JPS63196648A - Plastic molding material - Google Patents

Abstract

PURPOSE:To obtain the title material excellent in heat resistance and rigidity and remarkably improved in impact resistance, by mixing a specified particulate cured phenolic resin with a modified polyolefin, a polyamide resin and a modified ethylene/propylene random copolymer. CONSTITUTION:The title molding material prepared by mixing a particulate cured phenolic resin (A) having reactive methylol groups in the molecule with a modified polyolefin (B) formed by grafting a monomer selected from an unsaturated carboxylic acid and its derivative with at least part of a polyolefin, a polyamide resin (C) and a modified amorphous ethylene/propylene random copolymer prepared by grafting a monomer selected from an unsaturated carboxylic acid and its derivative with at least part of an amorphous ethylene/propylene random copolymer. This material is excellent in heat resistance and rigidity, has remarkably improved impact resistance and is very good also in adhesion to a paint.

Description

Detailed Description of the Invention (Field of Industrial Application) This invention relates to a plastic molding material, and more specifically, a plastic molding material mainly composed of modified polypropylene that has good heat resistance, rigidity, and impact resistance. It is related to.

(Prior Art) Polypropylene is a plastic molding material that is inexpensive, has good moldability, and exhibits well-balanced physical properties, and is used in a wide range of fields. However, such polypropylene molding materials also have a problem in that they have insufficient heat resistance when integrally baked with other steel plate parts for automobiles. This means that the baking temperature of the integral coating is approximately 15
Because the temperature is 0°C, polypropylene undergoes thermal deformation. In an attempt to improve this, a method has been proposed in which a polar group is introduced by graft copolymerizing polypropylene with an unsaturated carboxylic acid such as maleic anhydride, and this is combined with glass fiber whose surface has been treated with a silane coupling agent. known (see Japanese Patent Publication No. 51-10265).

(Problems to be Solved by the Invention) However, in the method described above, a sufficient improvement in heat resistance cannot be obtained unless at least 30% by weight of glass fiber is added. This is because the carboxylic acid group graft-polymerized to polypropylene and the silanol group on the surface of the glass fiber bond together, contributing to improved heat resistance. When such a large amount of glass fiber is added, there are problems in that the fluidity of the molding material decreases and the surface smoothness of the molded product is insufficient.

In order to solve the above problems, the present applicant has developed: (1) a particulate cured phenol resin having a reactive methylol group in the molecule; and (2) a polyolefin in which part or all of the polyolefin is selected from unsaturated carboxylic acids or derivatives thereof. We have developed a plastic molding material made by blending a modified polyolefin grafted with at least one monomer, (1) a polyamide resin, and (2) an unmodified polyolefin. However, although this molding material has good heat resistance, it has a problem that its impact resistance, especially impact resistance at low temperatures, is not large enough to be used for impact members such as bumpers and fenders.

(Means for solving the problem) As a result of subsequent studies, the present inventors discovered that polyamide (hereinafter referred to as
The present inventors have discovered that impact resistance can be improved if the compatibility between the elastomer (referred to as PA) and the impact-absorbing element is good, and the present invention has been achieved.

The plastic molding material of the present invention thus achieved consists of (a) a particulate cured phenolic resin having a reactive methylol group in its molecule, and ('b) a polyolefin in which part or all of the polyolefin is an unsaturated carbon (c) a modified polyolefin grafted with at least one monomer selected from acids or derivatives thereof; (c) a polyamide resin;
b) Part or all of the amorphous ethylene propylene random copolymer is blended with a modified amorphous ethylene propylene random copolymer grafted with at least one monomer selected from unsaturated carboxylic acids or derivatives thereof. It is characterized by

The particulate cured phenol resin having a reactive methylol group in the molecule of component (a) used in this invention includes:
It is generally obtained by putting a phenol solution into a hydrochloric acid and formalin solution and causing a polycondensation reaction, but it is not limited to this, and it may be obtained by any method, but the condensation reaction here However, the phenolic resin was not completely cured. That is, it is necessary that a reactive methylol group remains in the molecule. However, if the degree of curing reaction is insufficient, a granular cured phenol resin product will not be obtained, and workability will be poor, as well as
It reacts when mixed and kneaded with other components, making stable processing impossible. For this reason, heat-infusible materials are preferred.

In addition, the modified polyolefin used as the (oral) component used in this invention is one in which part or all of the polyolefin is grafted with at least one type of monomer selected from unsaturated carboxylic acids or derivatives thereof. Maleic anhydride is used. Grafting methods include a method using an extruder as shown in Japanese Patent Publication No. 51-10265, a method using a Pambari mixer as shown in Japanese Patent Publication No. 55-5766, and a method using hexane as an organic solvent. Japanese Patent Application Publication No. 58-47002 used
Although the method shown in the above publication is known, any method can be used in the present invention. Further, the amount of unsaturated carboxylic acid or its derivative added (hereinafter referred to as grafting rate) is generally in the range of 0.01 to 10%, preferably 0.03 to 5%, and more preferably 0.01 to 10%.
．． 05-1%.

In addition, the polyamide resin of component (c) used in this invention is generally nylon 4, nylon 6, nylon 1
1. Nylon 12, Nylon 6/6, Nylon 6/lO
, nylon 6/12, etc., among which nylon 6 and nylon 6/6 are preferred and have the best modification effect. Note that nylon 6 is preferred from the viewpoint of ease of material production and molding.

In addition, a modified amorphous ethylene propylene random copolymer (hereinafter referred to as modified EP) as component (d) used in this invention
In this method, a part or all of an amorphous ethylene propylene random copolymer (hereinafter referred to as unmodified EP) that has not been acid-modified is grafted with a small number of unsaturated carboxylic acids or derivatives thereof (all of which are grafted with one type of 7-year-old copolymer). However, maleic anhydride is generally used. Examples of grafting methods include a method using an extruder as shown in Japanese Patent Publication No. 51-10265, etc.;
In addition to the method using a Pambari mixer as shown in the publication, JP-A-5
Although the method disclosed in Japanese Patent No. 8-47002 is known, any method can be used in the present invention. Further, the amount of unsaturated carboxylic acid or its derivative added (hereinafter referred to as grafting rate) is -FG in the range of 0.01 to 10%, preferably 0.03 to 5%, and more preferably 0.01 to 10%. 05-1%.

Furthermore, unmodified EP, which is the raw material for modified EP, has an ethylene content of 20 to 80% by weight and a melt flow rate (230°Cg/10 minutes) (hereinafter referred to as MFR) that correlates with molecular weight of 0. It is preferable to choose between 5 and 3. If the ethylene content is outside the above range, crystallinity will occur and impact resistance will be insufficient. In addition, when MFR exceeds 3, the effect of improving impact resistance is small due to the small molecular weight, and MFR
If R is less than 0.5, it will be difficult to disperse in polyolefin.

This is because the VFR of polyolefin is generally 10 to 60, and the difference from EP is too large.

In this invention, modified EP and unmodified EP can be used together, which is more advantageous in terms of cost.

In this case, it is desirable that the amount of modified EP is 30% by weight or more based on the total amount of both.

In this invention, in addition to the above four components, polypropylene, polyethylene, ethylene/vinyl acetate copolymer (EV
A), unmodified thermoplastic resin such as ethylene acrylate copolymer (EEA), fibers such as talc, mica, calcium carbonate, glass fiber, carbon fiber, etc. can be added as appropriate. In addition, the above fish,
Glass fibers may be surface-treated or untreated, and the thermoplastic resin may be crystalline ethylene propylene block copolymer (hereinafter referred to as BPP).
) is preferably used. This means that BPP (b
This is because the mutual dispersibility with component ) and component (d) is good and the impact strength is high. Further, talc is preferably used as the fiber, and short glass fiber is preferably used as the fiber from an economical standpoint.

Next, the composition ratio of the molding material of the present invention will be explained.

The composition ratio of the particulate cured phenol resin product of component (a) cannot be uniformly determined because it varies depending on the concentration of reactive methylol groups contained therein. However, if it is less than 1% by weight, dispersion is difficult and no effect can be obtained;
If it exceeds 0% by weight, the fluidity and impact resistance of a thermoplastic resin cannot be obtained, so it is usually set at 1 to 30% by weight.
In particular, it is preferably 3 to 20% by weight.

Similarly, the amount of modified polyolefin as component (b) varies depending on the grafting rate and cannot be determined uniformly, but it is generally 1 to 30% by weight, particularly 3 to 30% by weight.
The content is preferably 20% by weight.

(b) If the amount of the ingredient is less than the above amount, no effect can be expected, and if the amount is more than the above amount, the effect will hardly change and the cost will increase. It is desirable to set the amount to be blended.

In addition, the blending amount of the polyamide resin as component (c) is 1 to 50
It is preferably 5 to 40% by weight, especially 5 to 40% by weight. (c
) If the amount of the ingredient is less than the above amount, no effect can be expected from the addition, and even if it is more than the above amount, the effect will remain almost the same, and the cost and water absorption, which is a drawback of nylon, will only increase (c ) It is desirable that the ingredients be blended in the above-mentioned amounts.

In addition, the blend (d) of modified EP component (d) is 5 to 30% by weight.
, preferably 10-250-25 weight, preferably 15-25 weight
2 (lffi%) If it is less than 1% by weight, the impact resistance is insufficient, and if it is more than 30% by weight, the rigidity and heat resistance are insufficient. may be replaced with unmodified EP.

In addition, when adding fibrous material to improve rigidity and heat resistance, it is preferable that the amount of fibrous material is 5 to 20% by weight and the amount of fiber is 5% by weight or less.

) If the filler content is less than 5% by weight, the improvement effect is insufficient, and if it is 20% by weight or more, the impact resistance is insufficient. In addition, 5 fibers
If it is added in excess of this amount by weight, the surface smoothness tends to deteriorate, which is undesirable.

The blending amount of the thermoplastic resin such as BPP mentioned above is as follows (
It can be determined based on almost the remainder other than additions such as a) to (d) and talc added as necessary,
Generally it is 10 to 60% by weight, preferably 20 to 40% by weight.

When manufacturing the plastic molding material of this invention,
In the above components (a) to (d), if necessary, the above-mentioned BP
A thermoplastic resin such as P, a fiber such as talc, and other additives such as an elastomer are added and kneaded, and then molded into a desired shape. In the kneading process, (a), (b), (
c), (d) ingredients may be kneaded together, but (a)
The granular cured phenolic resin component and BPP etc. are kneaded in advance, and then (b) and (
c) (d) can be kneaded. In this case,
This is preferred because the cured phenol resin product of component (a) is well dispersed.

The term "kneading" used herein refers to a method of dispersing a molten composition while applying shear using a rotary kneader such as a single or twin screw extruder, kneader, or panburi mixer. During this kneading, if the modified polyolefin as component (b) or the modified EP as component (d) and the polyamide resin as component (c) are added, a reaction may occur during the kneading process depending on the temperature conditions, resulting in a decrease in fluidity as a molding material. In addition to this, other physical properties may also be unfavorable. When mixing the modified polypropylene and polyamide resin, a triblend may be used, or they may be melt-mixed using a single screw extruder or the like with as little shear as possible.

When adding the above-mentioned inorganic fibers such as talc and elastomer to the molding material of the present invention, it is preferable to add them during the kneading step. Further, it is preferable that glass fibers and carbon fibers are not added in the kneading step, but added in a subsequent step.

(Effect of the invention) As mentioned above, the plastic molding material of the present invention has (a
) Component; Particulate phenol resin cured product having a reactive methylol group in the molecule, (b) Component; Modified polyolefin (hereinafter referred to as modified PO), (c) Component; PA, (d)
Ingredients: Excellent heat resistance due to the combination of modified EP,
In addition to stiffness, it has significantly improved iJitX resistance. As expected from its composition, this material has excellent paint adhesion.

(Examples and Comparative Examples) The present invention will be explained below with reference to Examples and Comparative Examples. In addition, in the examples, the heat resistance and fluidity of the molding materials were evaluated according to the measurement method shown below.

(a) Heat resistance: Evaluated by heat sag test (hereinafter referred to as heat sag). FIG. 1 shows the heat sag device used. The test piece 1 has W = 12 mm, thickness t = 3 mm, length ffi, = 105 mm. =5 aua was fixed.

The distance from the bottom surface at the initial stage of fixation to the lower end of the test piece end was measured and defined as xo. After putting this in an oven at 150°C and leaving it for 1 hour, take it out and immediately measure the distance Xl5O from the bottom to the lower end of the test piece, ・1150 = X1
I asked for so xo.

(b) Fluidity was measured using a capillary rheometer. The test device used was one manufactured by Iwamoto Seisakusho, in which a flow test device was set in an Autobluff DC3-107 manufactured by Shimadzu Corporation. The nozzle used had a diameter of 1 mm and a length of 20 mm. The measurement was carried out at 230°C, and the viscosity at a shear rate of 1330/sec (test speed 200) was expressed in poise.

As a granular phenolic resin cured product, the product name is "R~800".
J (manufactured by!!!Spinning ■) 1kg, product name rP as modified PO
42o% 1'' (manufactured by Nippon Petrochemical ■) 1 kg, nylon 6 as PA: trade name rT802+ (manufactured by Toyobo) 4
kg, BPP with the trade name rAY564J (manufactured by Sumitomo Chemical) 2 kg, and the modified EP with the unmodified EP trade name rs40
Maleic anhydride and benzoyl peroxide were dissolved in acetone and added to "30" (manufactured by Mikata Petrochemical), mixed thoroughly in a Henschel mixer, then fed to an extruder sealed with nitrogen, and heated to about 170°C. The maleic anhydride was obtained by treatment under conditions such that the maleic anhydride remained at 0.
2 kg of 2% by weight grafted material (hereinafter referred to as DEP-1) was weighed and mixed in a Henschel mixer, then kneaded and granulated in a twin screw extruder (manufactured by Ikegai Iron Works, PCM30) to obtain pellets. . The formulation (wt%) is shown in Table 1. This is made into JIS K7203 by injection molding. Test pieces conforming to 7110 and 58741 were obtained.

Note that this test piece was heat treated at 120°C for 8 hours. The bending elastic modulus (JK
S K7203), tensile strength JIS K711
0), gloss (JIS 58741), and the above-mentioned heat sag characteristics were measured.

The results are shown in Example 1 in Table 3.

The same material as in Example 1 was used for the material. Product name "R-800" as granular cured phenolic resin 1kg
After kneading 3 kg of "rAY564" as BPP using a Panbury mixer at maximum speed without heating or cooling,
It was ground to obtain 4 kg of Premix A. To 4 kg of this premix A, 3 kg of "T803" (manufactured by Toyobo) as modified PO and rDEP-1,+2 kg as modified EP were added and kneaded, and then granulated using the above-mentioned twin screw extruder to obtain pellets. The formulation (wt%) is shown in Table 1.

A test piece was obtained from the pellet thus obtained in the same manner as in the example, and the performance was evaluated in the same manner. The results are shown in Example 2 in Table 3.

The procedure was the same as in Example 1, except that 42 kg of a commercially available modified EP (product name: N-Tafuma MP-0690J (manufactured by Mitsui Petrochemicals)) was used in place of rDEP-1j in Example 1. %) are shown in Table 1, and the results of performance evaluation are shown in Example 3 in Table 3.

Example 1 except that 1 kg of "N Tafuma MP-0690" and 1 kg of trade name "Tafuma P680" (manufactured by Mitsui Petrochemicals) as undenatured EP were used in place of rDEP-IJ in Example 1. The same is true. The formulation (wt%) is shown in Table 1, and the results of performance evaluation are shown in Table 3.

Example 111 In Example 3, the procedure was the same as in Example 3 except that 2 kg of BPP rAX568J and 1 kg of talc (trade name rLMS-200J (manufactured by Fuji Talc)) were used instead of 2 kg of BPP rAY564. The formulations (% by weight) are shown in Table 1, and the results of performance evaluation are shown in Table 3.

-16 to 10 υReturn leaves to Example 6 to
Test pieces of IO and Comparative Examples 1 to 3 were prepared. The performance of these test pieces was evaluated according to the measurement method described above, and the results are shown in Table 3.

The glass fibers (cF) shown in Table 1 are milled fibers; trade name rEFH100-31J (manufactured by Central Glass, cut length 0.122 ma+, single fiber diameter 11 μm).
It is. In addition, as styrene ethylene butadiene styrene rubber (SEBS), the product name [Krayton GJ
(shells) was used.

In addition, polybutene terephthalate (PBT) is -C
A material for injection molding was used.

This J old masu Ako = 1 As a glass material, chopped strand: Product name rE
Using csO3-874FJ (manufactured by Central Glass, cut length 3InI11, fiber diameter 13 μm) or the same milled fiber as above, the product name rMA2A is a homopolymer as polypropylene.

(manufactured by Mitsubishi Yuka) and FAX568 as BPP were used to prepare polypropylene materials of Comparative Examples 4 to 8, which were blended in the proportions shown in Table 2 and reinforced with talc and glass fiber.

Test pieces were made from these materials in the same manner as in Example 1, and their performance was evaluated according to the measurement method described above. The results are shown in Table 3. Further, each of the polypropylene materials described above was formed into a sheet 3 having the shape shown in FIG. 2, and the "warpage" at the end was measured as shown in FIG. 3. The results are also listed in Table 3. In Figure 2, 2 is 75III + 1.24 is 150m
m, C indicates the center, E indicates the end, G indicates the gate, and in FIG. 3, tl indicates the thickness of the material (3 mm), and x+ indicates the "warp".

[Brief explanation of the drawing]

Fig. 1 is a perspective view of a heat sag device used to measure the heat resistance of the plastic molding material of the present invention, Fig. 2 is a plan view of the plastic sheets of Comparative Examples 6 to 10, and Fig. 3 is a view of "warping". A side view of the sheet of FIG. 2 used for measurement is shown. 1... Test piece 2... Bolt 3... Plastic sheet Patent applicant Nissan Motor Co., Ltd. Figure 1

Claims (1)

[Claims] 1. (a) Particulate cured phenolic resin having a reactive methylol group in the molecule, and (b) Part or all of the polyolefin is made of at least one monomer selected from unsaturated carboxylic acids or derivatives thereof. Part or all of the grafted modified polyolefin, (c) polyamide resin, and (d) amorphous ethylene propylene random copolymer are grafted with at least one monomer selected from unsaturated carboxylic acids or derivatives thereof. A plastic molding material characterized in that it is blended with a modified amorphous ethylene propylene random copolymer.