, using a homopolymer with a melting point of 172 ° C. and using a homopolymer with a melting point of 172 ° C. and setting the ratio (171/35/, 15). The physical properties were measured.The results were as shown in 111 below.

, Tensile strength: z9oKy Shoulder/Total light transmittance: 86% fist haze
5% ・Shore hardness 1') -35 ・High temperature shape retention Unchanged deformation rate 4,96 Example 3 Kraton G-1,667 used in Example 2 with ms4+ hydrogenated block, as polypropylene, Complete sheet production 1 was carried out in the same manner as in Example-1 using a polypropylene random copolymer with a melting point of 165°C and the formulation shown in the table below.
-1 The physical properties were measured. The results are shown in the table below.

It is within the range of 1 to 4ti of the original IJ4 in the table, and both are 9. It is excellent in uIiL, flexibility, transparency, and sophistication. 5 tJ This is outside the range of 1 to 1, and although it is unsatisfactory in terms of strength and high temperature resistance, it is unsatisfactory in terms of transparency and flexibility.

Example-4 Water M Rock Friends 11 [As a partner Clayton G-
1650 and 16b7, melting point 1 as borizo 1J pyrene
Using a random copolymer at 65°C, each ratio was 50/
Mixed at a ratio of 25/25 ^1. Pellets were produced by extrusion in an extrusion chamber. A sheet with a thickness of approximately 0.4 m4 was prepared by extrusion using this coat hanger type die, and its rli' was measured.The results are shown in the table below. It was measured at a frequency of 1.1 (1.1%) using a viscoelasticity measuring machine.

As can be seen from the table, A t, 1. n ttC North I - Slightly inferior in terms of transparency and flexibility, but practical I - Shows reasonable values; A is clearly superior to B in terms of high temperature resistance, heating loss rate, and moisture permeability. I'm doing J'. V! The temperature change in the elastic modulus of A is much more gradual than BVC, and the operating temperature range is much wider than 1'. Since it does not include
It's very hygienic.

In addition, reference examples and 1. A soft polyvinyl chloride sheet was prepared using 1,000 tIj as a plasticizer.

I posted the results to B.

Claims (1)

[Claims] (1) In a block copolymer consisting of both end blocks made of a polymer of an aromatic vinyl compound and an intermediate block made of a conjugated diene polymer, the end blocks in the copolymer are 10-40% by weight, and 1096 or less of them are water. 60 to 98% by weight of a block copolymer in which the intermediate block is hydrogenated by 90% or more, and a melting point 1 blended therein.
An improved molding resin composition comprising 40 to 2% by weight of isotactic polypropylene of 50'C or higher or a copolymer mainly composed thereof.