JPS5966431A - Olefinic resin foam composition - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to synthetic resins used for molding industrial applications such as automobiles and household electrical appliances.

Structure of conventional example and its problems Olefin resin has good processability, excellent flexibility, excellent chemical resistance, high rigidity and hardness, and low cost. Widely used in the automobile and home appliance fields.

However, since olefin resins are generally highly crystalline, they have a large molding shrinkage rate, and if the molded product has changes in wall thickness such as ribs or bosses, so-called sink marks are likely to occur in those areas.
In addition, the warpage often greatly limits its use.

One way to improve this drawback is to add inorganic fillers such as barium sulfate, talc, and calcium carbonate to the olefin resin, but in this case, in order to improve the sink marks and warpage of the olefin resin, The amount of inorganic filler blended must be at least 40 to 50% by weight, as the gloss of the olefin resin will be significantly reduced. When the amount of inorganic filler added is 5 to 40% by weight, the reduction in gloss can be suppressed to some extent, but it is not sufficient to improve sink marks and warpage.

In addition, as a method for improving these drawbacks, aliphatic dicarboxylic acids or their anhydrides, aromatic monocarboxylic acids or their metal salts, aromatic dicarboxylic acids or their anhydrides and metal salts,
Addition of inorganic powders such as talc and silica, phosphorus compounds, and crystal nucleating agents such as dibenzylidene sorbitol to cows has been carried out, but there is no method that simultaneously satisfies sink mark and warpage prevention and high gloss. In addition, olefin resin paste containing inorganic fillers, aliphatic dicarboxylic acids or their anhydrides, aromatic monocarboxylic acids or their metal salts, aromatic dicarboxylic acids or their anhydrides and metal salts, dibenzylidene sorbitol, etc. A method of adding a small amount of a crystal nucleating agent [↑1] has been considered, but it has not been possible to eliminate sink marks and warpage and satisfy high gloss at the same time.

Furthermore, it has been practiced to add an azodicarboxylic acid amide blowing agent (hereinafter referred to as A) to an olefin resin, but if ADCA is simply added, the amount of ADCA added increases. As the molded product surface ages, the appearance of the molded product is damaged by a silvery horizontal pattern due to partial foaming, and the gloss decreases.Also, it is difficult to make the foam cells uniform, so it is difficult to prevent sink marks to some extent. It is difficult to improve. Furthermore, in order to prevent sink marks in olefin resin molded products using ADCA, the wall thickness of the molded product must be 5 mm, which limits its use.

Purpose of the invention: Less sink marks and warpage occur during molding.
To provide an olefin resin foam composition with excellent surface gloss.

Structure of the Invention An olefin resin using ADeA is foam-molded (IL), 0.05 to 1.0 mold part % of 1.312.4-di(alkylbenzylidene) sorbitol (hereinafter referred to as A), and G(IL). Aluminum para-t-butylbenzoate) 0.
05 to 1.0% by weight (hereinafter referred to as (13)) was added to the olefin resin.

Description of Examples Examples 1 to 4 To polypropylene with a melt flow rate of 9, 0.5% of an azodicarboxylic acid amide foaming agent with a decomposition temperature of 208°C and a gas generation rate of 200 md/g was added, and further (A
) 1,3,2,4-di(alkylbenzylidene)sorbitol and (B) di(para-monobutylaluminum benzoate) were added in the specified amount, mixed uniformly using a Henschel mixer, and mixed using an extruder. The mixture was kneaded and pelletized at a resin temperature of 1.90°C. Using this composition, injection molding was carried out at a mold pressure of 400 Kg/cm" and a resin temperature of 205° C. to produce a "1" shaped plate with ribs on the disc and medium heat section,
Glossiness, sink mark 1i and amount of warp were measured.

Disc shape; diameter 30Crn x thickness 2I7# and 6-gate gloss measurement method: Use a 2M thick disc, and place any 5
A point was determined and measured using a gloss meter at an incident angle of 60 degrees, and the average value was taken as the glossiness.

Sink mark measurement method Using a 111-shaped board, the rotation on the top plate on the opposite side to the rib portion was measured using a surface roughness meter, and the maximum value was taken as the sink mark amount.

Warpage measurement method: Using a disk, hold three points on the concentric circle on the outer periphery horizontally, measure the outer periphery using a three-dimensional measuring machine, and find the height of the horizontal plane where the warp is maximum. Quantity.

Table 1 does not show the additive formulation ratio, glossiness, sink mark amount, and warp ml measurement results for the compositions of Examples 1 to 4.

Table 1 Comparative Example 1 The polypropylene used in Examples 1 to 4 was
The molding was performed under the same conditions as above, and the gloss, sink mark h1, and warpage were measured. The results are not shown in Table 2.

Comparative Example 2 In Examples 1 to 4, the glossiness, sink mark M, and amount of warp were measured in the same manner as in Examples 1 to 4, except that no additives were used. The results are shown in Table 2.

Table 2 Examples 5 to 12 Ethylene-propylene block copolymer with a melt flow rate of 30 (to which 0.3% by weight of the blowing agent used in Examples 1 to 4 and a fixed amount of additives were added, Example 1
The amount of gloss and warpage were measured in the same way as in 4. Table 3 shows the additive content and measurement results.

Table 3 Example 13 Mixture (blend) with the same composition as Example 6
A disk and a 111-character plate were produced by direct injection molding using the same method, and the gloss, sink marks, and amount of warp were measured. The results are shown in Table 4.

Example 14 The ethylene-propylene block copolymer powder and additives used in Example 6 were uniformly mixed in the same formulation as in Example 6. Further kneading and granulation were performed, and injection molding was performed using a mixture of the obtained pellets and a blowing agent in the same proportion as in Example 6, and the glossiness, sinkage amount, and IJl were measured. The results are shown in Table 4.

Example 15 The mixture of Example 14 was kneaded and granulated again, and the resulting pellets were injection molded to determine gloss, sinkage amount, and IJ i
Measure. The results are shown in Table 4.

As is clear from a comparison of Examples 1 to 4 in Table 4 and Comparative Example 1.2, the composition of the present invention has an excellent effect of simultaneously significantly improving the gloss, sink marks, and warpage of polyolefin.

Moreover, as is clear from Examples 5 to 12, additives (
A) 1.3.2.4-di(alkylbenzylidene)sorbitol and (B) di(para-1.-butyl 33-67
The effect aimed at by the present invention is greatest when the weight% is [AIo, 1% by weight, (1310, 2% by weight or
) 0.15% and (B) 0.30% is the maximum.

Furthermore, as is clear from a comparison of Examples 13.6 and 14.15, it is better to uniformly mix and knead the additives with the polyolefin in advance to achieve the desired effect of the present invention. is a person.

According to the above example, when (A) and (1() are blended, the foamed cells become uniform and fine, and as a result, [Al is particularly effective in improving gloss, and (Bl is effective in preventing sink marks and warpage. There is.

In addition, if the wall thickness of the conventional molded product is 5 mm or more, it is not possible to prevent sink marks without damaging the gloss of the olefin resin. By adding it, it is possible to prevent sink marks without impairing gloss when the wall thickness of a molded product is 1 nm or more.

1. The blending amount of ADCA to the polyolefin used in the present invention is 0.1 to 2.0% by weight, and if it is less than 0.1% by weight, the improvement in sink marks and warpage that is the objective of the present invention cannot be achieved. If it exceeds 2.0% by weight, it cannot be used because the gloss decreases significantly. In addition, as for the method of blending this additive, when blending a prescribed cloth of ADCA with polyolefin,
The mixture is added simultaneously and mixed uniformly with a stirrer such as a Henschel mixer, and then the mixture is directly molded, or the mixture is kneaded and granulated using a mixer at a temperature below the decomposition temperature of ADCA. Any method for forming pellets may be used, but first, powdered polyolefin and additives are uniformly mixed in a predetermined amount, then kneaded and granulated, and the resulting pellets and a predetermined amount of ADCA (ADUA master pellets are used). A method of homogeneously mixing (which may be mixed) and molding using this mixture, or a method of mixing and granulating the mixture again and molding using the obtained pellets is more suitable for the purpose of the present invention. In other words, if the polyolefin and additives are uniformly mixed and kneaded in advance, they will be more uniformly dispersed in the polyolefin, and as a result, it will be effective in forming uniform fine foam cells during molding. .

Furthermore, for blending with olefin resins containing ADCA (Ai and (B)), 005 to 1.
Although 0% by weight is sufficient, there is a mixing ratio of (Al and (13)), and it is preferable to use them together at this mixing ratio.

In addition, 0.1% by weight of AI based on the olefin resin, (
1310.2% by weight or (AI 0.15% by weight, (,
B) The desired effect of the present invention is maximized when 0.3% by weight is added.

The olefin resin used in the present invention includes propylene polymer, ethylene-propylene block copolymer, ethylene-propylene random copolymer, ethylene-propylene rubber, ethylene-propylene-Sheff ternary copolymer, and mixtures thereof. It can be anything including.

Effects of the invention In olefin resin, AD OA 7i-0,1~2
．． 1・3.2・4− for the composition containing 0% by weight
Di(alkylbenzylidene)sorbitol from 0.05 to
By adding 1.0% by weight and 0.05 to 1.0% by weight of G (aluminum para-1-butylbenzoate), an olefin-based product with excellent surface gloss and less sink marks and warpage during molding. of synthetic resins.

Agent: Patent Attorney Oshima -Ko 1+ C, V. Commissioner of the Patent Office: Mr. Kazuo Wakasugi ■, Indication of the case, Patent Application No. 178140 filed in 1982 2, Name of the invention: Olefin Resin Foam Composition 4, Agent 5 , Date of order for amendment or notice of reasons for refusal February 22, 1982 6 Column 7 for detailed explanation of the invention in the specification to be amended Contents of the amendment ill Description No. 6B, No. 7, No. 9 White, No. 11- Correct the image on a separate sheet. (Contents have not been changed due to engraving) The sieve was used as a sori lid.

Table 1 shows the amounts of additives and the results of gloss, sink marks, and So'JM measurements for the compositions of Examples 1 to 4.

Table 1 Comparative Example 1 The polypropylene used in Examples 1 to 4 was
It was injection molded under the same conditions as above, and its gloss, sink mark resistance, and warpage resistance were measured. The results are shown in Table 2.

Comparative Example 2 In Examples 1 to 4, the gloss, sink resistance, and IJ m were measured in the same manner as in Examples 1 to 4, except that no additives were used. The results are not shown in Table 2.

Table 2 Table 3 Example 13 Mixture (blend) with the same composition as Example 6
Comparing Examples 1 to 4 of Table 4 with Comparative Example 1.2, it is clear that the composition of the present invention improves the gloss, sink marks, and It has an excellent effect that can greatly improve the sled at the same time.

Claims (1)

[Claims] (1) For a composition containing 0.1 to 2.0% by weight of an azodicarboxylic acid amide yarn blowing agent in an olefin resin,
An olefin-based resin foam composition characterized in that 0.05 to 1.0% by weight of aluminum-butylbenzoate) is added in combination.