JPS63264651A - Polypropylene composition - Google Patents

Abstract

PURPOSE:To obtain the title composition excellent in moldability and appearance, comprising an unsaturated acid-modified PP, a surface-treated glass fiber, a specified nucleator and an organic peroxide radical initiator. CONSTITUTION:0.05-1wt.% metal montanate (e.g., sodium montanate) as a nucleator and 0.01-0.1wt.% organic peroxide radical initiator (e.g., dicumyl peroxide) are added to 100pts.wt. mixture of 50-95wt.% mixture of 1-50wt.% unsaturated acid-modified PP (e.g., maleic anhydride-modified PP) with 99-50wt.% PP with 50-5wt.% 3-5mm-thick glass fiber surface-treated with, e.g., a silane coupling agent.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to polypropylene compositions, especially glass IJlil
Fiber-reinforced thermoplastics (F, R
, T, P,) composition.

Prior Art It is well known that glass fibers are blended into polypropylene in order to improve the mechanical strength, rigidity, heat deformation resistance, etc. of molded products made from polypropylene compositions.
It is used in automobiles, home appliances, and other industrial products and parts.

Such l11-reinforced polypropylene compositions are made of glass fibers obtained by subjecting modified polypropylene modified with an unsaturated acid to a surface treatment for reinforcing resin, as disclosed in, for example, JP-A No. 61-98758. The product is obtained by melt-kneading and mainly by injection molding.

Problems to be Solved by the Invention However, in the conventional fiber-reinforced polypropylene compositions as described above, the rate of crystallization when the melt is cooled is slow and the fluidity during melting is poor, resulting in a long molding cycle. Otherwise, the appearance of the molded product is not beautiful, there are problems with molding such as sink marks, and the physical properties of the molded product are -t.
There were problems such as not having +'.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a polypropylene composition that has excellent moldability and can yield molded articles with uniform physical properties and appearance.

Ways to Solve the Problems ``9'' In order to solve the above problems, the polypropylene composition of the present invention contains 100% by weight of the A component, which is composed of the following components (a) and (b), and 0% of the B component. .05-1 standard% and C
It is characterized by containing 0.01-0.1% by weight of the components.

A component B component: Crystallization nucleating agent of moncnic acid metal salt C component: Organic peroxide-based radical initiator Here, the unsaturated acid-modified polypropylene which is the component (a) forming the A component of the present invention is polypropylene. and an unsaturated acid are melt-kneaded in the presence of a radical generator. As unsaturated acids, unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid, fumaric acid, and citraconic acid, and anhydrides of unsaturated carboxylic acids such as maleic anhydride and itaconic anhydride are used, but especially It is preferable to use maleic anhydride.

The polypropylene used to form the unsaturated acid-modified polypropylene may be a propylene homopolymer, or a random or block copolymer of propylene and ethylene or an α-olefin such as butene-1, hexene-1, octene-1, etc. etc. are used.

Component (a) may be unsaturated acidic polypropylene alone, but it may also be mixed with polypropylene. In this case, the polypropylene used in the formation of the unsaturated acid-modified polypropylene is The acid-modified polypropylene is blended in an amount of 1 to 50% by weight, preferably 3 to 20% by weight of the total resin amount.

Furthermore, a component A is formed together with the component (a) (b
) The surface-treated glass fiber that is the component is one that has been generally used for reinforcing resins, for example, a glass fiber with a length of 3 to 3.
A chopped strand of about 6# and whose surface has been treated with a silane coupling agent or the like is used to improve the adhesion between polypropylene and glass fiber.

The combination υ1 of component (a) and component (b) forming Δ component is (b) for 50 to 95 weight percent of component (a).
) component is 5 to 50% by weight. That is, component (b) is 5
If the amount is less than 50% by weight, no reinforcing effect will be observed, and if it exceeds 50% by weight, the moldability will be significantly reduced, so the content should be within this range. Especially considering the physical properties and processability of the molded product, (a) component 60-90% by weight (b)
It is desirable to blend the components in a range of 10 to 40% by weight.

Next, as a crystallization nucleating agent, which is a daily component, a metal salt type of montanic acid, preferably a sodium salt thereof, is used.

This crystallization nucleating agent, like those conventionally used in many synthetic resins, shortens the molding cycle by increasing the speed of crystallization when the molten material cools, and also reduces the size of spherulites, making it easier to machine. Talc, sodium benzoate, alkyl-substituted dibenzylidene sorbidol, etc. are known as commonly used substances. However, when these crystallization nucleating agents are used in polypropylene compositions such as the present invention, they do not have sufficient nucleation effect and dispersibility, and also react with other additives and lose their effects, resulting in poor physical properties. Also, sufficient effects cannot be obtained in terms of moldability.

On the other hand, a crystal nucleating agent made of a metal salt of montanic acid, preferably its sodium salt, has a dropping point below the melting temperature of polypropylene resin, so it has very good dispersibility in polypropylene resin, and has a sufficient It can be effective. Therefore, it is suitable for polypropylene compositions such as the present invention. Furthermore, since the metal salt-based crystallization nucleating agent of montanic acid is harmful to W, there is no need to worry about the manufacturing process or the molded product. In addition, unlike the conventional crystallization nucleating agent mentioned above, it has the effect of imparting appropriate lubricity to polypropylene resin, and as it exhibits extremely smooth fluidity when melted, it can shorten the molding cycle and facilitate injection molding. Improves the mold releasability of the product.

In the present invention, component B is blended in a range of 0.05 to 1.0% by weight based on 100% by weight of component B, and if it is less than 0.05% by weight, it has no effect as a crystallization nucleating agent. If the amount is not sufficient and exceeds 1.0% by weight, the effect will reach an equilibrium and no further effect can be expected, and not only will the thermal stability of nails decrease, causing more burns, which is undesirable. In addition, in the range of 0.05 to 1.0 weight to 1%, the strength and rigidity of the molded product uniformly improves, the injection molding cycle can be shortened by about 20 to 50%, and the occurrence of sink marks can be prevented. can.

Furthermore, as the organic peroxide radical initiator which is component C constituting the present invention, dicumyl peroxide, 1.3bis(t-butylberoxyinbutyl)benzene, 2. 5-dimethyl-2-5-di(t-butylperoxy)hexane and the like are used. This radical initiator has the effect of artificially generating radicals, cleaving the molecular chains of unsaturated acid-modified polypropylene and polypropylene, and aligning the molecular groups. Therefore, it is possible to further improve the fluidity, and in particular, it is preferable that the temperature at a half-life of 1 minute is around 160 to 230°C, which is around the melting temperature of unsaturated acid-modified polypropylene and polypropylene resin.

In addition, in the present invention, component C is 100% of the weight of component A.
It is blended at a ratio of 0.01 to 0.1% by weight to o
, oe>:U is preferably used within the range of %.

The polypropylene composition of the present invention having such a structure can be produced by injection molding, for example, by mixing the respective components at a predetermined distance, then melt-kneading and injection molding using an extrusion method in the same manner as conventional polypropylene compositions. H
B.

It goes without saying that the polypropylene composition of the present invention may further contain various additives such as antioxidants, ultraviolet absorbers, lubricants, B1-free fillers, pigments, and antistatic agents.

EXAMPLES Examples of the present invention will be described below, but the present invention is not limited to these examples.

Tables 1 and XX2 show examples of the present invention in which homopolymers and copolymers were used as polypropylene, and comparative examples in which only either a crystallization nucleating agent or a radical initiator was combined. The samples were prepared using polypropylene (homopolymer) [trade name MS-240 manufactured by Tokuyama Soda Co., Ltd.], polypropylene (copolymer) [trade name manufactured by Tokuyama Soda Co., Ltd.] Is-6401, and modified polypropylene (I>(trade name manufactured by Tokuyama Soda Co., Ltd.) maleic acid-modified polypropylene) [manufactured by Tokuyama Soda Co., Ltd., product name AD-89G], modified polypropylene (■
) (maleic acid-modified polypropylene) [manufactured by Sumitomo Chemical Co., Ltd.]
Product name MPE-331], surface treated glass fiber tIri
[Manufactured by Asahi Fiberglass Co., Ltd. Product name: C5-0311A-
486＾], Crystallization nucleating agent (Moncunate sodium salt) [
Hoechst Japan company product name Hostalb VP-Na
・To2], a radical initiator (1,3bis(t-butylperoxyisobutyl)benzene) [manufactured by Kayaku Nouri Co., Ltd., trade name Parryoku Dox 14/40 (calcium carbonate base 40% Materbadge product)], and An antioxidant (hindered phenol antioxidant) [trade name Irganox #1010, manufactured by Diba Geigy Co., Ltd.] was used and these were blended in the proportions shown in Tables 1 and 2.

In addition, samples were prepared by the following method.

■Bellet granulation method Each component was granulated using a twin-screw kneader (kneading hot water level: 200-240°C). Incidentally, the surface-treated glass fibers were introduced by a side feed method.

■How to prepare samples for physical property tests The pellet was molded using an injection molding machine [manufactured by Toshiba Corporation]. Product name 15-50] was injection molded.

The injection conditions are: nozzle temperature 200°C, front part 200°C,
Middle part 190℃, rear 180℃, q1 output pressure 110g
/ci, rF1 exit opening time 10SeC injection speed 5/20
, cooling lJ for 1 hour 5 osec, mold temperature 40°C.

■How to prepare samples for moldability test The above pellets are molded using an injection molding machine [manufactured by 0 Kasu Jushi Co., Ltd., product name: TS]
-200DX] was injection molded.

In addition, for injection mounting, the temperature is 210 to 230°C at the nozzle and the front part 2.
10-230℃, middle 200-220℃, rear 1'lO
~210°C, q4 output pressure 100 gf/cm.

The injection time was 4 to 7 seconds, the injection speed was 8/10, the cooling time was 35 to 55 seconds, the mold temperature was 40°C, and the mold (
Color plate t” 43#lff1 X 88mrt
r x 4 mfR and 43mm x 88m/ll
X 2 am) was used.

The effectiveness of the measurement of tensile strength [JrS 711
As good as 3! /A], measurement of bending strength [JIS K7203
1 Melt melt 0-rate measurement according to JIS 7201
Based on (temperature 230℃, load 2.16K (Jf/ci
)], and also measured the molding cycle and visually observed the appearance, presence of sink marks and discoloration, etc.

(Left below) Table 1 Table 2 According to Tables 1 and 2 above, Examples No. 1 to No. 4 of the polypropylene composition of the present invention containing a crystal nucleating agent and a radical initiator are crystal nuclei. Comparative examples N011 to N01 in which only one of the agent and the radical initiator was blended
Compared to No. 6, the strength trends of physical properties such as tensile strength, flexural modulus, and flexural strength are remarkable. In addition, compared to the comparative example, the molding temperature of the example is lower, the molding cycle is extremely short, and productivity is excellent, and the appearance is beautiful and there is no sink mark or discoloration, which confirms that there are no problems in molding. It was done.

Table 3 shows Examples and Comparative Examples in which the amounts of the crystallization nucleating agent and radical initiator added to the present invention were varied, and shows the influence of the amounts added on moldability. The ingredients and moldability are the same as shown in Table 1.2 above.

Table 3 According to Table 3, as shown in Comparative Example No. 7, when the blending ratio of the crystallization nucleating agent to the Δ component is 0.05% by weight, the molding cycle can be shortened and sink marks can be reduced. Effects as a crystallization nucleating agent such as prevention of crystallization cannot be expected, and Comparative Example N
As shown in Comparative Example No. 8 and Comparative Example No. 19, when it reaches 1.2%, thermal stability decreases and A7 occurs. Further, in Example No. 5, the moldability was good in all respects, whereas in Example No. 016, as shown in 1, the moldability was 0.7
In terms of weight percentage, some discoloration occurs.

Therefore, it was confirmed that the blending ratio of the crystallization nucleating agent in the present invention is desirably 0.1 to 0.5% by weight based on the component A.

Next, considering the radical initiator, Comparative Example No. 3
As shown in 8, the blending ratio to the component A is 0.01.
In the case of % by weight, no significant shortening of the molding cycle was observed, and the appearance was not excellent.

On the other hand, as shown in Example No. 055 and Examples No. 021 to 4 shown in Tables 1 and 2 above, the blending ratio is 0.03 to 0.
．． 061f? At 1%, it is excellent in all physical properties and moldability. Furthermore, when the blending ratio is 0.1% by weight as shown in Eggplant Example No. 6 J, the molding cycle is shortened, but some discoloration is observed. Therefore, the blending ratio of the interradical 9FI agent in the present invention is 0 to the component A.
．． It is desirable that the amount is 02 to 0.06% by weight.

Furthermore, Table 4 shows examples in which the type of crystallization nucleating agent added to the present invention was varied, and shows the effect of the type of crystallizing nucleating agent on physical properties and moldability. In addition, the judgment of compounding components and moldability is the same as shown in Tables 1 and 2 above, and as a comparative example, a crystallization nucleating agent (TI) was used.
(alkyl-substituted dibenzylidene sorbitol) [trade name Gluol 80, manufactured by Shin Nippon Rika Co., Ltd.], crystallization nucleating agent (■
) (Sodium benzoate) [Manufactured by Kanto Kagaku Co., Ltd. Reagent 1
and crystallization nucleating agent (IV) (talc) [trade name: Soapstone C, manufactured by Grandfather Industries Co., Ltd.].

(Left below) Table 4 From Table 4, it can be seen that the polypropylene composition of the present invention containing a crystallization nucleating agent based on a metal salt of montanic acid is a polypropylene composition containing various conventionally used crystallization nucleating agents. It is recognized that the composition shows superior evaluation in various physical properties and moldability compared to the composition. Furthermore, it was confirmed that the metal salt-based crystallization nucleating agent of montanic acid has the effect of increasing fluidity, improving lubricity and mold releasability, and is an R-suitable crystallization nucleating agent.

Effects of the Invention As described above, the polypropylene composition of the present invention has a short molding cycle and is excellent in productivity, and it is possible to obtain molded products with uniform and excellent physical properties and appearance.

Claims (1)

[Claims] Component A 1 consisting of the following components (a) and (b):
1. A polypropylene composition characterized in that 0.00% by weight is blended with 0.05 to 1% by weight of component B and 0.01 to 0.1% by weight of component C. A component [(a) component: unsaturated acid-modified polypropylene 50-95% by weight (or a mixture of unsaturated acid-modified polypropylene and polypropylene) (b) component: surface-treated glass fiber 5-50% by weight] B component: Montanic acid Metal salt crystallization nucleating agent C component: organic peroxide radical initiator